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Version 4.1.0Preface1. ForewordWireshark is the world’s foremost network protocol analyzer, but the rich feature set can be daunting for the unfamiliar. This document is part of an effort by the Wireshark team to improve Wireshark’s usability. We hope that you find it useful and look forward to your comments. 2. Who should read this document?The intended audience of this book is anyone using Wireshark. This book explains all of the basic and some advanced features of Wireshark. As Wireshark has become a very complex program, not every feature may be explained in this book. This book is not intended to explain network sniffing in general and it will not provide details about specific network protocols. A lot of useful information regarding these topics can be found at the Wireshark Wiki at https://gitlab.com/wireshark/wireshark/wikis/. By reading this book, you will learn how to install Wireshark, how to use the basic elements of the graphical user interface (such as the menu) and what’s behind some of the advanced features that are not always obvious at first sight. It will hopefully guide you around some common problems that frequently appear for new (and sometimes even advanced) Wireshark users. 3. AcknowledgementsThe authors would like to thank the whole Wireshark team for their assistance. In particular, the authors would like to thank:
The authors would also like to thank the following people for their helpful feedback on this document:
The authors would like to acknowledge those man page and README authors for the Wireshark project from who sections of this document borrow heavily:
4. About this documentThis book was originally developed by Richard Sharpe with funds provided from the Wireshark Fund. It was updated by Ed Warnicke and more recently redesigned and updated by Ulf Lamping. It was originally written in DocBook/XML and converted to AsciiDoc by Gerald Combs. 6. Providing feedback about this documentShould you have any feedback about this document, please send it to the authors through wireshark-dev[AT]wireshark.org. 7. Typographic ConventionsThe following table shows the typographic conventions that are used in this guide. Table 1. Typographic Conventions
7.1. AdmonitionsImportant and notable items are marked as follows:
7.2. Shell Prompt and Source Code ExamplesBourne shell, normal user. $ # This is a comment $ git config --global log.abbrevcommit true Bourne shell, root user. # # This is a comment # ninja install Command Prompt (cmd.exe). >rem This is a comment >cd C:\Development PowerShell. PS$># This is a comment PS$> choco list -l C Source Code. #include "config.h" /* This method dissects foos */ static int dissect_foo_message(tvbuff_t *tvb, packet_info *pinfo _U_, proto_tree *tree _U_, void *data _U_) { /* TODO: implement your dissecting code */ return tvb_captured_length(tvb); } Chapter 1. Introduction1.1. What is Wireshark?Wireshark is a network packet analyzer. A network packet analyzer presents captured packet data in as much detail as possible. You could think of a network packet analyzer as a measuring device for examining what’s happening inside a network cable, just like an electrician uses a voltmeter for examining what’s happening inside an electric cable (but at a higher level, of course). In the past, such tools were either very expensive, proprietary, or both. However, with the advent of Wireshark, that has changed. Wireshark is available for free, is open source, and is one of the best packet analyzers available today. 1.1.1. Some intended purposesHere are some reasons people use Wireshark:
Wireshark can also be helpful in many other situations. 1.1.2. FeaturesThe following are some of the many features Wireshark provides:
However, to really appreciate its power you have to start using it. Figure 1.1, “Wireshark captures packets and lets you examine their contents.” shows Wireshark having captured some packets and waiting for you to examine them. Figure 1.1. Wireshark captures packets and lets you examine their contents. 1.1.3. Live capture from many different network mediaWireshark can capture traffic from many different network media types, including Ethernet, Wireless LAN, Bluetooth, USB, and more. The specific media types supported may be limited by several factors, including your hardware and operating system. An overview of the supported media types can be found at https://gitlab.com/wireshark/wireshark/wikis/CaptureSetup/NetworkMedia. 1.1.4. Import files from many other capture programsWireshark can open packet captures from a large number of capture programs. For a list of input formats see Section 5.2.2, “Input File Formats”. 1.1.5. Export files for many other capture programsWireshark can save captured packets in many formats, including those used by other capture programs. For a list of output formats see Section 5.3.2, “Output File Formats”. 1.1.7. Open Source SoftwareWireshark is an open source software project, and is released under the GNU General Public License (GPL). You can freely use Wireshark on any number of computers you like, without worrying about license keys or fees or such. In addition, all source code is freely available under the GPL. Because of that, it is very easy for people to add new protocols to Wireshark, either as plugins, or built into the source, and they often do! 1.1.8. What Wireshark is notHere are some things Wireshark does not provide:
1.2. System RequirementsThe amount of resources Wireshark needs depends on your environment and on the size of the capture file you are analyzing. The values below should be fine for small to medium-sized capture files no more than a few hundred MB. Larger capture files will require more memory and disk space.
If Wireshark runs out of memory it will crash. See https://gitlab.com/wireshark/wireshark/wikis/KnownBugs/OutOfMemory for details and workarounds. Although Wireshark uses a separate process to capture packets, the packet analysis is single-threaded and won’t benefit much from multi-core systems. 1.2.1. Microsoft WindowsWireshark should support any version of Windows that is still within its extended support lifetime. At the time of writing this includes Windows 10, 8.1, Server 2019, Server 2016, Server 2012 R2, and Server 2012. It also requires the following:
Older versions of Windows which are outside Microsoft’s extended lifecycle support window are no longer supported. It is often difficult or impossible to support these systems due to circumstances beyond our control, such as third party libraries on which we depend or due to necessary features that are only present in newer versions of Windows such as hardened security or memory management.
See the Wireshark release lifecycle page for more details. 1.2.2. macOSWireshark supports macOS 10.14 and later. Similar to Windows, supported macOS versions depend on third party libraries and on Apple’s requirements. Apple Silicon hardware is supported natively starting with version 4.0
The system requirements should be comparable to the specifications listed above for Windows. 1.2.3. UNIX, Linux, and BSDWireshark runs on most UNIX and UNIX-like platforms including Linux and most BSD variants. The system requirements should be comparable to the specifications listed above for Windows. Binary packages are available for most Unices and Linux distributions including the following platforms:
If a binary package is not available for your platform you can download the source and try to build it. Please report your experiences to wireshark-dev[AT]wireshark.org. 1.3. Where To Get WiresharkYou can get the latest copy of the program from the Wireshark website at https://www.wireshark.org/download.html. The download page should automatically highlight the appropriate download for your platform and direct you to the nearest mirror. Official Windows and macOS installers are signed using trusted certificates on those platforms. macOS installers are additionally notarized. A new Wireshark version typically becomes available every six weeks. If you want to be notified about new Wireshark releases you should subscribe to the wireshark-announce mailing list. You will find more details in Section 1.6.5, “Mailing Lists”. Each release includes a list of file hashes which are sent to the wireshark-announce mailing list and placed in a file named SIGNATURES-x.y.z.txt. Announcement messages are archived at https://www.wireshark.org/lists/wireshark-announce/ and SIGNATURES files can be found at https://www.wireshark.org/download/src/all-versions/. Both are GPG-signed and include verification instructions for Windows, Linux, and macOS. As noted above, you can also verify downloads on Windows and macOS using the code signature validation features on those systems. 1.4. A Brief History Of WiresharkIn late 1997 Gerald Combs needed a tool for tracking down network problems and wanted to learn more about networking so he started writing Ethereal (the original name of the Wireshark project) as a way to solve both problems. Ethereal was initially released after several pauses in development in July 1998 as version 0.2.0. Within days patches, bug reports, and words of encouragement started arriving and Ethereal was on its way to success. Not long after that Gilbert Ramirez saw its potential and contributed a low-level dissector to it. In October, 1998 Guy Harris was looking for something better than tcpview so he started applying patches and contributing dissectors to Ethereal. In late 1998 Richard Sharpe, who was giving TCP/IP courses, saw its potential on such courses and started looking at it to see if it supported the protocols he needed. While it didn’t at that point new protocols could be easily added. So he started contributing dissectors and contributing patches. The list of people who have contributed to the project has become very long since then, and almost all of them started with a protocol that they needed that Wireshark did not already handle. So they copied an existing dissector and contributed the code back to the team. In 2006 the project moved house and re-emerged under a new name: Wireshark. In 2008, after ten years of development, Wireshark finally arrived at version 1.0. This release was the first deemed complete, with the minimum features implemented. Its release coincided with the first Wireshark Developer and User Conference, called Sharkfest. In 2015 Wireshark 2.0 was released, which featured a new user interface. 1.5. Development And Maintenance Of Wireshark
Wireshark was initially developed by Gerald Combs. Ongoing development and maintenance of Wireshark is handled by the Wireshark team, a loose group of individuals who fix bugs and provide new functionality. There have also been a large number of people who have contributed protocol dissectors to Wireshark, and it is expected that this will continue. You can find a list of the people who have contributed code to Wireshark by checking the about dialog box of Wireshark, or at the authors page on the Wireshark web site. Wireshark is an open source software project, and is released under the GNU General Public License (GPL) version 2. All source code is freely available under the GPL. You are welcome to modify Wireshark to suit your own needs, and it would be appreciated if you contribute your improvements back to the Wireshark team. You gain three benefits by contributing your improvements back to the community:
The Wireshark source code and binary kits for some platforms are all available on the download page of the Wireshark website: https://www.wireshark.org/download.html. 1.6. Reporting Problems And Getting HelpIf you have problems or need help with Wireshark there are several places that may be of interest (besides this guide, of course). 1.6.2. WikiThe Wireshark Wiki at https://gitlab.com/wireshark/wireshark/wikis/ provides a wide range of information related to Wireshark and packet capture in general. You will find a lot of information not part of this user’s guide. For example, it contains an explanation how to capture on a switched network, an ongoing effort to build a protocol reference, protocol-specific information, and much more. And best of all, if you would like to contribute your knowledge on a specific topic (maybe a network protocol you know well), you can edit the wiki pages with your web browser. 1.6.3. Q&A SiteThe Wireshark Q&A site at https://ask.wireshark.org/ offers a resource where questions and answers come together. You can search for questions asked before and see what answers were given by people who knew about the issue. Answers are ranked, so you can easily pick out the best ones. If your question hasn’t been discussed before you can post one yourself. 1.6.4. FAQThe Frequently Asked Questions lists often asked questions and their corresponding answers.
You will find the FAQ inside Wireshark by clicking the menu item Help/Contents and selecting the FAQ page in the dialog shown. An online version is available at the Wireshark website at https://www.wireshark.org/faq.html. You might prefer this online version, as it’s typically more up to date and the HTML format is easier to use. 1.6.5. Mailing ListsThere are several mailing lists of specific Wireshark topics available: wireshark-announce Information about new program releases, which usually appear about every six weeks. wireshark-users Topics of interest to users of Wireshark. People typically post questions about using Wireshark and others (hopefully) provide answers. wireshark-dev Topics of interest to developers of Wireshark. If you want to develop a protocol dissector or update the user interface, join this list. You can subscribe to each of these lists from the Wireshark web site: https://www.wireshark.org/lists/. From there, you can choose which mailing list you want to subscribe to by clicking on the Subscribe/Unsubscribe/Options button under the title of the relevant list. The links to the archives are included on that page as well.
1.6.6. Reporting Problems
When reporting problems with Wireshark please supply the following information:
1.6.7. Reporting Crashes on UNIX/Linux platformsWhen reporting crashes with Wireshark it is helpful if you supply the traceback information along with the information mentioned in “Reporting Problems”. You can obtain this traceback information with the following commands on UNIX or Linux (note the backticks): $ gdb `whereis wireshark | cut -f2 -d: | cut -d' ' -f2` core >& backtrace.txt backtrace ^D If you do not have gdb available, you will have to check out your operating system’s debugger. Email backtrace.txt to wireshark-dev[AT]wireshark.org. Chapter 2. Building and Installing Wireshark
2.1. IntroductionAs with all things there must be a beginning and so it is with Wireshark. To use Wireshark you must first install it. If you are running Windows or macOS you can download an official release at https://www.wireshark.org/download.html, install it, and skip the rest of this chapter. If you are running another operating system such as Linux or FreeBSD you might want to install from source. Several Linux distributions offer Wireshark packages but they commonly provide out-of-date versions. No other versions of UNIX ship Wireshark so far. For that reason, you will need to know where to get the latest version of Wireshark and how to install it. This chapter shows you how to obtain source and binary packages and how to build Wireshark from source should you choose to do so. The general steps are the following:
2.2. Obtaining the source and binary distributionsYou can obtain both source and binary distributions from the Wireshark main page or the download page at https://www.wireshark.org/download.html. Select the package most appropriate for your system. 2.3. Installing Wireshark under WindowsThe official Windows packages can be downloaded from the Wireshark main page or the download page. Installer names contain the platform and version. For example, Wireshark-win64-4.1.0.exe installs Wireshark 4.1.0 for 64-bit Windows. The Wireshark installer includes Npcap which is required for packet capture. Windows packages automatically update. See Section 2.8, “Updating Wireshark” for details. Simply download the Wireshark installer from https://www.wireshark.org/download.html and execute it. Official packages are signed by Sysdig, Inc.. You can choose to install several optional components and select the location of the installed package. The default settings are recommended for most users. 2.3.1. Installation ComponentsOn the Choose Components page of the installer you can select from the following:
2.3.2. Additional Tasks
2.3.3. Install LocationBy default Wireshark installs into 2.3.4. Installing NpcapThe Wireshark installer contains the latest Npcap installer. If you don’t have Npcap installed you won’t be able to capture live network traffic but you will still be able to open saved capture files. By default the latest version of Npcap will be installed. If you don’t wish to do this or if you wish to reinstall Npcap you can check the Install Npcap box as needed. For more information about Npcap see https://npcap.com/ and https://gitlab.com/wireshark/wireshark/wikis/Npcap. 2.3.5. Windows installer command line optionsFor special cases, there are some command line parameters available:
Example: > Wireshark-win64-wireshark-2.0.5.exe /NCRC /S /desktopicon=yes /quicklaunchicon=no /D=C:\Program Files\Foo > Wireshark-win64-3.3.0.exe /S /EXTRACOMPONENTS=sshdump,udpdump Running the installer without any parameters shows the normal interactive installer. 2.3.6. Manual Npcap InstallationAs mentioned above, the Wireshark installer also installs Npcap. If you prefer to install Npcap manually or want to use a different version than the one included in the Wireshark installer, you can download Npcap from the main Npcap site at https://npcap.com/. 2.3.7. Update NpcapWireshark updates may also include a new version of Npcap. Manual Npcap updates instructions can be found on the Npcap web site at https://npcap.com/. You may have to reboot your machine after installing a new Npcap version. 2.3.8. Uninstall WiresharkYou can uninstall Wireshark using the Programs and Features control panel. Select the “Wireshark” entry to start the uninstallation procedure. The Wireshark uninstaller provides several options for removal. The default is to remove the core components but keep your personal settings and Npcap. Npcap is kept in case other programs need it. 2.3.9. Uninstall NpcapYou can uninstall Npcap independently of Wireshark using the Npcap entry in the Programs and Features control panel. Remember that if you uninstall Npcap you won’t be able to capture anything with Wireshark. 2.5. Installing Wireshark under macOSThe official macOS packages can be downloaded from the Wireshark main page or the download page. Packages are distributed as disk images (.dmg) containing the application bundle. Package names contain the platform and version. To install Wireshark simply open the disk image and drag Wireshark to your /Applications folder. macOS packages automatically update. See Section 2.8, “Updating Wireshark” for details. In order to capture packets, you must install the “ChmodBPF” launch daemon. You can do so by opening the Install ChmodBPF.pkg file in the Wireshark .dmg or from Wireshark itself by opening → selecting the “Folders” tab, and double-clicking “macOS Extras”. The installer package includes Wireshark along with ChmodBPF and system path packages. See the included Read me first.html file for more details. 2.6. Installing the binaries under UNIXIn general installing the binary under your version of UNIX will be specific to the installation methods used with your version of UNIX. For example, under AIX, you would use smit to install the Wireshark binary package, while under Tru64 UNIX (formerly Digital UNIX) you would use setld. 2.6.1. Installing from RPMs under Red Hat and alikeBuilding RPMs from Wireshark’s source code results in several packages (most distributions follow the same system):
Many distributions use yum install wireshark wireshark-qt If you’ve built your own RPMs from the Wireshark sources you can install them by running, for example: rpm -ivh wireshark-2.0.0-1.x86_64.rpm wireshark-qt-2.0.0-1.x86_64.rpm If the above command fails because of missing dependencies, install the dependencies first, and then retry the step above. 2.6.2. Installing from debs under Debian, Ubuntu and other Debian derivativesIf you can just install from the repository then use apt install wireshark Apt should take care of all of the dependency issues for you. 2.6.3. Installing from portage under Gentoo LinuxUse the following command to install Wireshark under Gentoo Linux with all of the extra features: USE="c-ares ipv6 snmp ssl kerberos threads selinux" emerge wireshark 2.6.4. Installing from packages under FreeBSDUse the following command to install Wireshark under FreeBSD: pkg_add -r wireshark pkg_add should take care of all of the dependency issues for you. 2.8. Updating WiresharkBy default, Wireshark on Windows and macOS will check for new versions and notify you when they are available. If you have the Check for updates preference disabled or if you run Wireshark in an isolated environment you should subscribe to the wireshark-announce mailing list to be notified of new versions. See Section 1.6.5, “Mailing Lists” for details on subscribing to this list. New versions of Wireshark are usually released every four to six weeks. Updating Wireshark is done the same way as installing it. Simply download and run the installer on Windows, or download and drag the application on macOS. A reboot is usually not required and all your personal settings will remain unchanged. We offer two update channels, Stable and Development. The Stable channel is the default, and only installs packages from stable (even-numbered) release branches. The Development channel installs development and release candidate packages when they are available, and stable releases otherwise. To configure your release channel, go to → and search for “update.channel”. See Section 11.5, “Preferences” for details. Chapter 3. User Interface3.1. IntroductionBy now you have installed Wireshark and are likely keen to get started capturing your first packets. In the next chapters we will explore:
3.2. Start WiresharkYou can start Wireshark from your shell or window manager. The following chapters contain many screenshots of Wireshark. As Wireshark runs on many different platforms with many different window managers, different styles applied and there are different versions of the underlying GUI toolkit used, your screen might look different from the provided screenshots. But as there are no real differences in functionality these screenshots should still be well understandable. 3.3. The Main windowLet’s look at Wireshark’s user interface. Figure 3.1, “The Main window” shows Wireshark as you would usually see it after some packets are captured or loaded (how to do this will be described later). Figure 3.1. The Main window Wireshark’s main window consists of parts that are commonly known from many other GUI programs.
3.3.1. Main Window NavigationPacket list and detail navigation can be done entirely from the keyboard. Table 3.1, “Keyboard Navigation” shows a list of keystrokes that will let you quickly move around a capture file. See Table 3.6, “Go menu items” for additional navigation keystrokes. Table 3.1. Keyboard Navigation
→ → will show a list of all shortcuts in the main window. Additionally, typing anywhere in the main window will start filling in a display filter. 3.4. The MenuWireshark’s main menu is located either at the top of the main window (Windows, Linux) or at the top of your main screen (macOS). An example is shown in Figure 3.2, “The Menu”.
The main menu contains the following items: This menu contains items to open and merge capture files, save, print, or export capture files in whole or in part, and to quit the Wireshark application. See Section 3.5, “The “File” Menu”. This menu contains items to find a packet, time reference or mark one or more packets, handle configuration profiles, and set your preferences; (cut, copy, and paste are not presently implemented). See Section 3.6, “The “Edit” Menu”. This menu controls the display of the captured data, including colorization of packets, zooming the font, showing a packet in a separate window, expanding and collapsing trees in packet details, …. See Section 3.7, “The “View” Menu”. This menu contains items to go to a specific packet. See Section 3.8, “The “Go” Menu”. This menu allows you to start and stop captures and to edit capture filters. See Section 3.9, “The “Capture” Menu”. This menu contains items to manipulate display filters, enable or disable the dissection of protocols, configure user specified decodes and follow a TCP stream. See Section 3.10, “The “Analyze” Menu”. This menu contains items to display various statistic windows, including a summary of the packets that have been captured, display protocol hierarchy statistics and much more. See Section 3.11, “The “Statistics” Menu”. This menu contains items to display various telephony related statistic windows, including a media analysis, flow diagrams, display protocol hierarchy statistics and much more. See Section 3.12, “The “Telephony” Menu”. This menu contains items to display Bluetooth and IEEE 802.11 wireless statistics. This menu contains various tools available in Wireshark, such as creating Firewall ACL Rules. See Section 3.14, “The “Tools” Menu”. This menu contains items to help the user, e.g., access to some basic help, manual pages of the various command line tools, online access to some of the webpages, and the usual about dialog. See Section 3.15, “The “Help” Menu”. Each of these menu items is described in more detail in the sections that follow.
3.5. The “File” MenuThe Wireshark file menu contains the fields shown in Table 3.2, “File menu items”. Figure 3.3. The “File” Menu Table 3.2. File menu items
3.6. The “Edit” MenuThe Wireshark Edit menu contains the fields shown in Table 3.3, “Edit menu items”. Figure 3.4. The “Edit” Menu Table 3.3. Edit menu items
3.7. The “View” MenuThe Wireshark View menu contains the fields shown in Table 3.4, “View menu items”. Figure 3.5. The “View” Menu Table 3.4. View menu items
Table 3.5. Internals menu items
3.8. The “Go” MenuThe Wireshark Go menu contains the fields shown in Table 3.6, “Go menu items”. Figure 3.6. The “Go” Menu Table 3.6. Go menu items
3.9. The “Capture” MenuThe Wireshark Capture menu contains the fields shown in Table 3.7, “Capture menu items”. Figure 3.7. The “Capture” Menu Table 3.7. Capture menu items
3.10. The “Analyze” MenuThe Wireshark Analyze menu contains the fields shown in Table 3.8, “Analyze menu items”. Figure 3.8. The “Analyze” Menu Table 3.8. Analyze menu items
3.11. The “Statistics” MenuThe Wireshark Statistics menu contains the fields shown in Table 3.9, “Statistics menu items”. Figure 3.9. The “Statistics” Menu Each menu item brings up a new window showing specific statistics. Table 3.9. Statistics menu items
3.12. The “Telephony” MenuThe Wireshark Telephony menu contains the fields shown in Table 3.10, “Telephony menu items”. Figure 3.10. The “Telephony” Menu Each menu item shows specific telephony related statistics. Table 3.10. Telephony menu items
3.13. The “Wireless” MenuThe Wireless menu lets you analyze Bluetooth and IEEE 802.11 wireless LAN activity as shown in Figure 3.11, “The “Wireless” Menu”. Figure 3.11. The “Wireless” Menu Each menu item shows specific Bluetooth and IEEE 802.11 statistics. Table 3.11. Wireless menu items 3.14. The “Tools” MenuThe Wireshark Tools menu contains the fields shown in Table 3.12, “Tools menu items”. Figure 3.12. The “Tools” Menu Table 3.12. Tools menu items
3.15. The “Help” MenuThe Wireshark Help menu contains the fields shown in Table 3.13, “Help menu items”. Figure 3.13. The “Help” Menu Table 3.13. Help menu items
3.16. The “Main” ToolbarThe main toolbar provides quick access to frequently used items from the menu. This toolbar cannot be customized by the user, but it can be hidden using the View menu if the space on the screen is needed to show more packet data. Items in the toolbar will be enabled or disabled (greyed out) similar to their corresponding menu items. For example, in the image below shows the main window toolbar after a file has been opened. Various file-related buttons are enabled, but the stop capture button is disabled because a capture is not in progress. Figure 3.14. The “Main” toolbar Table 3.14. Main toolbar items
3.17. The “Filter” ToolbarThe filter toolbar lets you quickly edit and apply display filters. More information on display filters is available in Section 6.3, “Filtering Packets While Viewing”. Figure 3.15. The “Filter” toolbar Table 3.15. Filter toolbar items
3.18. The “Packet List” PaneThe packet list pane displays all the packets in the current capture file. Figure 3.16. The “Packet List” pane Each line in the packet list corresponds to one packet in the capture file. If you select a line in this pane, more details will be displayed in the “Packet Details” and “Packet Bytes” panes. While dissecting a packet, Wireshark will place information from the protocol dissectors into the columns. As higher-level protocols might overwrite information from lower levels, you will typically see the information from the highest possible level only. For example, let’s look at a packet containing TCP inside IP inside an Ethernet packet. The Ethernet dissector will write its data (such as the Ethernet addresses), the IP dissector will overwrite this by its own (such as the IP addresses), the TCP dissector will overwrite the IP information, and so on. There are many different columns available. You can choose which columns are displayed in the preferences. See Section 11.5, “Preferences”. The default columns will show:
The first column shows how each packet is related to the selected packet. For example, in the image above the first packet is selected, which is a DNS request. Wireshark shows a rightward arrow for the request itself, followed by a leftward arrow for the response in packet 2. Why is there a dashed line? There are more DNS packets further down that use the same port numbers. Wireshark treats them as belonging to the same conversation and draws a line connecting them. Table 3.16. Related packet symbols
The packet list has an Intelligent Scrollbar which shows a miniature map of nearby packets. Each raster line of the scrollbar corresponds to a single packet, so the number of packets shown in the map depends on your physical display and the height of the packet list. A tall packet list on a high-resolution (“Retina”) display will show you quite a few packets. In the image above the scrollbar shows the status of more than 500 packets along with the 15 shown in the packet list itself. Right clicking will show a context menu, described in Figure 6.4, “Pop-up menu of the “Packet List” pane”. 3.19. The “Packet Details” PaneThe packet details pane shows the current packet (selected in the “Packet List” pane) in a more detailed form. Figure 3.17. The “Packet Details” pane This pane shows the protocols and protocol fields of the packet selected in the “Packet List” pane. The protocol summary lines (subtree labels) and fields of the packet are shown in a tree which can be expanded and collapsed. There is a context menu (right mouse click) available. See details in Figure 6.5, “Pop-up menu of the “Packet Details” pane”. Some protocol fields have special meanings.
3.20. The “Packet Bytes” PaneThe packet bytes pane shows the data of the current packet (selected in the “Packet List” pane) in a hexdump style. Figure 3.18. The “Packet Bytes” pane The “Packet Bytes” pane shows a canonical hex dump of the packet data. Each line contains the data offset, sixteen hexadecimal bytes, and sixteen ASCII bytes. Non-printable bytes are replaced with a period (“.”). Depending on the packet data, sometimes more than one page is available, e.g. when Wireshark has reassembled some packets into a single chunk of data. (See Section 7.8, “Packet Reassembly” for details). In this case you can see each data source by clicking its corresponding tab at the bottom of the pane. The default mode for viewing will highlight the bytes for a field where the mouse pointer is hovering above. The highlight will follow the mouse cursor as it moves. If this highlighting is not required or wanted, there are two methods for deactivating the functionality:
Figure 3.19. The “Packet Bytes” pane with tabs Additional tabs typically contain data reassembled from multiple packets or decrypted data. 3.21. The “Packet Diagram” PaneThe packet diagram pane shows the current packet (selected in the “Packet List” pane) as a diagram, similar to ones used in textbooks and IETF RFCs. Figure 3.20. The “Packet Diagram” pane This pane shows the protocols and top-level protocol fields of the packet selected in the “Packet List” pane as a series of diagrams. There is a context menu (right mouse click) available. For details see Figure 6.7, “Pop-up menu of the “Packet Diagram” pane”. 3.22. The StatusbarThe statusbar displays informational messages. In general, the left side will show context related information, the middle part will show information about the current capture file, and the right side will show the selected configuration profile. Drag the handles between the text areas to change the size. Figure 3.21. The initial Statusbar This statusbar is shown while no capture file is loaded, e.g., when Wireshark is started. Figure 3.22. The Statusbar with a loaded capture file The colorized bullet… on the left shows the highest expert information level found in the currently loaded capture file. Hovering the mouse over this icon will show a description of the expert info level, and clicking the icon will bring up the Expert Information dialog box. For a detailed description of this dialog and each expert level, see Section 7.4, “Expert Information”. The edit icon… on the left side lets you add a comment to the capture file using the Capture File Properties dialog. The left side… shows the capture file name by default. It also shows field information when hovering over and selecting items in the packet detail and packet bytes panes, as well as general notifications. The middle… shows the current number of packets in the capture file. The following values are displayed: Packets The number of captured packets. Displayed The number of packets currently being displayed. Marked The number of marked packets. Only displayed if you marked any packets. Dropped The number of dropped packets Only displayed if Wireshark was unable to capture all packets. Ignored The number of ignored packets Only displayed if you ignored any packets. The right side… shows the selected configuration profile. Clicking on this part of the statusbar will bring up a menu with all available configuration profiles, and selecting from this list will change the configuration profile. Figure 3.23. The Statusbar with a configuration profile menu For a detailed description of configuration profiles, see Section 11.6, “Configuration Profiles”. Figure 3.24. The Statusbar with a selected protocol field This is displayed if you have selected a protocol field in the “Packet Details” pane.
Figure 3.25. The Statusbar with a display filter message This is displayed if you are trying to use a display filter which may have unexpected results. Chapter 4. Capturing Live Network Data4.1. IntroductionCapturing live network data is one of the major features of Wireshark. The Wireshark capture engine provides the following features:
The capture engine still lacks the following features:
4.2. PrerequisitesSetting up Wireshark to capture packets for the first time can be tricky. A comprehensive guide “How To setup a Capture” is available at https://gitlab.com/wireshark/wireshark/wikis/CaptureSetup. Here are some common pitfalls:
If you have any problems setting up your capture environment, you should have a look at the guide mentioned above. 4.3. Start CapturingThe following methods can be used to start capturing packets with Wireshark:
$ wireshark -i eth0 -k This will start Wireshark capturing on interface 4.4. The “Capture” Section Of The Welcome ScreenWhen you open Wireshark without starting a capture or opening a capture file it will display the “Welcome Screen,” which lists any recently opened capture files and available capture interfaces. Network activity for each interface will be shown in a sparkline next to the interface name. It is possible to select more than one interface and capture from them simultaneously. Figure 4.1. Capture interfaces on Microsoft Windows Figure 4.2. Capture interfaces on macOS Some interfaces allow or require configuration prior to capture. This will be indicated by a configuration icon () to the left of the interface name. Clicking on the icon will show the configuration dialog for that interface. Hovering over an interface will show any associated IPv4 and IPv6 addresses and its capture filter. Wireshark isn’t limited to just network interfaces — on most systems you can also capture USB, Bluetooth, and other types of packets. Note also that an interface might be hidden if it’s inaccessible to Wireshark or if it has been hidden as described in Section 4.6, “The “Manage Interfaces” Dialog Box”. 4.5. The “Capture Options” Dialog BoxWhen you select → (or use the corresponding item in the main toolbar), Wireshark pops up the “Capture Options” dialog box as shown in Figure 4.3, “The “Capture Options” input tab”. If you are unsure which options to choose in this dialog box, leaving the defaults settings as they are should work well in many cases. Figure 4.3. The “Capture Options” input tab The “Input” tab contains the “Interface” table, which shows the following columns: Interface The interface name. Some interfaces allow or require configuration prior to capture. This will be indicated by a configuration icon () to the left of the interface name. Clicking on the icon will show the configuration dialog for that interface. Traffic A sparkline showing network activity over time. Link-layer Header The type of packet captured by this interface. In some cases it is possible to change this. See Section 4.9, “Link-layer header type” for more details. Promiscuous Lets you put this interface in promiscuous mode while capturing. Note that another application might override this setting. Snaplen The snapshot length, or the number of bytes to capture for each packet. You can set an explicit length if needed, e.g., for performance or privacy reasons. Buffer The size of the kernel buffer that is reserved for capturing packets. You can increase or decrease this as needed, but the default is usually sufficient. Monitor Mode Lets you capture full, raw 802.11 headers. Support depends on the interface type, hardware, driver, and OS. Note that enabling this might disconnect you from your wireless network. Capture Filter The capture filter applied to this interface. You can edit the filter by double-clicking on it. See Section 4.10, “Filtering while capturing” for more details about capture filters.Hovering over an interface or expanding it will show any associated IPv4 and IPv6 addresses. If “Enable promiscuous mode on all interfaces” is enabled, the individual promiscuous mode settings above will be overridden. “Capture filter for selected interfaces” can be used to set a filter for more than one interface at the same time. Manage Interfaces opens the Figure 4.6, “The “Manage Interfaces” dialog box” where pipes can be defined, local interfaces scanned or hidden, or remote interfaces added. Compile Selected BPFs opens Figure 4.7, “The “Compiled Filter Output” dialog box”, which shows you the compiled bytecode for your capture filter. This can help to better understand the capture filter you created.
Figure 4.4. The “Capture Options” output tab The “Output” tab shows the following information: Capture to a permanent file File This field allows you to specify the file name that will be used for the capture file. It is left blank by default. If left blank, the capture data will be stored in a temporary file. See Section 4.8, “Capture files and file modes” for details. You can also click on the button to the right of this field to browse through the filesystem. Output format Allows you to set the format of the capture file. pcapng is the default and is more flexible than pcap. pcapng might be required, e.g., if more than one interface is chosen for capturing. See https://gitlab.com/wireshark/wireshark/wikis/Development/PcapNg for more details on pcapng. Create a new file automatically…Sets the conditions for switching a new capture file. A new capture file can be created based on the following conditions:
More details about capture files can be found in Section 4.8, “Capture files and file modes”. Figure 4.5. The “Capture Options” options tab The “Options” tab shows the following information: Display Options Update list of packets in real-time Updates the packet list pane in real time during capture. If you do not enable this, Wireshark will not display any packets until you stop the capture. When you check this, Wireshark captures in a separate process and feeds the captures to the display process. Automatically scroll during live capture Scroll the packet list pane as new packets come in, so you are always looking at the most recent packet. If you do not specify this Wireshark adds new packets to the packet list but does not scroll the packet list pane. This option is greyed out if “Update list of packets in real-time” is disabled. Show capture information during capture If this option is enabled, the capture information dialog described in Section 4.11, “While a Capture is running …” will be shown while packets are captured. Name ResolutionResolve MAC addresses Translate MAC addresses into names. Resolve network names Translate network addresses into names. Resolve transport names Translate transport names (port numbers). See Section 7.9, “Name Resolution” for more details on each of these options. Stop capture automatically after… Capturing can be stopped based on the following conditions:
You can double click on an interface row in the “Input“ tab or click Start from any tab to commence the capture. You can click Cancel to apply your changes and close the dialog. 4.6. The “Manage Interfaces” Dialog BoxFigure 4.6. The “Manage Interfaces” dialog box The “Manage Interfaces” dialog box initially shows the “Local Interfaces” tab, which lets you manage the following: Show Whether or not to show or hide this interface in the welcome screen and the “Capture Options” dialog. Friendly Name A name for the interface that is human readable. Interface Name The device name of the interface. Comment Can be used to add a descriptive comment for the interface. The “Pipes” tab lets you capture from a named pipe. To successfully add a pipe, its associated named pipe must have already been created. Click + and type the name of the pipe including its path. Alternatively, Browse can be used to locate the pipe. To remove a pipe from the list of interfaces, select it and press -. On Microsoft Windows, the “Remote Interfaces” tab lets you capture from an interface on a different machine. The Remote Packet Capture Protocol service must first be running on the target platform before Wireshark can connect to it. On Linux or Unix you can capture (and do so more securely) through an SSH tunnel. To add a new remote capture interface, click + and specify the following: Host The IP address or host name of the target platform where the Remote Packet Capture Protocol service is listening. The drop-down list contains the hosts that have previously been successfully contacted. The list can be emptied by choosing “Clear list” from the drop-down list. Port Set the port number where the Remote Packet Capture Protocol service is listening on. Leave blank to use the default port (2002). Null authentication Select this if you don’t need authentication to take place for a remote capture to be started. This depends on the target platform. This is exactly as secure as it appears, i.e., it is not secure at all. Password authentication Lets you specify the username and password required to connect to the Remote Packet Capture Protocol service. Each interface can optionally be hidden. In
contrast to the local interfaces, they are not saved in the
To remove a host including all its interfaces from the list, select it and click the - button. 4.7. The “Compiled Filter Output” Dialog BoxThis figure shows the results of compiling the BPF filter for the selected interfaces. Figure 4.7. The “Compiled Filter Output” dialog box In the list on the left the interface names are listed. The results of compiling a filter for the selected interface are shown on the right. 4.8. Capture files and file modesWhile capturing, the underlying libpcap capturing engine will grab the packets from the network card and keep the packet data in a (relatively) small kernel buffer. This data is read by Wireshark and saved into a capture file. By default, Wireshark saves packets to a temporary file. You can also tell Wireshark to save to a specific (“permanent”) file and switch to a different file after a given time has elapsed or a given number of packets have been captured. These options are controlled in the “Capture Options” dialog’s “Output” tab. Figure 4.8. Capture output options
Using the “Multiple files” option may cut context related information. Wireshark keeps context information of the loaded packet data, so it can report context related problems (like a stream error) and keeps information about context related protocols (e.g., where data is exchanged at the establishing phase and only referred to in later packets). As it keeps this information only for the loaded file, using one of the multiple file modes may cut these contexts. If the establishing phase is saved in one file and the things you would like to see is in another, you might not see some of the valuable context related information. Information about the folders used for capture files can be found in Appendix B, Files and Folders. Table 4.1. Capture file mode selected by capture options
Single temporary file A temporary file will be created and used (this is the default). After capturing is stopped this file can be saved later under a user specified name. Single named file A single capture file will be used. Choose this mode if you want to place the new capture file in a specific folder. Multiple files, continuous Like the “Single named file” mode, but a new file is created and used after reaching one of the multiple file switch conditions (one of the “Next file every…” values). Multiple files, ring buffer Much like “Multiple files continuous”, reaching one of the multiple files switch conditions (one of the “Next file every …” values) will switch to the next file. This will be a newly created file if value of “Ring buffer with n files” is not reached, otherwise it will replace the oldest of the formerly used files (thus forming a “ring”). This mode will limit the maximum disk usage, even for an unlimited amount of capture input data, only keeping the latest captured data. 4.9. Link-layer header typeIn most cases you won’t have to modify link-layer header type. Some exceptions are as follows: If you are capturing on an Ethernet device you might be offered a choice of “Ethernet” or “DOCSIS”. If you are capturing traffic from a Cisco Cable Modem Termination System that is putting DOCSIS traffic onto the Ethernet to be captured, select “DOCSIS”, otherwise select “Ethernet”. If you are capturing on an 802.11 device on some versions of BSD you might be offered a choice of “Ethernet” or “802.11”. “Ethernet” will cause the captured packets to have fake (“cooked”) Ethernet headers. “802.11” will cause them to have full IEEE 802.11 headers. Unless the capture needs to be read by an application that doesn’t support 802.11 headers you should select “802.11”. If you are capturing on an Endace DAG card connected to a synchronous serial line you might be offered a choice of “PPP over serial” or “Cisco HDLC”. If the protocol on the serial line is PPP, select “PPP over serial” and if the protocol on the serial line is Cisco HDLC, select “Cisco HDLC”. If you are capturing on an Endace DAG card connected to an ATM network you might be offered a choice of “RFC 1483 IP-over-ATM” or “Sun raw ATM”. If the only traffic being captured is RFC 1483 LLC-encapsulated IP, or if the capture needs to be read by an application that doesn’t support SunATM headers, select “RFC 1483 IP-over-ATM”, otherwise select “Sun raw ATM”. 4.10. Filtering while capturingWireshark supports limiting the packet capture to packets that match a capture filter. Wireshark capture filters are written in libpcap filter language. Below is a brief overview of the libpcap filter language’s syntax. Complete documentation can be found at the pcap-filter man page. You can find many Capture Filter examples at https://gitlab.com/wireshark/wireshark/wikis/CaptureFilters. You enter the capture filter into the “Filter” field of the Wireshark “Capture Options” dialog box, as shown in Figure 4.3, “The “Capture Options” input tab”. A capture filter takes the form of a series of primitive expressions connected by conjunctions (and/or) and optionally preceded by not: [not] primitive [and|or [not] primitive ...] An example is shown in Example 4.1, “A capture filter for telnet that captures traffic to and from a particular host”. Example 4.1. A capture filter for telnet that captures traffic to and from a particular host tcp port 23 and host 10.0.0.5 This example captures telnet traffic to and from the host 10.0.0.5, and shows how to use two primitives and the and conjunction. Another example is shown in Example 4.2, “Capturing all telnet traffic not from 10.0.0.5”, and shows how to capture all telnet traffic except that from 10.0.0.5. Example 4.2. Capturing all telnet traffic not from 10.0.0.5 tcp port 23 and not src host 10.0.0.5 A primitive is simply one of the following: [src|dst] host <host> This primitive allows you to filter on a host IP address or name. You can optionally precede the primitive with the keyword src|dst to specify that you are only interested in source or destination addresses. If these are not present, packets where the specified address appears as either the source or the destination address will be selected. ether [src|dst] host <ehost> This primitive allows you to filter on Ethernet host addresses. You can optionally include the keyword src|dst between the keywords ether and host to specify that you are only interested in source or destination addresses. If these are not present, packets where the specified address appears in either the source or destination address will be selected. gateway host <host> This primitive allows you to filter on packets that used host as a gateway. That is, where the Ethernet source or destination was host but neither the source nor destination IP address was host. [src|dst] net <net> [{mask <mask>}|{len <len>}] This primitive allows you to filter on network numbers. You can optionally precede this primitive with the keyword src|dst to specify that you are only interested in a source or destination network. If neither of these are present, packets will be selected that have the specified network in either the source or destination address. In addition, you can specify either the netmask or the CIDR prefix for the network if they are different from your own. [tcp|udp] [src|dst] port <port> This primitive allows you to filter on TCP and UDP port numbers. You can optionally precede this primitive with the keywords src|dst and tcp|udp which allow you to specify that you are only interested in source or destination ports and TCP or UDP packets respectively. The keywords tcp|udp must appear before src|dst. If these are not specified, packets will be selected for both the TCP and UDP protocols and when the specified address appears in either the source or destination port field. less|greater <length> This primitive allows you to filter on packets whose length was less than or equal to the specified length, or greater than or equal to the specified length, respectively. ip|ether proto <protocol> This primitive allows you to filter on the specified protocol at either the Ethernet layer or the IP layer. ether|ip broadcast|multicast This primitive allows you to filter on either Ethernet or IP broadcasts or multicasts. <expr> relop <expr> This primitive allows you to create complex filter expressions that select bytes or ranges of bytes in packets. Please see the pcap-filter man page at https://www.tcpdump.org/manpages/pcap-filter.7.html for more details.4.10.1. Automatic Remote Traffic FilteringIf Wireshark is running remotely (using e.g., SSH, an exported X11 window, a terminal server, …), the remote content has to be transported over the network, adding a lot of (usually unimportant) packets to the actually interesting traffic. To avoid this, Wireshark tries to figure out if it’s remotely connected (by looking at some specific environment variables) and automatically creates a capture filter that matches aspects of the connection. The following environment variables are analyzed:
On Windows it asks the operating system if it’s running in a Remote Desktop Services environment. 4.11. While a Capture is running …You might see the following dialog box while a capture is running: Figure 4.9. The “Capture Information” dialog box This dialog box shows a list of protocols and their activity over time. It can be enabled via the “capture.show_info” setting in the “Advanced” preferences. 4.11.1. Stop the running captureA running capture session will be stopped in one of the following ways:
4.11.2. Restart a running captureA running capture session can be restarted with the same capture options as the last time, this will remove all packets previously captured. This can be useful, if some uninteresting packets are captured and there’s no need to keep them. Restart is a convenience function and equivalent to a capture stop following by an immediate capture start. A restart can be triggered in one of the following ways:
Chapter 5. File Input, Output, And Printing5.1. IntroductionThis chapter will describe input and output of capture data.
5.2. Open Capture FilesWireshark can read in previously saved capture files. To read them, simply select the → menu or toolbar item. Wireshark will then pop up the “File Open” dialog box, which is discussed in more detail in Section 5.2.1, “The “Open Capture File” Dialog Box”.
If you haven’t previously saved the current capture file you will be asked to do so to prevent data loss. This warning can be disabled in the preferences. In addition to its native file format (pcapng), Wireshark can read and write capture files from a large number of other packet capture programs as well. See Section 5.2.2, “Input File Formats” for the list of capture formats Wireshark understands. 5.2.1. The “Open Capture File” Dialog BoxThe “Open Capture File” dialog box allows you to search for a capture file containing previously captured packets for display in Wireshark. The following sections show some examples of the Wireshark “Open File” dialog box. The appearance of this dialog depends on the system. However, the functionality should be the same across systems. Common dialog behavior on all systems:
Wireshark adds the following controls:
Figure 5.1. “Open” on Microsoft Windows This is the common Windows file open dialog along with some Wireshark extensions. Figure 5.2. “Open” - Linux and UNIX This is the common Qt file open dialog along with some Wireshark extensions. 5.2.2. Input File FormatsThe native capture file formats used by Wireshark are:
The following file formats from other capture tools can be opened by Wireshark:
New file formats are added from time to time. It may not be possible to read some formats dependent on the packet types captured. Ethernet captures are usually supported for most file formats but it may not be possible to read other packet types such as PPP or IEEE 802.11 from all file formats. 5.3. Saving Captured PacketsYou can save captured packets by using the → or → menu items. You can choose which packets to save and which file format to be used. Not all information will be saved in a capture file. For example, most file formats don’t record the number of dropped packets. See Section B.1, “Capture Files” for details. 5.3.1. The “Save Capture File As” Dialog BoxThe “Save Capture File As” dialog box allows you to save the current capture to a file. The exact appearance of this dialog depends on your system. However, the functionality is the same across systems. Examples are shown below. Figure 5.3. “Save” on Microsoft Windows This is the common Windows file save dialog with some additional Wireshark extensions. Figure 5.4. “Save” on Linux and UNIX This is the common Qt file save dialog with additional Wireshark extensions. You can perform the following actions:
If you don’t provide a file extension to the filename (e.g.,
If you wish to save some of the packets in your capture file you can do so via Section 5.7.1, “The “Export Specified Packets” Dialog Box”. 5.3.2. Output File FormatsWireshark can save the packet data in its native file format (pcapng) and in the file formats of other protocol analyzers so other tools can read the capture data.
The following file formats can be saved by Wireshark (with the known file extensions):
New file formats are added from time to time. Whether or not the above tools will be more helpful than Wireshark is a different question ;-)
5.4. Merging Capture FilesSometimes you need to merge several capture files into one. For example, this can be useful if you have captured simultaneously from multiple interfaces at once (e.g., using multiple instances of Wireshark). There are three ways to merge capture files using Wireshark:
5.4.1. The “Merge With Capture File” Dialog BoxThis lets you select a file to be merged into the currently loaded file. If your current data has not been saved you will be asked to save it first. Most controls of this dialog will work the same way as described in the “Open Capture File” dialog box. See Section 5.2.1, “The “Open Capture File” Dialog Box” for details. Specific controls of this merge dialog are: Prepend packets Prepend the packets from the selected file before the currently loaded packets. Merge chronologically Merge both the packets from the selected and currently loaded file in chronological order. Append packets Append the packets from the selected file after the currently loaded packets. Figure 5.5. “Merge” on Microsoft Windows This is the common Windows file open dialog with additional Wireshark extensions. Figure 5.6. “Merge” on Linux and UNIX This is the Qt file open dialog with additional Wireshark extensions.
5.5. Import Hex DumpWireshark can read in a hex dump and write the data described into a temporary libpcap capture file. It can read hex dumps with multiple packets in them, and build a capture file of multiple packets. It is also capable of generating dummy Ethernet, IP and UDP, TCP, or SCTP headers, in order to build fully processable packet dumps from hexdumps of application-level data only. Alternatively, a Dummy PDU header can be added to specify a dissector the data should be passed to initially. Two methods for converting the input are supported: 5.5.1. Standard ASCII HexdumpsWireshark understands a hexdump of the form generated by In normal operation, each line must begin with an offset describing the position in the packet, followed a colon, space, or tab separating it from the bytes. There is no limit on the width or number of bytes per line, but lines with only hex bytes without a leading offset are ignored (i.e., line breaks should not be inserted in long lines that wrap.) Offsets are more than two digits; they are in hex by default, but can also be in octal or decimal. Each packet must begin with offset zero, and an offset zero indicates the beginning of a new packet. Offset values must be correct; an unexpected value causes the current packet to be aborted and the next packet start awaited. There is also a single packet mode with no offsets. Packets may be preceded by a direction indicator ('I' or 'O') and/or a timestamp if indicated. If both are present, the direction indicator precedes the timestamp. The format of the timestamps must be specified. If no timestamp is parsed, in the case of the first packet the current system time is used, while subsequent packets are written with timestamps one microsecond later than that of the previous packet. Other text in the input data is ignored. Any text before the offset is ignored, including email forwarding characters '>'. Any text on a line after the bytes is ignored, e.g., an ASCII character dump (but see -a to ensure that hex digits in the character dump are ignored). Any line where the first non-whitespace character is a '#' will be ignored as a comment. Any lines of text between the bytestring lines are considered preamble; the beginning of the preamble is scanned for the direction indicator and timestamp as mentioned above and otherwise ignored. Any line beginning with #TEXT2PCAP is a directive and options can be inserted after this command to be processed by Wireshark. Currently there are no directives implemented; in the future, these may be used to give more fine-grained control on the dump and the way it should be processed e.g., timestamps, encapsulation type etc. In general, short of these restrictions, Wireshark is pretty liberal about reading in hexdumps and has been tested with a variety of mangled outputs (including being forwarded through email multiple times, with limited line wrap etc.) Here is a sample dump that can be imported, including optional directional indicator and timestamp: I 2019-05-14T19:04:57Z 000000 00 e0 1e a7 05 6f 00 10 ........ 000008 5a a0 b9 12 08 00 46 00 ........ 000010 03 68 00 00 00 00 0a 2e ........ 000018 ee 33 0f 19 08 7f 0f 19 ........ 000020 03 80 94 04 00 00 10 01 ........ 000028 16 a2 0a 00 03 50 00 0c ........ 000030 01 01 0f 19 03 80 11 01 ........ 5.5.2. Regular Text DumpsWireshark is also capable of scanning the input using a custom Perl regular expression as specified by GLib’s GRegex here. Using a regex capturing a single packet in the given file Wireshark will search the given file from start to the second to last character (the last character has to be Note that each named capturing subgroup has to match exactly once a packet, but they may be present multiple times in the regex. For example, the following dump: > 0:00:00.265620 a130368b000000080060 > 0:00:00.280836 a1216c8b00000000000089086b0b82020407 < 0:00:00.295459 a2010800000000000000000800000000 > 0:00:00.296982 a1303c8b00000008007088286b0bc1ffcbf0f9ff > 0:00:00.305644 a121718b0000000000008ba86a0b8008 < 0:00:00.319061 a2010900000000000000001000600000 > 0:00:00.330937 a130428b00000008007589186b0bb9ffd9f0fdfa3eb4295e99f3aaffd2f005 > 0:00:00.356037 a121788b0000000000008a18 could be imported using these settings: regex: ^(?<dir>[<>])\s(?<time>\d+:\d\d:\d\d.\d+)\s(?<data>[0-9a-fA-F]+)$ timestamp: %H:%M:%S.%f dir: in: < out: > encoding: HEX Caution has to
be applied when discarding the anchors Supported fields:
5.5.3. The “Import From Hex Dump” Dialog BoxThis dialog box lets you select a text file, containing a hex dump of packet data, to be imported and set import parameters. Figure 5.7. The “Import from Hex Dump” dialog in Hex Dump mode Specific controls of this import dialog are split in three sections: File Source Determine which input file has to be imported Input Format Determine how the input file has to be interpreted. Encapsulation Determine how the data is to be encapsulated. 5.5.4. File sourceFilename / Browse Enter the name of the text file to import. You can use Browse to browse for a file. 5.5.5. Input FormatThis section is split in the two alternatives for input conversion, accessible in the two Tabs "Hex Dump" and "Regular Expression" In addition to the conversion mode specific inputs, there are also common parameters, currently only the timestamp format. 5.5.5.1. The Hex Dump tabOffsets Select the radix of the offsets given in the text file to import. This is usually hexadecimal, but decimal and octal are also supported. Select None when only the bytes are present. These will be imported as a single packet. Direction indication Tick this box if the text file to import has direction indicators before each frame. These are on a separate line before each frame and start with either I or i for input and O or o for output. 5.5.5.2. The Regular Expression tabFigure 5.8. The "Regular Expression" tab inside the "Import from Hex Dump” dialog. Packet format regular expression This is the regex used for searching packets and metadata inside the input file. Named capturing subgroups are used to find the individual fields. Anchors The Encoding used for the binary data. Supported encodings are plain-hexadecimal, -octal, -binary and base64. Plain here means no additional characters are present in the data field beyond whitespaces, which are ignored. Any unexpected characters abort the import process. Ignored whitespaces are Any incomplete bytes at the field’s end are assumed to be padding to fill the last complete byte. These bits should be zero, however, this is not checked. Direction indication The lists of characters indicating incoming vs. outgoing packets. These fields are only available when the regex contains a(?<dir>…) group. 5.5.5.3. Common itemsTimestamp Format This is
the format specifier used to parse the timestamps in the text file to import. It uses the same format as In Regex mode this field is only available when a
In Hex Dump mode if there are no timestamps in the text file to import, leave this field empty and timestamps will be generated based on the time of import. 5.5.6. EncapsulationEncapsulation type Here you can select which type of frames you are importing. This all depends on from what type of medium the dump to import was taken. It lists all types that Wireshark understands, so as to pass the capture file contents to the right dissector. Dummy header When Ethernet encapsulation is selected you have to option to prepend dummy headers to the frames to import. These headers can provide artificial Ethernet, IP, UDP, TCP or SCTP headers or SCTP data chunks. When selecting a type of dummy header, the applicable entries are enabled, others are greyed out and default values are used. When the Wireshark Upper PDU export encapsulation is selected the option ExportPDU becomes available. This allows you to select the name of the dissector these frames are to be directed to. Maximum frame length You may not be interested in the full frames from the text file, just the first part. Here you can define how much data from the start of the frame you want to import. If you leave this open the maximum is set to 256kiB. Once all input and import parameters are setup click Import to start the import. If your current data wasn’t saved before you will be asked to save it first. If the import button doesn’t unlock, make sure all encapsulation parameters are in the expected range and all unlocked fields are populated when using regex mode (the placeholder text is not used as default). When completed there will be a new capture file loaded with the frames imported from the text file. 5.6. File SetsWhen using the “Multiple Files” option while doing a capture (see: Section 4.8, “Capture files and file modes”), the capture data is spread over several capture files, called a file set. As it can become tedious to work with a file set by hand, Wireshark provides some features to handle these file sets in a convenient way. The following features in the → submenu are available to work with file sets in a convenient way:
5.6.1. The “List Files” Dialog BoxFigure 5.9. The “List Files” dialog box Each line contains information about a file of the file set: Filename The name of the file. If you click on the filename (or the radio button left to it), the current file will be closed and the corresponding capture file will be opened. Created The creation time of the file. Last Modified The last time the file was modified. Size The size of the file. The last line will contain info about the currently used directory where all of the files in the file set can be found. The content of this dialog box is updated each time a capture file is opened/closed. The Close button will, well, close the dialog box. 5.7. Exporting DataWireshark provides a variety of options for exporting packet data. This section describes general ways to export data from the main Wireshark application. There are many other ways to export or extract data from capture files, including processing tshark output and customizing Wireshark and TShark using Lua scripts. 5.7.1. The “Export Specified Packets” Dialog BoxFigure 5.10. The “Export Specified Packets” dialog box This is similar to the “Save” dialog box, but it lets you save specific packets. This can be useful for trimming irrelevant or unwanted packets from a capture file. See Packet Range for details on the range controls. 5.7.2. The “Export Packet Dissections” Dialog BoxThis lets you save the packet list, packet details, and packet bytes as plain text, CSV, JSON, and other formats. Figure 5.11. The “Export Packet Dissections” dialog box The format can be selected from the “Export As” drop-down and further customized using the “Packet Range” and “Packet Format” controls. Some controls are unavailable for some formats, notably CSV and JSON. The following formats are supported:
Here are some examples of exported data: Plain text. No. Time Source Destination Protocol Length SSID Info 1 0.000000 200.121.1.131 172.16.0.122 TCP 1454 10554 → 80 [ACK] Seq=1 Ack=1 Win=65535 Len=1400 [TCP segment of a reassembled PDU] Frame 1: 1454 bytes on wire (11632 bits), 1454 bytes captured (11632 bits) Ethernet II, Src: 00:50:56:c0:00:01, Dst: 00:0c:29:42:12:13 Internet Protocol Version 4, Src: 200.121.1.131 (200.121.1.131), Dst: 172.16.0.122 (172.16.0.122) 0100 .... = Version: 4 .... 0101 = Header Length: 20 bytes (5) Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT) Total Length: 1440 Identification: 0x0141 (321) Flags: 0x0000 ...0 0000 0000 0000 = Fragment offset: 0 Time to live: 106 Protocol: TCP (6) Header checksum: 0xd390 [validation disabled] [Header checksum status: Unverified] Source: 200.121.1.131 (200.121.1.131) Destination: 172.16.0.122 (172.16.0.122) [Source GeoIP: PE, ASN 6147, Telefonica del Peru S.A.A.] Transmission Control Protocol, Src Port: 10554, Dst Port: 80, Seq: 1, Ack: 1, Len: 1400
CSV. "No.","Time","Source","Destination","Protocol","Length","SSID","Info","Win Size" "1","0.000000","200.121.1.131","172.16.0.122","TCP","1454","","10554 > 80 [ACK] Seq=1 Ack=1 Win=65535 Len=1400 [TCP segment of a reassembled PDU]","65535" "2","0.000011","172.16.0.122","200.121.1.131","TCP","54","","[TCP ACKed unseen segment] 80 > 10554 [ACK] Seq=1 Ack=11201 Win=53200 Len=0","53200" "3","0.025738","200.121.1.131","172.16.0.122","TCP","1454","","[TCP Spurious Retransmission] 10554 > 80 [ACK] Seq=1401 Ack=1 Win=65535 Len=1400 [TCP segment of a reassembled PDU]","65535" "4","0.025749","172.16.0.122","200.121.1.131","TCP","54","","[TCP Window Update] [TCP ACKed unseen segment] 80 > 10554 [ACK] Seq=1 Ack=11201 Win=63000 Len=0","63000" "5","0.076967","200.121.1.131","172.16.0.122","TCP","1454","","[TCP Previous segment not captured] [TCP Spurious Retransmission] 10554 > 80 [ACK] Seq=4201 Ack=1 Win=65535 Len=1400 [TCP segment of a reassembled PDU]","65535" JSON. { "_index": "packets-2014-06-22", "_type": "doc", "_score": null, "_source": { "layers": { "frame": { "frame.encap_type": "1", "frame.time": "Jun 22, 2014 13:29:41.834477000 PDT", "frame.offset_shift": "0.000000000", "frame.time_epoch": "1403468981.834477000", "frame.time_delta": "0.450535000", "frame.time_delta_displayed": "0.450535000", "frame.time_relative": "0.450535000", "frame.number": "2", "frame.len": "86", "frame.cap_len": "86", "frame.marked": "0", "frame.ignored": "0", "frame.protocols": "eth:ethertype:ipv6:icmpv6", "frame.coloring_rule.name": "ICMP", "frame.coloring_rule.string": "icmp || icmpv6" }, "eth": { "eth.dst": "33:33:ff:9e:e3:8e", "eth.dst_tree": { "eth.dst_resolved": "33:33:ff:9e:e3:8e", "eth.dst.oui": "3355647", "eth.addr": "33:33:ff:9e:e3:8e", "eth.addr_resolved": "33:33:ff:9e:e3:8e", "eth.addr.oui": "3355647", "eth.dst.lg": "1", "eth.lg": "1", "eth.dst.ig": "1", "eth.ig": "1" }, "eth.src": "00:01:5c:62:8c:46", "eth.src_tree": { "eth.src_resolved": "00:01:5c:62:8c:46", "eth.src.oui": "348", "eth.src.oui_resolved": "Cadant Inc.", "eth.addr": "00:01:5c:62:8c:46", "eth.addr_resolved": "00:01:5c:62:8c:46", "eth.addr.oui": "348", "eth.addr.oui_resolved": "Cadant Inc.", "eth.src.lg": "0", "eth.lg": "0", "eth.src.ig": "0", "eth.ig": "0" }, "eth.type": "0x000086dd" }, "ipv6": { "ipv6.version": "6", "ip.version": "6", "ipv6.tclass": "0x00000000", "ipv6.tclass_tree": { "ipv6.tclass.dscp": "0", "ipv6.tclass.ecn": "0" }, "ipv6.flow": "0x00000000", "ipv6.plen": "32", "ipv6.nxt": "58", "ipv6.hlim": "255", "ipv6.src": "2001:558:4080:16::1", "ipv6.addr": "2001:558:4080:16::1", "ipv6.src_host": "2001:558:4080:16::1", "ipv6.host": "2001:558:4080:16::1", "ipv6.dst": "ff02::1:ff9e:e38e", "ipv6.addr": "ff02::1:ff9e:e38e", "ipv6.dst_host": "ff02::1:ff9e:e38e", "ipv6.host": "ff02::1:ff9e:e38e", "ipv6.geoip.src_summary": "US, ASN 7922, Comcast Cable Communications, LLC", "ipv6.geoip.src_summary_tree": { "ipv6.geoip.src_country": "United States", "ipv6.geoip.country": "United States", "ipv6.geoip.src_country_iso": "US", "ipv6.geoip.country_iso": "US", "ipv6.geoip.src_asnum": "7922", "ipv6.geoip.asnum": "7922", "ipv6.geoip.src_org": "Comcast Cable Communications, LLC", "ipv6.geoip.org": "Comcast Cable Communications, LLC", "ipv6.geoip.src_lat": "37.751", "ipv6.geoip.lat": "37.751", "ipv6.geoip.src_lon": "-97.822", "ipv6.geoip.lon": "-97.822" } }, "icmpv6": { "icmpv6.type": "135", "icmpv6.code": "0", "icmpv6.checksum": "0x00005b84", "icmpv6.checksum.status": "1", "icmpv6.reserved": "00:00:00:00", "icmpv6.nd.ns.target_address": "2001:558:4080:16:be36:e4ff:fe9e:e38e", "icmpv6.opt": { "icmpv6.opt.type": "1", "icmpv6.opt.length": "1", "icmpv6.opt.linkaddr": "00:01:5c:62:8c:46", "icmpv6.opt.src_linkaddr": "00:01:5c:62:8c:46" } } } } } ] 5.7.3. The “Export Selected Packet Bytes” Dialog BoxExport the bytes selected in the “Packet Bytes” pane into a raw binary file. Figure 5.12. The “Export Selected Packet Bytes” dialog box File name The file name to export the packet data to. Save as type The file extension. 5.7.4. The “Export PDUs to File…” Dialog BoxThe “Export PDUs to File…” dialog box allows you to filter the captured Protocol Data Units (PDUs) and export them into the file. It allows you to export reassembled PDUs avoiding lower layers such as HTTP without TCP, and decrypted PDUs without the lower protocols such as HTTP without TLS and TCP.
5.7.5. The “Strip Headers…” Dialog BoxThe “Strip Headers…” dialog box allows you to filter known encapsulation types on whatever protocol layer they appear and export them into a new capture file, removing lower-level protocols. It allows you to export reassembled packets and frames without lower layers such as GPF, GRE, GSE, GTP-U, MPLS, MPE, PPP, and more. If Wireshark has performed decryption, then you can export decrypted IP from protocols like IEEE 802.11 or IPSec without having to save encryption keys. The procedure is similar to that of Section 5.7.4, “The “Export PDUs to File…” Dialog Box”:
5.7.6. The “Export TLS Session Keys…” Dialog BoxTransport Layer Security (TLS) encrypts the communication between a client and a server. The most common use for it is web browsing via HTTPS. Decryption of TLS traffic requires TLS secrets. You can get them in the form of stored session keys in a "key log file", or by using an RSA private key file. For more details, see the TLS wiki page. The → menu option generates a new "key log file" which contains TLS session secrets known by Wireshark. This feature is useful if you typically decrypt TLS sessions using the RSA private key file. The RSA private key is very sensitive because it can be used to decrypt other TLS sessions and impersonate the server. Session keys can be used only to decrypt sessions from the packet capture file. However, session keys are the preferred mechanism for sharing data over the Internet. To export captured TLS session keys, follow the steps below:
5.7.7. The “Export Objects” Dialog BoxThis feature scans through the selected protocol’s streams in the currently open capture file or running capture and allows the user to export reassembled objects to the disk. For example, if you select HTTP, you can export HTML documents, images, executables, and any other files transferred over HTTP to the disk. If you have a capture running, this list is automatically updated every few seconds with any new objects seen. The saved objects can then be opened or examined independently of Wireshark. Figure 5.15. The “Export Objects” dialog box Columns: Packet The packet number in which this object was found. In some cases, there can be multiple objects in the same packet. Hostname The hostname of the server that sent this object. Content Type The content type of this object. Size The size of this object in bytes. Filename: The filename for this object. Each protocol generates the filename differently. For example, HTTP uses the final part of the URI and IMF uses the subject of the email. Inputs: Text Filter Only displays objects containing the specified text string. Help Opens this section of the “User’s Guide”. Save All Saves all objects (including those not displayed) using the filename from the filename column. You will be asked what directory or folder to save them in. Close Closes the dialog without exporting. Save Saves the currently selected object as a filename you specify. The default filename to save as is taken from the filename column of the objects list. 5.8. Printing PacketsTo print packets, select the → menu item. Wireshark will display the “Print” dialog box as shown below.
5.8.1. The “Print” Dialog BoxFigure 5.16. The “Print” dialog box The “Print” dialog box shows a preview area which shows the result of changing the packet format settings. You can zoom in and out using the + and - keys and reset the zoom level using the 0 key. The following settings are available in the Print dialog box: Packet Format Lets you specify what gets printed. See Figure 5.18, “The “Packet Format” frame” for details. Summary line Include a summary line for each packet. The line will contain the same fields as the packet list. Details Print details for each packet. Bytes Print a hex dump of each packet. Packet Range Select the packets to be printed. See Section 5.9, “The “Packet Range” Frame” for details.Page Setup… lets you select the page size and orientation. Print… prints to your default printer. Cancel will close the dialog without printing. Help will display this section of the “User’s Guide”. 5.9. The “Packet Range” FrameThe packet range frame is a part of the “Export Specified Packets,” “Export Packet Dissections,” and “Print” dialog boxes. You can use it to specify which packets will be exported or printed. Figure 5.17. The “Packet Range” frame By default, the Displayed button is set, which only exports or prints the packets that match the current display filter. Selecting Captured will export or print all packets. You can further limit what you export or print to the following: All packets All captured or displayed packets depending on the primary selection above. Selected packet Only the selected packet. Marked packets Only marked packets. See Section 6.10, “Marking Packets”. First to last marked Lets you mark an inclusive range of packets. Range Lets you manually specify a range of packets, e.g., 5,10-15,20- will process the packet number five, the packets from packet number ten to fifteen (inclusive) and every packet from number twenty to the end of the capture. Remove ignored packets Don’t export or print ignored packets. See Section 6.11, “Ignoring Packets”. 5.10. The Packet Format FrameThe packet format frame is also a part of the “Export Packet Dissections” and “Print” dialog boxes. You can use it to specify which parts of dissection are exported or printed. Figure 5.18. The “Packet Format” frame Each of the settings below correspond to the packet list, packet detail, and packet bytes in the main window. Packet summary line Export or print each summary line as shown in the “Packet List” pane. Packet details Export or print the contents of the “Packet Details” tree. All collapsed Export or print as if the “Packet Details” tree is in the “all collapsed” state. As displayed Export or print as if the “Packet Details” tree is in the “as displayed” state. All expanded Export or print as if the “Packet Details” tree is in the “all expanded” state. Packet Bytes Export or print the contents of the “Packet Bytes” pane. Each packet on a new page For printing and some export formats, put each packet on a separate page. For example, when exporting to a text file this will put a form feed character between each packet. Capture information header Add a header to each page with capture filename and the number of total packets and shown packets.Chapter 6. Working With Captured Packets6.1. Viewing Packets You Have CapturedOnce you have captured some packets or you have opened a previously saved capture file, you can view the packets that are displayed in the packet list pane by simply clicking on a packet in the packet list pane, which will bring up the selected packet in the tree view and byte view panes. You can then expand any part of the tree to view detailed information about each protocol in each packet. Clicking on an item in the tree will highlight the corresponding bytes in the byte view. An example with a TCP packet selected is shown in Figure 6.1, “Wireshark with a TCP packet selected for viewing”. It also has the Acknowledgment number in the TCP header selected, which shows up in the byte view as the selected bytes. Figure 6.1. Wireshark with a TCP packet selected for viewing You can also select and view packets the same way while Wireshark is capturing if you selected “Update list of packets in real time” in the “Capture Preferences” dialog box. In addition you can view individual packets in a separate window as shown in Figure 6.2, “Viewing a packet in a separate window”. You can do this by double-clicking on an item in the packet list or by selecting the packet in which you are interested in the packet list pane and selecting → . This allows you to easily compare two or more packets, even across multiple files. Figure 6.2. Viewing a packet in a separate window Along with double-clicking the packet list and using the main menu there are a number of other ways to open a new packet window:
6.2. Pop-up MenusYou can open a pop-up menu over the “Packet List”, its column heading, “Packet Details”, or “Packet Bytes” by clicking your right mouse button on the corresponding item. 6.2.1. Pop-up Menu Of The “Packet List” Column HeaderFigure 6.3. Pop-up menu of the “Packet List” column header The following table gives an overview of which functions are available in this header, where to find the corresponding function in the main menu, and a description of each item. Table 6.1. The menu items of the “Packet List” column header pop-up menu
6.2.2. Pop-up Menu Of The “Packet List” PaneFigure 6.4. Pop-up menu of the “Packet List” pane The following table gives an overview of which functions are available in this pane, where to find the corresponding function in the main menu, and a short description of each item. Table 6.2. The menu items of the “Packet List” pop-up menu
6.2.3. Pop-up Menu Of The “Packet Details” PaneFigure 6.5. Pop-up menu of the “Packet Details” pane The following table gives an overview of which functions are available in this pane, where to find the corresponding function in the main menu, and a short description of each item. Table 6.3. The menu items of the “Packet Details” pop-up menu
6.2.4. Pop-up Menu Of The “Packet Bytes” PaneFigure 6.6. Pop-up menu of the “Packet Bytes” pane The following table gives an overview of which functions are available in this pane along with a short description of each item. Table 6.4. The menu items of the “Packet Bytes” pop-up menu
6.2.5. Pop-up Menu Of The “Packet Diagram” PaneFigure 6.7. Pop-up menu of the “Packet Diagram” pane The following table gives an overview of which functions are available in this pane along with a short description of each item. Table 6.5. The menu items of the “Packet Diagram” pop-up menu
6.3. Filtering Packets While ViewingWireshark has two filtering languages: capture filters and display filters. Capture filters are used for filtering when capturing packets and are discussed in Section 4.10, “Filtering while capturing”. Display filters are used for filtering which packets are displayed and are discussed below. For more information about display filter syntax, see the wireshark-filter(4) man page. Display filters allow you to concentrate on the packets you are interested in while hiding the currently uninteresting ones. They allow you to only display packets based on:
To only display packets containing a particular protocol, type the protocol name in the display filter toolbar of the Wireshark window and press enter to apply the filter. Figure 6.8, “Filtering on the TCP protocol” shows an example of what happens when you type tcp in the display filter toolbar.
Figure 6.8. Filtering on the TCP protocol As you may have noticed, only packets containing the TCP protocol are now displayed, so packets 1-10 are hidden and packet number 11 is the first packet displayed.
To remove the filter, click on the Clear button to the right of the display filter field. All packets will become visible again. Display filters can be very powerful and are discussed in further detail in Section 6.4, “Building Display Filter Expressions” It’s also possible to create display filters with the Display Filter Expression dialog box. More information about the Display Filter Expression dialog box is available in Section 6.5, “The “Display Filter Expression” Dialog Box”. 6.4. Building Display Filter ExpressionsWireshark provides a display filter language that enables you to precisely control which packets are displayed. They can be used to check for the presence of a protocol or field, the value of a field, or even compare two fields to each other. These comparisons can be combined with logical operators, like "and" and "or", and parentheses into complex expressions. The following sections will go into the display filter functionality in more detail. 6.4.1. Display Filter FieldsThe simplest display filter is one that displays a single protocol. To only display packets containing a particular protocol, type the protocol into Wireshark’s display filter toolbar. For example, to only display TCP packets, type tcp into Wireshark’s display filter toolbar. Similarly, to only display packets containing a particular field, type the field into Wireshark’s display filter toolbar. For example, to only display HTTP requests, type http.request into Wireshark’s display filter toolbar. You can filter on any protocol that Wireshark supports. You can also filter on any field that a dissector adds to the tree view, if the dissector has added an abbreviation for that field. A full list of the available protocols and fields is available through the menu item → → . 6.4.2. Comparing ValuesYou can build display filters that compare values using a number of different comparison operators. For example, to only display packets to or from the IP address 192.168.0.1, use A complete list of available comparison operators is shown in Table 6.6, “Display Filter comparison operators”.
Table 6.6. Display Filter comparison operators
All protocol fields have a type. Section 6.4.2.1, “Display Filter Field Types” provides a list of the types with examples of how to use them in display filters. 6.4.2.1. Display Filter Field TypesUnsigned integer Can be 8, 16, 24, 32, or 64 bits. You can express integers in decimal, octal, hexadecimal or binary. The following display filters are equivalent:
Can be 1 or "True" or "TRUE", 0 or "False" or "FALSE" (without quotes). A Boolean field is
present regardless if its value is true or false. For example, 6 bytes separated by a colon (:), dot (.), or dash (-) with one or two bytes between separators:
Classless InterDomain Routing (CIDR) notation can be used to test if an IPv4 address is in a certain subnet. For example, this display filter will find all packets in the 129.111 Class-B network:
As with IPv4 addresses, IPv6 addresses can match a subnet. Text string
Strings are a sequence of bytes. Functions like
Alternatively, a raw string syntax can be used. Such strings are prefixed with
The value of an absolute time field is expressed as a string, using one of the two formats above. Fractional seconds can be omitted or specified up to nanosecond precision; extra trailing zeros are allowed but not other digits. The string cannot take a time zone suffix, and is always parsed as in the local time zone, even for fields that are displayed in UTC. In the first format, the abbreviated month names must be in English regardless of locale. In the second format, any number of time fields may be omitted, in the order from least significant (seconds) to most, but at least the entire date must be specified:
In the second format, a 6.4.2.2. Some Examplesudp contains 81:60:03 The display filter above matches packets that contains the 3-byte sequence 0x81, 0x60, 0x03 anywhere in the UDP header or payload. sip.To contains "a1762" The display filter above matches packets where the SIP To-header contains the string "a1762" anywhere in the header. http.host matches "acme\\.(org|com|net)" The display filter above matches HTTP packets where the HOST header contains acme.org, acme.com, or acme.net. Comparisons are case-insensitive. tcp.flags & 0x02 That display filter will match all packets that contain the “tcp.flags” field with the 0x02 bit, i.e., the SYN bit, set. 6.4.2.3. Possible Pitfalls Using Regular ExpressionsString literals containing regular expressions are parsed twice. Once by Wireshark’s display filter engine and again by the PCRE2 library. It’s important to keep this in mind when using the "matches" operator with regex escape sequences and special characters. For example, the filter
expression An example where this fails badly is
6.4.3. Combining ExpressionsYou can combine filter expressions in Wireshark using the logical operators shown in Table 6.7, “Display Filter Logical Operations” Table 6.7. Display Filter Logical Operations
6.4.4. Slice OperatorWireshark allows you to select a subsequence of a sequence in rather elaborate ways. After a label you can place a pair of brackets [] containing a comma separated list of range specifiers. eth.src[0:3] == 00:00:83 The example above uses the n:m format to specify a single range. In this case n is the beginning offset and m is the length of the range being specified. eth.src[1-2] == 00:83 The example above uses the n-m format to specify a single range. In this case n is the beginning offset and m is the ending offset. eth.src[:4] == 00:00:83:00 The example above uses the :m format, which takes everything from the beginning of a sequence to offset m. It is equivalent to 0:m eth.src[4:] == 20:20 The example above uses the n: format, which takes everything from offset n to the end of the sequence. eth.src[2] == 83 The example above uses the n format to specify a single range. In this case the element in the sequence at offset n is selected. This is equivalent to n:1. eth.src[0:3,1-2,:4,4:,2] == 00:00:83:00:83:00:00:83:00:20:20:83 Wireshark allows you to string together single ranges in a comma separated list to form compound ranges as shown above. 6.4.5. Membership OperatorWireshark allows you to test a field for membership in a set of values or fields. After the field name, use the
Sets are not just limited to numbers, other types can be used as well: http.request.method in {"HEAD", "GET"} ip.addr in {10.0.0.5 .. 10.0.0.9, 192.168.1.1..192.168.1.9} frame.time_delta in {10 .. 10.5} 6.4.6. Arithmetic operatorsYou can perform the arithmetic operations on numeric fields shown in Table 6.8, “Display Filter Arithmetic Operations”
Table 6.8. Display Filter Arithmetic Operations
Arithmetic expressions can be grouped using curly braces. 6.4.7. FunctionsThe display filter language has a number of functions to convert fields, see Table 6.9, “Display Filter Functions”. Table 6.9. Display Filter Functions
The To find HTTP requests with long request URIs: Usually an IP frame has only two addresses (source and destination), but in case of ICMP errors or tunneling, a single packet might contain even more addresses. These packets can be found with
The For example, to match odd frame numbers: string(frame.number) matches "[13579]$" To match IP addresses ending in 255 in a block of subnets (172.16 to 172.31): string(ip.dst) matches r"^172\.(1[6-9]|2[0-9]|3[0-1])\.[0-9]{1,3}\.255" The functions max() and min() take any number of arguments of the same type and returns the largest/smallest respectively of the set. max(tcp.srcport, tcp.dstport) <= 1024 6.4.8. Sometimes Fields Change NamesAs protocols evolve they sometimes change names or are superseded by newer standards. For example, DHCP extends and has largely replaced BOOTP and TLS has replaced SSL. If a protocol dissector originally used the older names and fields for a protocol the Wireshark development team might update it to use the newer names and fields. In such cases they will add an alias from the old protocol name to the new one in order to make the transition easier. For example, the DHCP dissector was originally developed for the BOOTP protocol but as of Wireshark 3.0 all of the “bootp” display filter fields have been renamed to their “dhcp” equivalents. You can still use the old filter names for the time being, e.g., “bootp.type” is equivalent to “dhcp.type” but Wireshark will show the warning “"bootp" is deprecated” when you use it. Support for the deprecated fields may be removed in the future. 6.4.9. Some protocol names can be ambiguousIn some particular cases relational expressions (equal, less than, etc.) can be ambiguous. The filter name of a protocol or protocol field can contain any letter and digit in any
order, possibly separated by dots. That can be indistinguishable from a literal value (usually numerical values in hexadecimal). For example the semantic value of Any value that matches a registered protocol or protocol field filter name is interpreted semantically as such. If it doesn’t match a protocol name the normal rules for parsing literal values apply. So in the case of 'fc' the lexical token is interpreted as "Fibre Channel" and not 0xFC. In the case of 'fd' it would be interpreted as 0xFD because it is a well-formed hexadecimal literal value (according to the rules of display filter language syntax) and there is no protocol registered with the filter name 'fd'. How ambiguous values are interpreted may change in the future. To avoid this problem and resolve the ambiguity there is additional syntax available. Values in-between angle brackets are always and only treated as literal values. Bytes arrays and numeric values can also be prefixed with a colon to force interpretation as a literal value. Values prefixed with a dot are always treated as a protocol name. The dot stands for the root of the protocol namespace and is optional) frame[10:] contains .fc or frame[10] == :fc and not frame contains <cafe.face> If you are writing a script, or you think your expression may not be giving the expected results because of the syntactical ambiguity of some filter expression it is advisable to use the explicit syntax to indicate the correct meaning for that expression. 6.5. The “Display Filter Expression” Dialog BoxWhen you are accustomed to Wireshark’s filtering system and know what labels you wish to use in your filters it can be very quick to simply type a filter string. However, if you are new to Wireshark or are working with a slightly unfamiliar protocol it can be very confusing to try to figure out what to type. The “Display Filter Expression” dialog box helps with this.
Figure 6.9. The “Display Filter Expression” dialog box When you first bring up the Display Filter Expression dialog box you are shown a tree of field names, organized by protocol, and a box for selecting a relation. Field Name Select a protocol field from the protocol field tree. Every protocol with filterable fields is listed at the top level. You can search for a particular protocol entry by entering the first few letters of the protocol name. By expanding a protocol name you can get a list of the field names available for filtering for that protocol. Relation Select a relation from the list of available relation. The is present is a unary relation which is true if the selected field is present in a packet. All other listed relations are binary relations which require additional data (e.g. a Value to match) to complete. When you select a field from the field name list and select a binary relation (such as the equality relation ==) you will be given the opportunity to enter a value, and possibly some range information. Value You may enter an appropriate value in the Value text box. The Value will also indicate the type of value for the Field Name you have selected (like character string). Predefined Values Some of the protocol fields have predefined values available, much like enumerations in C. If the selected protocol field has such values defined, you can choose one of them here. Search Lets you search for a full or partial field name or description. Regular expressions are supported. For example, searching for “tcp.*flag” shows the TCP flags fields supported by a wide variety of dissectors, while “^tcp.flag” shows only the TCP flags fields supported by the TCP dissector. Range A range of integers or a group of ranges, such as1-12 or 39-42,98-2000 . Help Opens this section of the User’s Guide. OK When you have built a satisfactory expression click OK and a filter string will be built for you. Cancel You can leave the “Add Expression…”
dialog box without any effect by clicking the Cancel button. 6.6. Defining And Saving FiltersYou create pre-defined filters that appear in the capture and display filter bookmark menus (). This can save time in remembering and retyping some of the more complex filters you use. To create or edit capture filters, select from the capture filter bookmark menu or → from the main menu. Display filters can be created or edited by selecting from the display filter bookmark menu or → from the main menu. Wireshark will open the corresponding dialog as shown in Figure 6.10, “The “Capture Filters” and “Display Filters” dialog boxes”. The two dialogs look and work similar to one another. Both are described here, and the differences are noted as needed. Figure 6.10. The “Capture Filters” and “Display Filters” dialog boxes + Adds a new filter to the list. You can edit the filter name or expression by double-clicking on it. The filter name is used in this dialog to identify the filter for your convenience and is not used elsewhere. You can create multiple filters with the same name, but this is not very useful. When typing in a filter string, the background color will change depending on the validity of the filter similar to the main capture and display filter toolbars. - Delete the selected filter. This will be greyed out if no filter is selected.Copy Copy the selected filter. This will be greyed out if no filter is selected. OK Saves the filter settings and closes the dialog. Cancel Closes the dialog without saving any changes. 6.7. Defining And Saving Filter MacrosYou can define a filter macro with Wireshark and label it for later use. This can save time in remembering and retyping some of the more complex filters you use. To define and save your own filter macros, follow the steps below:
To learn more about display filter macro syntax, see Section 11.8, “Display Filter Macros”. 6.8. Finding PacketsYou can easily find packets once you have captured some packets or have read in a previously saved capture file. Simply select → in the main menu. Wireshark will open a toolbar between the main toolbar and the packet list shown in Figure 6.12, “The “Find Packet” toolbar”. 6.8.1. The “Find Packet” ToolbarFigure 6.12. The “Find Packet” toolbar You can search using the following criteria: Display filter Enter a display filter string into the text entry field and click the Find button. + For example, to find the three-way handshake for a connection from host 192.168.0.1, use the following filter string: ip.src==192.168.0.1 and tcp.flags.syn==1 The value to be found will be syntax checked while you type it in. If the syntax check of your value succeeds, the background of the entry field will turn green, if it fails, it will turn red. For more details see Section 6.3, “Filtering Packets While Viewing” Hexadecimal ValueSearch for a specific byte sequence in the packet data. For example, use “ef:bb:bf” to find the next packet that contains the UTF-8 byte order mark. String Find a string in the packet data, with various options. Regular Expression Search the packet data using Perl-compatible regular expressions. PCRE patterns are beyond the scope of this document, but typing “pcre test” into your favorite search engine should return a number of sites that will help you test and explore your expressions.
6.9. Go To A Specific PacketYou can easily jump to specific packets with one of the menu items in the menu. 6.9.1. The “Go Back” CommandGo back in the packet history, works much like the page history in most web browsers. 6.9.2. The “Go Forward” CommandGo forward in the packet history, works much like the page history in most web browsers. 6.9.3. The “Go to Packet” ToolbarFigure 6.13. The “Go To Packet” toolbar This toolbar can be opened by selecting → from the main menu. It appears between the main toolbar and the packet list, similar to the ”Find Packet” toolbar. When you enter a packet number and press Go to packet Wireshark will jump to that packet. 6.9.4. The “Go to Corresponding Packet” CommandIf a protocol field is selected which points to another packet in the capture file, this command will jump to that packet. As these protocol fields now work like links (just as in your Web browser), it’s easier to simply double-click on the field to jump to the corresponding field. 6.9.5. The “Go to First Packet” CommandThis command will jump to the first packet displayed. 6.9.6. The “Go to Last Packet” CommandThis command will jump to the last packet displayed. 6.10. Marking PacketsYou can mark packets in the “Packet List” pane. A marked packet will be shown with black background, regardless of the coloring rules set. Marking a packet can be useful to find it later while analyzing in a large capture file. Marked packet information is not stored in the capture file or anywhere else. It will be lost when the capture file is closed. You can use packet marking to control the output of packets when saving, exporting, or printing. To do so, an option in the packet range is available, see Section 5.9, “The “Packet Range” Frame”. There are several ways to mark and unmark packets. From the menu you can select from the following:
You can also mark and unmark a packet by clicking on it in the packet list with the middle mouse button. 6.11. Ignoring PacketsYou can ignore packets in the “Packet List” pane. Wireshark will then pretend that they not exist in the capture file. An ignored packet will be shown with white background and grey foreground, regardless of the coloring rules set. Ignored packet information is not stored in the capture file or anywhere else. It will be lost when the capture file is closed. There are several ways to ignore and unignore packets. From the menu you can select from the following:
6.12. Time Display Formats And Time ReferencesWhile packets are captured, each packet is timestamped. These timestamps will be saved to the capture file, so they will be available for later analysis. A detailed description of timestamps, timezones and alike can be found at: Section 7.6, “Time Stamps”. The timestamp presentation format and the precision in the packet list can be chosen using the View menu, see Figure 3.5, “The “View” Menu”. The available presentation formats are:
The available precisions (aka. the number of displayed decimal places) are:
Precision example: If you have a timestamp and it’s displayed using, “Seconds Since Previous Packet” the value might be 1.123456. This will be displayed using the “Automatic” setting for libpcap files (which is microseconds). If you use Seconds it would show simply 1 and if you use Nanoseconds it shows 1.123456000. 6.12.1. Packet Time ReferencingThe user can set time references to packets. A time reference is the starting point for all subsequent packet time calculations. It will be useful, if you want to see the time values relative to a special packet, e.g., the start of a new request. It’s possible to set multiple time references in the capture file. The time references will not be saved permanently and will be lost when you close the capture file. Time referencing will only be useful if the time display format is set to “Seconds Since First Captured Packet”. If one of the other time display formats are used, time referencing will have no effect (and will make no sense either). To work with time references, choose one of the items in the menu:[Edit] menu or from the pop-up menu of the “Packet List” pane. See Section 3.6, “The “Edit” Menu”.
Figure 6.14. Wireshark showing a time referenced packet A time referenced packet will be marked with the string *REF* in the Time column (see packet number 10). All subsequent packets will show the time since the last time reference. Chapter 7. Advanced Topics7.1. IntroductionThis chapter will describe some of Wireshark’s advanced features. 7.2. Following Protocol StreamsIt can be very helpful to see a protocol in the way that the application layer sees it. Perhaps you are looking for passwords in a Telnet stream, or you are trying to make sense of a data stream. Maybe you just need a display filter to show only the packets in a TLS or SSL stream. If so, Wireshark’s ability to follow protocol streams will be useful to you. To filter to a particular stream, select a TCP, UDP, DCCP, TLS, HTTP, HTTP/2, QUIC or SIP packet in the packet list of the stream/connection you are interested in and then select the menu item → → (or use the context menu in the packet list). Wireshark will set an appropriate display filter and display a dialog box with the data from the stream laid out, as shown in Figure 7.1, “The “Follow TCP Stream” dialog box”.
Figure 7.1. The “Follow TCP Stream” dialog box The stream content is displayed in the same sequence as it appeared on the network. Non-printable characters are replaced by dots. Traffic from the client to the server is colored red, while traffic from the server to the client is colored blue. These colors can be changed by opening → and under → , selecting different colors for the Sample "Follow Stream" client text and Sample "Follow Stream" server text options. The stream content won’t be updated while doing a live capture. To get the latest content you’ll have to reopen the dialog. You can choose from the following actions: Help Show this help. Filter out this stream Apply a display filter removing the current stream data from the display. Print Print the stream data in the currently selected format. Save as… Save the stream data in the currently selected format. Back Close this dialog box and restore the previous display filter. Close Close this dialog box, leaving the current display filter in effect. By default, Wireshark displays both client and server data. You can select the to switch between both, client to server, or server to client data. You can choose to view the data in one of the following formats: In this view you see the data from each direction in ASCII. Obviously best for ASCII based protocols, e.g., HTTP. This allows you to import the stream data into your own C program. For the big-iron freaks out there. This allows you to see all the data. This will require a lot of screen space and is best used with binary protocols. Like ASCII, but decode the data as UTF-8. Like ASCII, but decode the data as UTF-16. This allows you to load the stream as YAML. The YAML output is divided into 2 main sections:
Example 7.1. Follow Stream YAML output peers: - peer: 0 host: 127.0.0.1 port: 54048 - peer: 1 host: 127.0.10.1 port: 5000 packets: - packet: 1 peer: 0 index: 0 timestamp: 1599485409.693955274 data: !!binary | aGVsbG8K - packet: 3 peer: 1 index: 0 timestamp: 1599485423.885866692 data: !!binary | Ym9uam91cgo= The same example but in old YAML format (before version 3.5): # Packet 1 peer0_0: !!binary | aGVsbG8K # Packet 3 peer1_0: !!binary | Ym9uam91cgo= How the old format data can be found in the new format:
This allows you to load the unaltered stream data into a different program for further examination. The display will look the same as the ASCII setting, but “Save As” will result in a binary file. You can switch between streams using the “Stream” selector. You can search for text by entering it in the “Find” entry box and pressing Find Next. Figure 7.2. The “Follow HTTP/2 Stream” dialog box The HTTP/2 Stream dialog is similar to the "Follow TCP Stream" dialog, except for an additional "Substream" dialog field. HTTP/2 Streams are identified by a HTTP/2 Stream Index (field name The QUIC protocol is similar, the first number selects the QUIC connection number while the "Substream" field selects the QUIC Stream ID. Figure 7.3. The “Follow SIP Call” dialog box The SIP call is shown with same dialog, just filter is based on sip.Call-ID field. Count of streams is fixed to 0 and the field is disabled. 7.3. Show Packet BytesIf a selected packet field does not show all the bytes (i.e., they are truncated when displayed) or if they are shown as bytes rather than string or if they require more formatting because they contain an image or HTML then this dialog can be used. This dialog can also be used to decode field bytes from base64, zlib compressed or quoted-printable and show the decoded bytes as configurable output. It’s also possible to select a subset of bytes setting the start byte and end byte. You can choose from the following actions: Help Show this help. Print Print the bytes in the currently selected format. Copy Copy the bytes to the clipboard in the currently selected format. Save As Save the bytes in the currently selected format. Close Close this dialog box. You can choose to decode the data from one of the following formats: This is the default which does not decode anything. This will decode from Base64. This will decompress the buffer using zlib. This will decode from a string of hex digits. Non-hex characters are skipped. This will decode from a Quoted-Printable string. This will decode ROT-13 encoded text. You can choose to view the data in one of the following formats: In this view you see the bytes as ASCII. All control characters and non-ASCII bytes are replaced by dot. In this view all control characters are shown using a UTF-8 symbol and all non-ASCII bytes are replaced by dot. This allows you to import the field data into your own C program. For the big-iron freaks out there. This allows you to see all the data. This will require a lot of screen space and is best used with binary protocols. This allows you to see all the data formatted as a HTML document. The HTML supported is what’s supported by the Qt QTextEdit class. This will try to convert the bytes into an image. Most popular formats are supported including PNG, JPEG, GIF, and BMP. In this view you see the bytes as ISO 8859-1. This allows you to load the unaltered stream data into a different program for further examination. The display will show HEX data, but “Save As” will result in a binary file. In this view you see the bytes as UTF-8. In this view you see the bytes as UTF-16. This will show the bytes as a YAML binary dump. You can search for text by entering it in the “Find” entry box and pressing Find Next. 7.4. Expert InformationWireshark keeps track of any anomalies and other items of interest it finds in a capture file and shows them in the Expert Information dialog. The goal is to give you a better idea of uncommon or notable network behavior and to let novice and expert users find network problems faster than manually scanning through the packet list.
The amount of expert information largely depends on the protocol being used. While dissectors for some common protocols like TCP and IP will show detailed information, other dissectors will show little or none. The following describes the components of a single expert information entry along with the expert user interface. 7.4.1. Expert Information EntriesExpert information entries are grouped by severity level (described below) and contain the following: Table 7.1. Example expert information items
7.4.1.1. SeverityEvery expert information item has a severity level. The following levels are used, from lowest to highest. Wireshark marks them using different colors, which are shown in parentheses: Chat (blue) Information about usual workflow, e.g., a TCP packet with the SYN flag set. Note (cyan) Notable events, e.g., an application returned a common error code such as HTTP 404. Warn (yellow) Warnings, e.g., application returned an unusual error code like a connection problem. Error (red) Serious problems, such as malformed packets. 7.4.1.2. SummaryShort explanatory text for each expert information item. 7.4.1.3. GroupAlong with severity levels, expert information items are categorized by group. The following groups are currently implemented: Assumption The protocol field has incomplete data and was dissected based on assumed value. Checksum A checksum was invalid. Comment Packet comment. Debug Debugging information. You shouldn’t see this group in release versions of Wireshark. Decryption A decryption issue. Deprecated The protocol field has been deprecated. Malformed Malformed packet or dissector has a bug. Dissection of this packet aborted. Protocol Violation of a protocol’s specification (e.g., invalid field values or illegal lengths). Dissection of this packet probably continued. Reassemble Problems while reassembling, e.g., not all fragments were available or an exception happened during reassembly. Request Code An application request (e.g., File Handle == x). Usually assigned the Chat severity level. Response Code An application response code indicates a potential problem, e.g., HTTP 404 page not found. Security A security problem, e.g., an insecure implementation. Sequence A protocol sequence number was suspicious, e.g., it wasn’t continuous or a retransmission was detected. Undecoded Dissection incomplete or data can’t be decoded for other reasons. It’s possible that more groups will be added in the future. 7.4.1.4. ProtocolThe protocol dissector that created the expert information item. 7.4.2. The “Expert Information” DialogYou can open the expert info dialog by selecting → or by clicking the expert level indicator in the main status bar. Right-clicking on an item will allow you to apply or prepare a filter based on the item, copy its summary text, and other tasks. Figure 7.4. The “Expert Information” dialog box You can choose from the following actions: Limit to display filter Only show expert information items present in packets that match the current display filter. Group by summary Group items by their summary instead of the groups described above. Search Only show items that match the search string, such as “dns”. Regular expressions are supported. Lets you show or hide each severity level. For example, you can deselect Chat and Note severities if desired. Help Takes you to this section of the User’s Guide. Close Closes the dialog 7.4.3. “Colorized” Protocol Details TreeFigure 7.5. The “Colorized” protocol details tree The packet detail tree marks fields with expert information based on their severity level color, e.g., “Warning” severities have a yellow background. This color is propagated to the top-level protocol item in the tree in order to make it easy to find the field that created the expert information. For the example screenshot above, the IP “Time to live” value is very low (only 1), so the corresponding protocol field is marked with a cyan background. To make it easier find that item in the packet tree, the IP protocol toplevel item is marked cyan as well. 7.4.4. “Expert” Packet List Column (Optional)Figure 7.6. The “Expert” packet list column An optional “Expert Info Severity” packet list column is available that displays the most significant severity of a packet or stays empty if everything seems OK. This column is not displayed by default but can be easily added using the Preferences Columns page described in Section 11.5, “Preferences”. 7.5. TCP AnalysisBy default, Wireshark’s TCP dissector tracks the state of each TCP session and provides additional information when problems or potential problems are detected. Analysis is done once for each TCP packet when a capture file is first opened. Packets are processed in the order in which they appear in the packet list. You can enable or disable this feature via the “Analyze TCP sequence numbers” TCP dissector preference. For analysis of data or protocols layered on top of TCP (such as HTTP), see Section 7.8.3, “TCP Reassembly”. Figure 7.7. “TCP Analysis” packet detail items TCP Analysis flags are added to the TCP protocol tree under “SEQ/ACK analysis”. Each flag is described below. Terms such as “next expected sequence number” and “next expected acknowledgement number” refer to the following”: Next expected sequence number The last-seen sequence number plus segment length. Set when there are no analysis flags and for zero window probes. This is initially zero and calculated based on the previous packet in the same TCP flow. Note that this may not be the same as the tcp.nxtseq protocol field. Next expected acknowledgement number The last-seen sequence number for segments. Set when there are no analysis flags and for zero window probes. Last-seen acknowledgment number Always set. Note that this is not the same as the next expected acknowledgment number. Last-seen acknowledgment number Always updated for each packet. Note that this is not the same as the next expected acknowledgment number. TCP ACKed unseen segmentSet when the expected next acknowledgement number is set for the reverse direction and it’s less than the current acknowledgement number. TCP Dup ACK <frame>#<acknowledgement number>Set when all of the following are true:
TCP Fast RetransmissionSet when all of the following are true:
Supersedes “Out-Of-Order” and “Retransmission”. TCP Keep-AliveSet when the segment size is zero or one, the current sequence number is one byte less than the next expected sequence number, and none of SYN, FIN, or RST are set. Supersedes “Fast Retransmission”, “Out-Of-Order”, “Spurious Retransmission”, and “Retransmission”. TCP Keep-Alive ACKSet when all of the following are true:
Supersedes “Dup ACK” and “ZeroWindowProbeAck”. TCP Out-Of-OrderSet when all of the following are true:
Supersedes “Retransmission”. TCP Port numbers reusedSet when the SYN flag is set (not SYN+ACK), we have an existing conversation using the same addresses and ports, and the sequence number is different than the existing conversation’s initial sequence number. TCP Previous segment not capturedSet when the current sequence number is greater than the next expected sequence number. TCP Spurious RetransmissionChecks for a retransmission based on analysis data in the reverse direction. Set when all of the following are true:
Supersedes “Fast Retransmission”, “Out-Of-Order”, and “Retransmission”. TCP RetransmissionSet when all of the following are true:
TCP Window FullSet when the segment size is non-zero, we know the window size in the reverse direction, and our segment size exceeds the window size in the reverse direction. TCP Window UpdateSet when the all of the following are true:
TCP ZeroWindowSet when the receive window size is zero and none of SYN, FIN, or RST are set. The window field in each TCP header advertises the amount of data a receiver can accept. If the receiver can’t accept any more data it will set the window value to zero, which tells the sender to pause its transmission. In some specific cases this is normal — for example, a printer might use a zero window to pause the transmission of a print job while it loads or reverses a sheet of paper. However, in most cases this indicates a performance or capacity problem on the receiving end. It might take a long time (sometimes several minutes) to resume a paused connection, even if the underlying condition that caused the zero window clears up quickly. TCP ZeroWindowProbeSet when the sequence number is equal to the next expected sequence number, the segment size is one, and last-seen window size in the reverse direction was zero. If the single data byte from a Zero Window Probe is dropped by the receiver (not ACKed), then a subsequent segment should not be flagged as retransmission if all of the following conditions are true for that segment: * The segment size is larger than one. * The next expected sequence number is one less than the current sequence number. This affects “Fast Retransmission”, “Out-Of-Order”, or “Retransmission”. TCP ZeroWindowProbeAckSet when the all of the following are true:
Supersedes “TCP Dup ACK”. TCP Ambiguous InterpretationsSome captures are quite difficult to analyze automatically, particularly when the time frame may cover both Fast Retransmission and Out-Of-Order packets. A TCP preference allows to switch the precedence of these two interpretations at the protocol level. TCP Conversation CompletenessTCP conversations are said to be complete when they have both opening and closing handshakes, independently of any data transfer. However, we might be interested in identifying complete conversations with some data sent, and we are using the following bit values to build a filter value on the tcp.completeness field :
For example, a conversation containing only a three-way handshake will be found with the filter 'tcp.completeness==7' (1+2+4) while a complete conversation with data transfer will be found with a longer filter as closing a connection can be associated with FIN or RST packets, or even both : 'tcp.completeness==31 or tcp.completeness==47 or tcp.completeness==63' 7.6. Time StampsTime stamps, their precisions and all that can be quite confusing. This section will provide you with information about what’s going on while Wireshark processes time stamps. While packets are captured, each packet is time stamped as it comes in. These time stamps will be saved to the capture file, so they also will be available for (later) analysis. So where do these time stamps come from? While capturing, Wireshark gets the time stamps from the libpcap (Npcap) library, which in turn gets them from the operating system kernel. If the capture data is loaded from a capture file, Wireshark obviously gets the data from that file. 7.6.1. Wireshark InternalsThe internal format that Wireshark uses to keep a packet time stamp consists of the date (in days since 1.1.1970) and the time of day (in nanoseconds since midnight). You can adjust the way Wireshark displays the time stamp data in the packet list, see the “Time Display Format” item in the Section 3.7, “The “View” Menu” for details. While reading or writing capture files, Wireshark converts the time stamp data between the capture file format and the internal format as required. While capturing, Wireshark uses the libpcap (Npcap) capture library which supports microsecond resolution. Unless you are working with specialized capturing hardware, this resolution should be adequate. 7.6.2. Capture File FormatsEvery capture file format that Wireshark knows supports time stamps. The time stamp precision supported by a specific capture file format differs widely and varies from one second “0” to one nanosecond “0.123456789”. Most file formats store the time stamps with a fixed precision (e.g., microseconds), while some file formats are even capable of storing the time stamp precision itself (whatever the benefit may be). The common libpcap capture file format that is used by Wireshark (and a lot of other tools) supports a fixed microsecond resolution “0.123456” only. Writing data into a capture file format that doesn’t provide the capability to store the actual precision will lead to loss of information. For example, if you load a capture file with nanosecond resolution and store the capture data in a libpcap file (with microsecond resolution) Wireshark obviously must reduce the precision from nanosecond to microsecond. 7.6.3. AccuracyPeople often ask “Which time stamp accuracy is provided by Wireshark?”. Well, Wireshark doesn’t create any time stamps itself but simply gets them from “somewhere else” and displays them. So accuracy will depend on the capture system (operating system, performance, etc.) that you use. Because of this, the above question is difficult to answer in a general way.
7.7. Time ZonesIf you travel across the planet, time zones can be confusing. If you get a capture file from somewhere around the world time zones can even be a lot more confusing ;-) First of all, there are two reasons why you may not need to think about time zones at all:
Further time zone and DST information can be found at https://wwp.greenwichmeantime.com/ and https://www.timeanddate.com/worldclock/. Set your computer’s time correctly!If you work with people around the world it’s very helpful to set your computer’s time and time zone right. You should set your computers time and time zone in the correct sequence:
This way you will tell your computer both the local time and also the time offset to UTC. Many organizations simply set the time zone on their servers and networking gear to UTC in order to make coordination and troubleshooting easier.
You can use the Network Time Protocol (NTP) to automatically adjust your computer to the correct time, by synchronizing it to Internet NTP clock servers. NTP clients are available for all operating systems that Wireshark supports (and for a lot more), for examples see http://www.ntp.org/. 7.7.1. Wireshark and Time ZonesSo what’s the relationship between Wireshark and time zones anyway? Wireshark’s native capture file format (libpcap format), and some other capture file formats, such as the Windows Sniffer, *Peek, Sun snoop formats, and newer versions of the Microsoft Network Monitor and Network Instruments/Viavi Observer formats, save the arrival time of packets as UTC values. UN*X systems, and “Windows NT based” systems represent time internally as UTC. When Wireshark is capturing, no conversion is necessary. However, if the system time zone is not set correctly, the system’s UTC time might not be correctly set even if the system clock appears to display correct local time. When capturing, Npcap has to convert the time to UTC before supplying it to Wireshark. If the system’s time zone is not set correctly, that conversion will not be done correctly. Other capture file formats, such as the OOS-based Sniffer format and older versions of the Microsoft Network Monitor and Network Instruments/Viavi Observer formats, save the arrival time of packets as local time values. Internally to Wireshark, time stamps are represented in UTC. This means that when reading capture files that save the arrival time of packets as local time values, Wireshark must convert those local time values to UTC values. Wireshark in turn will display the time stamps always in local time. The displaying computer will convert them from UTC to local time and displays this (local) time. For capture files saving the arrival time of packets as UTC values, this means that the arrival time will be displayed as the local time in your time zone, which might not be the same as the arrival time in the time zone in which the packet was captured. For capture files saving the arrival time of packets as local time values, the conversion to UTC will be done using your time zone’s offset from UTC and DST rules, which means the conversion will not be done correctly; the conversion back to local time for display might undo this correctly, in which case the arrival time will be displayed as the arrival time in which the packet was captured. Table 7.2. Time zone examples for UTC arrival times (without DST)
For example, let’s assume that someone in Los Angeles captured a packet with Wireshark at exactly 2 o’clock local time and sends you this capture file. The capture file’s time stamp will be represented in UTC as 10 o’clock. You are located in Berlin and will see 11 o’clock on your Wireshark display. Now you have a phone call, video conference or Internet meeting with that one to talk about that capture file. As you are both looking at the displayed time on your local computers, the one in Los Angeles still sees 2 o’clock but you in Berlin will see 11 o’clock. The time displays are different as both Wireshark displays will show the (different) local times at the same point in time. Conclusion: You may not bother about the date/time of the time stamp you currently look at unless you must make sure that the date/time is as expected. So, if you get a capture file from a different time zone and/or DST, you’ll have to find out the time zone/DST difference between the two local times and “mentally adjust” the time stamps accordingly. In any case, make sure that every computer in question has the correct time and time zone setting. 7.8. Packet Reassembly7.8.1. What Is It?Network protocols often need to transport large chunks of data which are complete in themselves, e.g., when transferring a file. The underlying protocol might not be able to handle that chunk size (e.g., limitation of the network packet size), or is stream-based like TCP, which doesn’t know data chunks at all. In that case the network protocol has to handle the chunk boundaries itself and (if required) spread the data over multiple packets. It obviously also needs a mechanism to determine the chunk boundaries on the receiving side. Wireshark calls this mechanism reassembly, although a specific protocol specification might use a different term for this (e.g., desegmentation, defragmentation, etc.). 7.8.2. How Wireshark Handles ItFor some of the network protocols Wireshark knows of, a mechanism is implemented to find, decode and display these chunks of data. Wireshark will try to find the corresponding packets of this chunk, and will show the combined data as additional tabs in the “Packet Bytes” pane (for information about this pane. See Section 3.20, “The “Packet Bytes” Pane”). Figure 7.8. The “Packet Bytes” pane with a reassembled tab Reassembly might take place at several protocol layers, so it’s possible that multiple tabs in the “Packet Bytes” pane appear.
For example, in a HTTP GET response, the requested data (e.g., an HTML page) is returned. Wireshark will show the hex dump of the data in a new tab “Uncompressed entity body” in the “Packet Bytes” pane. Reassembly is enabled in the preferences by default but can be disabled in the preferences for the protocol in question. Enabling or disabling reassembly settings for a protocol typically requires two things:
The tooltip of the higher-level protocol setting will notify you if and which lower-level protocol setting also has to be considered.
7.8.3. TCP ReassemblyProtocols such as HTTP or TLS are likely to span multiple TCP segments. The TCP protocol preference “Allow subdissector to reassemble TCP streams” (enabled by default) makes it possible for Wireshark to collect a contiguous sequence of TCP segments and hand them over to the higher-level protocol (for example, to reconstruct a full HTTP message). All but the final segment will be marked with “[TCP segment of a reassembled PDU]” in the packet list. Disable this preference to reduce memory and processing overhead if you are only interested in TCP sequence number analysis (Section 7.5, “TCP Analysis”). Keep in mind, though, that higher-level protocols might be wrongly dissected. For example, HTTP messages could be shown as “Continuation” and TLS records could be shown as “Ignored Unknown Record”. Such results can also be observed if you start capturing while a TCP connection was already started or when TCP segments are lost or delivered out-of-order. To reassemble of out-of-order TCP segments, the TCP protocol preference “Reassemble out-of-order segments” (currently disabled by default) must be enabled in addition to the previous preference. If all packets are received in-order, this preference will not have any effect. Otherwise (if missing segments are encountered while sequentially processing a packet capture), it is assuming that the new and missing segments belong to the same PDU. Caveats:
Regardless of the setting of these two reassembly-related preferences, you can always use the “Follow TCP Stream” option (Section 7.2, “Following Protocol Streams”) which displays segments in the expected order. 7.9. Name ResolutionName resolution tries to convert some of the numerical address values into a human readable format. There are two possible ways to do these conversions, depending on the resolution to be done: calling system/network services (like the gethostname() function) and/or resolve from Wireshark specific configuration files. For details about the configuration files Wireshark uses for name resolution and alike, see Appendix B, Files and Folders. The name resolution feature can be enabled individually for the protocol layers listed in the following sections. 7.9.1. Name Resolution DrawbacksName resolution can be invaluable while working with Wireshark and may even save you hours of work. Unfortunately, it also has its drawbacks.
Name resolution in the packet list is done while the list is filled. If a name can be resolved after a packet is added to the list, its former entry won’t be changed. As the name resolution results are cached, you can use → to rebuild the packet list with the correctly resolved names. However, this isn’t possible while a capture is in progress. 7.9.2. Ethernet Name Resolution (MAC Layer)Try to resolve an Ethernet MAC address (e.g., 00:09:5b:01:02:03) to a human readable name. ARP name resolution (system service): Wireshark will ask the operating system to convert an Ethernet address to the corresponding IP address (e.g. 00:09:5b:01:02:03 → 192.168.0.1). Ethernet codes (ethers file): If the ARP name resolution failed, Wireshark tries to convert the Ethernet address to a known device name, which has been assigned by the user using an ethers file (e.g., 00:09:5b:01:02:03 → homerouter). Ethernet manufacturer codes (manuf file): If neither ARP or ethers returns a result, Wireshark tries to convert the first 3 bytes of an ethernet address to an abbreviated manufacturer name, which has been assigned by the IEEE (e.g. 00:09:5b:01:02:03 → Netgear_01:02:03). 7.9.3. IP Name Resolution (Network Layer)Try to resolve an IP address (e.g., 216.239.37.99) to a human readable name. DNS name resolution (system/library service): Wireshark will use a name resolver to convert an IP address to the hostname associated with it (e.g., 216.239.37.99 → www.1.google.com). Most applications use synchronously DNS name resolution. For example, your web browser must resolve the host name portion of a URL before it can connect to the server. Capture file analysis is different. A given file might have hundreds, thousands, or millions of IP addresses so for usability and performance reasons Wireshark uses asynchronous resolution. Both mechanisms convert IP addresses to human readable (domain) names and typically use different sources such as the system hosts file (/etc/hosts) and any configured DNS servers. Since Wireshark doesn’t wait for DNS responses, the host name for a given address might be missing from a given packet when you view it the first time but be present when you view it subsequent times. You can adjust name resolution behavior in the Name Resolution section in the Preferences Dialog. You can control resolution itself by adding a hosts file to your personal configuration directory. You can also edit your system hosts file, but that isn’t generally recommended. 7.9.4. TCP/UDP Port Name Resolution (Transport Layer)Try to resolve a TCP/UDP port (e.g., 80) to a human readable name. TCP/UDP port conversion (system service): Wireshark will ask the operating system to convert a TCP or UDP port to its well-known name (e.g., 80 → http). 7.9.5. VLAN ID ResolutionTo get a descriptive name for a VLAN tag ID a vlans file can be used. 7.9.6. SS7 Point Code ResolutionTo get a node name for a SS7 point code a ss7pcs file can be used. 7.10. ChecksumsSeveral network protocols use checksums to ensure data integrity. Applying checksums as described here is also known as redundancy checking. 7.10.1. Wireshark Checksum ValidationWireshark will validate the checksums of many protocols, e.g., IP, TCP, UDP, etc. It will do the same calculation as a “normal receiver” would do, and shows the checksum fields in the packet details with a comment, e.g., [correct] or [invalid, must be 0x12345678]. Checksum validation can be switched off for various protocols in the Wireshark protocol preferences, e.g., to (very slightly) increase performance. If the checksum validation is enabled and it detected an invalid checksum, features like packet reassembly won’t be processed. This is avoided as incorrect connection data could “confuse” the internal database. 7.10.2. Checksum OffloadingThe checksum calculation might be done by the network driver, protocol driver or even in hardware. For example: The Ethernet transmitting hardware calculates the Ethernet CRC32 checksum and the receiving hardware validates this checksum. If the received checksum is wrong Wireshark won’t even see the packet, as the Ethernet hardware internally throws away the packet. Higher-level checksums are “traditionally” calculated by the protocol implementation and the completed packet is then handed over to the hardware. Recent network hardware can perform advanced features such as IP checksum calculation, also known as checksum offloading. The network driver won’t calculate the checksum itself but will simply hand over an empty (zero or garbage filled) checksum field to the hardware.
Checksum offloading can be confusing and having a lot of [invalid] messages on the screen can be quite annoying. As mentioned above, invalid checksums may lead to unreassembled packets, making the analysis of the packet data much harder. You can do two things to avoid this checksum offloading problem:
Chapter 8. Statistics8.1. IntroductionWireshark provides a wide range of network statistics which can be accessed via the menu. These statistics range from general information about the loaded capture file (like the number of captured packets), to statistics about specific protocols (e.g., statistics about the number of HTTP requests and responses captured). General statistics
Protocol specific statistics
Wireshark has many other statistics windows that display detailed information about specific protocols and might be described in a later version of this document. Some of these statistics are described at https://gitlab.com/wireshark/wireshark/wikis/Statistics. 8.2. The “Capture File Properties” DialogGeneral information about the current capture file. Figure 8.1. The “Capture File Properties” dialog This dialog shows the following information: Details Notable information about the capture file. File General information about the capture file, including its full path, size, cryptographic hashes, file format, and encapsulation. Time The timestamps of the first and the last packet in the file along with their difference. Capture Information about the capture environment. This will only be shown for live captures or if this information is present in a saved capture file. The pcapng format supports this, while pcap doesn’t. Interfaces Information about the capture interface or interfaces. Statistics A statistical summary of the capture file. If a display filter is set, you will see values in the Captured column, and if any packets are marked, you will see values in the Marked column. The values in the Captured column will remain the same as before, while the values in the Displayed column will reflect the values corresponding to the packets shown in the display. The values in the Marked column will reflect the values corresponding to the marked packages. Capture file comments Some capture file formats (notably pcapng) allow a text comment for the entire file. You can view and edit this comment here. Refresh Updates the information in the dialog. Save Comments Saves the contents of the “Capture file comments” text entry. Close Closes the dialog Copy To Clipboard Copies the “Details” information to the clipboard. Help Opens this section of the User’s Guide.8.3. Resolved AddressesThe Resolved Addresses window shows the list of resolved addresses and their host names. Users can choose the
The Wireshark reads the entries for port mappings from the Figure 8.2. Resolved Addresses window
8.4. The “Protocol Hierarchy” WindowThe protocol hierarchy of the captured packets. Figure 8.3. The “Protocol Hierarchy” Window This is a tree of all the protocols in the capture. Each row contains the statistical values of one protocol. Two of the columns (Percent Packets and Percent Bytes) serve double duty as bar graphs. If a display filter is set it will be shown at the bottom. The Copy button will let you copy the window contents as CSV or YAML. Protocol hierarchy columns Protocol This protocol’s name. Percent Packets The percentage of protocol packets relative to all packets in the capture. Packets The total number of packets that contain this protocol. Percent Bytes The percentage of protocol bytes relative to the total bytes in the capture. Bytes The total number of bytes of this protocol. Bits/s The bandwidth of this protocol relative to the capture time. End Packets The absolute number of packets of this protocol where it was the highest protocol in the stack (last dissected). End Bytes The absolute number of bytes of this protocol where it was the highest protocol in the stack (last dissected). End Bits/s The bandwidth of this protocol relative to the capture time where was the highest protocol in the stack (last dissected). PDUs The total number of PDUs of this protocol.Packets usually contain multiple protocols. As a result, more than one protocol will be counted for each packet. Example: In the screenshot 100% of packets are IP and 99.3% are TCP (which is together much more than 100%). Protocol layers can consist of packets that won’t contain any higher layer protocol, so the sum of all higher layer packets may not sum to the protocol’s packet count. This can be caused by segments and fragments reassembled in other frames, TCP protocol overhead, and other undissected data. Example: In the screenshot 99.3% of the packets are TCP but the sum of the subprotocols (TLS, HTTP, Git, etc.) is much less. A single packet can
contain the same protocol more than once. In this case, the entry in the 8.5. ConversationsA network conversation is the traffic between two specific endpoints. For example, an IP conversation is all the traffic between two IP addresses. The description of the known endpoint types can be found in Section 8.6, “Endpoints”. 8.5.1. The “Conversations” WindowThe conversations window is similar to the endpoint Window. See Section 8.6.1, “The “Endpoints” Window” for a description of their common features. Along with addresses, packet counters, and byte counters the conversation window adds four columns: the start time of the conversation (“Rel Start”) or (“Abs Start”), the duration of the conversation in seconds, and the average bits (not bytes) per second in each direction. A timeline graph is also drawn across the “Rel Start” / “Abs Start” and “Duration” columns. Additionally Figure 8.4. The “Conversations” window Each row in the list shows the statistical values for exactly one conversation. Name resolution will be done if selected in the window and if it is active for the specific protocol layer (MAC layer for the selected Ethernet endpoints page). Limit to display filter will only show conversations matching the current display filter. Absolute start time switches the start time column between relative (“Rel Start”) and absolute (“Abs Start”) times. Relative start times match the “Seconds Since First Captured Packet” time display format in the packet list and absolute start times match the “Time of Day” display format. If a display filter had been applied before the dialog is opened, Limit to display filter will be set automatically. Additionally, after a display filter had been applied, two columns ("Total Packets") and ("Percent Filtered") show the number of unfiltered total packets and the percentage of packets in this filter display. The Copy button will copy the list values to the clipboard in CSV (Comma Separated Values), YAML format or JSON format. The numbers are generally exported without special formatting, but this can be enabled if needed. The Follow Stream… button will show the stream contents as described in Figure 7.1, “The “Follow TCP Stream” dialog box” dialog. The Graph… button will show a graph as described in Section 8.8, “The “I/O Graphs” Window”. Conversation Types lets you choose which traffic type tabs are shown. See Section 8.6, “Endpoints” for a list of endpoint types. The enabled types are saved in your profile settings.
8.6. EndpointsA network endpoint is the logical endpoint of separate protocol traffic of a specific protocol layer. The endpoint statistics of Wireshark will take the following endpoints into account:
Endpoint and Conversation types Bluetooth A MAC-48 address similar to Ethernet. Ethernet Identical to the Ethernet device’s MAC-48 identifier. Fibre Channel A MAC-48 address similar to Ethernet. IEEE 802.11 A MAC-48 address similar to Ethernet. FDDI Identical to the FDDI MAC-48 address. IPv4 Identical to the 32-bit IPv4 address. IPv6 Identical to the 128-bit IPv6 address. IPX A concatenation of a 32-bit network number and 48-bit node address, by default the Ethernet interface’s MAC-48 address. JXTA A 160-bit SHA-1 URN. NCP Similar to IPX. RSVP A combination of various RSVP session attributes and IPv4 addresses. SCTP A combination of the host IP addresses (plural) and the SCTP port used. So different SCTP ports on the same IP address are different SCTP endpoints, but the same SCTP port on different IP addresses of the same host are still the same endpoint. TCP A combination of the IP address and the TCP port used. Different TCP ports on the same IP address are different TCP endpoints. Token Ring Identical to the Token Ring MAC-48 address. UDP A combination of the IP address and the UDP port used, so different UDP ports on the same IP address are different UDP endpoints. USB Identical to the 7-bit USB address.
8.6.1. The “Endpoints” WindowThis window shows statistics about the endpoints captured. Figure 8.5. The “Endpoints” window For each supported protocol, a tab is shown in this window. Each tab label shows the number of endpoints captured (e.g., the tab label “Ethernet · 4” tells you that four ethernet endpoints have been captured). If no endpoints of a specific protocol were captured, the tab label will be greyed out (although the related page can still be selected). Each row in the list shows the statistical values for exactly one endpoint. Name resolution will be done if selected in the window and if it is active for the specific protocol layer (MAC layer for the selected Ethernet endpoints page). Limit to display filter will only show conversations matching the current display filter. Note that in this example we have MaxMind DB configured which gives us extra geographic columns. See Section 11.10, “MaxMind Database Paths” for more information. If a display filter had been applied before the dialog is opened, Limit to display filter will be set automatically. Additionally, after a display filter had been applied, two columns ("Total Packets") and ("Percent Filtered") show the number of unfiltered total packets and the percentage of packets in this filter display. The Copy button will copy the list values to the clipboard in CSV (Comma Separated Values), YAML format or JSON format. The numbers are generally exported without special formatting, but this can be enabled if needed. The Map button will show the endpoints mapped in your web browser. Endpoint Types lets you choose which traffic type tabs are shown. See Section 8.6, “Endpoints” above for a list of endpoint types. The enabled types are saved in your profile settings.
8.7. Packet LengthsShows the distribution of packet lengths and related information. Figure 8.6. The “Packet Lengths” window Information is broken down by packet length ranges as shown above. Packet Lengths The range of packet lengths. Ranges can be configured in the “Statistics → Stats Tree” section of the Preferences Dialog. Count The number of packets that fall into this range. Average The arithmetic mean of the packet lengths in this range. Min Val, Max Val The minimum and maximum lengths in this range. Rate (ms) The average packets per millisecond for the packets in this range. Percent The percentage of packets in this range, by count. Burst RatePacket bursts are detected by counting the number of packets in a given time interval and comparing that count to the intervals across a window of time. Statistics for the interval with the maximum number of packets are shown. By default, bursts are detected across 5 millisecond intervals and intervals are compared across 100 millisecond windows. These calculations can be adjusted in the “Statistics” section of the Preferences Dialog. Burst Start The start time, in seconds from the beginning of the capture, for the interval with the maximum number of packets.You can show statistics for a portion of the capture by entering a display filter into the Display filter entry and pressing Apply. Copy copies the statistics to the clipboard. Save as… lets you save the data as text, CSV, YAML, or XML. 8.8. The “I/O Graphs” WindowLets you plot packet and protocol data in a variety of ways. Figure 8.7. The “I/O Graphs” window As shown above, this window contains a chart drawing area along with a customizable list of graphs. Graphs are saved in your current profile. They are divided into time intervals, which can be set as described below. Hovering over the graph shows the last packet in each interval except as noted below. Clicking on the graph takes you to the associated packet in the packet list. Individual graphs can be configured using the following options: Enabled Draw or don’t draw this graph. Graph Name The name of this graph. Display Filter Limits the graph to packets that match this filter. Color The color to use for plotting the graph’s lines, bars, or points. Style How to visually represent the graph’s data, e.g., by drawing a line, bar, circle, plus, etc. Y Axis The value to use for the graph’s Y axis. Can be one of: Packets, Bytes, or Bits The total number of packets, packet bytes, or packet bits that match the graph’s display filter per interval. Zero values are omitted in some cases. SUM(Y Field) The sum of the values of the field specified in “Y Field” per interval. COUNT FRAMES(Y Field) The number of frames that contain the field specified in “Y Field” per interval. Unlike the plain “Packets” graph, this always displays zero values. COUNT FIELDS(Y Field) The number of instances of the field specified in “Y Field” per interval. Some fields, such as dns.resp.name, can show up multiple times in a packet. MAX(Y Field), MIN(Y Field), AVG(Y Field) The maximum, minimum, and arithmetic mean values of the specified “Y Field” per interval. For MAX and MIN values, hovering and clicking the graph will show and take you to the packet with the MAX or MIN value in the interval instead of the most recent packet. LOAD(Y Field) If the “Y Field” is a relative time value, this is the sum of the “Y Field” values divided by the interval time. This can be useful for tracking response times. Y Field The display filter field from which to extract values for the Y axis calculations listed above. SMA Period Show an average of values over a specified period of intervals. The chart as a whole can be configured using the controls under the graph list: + Add a new graph. - Add a new graph. Copy Copy the selected graph. Clear Remove all graphs. Mouse drags / zooms When using the mouse inside the graph area, either drag the graph contents or select a zoom area. Interval Set the interval period for the graph. Time of day Switch between showing the absolute time of day or the time relative from the start of capture in the X axis. Log scale Switch between a logarithmic or linear Y axis. The main dialog buttons along the bottom let you do the following: The Help button will take you to this section of the User’s Guide. The Copy button will copy values from selected graphs to the clipboard in CSV (Comma Separated Values) format. Copy from will let you copy graphs from another profile. Close will close this dialog. Save As… will save the currently displayed graph as an image or CSV data.
Missing Values Are ZeroWireshark’s I/O Graph window doesn’t distinguish between missing and zero values. For scatter plots it is assumed that zero values indicate missing data, and those values are omitted. Zero values are shown in line graphs, and bar charts. 8.9. Service Response TimeThe service response time is the time between a request and the corresponding response. This information is available for many protocols, including the following:
As an example, the SMB2 service response time is described below in more detail. The other Service Response Time windows will show statistics specific to their respective protocols, but will offer the same menu options. 8.9.1. The “SMB2 Service Response Time Statistics” WindowThis window shows the number of transactions for each SMB2 opcode present in the capture file along with various response time statistics. Right-clicking on a row will let you apply or prepare filters for, search for, or colorize a specific opcode. You can also copy all of the response time information or save it in a variety of formats. Figure 8.8. The “SMB2 Service Response Time Statistics” window You can optionally apply a display filter in order to limit the statistics to a specific set of packets. The main dialog buttons along the bottom let you do the following: The Copy button will copy the response time information as text. Save As… will save the response time information in various formats. Close will close this dialog. 8.10. DHCP (BOOTP) StatisticsThe Dynamic Host Configuration Protocol (DHCP) is an option of the Bootstrap Protocol (BOOTP). It dynamically assigns IP addresses and other parameters to a DHCP client. The DHCP (BOOTP) Statistics window displays a table over the number of occurrences of a DHCP message type. The user can filter, copy or save the data into a file. 8.11. NetPerfMeter StatisticsThe NetPerfMeter Protocol (NPMP) is the control and data transfer protocol of NetPerfMeter, the transport protocol performance testing tool. It transmits data streams over TCP, SCTP, UDP and DCCP with given parameters, such as frame rate, frame size, saturated flows, etc. With these statistics you can:
See NetPerfMeter – A TCP/MPTCP/UDP/SCTP/DCCP Network Performance Meter Tool and Section 6.3 of Evaluation and Optimisation of Multi-Path Transport using the Stream Control Transmission Protocol for more details about NetPerfMeter and the NetPerfMeter Protocol. Figure 8.9. NetPerfMeter Statistics window 8.12. ONC-RPC ProgramsOpen Network Computing (ONC) Remote Procedure Call (RPC) uses TCP or UDP protocols to map a program number to a specific port on a remote machine and call a required service at that port. The ONC-RPC Programs window shows the description for captured program calls, such as program name, its number, version, and other data. 8.13. 29WestThe 29West technology now refers to Ultra-Low Latency Messaging (ULLM) technology. It allows sending and receiving a high number of messages per second with microsecond delivery times for zero-latency data delivery. The → shows:
8.14. ANCPThe Access Node Control Protocol (ANCP) is an TCP based protocol, which operates between an Access Node and Network Access Server. The Wireshark ANCP dissector supports the listed below messages:
The ANCP window shows the related statistical data. The user can filter, copy or save the data into a file. 8.15. BACnetBuilding Automation and Control Networks (BACnet) is a communication protocol which provides control for various building automated facilities, such as light control, fire alarm control, and others. Wireshark provides the BACnet statistics which is a packet counter. You can sort packets by instance ID, IP address, object type or service. 8.16. CollectdCollectd is a system statistics collection daemon. It collects various statistics from your system and converts it for the network use. The Collectd statistics window shows counts for values, which split into type, plugin, and host as well as total packets counter. You can filter, copy or save the data to a file. 8.17. DNSThe Domain Name System (DNS) associates different information, such as IP addresses, with domain names. DNS returns different codes, request-response and counters for various aggregations. The DNS statistics window enlists a total count of DNS messages, which are divided into groups by request types (opcodes), response code (rcode), query type, and others. Figure 8.10. DNS statistics window You might find these statistics useful for quickly examining the health of a DNS service or other investigations. See the few possible scenarios below:
You can filter, copy or save the data into a file. 8.18. Flow GraphThe Flow Graph window shows connections between hosts. It displays the packet time, direction, ports and comments for each captured connection. You can filter all connections by ICMP Flows, ICMPv6 Flows, UIM Flows and TCP Flows. Flow Graph window is used for showing multiple different topics. Based on it, it offers different controls. Figure 8.11. Flow Graph window Each vertical line represents the specific host, which you can see in the top of the window. The numbers in each row at the very left of the window represent the time packet. You can change the time format in the → . If you change the time format, you must relaunch the Flow Graph window to observe the time in a new format. The numbers at the both ends of each arrow between hosts represent the port numbers. Left-click a row to select a corresponding packet in the packet list. Right-click on the graph for additional options, such as selecting the previous, current, or next packet in the packet list. This menu also contains shortcuts for moving the diagram. Available controls:
Figure 8.12. Flow Graph window showing VoIP call sequences Additional shortcuts available for VoIP calls:
Additional controls available for VoIP calls:
8.19. HART-IPHighway Addressable Remote Transducer over IP (HART-IP) is an application layer protocol. It sends and receives digital information between smart devices and control or monitoring systems. The HART-IP statistics window shows the counter for response, request, publish and error packets. You can filter, copy or save the data to a file. 8.20. HPFEEDSHpfeeds protocol provides a lightweight authenticated publishing and subscription. It supports arbitrary binary payloads which can be separated into different channels. HPFEEDS statistics window shows a counter for payload size per channel and opcodes. You can filter, copy or save the data to a file. 8.21. HTTP Statistics8.21.1. HTTP Packet CounterStatistics for HTTP request types and response codes.
8.21.2. HTTP RequestsHTTP statistics based on the host and URI. 8.21.3. HTTP Load DistributionHTTP request and response statistics based on the server address and host. 8.21.4. HTTP Request SequencesHTTP Request Sequences uses HTTP’s Referer and Location headers to sequence a capture’s HTTP requests as a tree. This enables analysts to see how one HTTP request leads to the next. Figure 8.13. The “HTTP Request Sequences” window 8.22. HTTP2Hypertext Transfer Protocol version 2 (HTTP/2) allows multiplexing various HTTP requests and responses over a single connection. It uses a binary encoding
which is consisting of frames. The HTTP/2 statistics window shows the total number of HTTP/2 frames and also provides a breakdown per frame types, such as As HTTP/2 traffic is typically encrypted with TLS, you must configure decryption to observe HTTP/2 traffic. For more details, see the TLS wiki page. 8.23. SametimeSametime is a protocol for the IBM Sametime software. The Sametime statistics window shows the counter for message type, send type, and user status. 8.24. TCP Stream GraphsShow different visual representations of the TCP streams in a capture. Time Sequence (Stevens) This is a simple graph of the TCP sequence number over time, similar to the ones used in Richard Stevens’ “TCP/IP Illustrated” series of books. Time Sequence (tcptrace) Shows TCP metrics similar to the tcptrace utility, including forward segments, acknowledgements, selective acknowledgements, reverse window sizes, and zero windows. Throughput Average throughput and goodput. Round Trip Time Round trip time vs time or sequence number. RTT is based on the acknowledgement timestamp corresponding to a particular segment. Window Scaling Window size and outstanding bytes. 8.25. UDP Multicast StreamsThe UDP Multicast Streams window shows statistics for all UDP multicast streams. It includes source addresses and ports, destination addresses and ports, packets counter and other data. You can specify the burst interval, the alarm limits and output speeds. To apply new settings, press Enter. With these statistics you can:
Figure 8.14. UDP Multicast Streams window 8.26. Reliable Server Pooling (RSerPool)The Reliable Server Pooling (RSerPool) windows show statistics for the different protocols of Reliable Server Pooling (RSerPool):
Furthermore, statistics for application protocols provided by RSPLIB are provided as well:
With these statistics you can:
See Thomas Dreibholz’s Reliable Server Pooling (RSerPool) Page and Chapter 3 of Reliable Server Pooling – Evaluation, Optimization and Extension of a Novel IETF Architecture for more details about RSerPool and its protocols. Figure 8.15. ASAP Statistics window Figure 8.16. ENRP Statistics window Figure 8.17. Component Status Protocol Statistics window Figure 8.18. CalcApp Protocol Statistics window Figure 8.19. Fractal Generator Protocol Statistics window Figure 8.20. Ping Pong Protocol Statistics window Figure 8.21. Scripting Service Protocol Statistics window 8.27. F5In F5 Networks, TMM stands for Traffic Management Microkernel. It processes all load-balanced traffic on the BIG-IP system. The F5 statistics menu shows packet and byte counts for both Each
Each
8.28. IPv4 StatisticsInternet Protocol version 4 (IPv4) is a core protocol for the internet layer. It uses 32-bit addresses and allows packets routing from one source host to the next one. The → menu provides the packet counter by submenus:
You can see similar statistics in the → and → menus. 8.29. IPv6 StatisticsInternet Protocol version 6 (IPv6) is a core protocol for the internet layer. It uses 128-bit addresses and routes internet traffic. Similar to Section 8.28, “IPv4 Statistics”, the → menu shows the packet counter in each submenu. Chapter 9. Telephony9.1. IntroductionWireshark provides a wide range of telephony related network statistics which can be accessed via the menu. These statistics range from specific signaling protocols, to analysis of signaling and media flows. If encoded in a compatible encoding the media flow can even be played. The protocol specific statistics windows display detailed information of specific protocols and might be described in a later version of this document. Some of these statistics are described at the https://gitlab.com/wireshark/wireshark/wikis/Statistics pages. 9.2. Playing VoIP CallsThe tool for playing VoIP calls is called RTP Player. It shows RTP streams and its waveforms, allows play stream and export it as audio or payload to file. Its capabilities depend on supported codecs. 9.2.1. Supported codecsRTP Player is able to play any codec supported by an installed plugin. The codecs supported by RTP Player depend on the version of Wireshark you’re using. The official builds contain all of the plugins maintained by the Wireshark developers, but custom/distribution builds might not include some of those codecs. To check your Wireshark installation’s installed codec plugins, do the following:
Figure 9.1. List of supported codecs 9.2.2. Work with RTP streams - PlaylistWireshark can be used for RTP stream analysis. User can select one or more streams which can be played later. RTP Player window maintains playlist (list of RTP streams) for this purpose. Playlist is created empty when RTP Player window is opened and destroyed when window is closed. RTP Player window can be opened on background when not needed and put to front later. During its live, playlist is maintained. When RTP Player window is opened, playlist can be modified from other tools (Wireshark windows) in three ways:
Figure 9.2. Play Streams button with opened action menu Play Streams button can be clicked directly and opens RTP Player window directly with Set playlist action. All actions can be selected with the small down arrow next to the button. When the playlist is empty, there is no difference between Set playlist and Add to playlist. When the RTP Player window is not opened, all three actions above open it. Remove from playlist is useful e.g. in case user selected all RTP streams and wants to remove RTP streams from specific calls found with . Tools below can be used to maintain content of playlist, they contain Play Streams button. You can use one of procedures (Note: Add to playlist action is demonstrated):
Figure 9.3. Tools for modifying playlist in RTP Player window
9.2.3. Playing audio during live captureDecoding RTP payload and showing waveforms is time consuming task. To speedup it RTP Player window uses copy of packet payload for all streams in the playlist. During live capture the dialog is not refreshed automatically as other Wireshark dialogs, but user must initiate it. The copy is created or refreshed and dialog updated:
When capture file is opened (no live capturing), streams are read complete, no user action is required. Button Refresh streams is disabled as it is useless. When live capture is running, streams are read only till "now" and are shown. When stream is continuous and user would like to see additional part, they must press Refresh stream. When the user ends live capture, view is refreshed and button is disabled.
9.2.4. RTP Decoding SettingsRTP is carried usually in UDP packets with random source and destination ports. Therefore, Wireshark can only recognize RTP streams based on VoIP signaling, e.g., based on SDP messages in SIP signaling. If signaling is not captured, Wireshark shows just UDP packets. However, there are multiple settings which help Wireshark recognize RTP even when there is no related signaling. You can use Decode As… function from → menu or in mouse context menu. Here you can set that traffic on specific source or destination should be decoded as RTP. You can save settings for later use. Use of menu works fine, but is arduous for many streams. You can enable heuristic dissector in → . See Section 11.4, “Control Protocol dissection” for details. Once is enabled, Wireshark tries to decode every UDP packet as RTP. If decoding is possible, packet (and entire UDP stream) is decoded as RTP. When an RTP stream uses a well-known port, the heuristic dissector ignores it. So you might miss some RTP streams. You can enable setting for udp protocol → → → , see Section 11.5, “Preferences”. In this case heuristics dissector tries to decode UDP packet even it uses a well-known port.
RTP Player must store decoded data somewhere to be able to play it. When data are decoded, there are audio samples and dictionary for fast navigation. Both types of data are stored in memory for default, but you can configure Wireshark to store it on disk. There are two settings:
When any data are configured to be stored on disk, one file is created for each stream. Therefore, there might be up to two files for one RTP stream (audio samples and dictionary). If your OS or user has OS enforced limit for count of opened files (most of Unix/Linux systems), you can see fewer streams that was added to playlist. Warnings are printed on console in this case and you will see fewer streams in the playlist than you send to it from other tools. For common use you can use default settings - store everything in memory. When you will be out of memory, switch ui.rtp_player_use_disk1 to TRUE first - it saves much more memory than ui.rtp_player_use_disk2. 9.2.5. VoIP Processing Performance and Related LimitsProcessing of RTP and decoding RTP voice takes resources. There are raw estimates you can use as guidelines… RTP Streams window can show as many streams as found in the capture. Its performance is limited just by memory and CPU. RTP Player can handle 1000+ streams, but take into account that waveforms are very small and difficult to recognize in this case. RTP Player plays audio by OS sound system and OS is responsible for mixing audio when multiple streams are played. In many cases OS sound system has limited count of mixed streams it can play/mix. RTP Player tries to handle playback failures and show warning. If it happens, just mute some streams and start playback again. RTP Analysis window can handle 1000+ streams, but it is difficult to use it with so many streams - it is difficult to navigate between them. It is expected that RTP Analysis window will be used for analysis of lower tens of streams. 9.3. VoIP Calls WindowThe VoIP Calls window shows a list of all detected VoIP calls in the captured traffic. It finds calls by their signaling and shows related RTP streams. The current VoIP supported protocols are:
See VOIPProtocolFamily for an overview of the used VoIP protocols. VoIP Calls window can be opened as window showing all protocol types ( → window) or limited to SIP messages only ( → window). Figure 9.4. VoIP Calls window User can use shortcuts:
Available controls are:
9.4. ANSIThis menu shows groups of statistic data for mobile communication protocols according to ETSI GSM standards. 9.4.1. A-I/F BSMAP Statistics WindowThe A-Interface Base Station Management Application Part (BSMAP) Statistics window shows the messages list and the number of the captured messages. There is a possibility to filter the messages, copy or save the date into a file. 9.4.2. A-I/F DTAP Statistics WindowThe A-Interface Direct Transfer Application Part (DTAP) Statistics widow shows the messages list and the number of the captured messages. There is a possibility to filter the messages, copy or save the date into a file. 9.5. GSM WindowsThe Global System for Mobile Communications (GSM) is a standard for mobile networks. This menu shows a group of statistic data for mobile communication protocols according to ETSI GSM standard. 9.6. IAX2 Stream Analysis WindowThe “IAX2 Stream Analysis” window shows statistics for the forward and reverse streams of a selected IAX2 call along with a graph. 9.7. ISUP Messages WindowIntegrated Service User Part (ISUP) protocol provides voice and non-voice signaling for telephone communications. ISUP Messages menu opens the window which shows the related statistics. The user can filter, copy or save the data into a file. 9.8. LTE9.8.1. LTE MAC Traffic Statistics WindowStatistics of the captured LTE MAC traffic. This window will summarize the LTE MAC traffic found in the capture. Figure 9.5. The “LTE MAC Traffic Statistics” window The top pane shows statistics for common channels. Each row in the middle pane shows statistical highlights for exactly one UE/C-RNTI. In the lower pane, you can see the for the currently selected UE/C-RNTI the traffic broken down by individual channel. 9.8.2. LTE RLC Graph WindowThe LTE RLC Graph menu launches a graph which shows LTE Radio Link Control protocol sequence numbers changing over time along with acknowledgements which are received in the opposite direction.
Figure 9.6. The RLC Graph window The image of the RLC Graph is borrowed from Wireshark wiki. 9.8.3. LTE RLC Traffic Statistics WindowStatistics of the captured LTE RLC traffic. This window will summarize the LTE RLC traffic found in the capture. Figure 9.7. The “LTE RLC Traffic Statistics” window At the top, the check-box allows this window to include RLC PDUs found within MAC PDUs or not. This will affect both the PDUs counted as well as the display filters generated (see below). The upper list shows summaries of each active UE. Each row in the lower list shows statistical highlights for individual channels within the selected UE. The lower part of the windows allows display filters to be generated and set for the selected channel. Note that in the case of Acknowledged Mode channels, if a single direction is chosen, the generated filter will show data in that direction and control PDUs in the opposite direction. 9.9. MTP3 WindowsThe Message Transfer Part level 3 (MTP3) protocol is a part of the Signaling System 7 (SS7). The Public Switched Telephone Networks use it for reliable, unduplicated and in-sequence transport of SS7 messaging between communication partners. This menu shows MTP3 Statistics and MTP3 Summary windows. 9.10. Osmux WindowsOSmux is a multiplex protocol designed to reduce bandwidth usage of satellite-based GSM systems’s voice (RTP-AMR) and signaling traffic. The OSmux menu opens the packet counter window with the related statistic data. The user can filter, copy or save the data into a file. 9.11. RTP9.11.1. RTP Streams WindowThe RTP streams window shows all RTP streams in capture file. Streams can be selected there and on selected streams other tools can be initiated. Figure 9.8. The “RTP Streams” window User can use shortcuts:
Available controls are:
9.11.2. RTP Stream Analysis WindowThe RTP analysis function takes the selected RTP streams and generates a list of statistics on it including graph. Menu → → is enabled only when selected packed is RTP packet. When window is opened, selected RTP stream is added to analysis. If Ctrl is pressed during menu opening, reverse RTP stream (if exists) is added to the window too. Every stream is shown on own tab. Tabs are numbered as streams are added and its tooltip shows identification of the stream. When tab is closed, number is not reused. Color of tab matches color of graphs on graph tab. Figure 9.9. The “RTP Stream Analysis” window Figure 9.10. Error indicated in “RTP Stream Analysis” window Per packet statistic shows:
Side panel left to packet list shows stream statistics:
Available shortcuts are:
Available controls are:
Figure 9.11. Graph in “RTP Stream Analysis” window Graph view shows graph of:
for every stream. Checkboxes below graph are enabling or disabling showing of a graph for every stream. Stream X checkbox enables or disables all graphs for the stream.
9.11.3. RTP Player WindowThe RTP Player function is tool for playing VoIP calls. It shows RTP streams and its waveforms, allows play stream and export it as audio or payload to file. See related concepts in Section 9.2, “Playing VoIP Calls”. Menu → → is enabled only when selected packed is RTP packet. When window is opened, selected RTP stream is added to playlist. If Ctrl is pressed during menu opening, reverse RTP stream (if exists) is added to the playlist too. Figure 9.12. RTP Player window RTP Player Window consists of three parts:
Waveform view shows visual presentation of RTP stream. Color of waveform and playlist row are matching. Height of wave shows volume. Waveform shows error marks for Out of Sequence, Jitter Drops, Wrong Timestamps and Inserted Silence marks if it happens in a stream. Figure 9.13. Waveform with error marks Playlist shows information about every stream:
Controls allow a user to:
Figure 9.14. RTP stream state indication Waveform view and playlist shows state of a RTP stream:
User can control to where audio of a stream is routed to:
Audio routing can be changed by double clicking on first column of a row, by shortcut or by menu. User can use shortcuts:
9.11.3.1. Export
Export options available:
Audio is exported as multi-channel file - one channel per RTP stream. One or two channels are equal to mono or stereo, but Wireshark can export e.g., 100 channels. For playing a tool with multi-channel support must be used (e.g., https://www.audacityteam.org/). Export of payload function is useful for codecs not supported by Wireshark.
9.12. RTSP WindowIn the Real Time Streaming Protocol (RTSP) menu the user can check the Packet Counter window. It shows Total RTCP Packets and divided into RTSP Response Packets, RTSP Request Packets and Other RTSP packets. The user can filter, copy or save the data into a file. 9.13. SCTP WindowsStream Control Transmission Protocol (SCTP) is a computer network protocol which provides a message transfer in telecommunication in the transport layer. It overcomes some lacks of User Datagram Protocol (UDP) and Transmission Control Protocol (TCP). The SCTP packets consist of the common header and the data chunks. The SCTP Analyze Association window shows the statistics of the captured packets between two Endpoints. You can check the different chunk
types by pressing Chunk Statistics button in the Figure 9.15. SCTP Analyze Association window The SCTP Associations window shows the table with the data for captured packets, such as port and counter. You can also call for the SCTP Analyze Association window by pressing the Analyze button. Figure 9.16. SCTP Associations window 9.14. SMPP Operations WindowShort Message Peer-to-Peer (SMPP) protocol uses TCP protocol as its transfer for exchanging Short Message Service (SMS) Messages, mainly between Short Message Service Centers (SMSC). The dissector determines whether the captured packet is SMPP or not by using the heuristics in the fixed header. The SMPP Operations window displays the related statistical data. The user can filter, copy or save the data into a file. 9.15. UCP Messages WindowThe Universal Computer Protocol (UCP) plays role in transferring Short Messages between a Short Message Service Centre (SMSC) and an application, which is using transport protocol, such as TCP or X.25. The UCP Messages window displays the related statistical data. The user can filter, copy or save the data into a file. 9.16. H.225 WindowH.225 telecommunication protocol which is responsible for messages in call signaling and media stream packetization for packet-based multimedia communication systems. The H.225 window shows the counted messages by types and reasons. The user can filter, copy or save the data into a file. 9.17. SIP Flows WindowSession Initiation Protocol (SIP) Flows window shows the list of all captured SIP transactions, such as client registrations, messages, calls and so on. This window will list both complete and in-progress SIP transactions. Window has same features as VoIP Calls window.
9.18. SIP Statistics WindowSIP Statistics window shows captured SIP transactions. It is divided into SIP Responses and SIP Requests. In this window the user can filter, copy or save the statistics into a file. 9.19. WAP-WSP Packet Counter WindowThe WAP-WSP Packet Counter menu displays the number of packets for each Status Code and PDU Type in Wireless Session Protocol traffic. The user can filter, copy or save the data into a file. Chapter 10. Wireless10.1. IntroductionThe Wireless menu provides access to statistics related to wireless traffic. 10.2. Bluetooth ATT Server AttributesBluetooth ATT Server Attributes window displays a list of captured Attribute Protocol (ATT) packets. The user can filter the list by the interfaces or devices, and also exclude repetitions by checking the
10.3. Bluetooth DevicesThe Bluetooth Devices window displays the list of the captured information about devices, such as MAC address, Organizationally Unique Identifier (OUI), Name and other. Users can filter it by interface. Figure 10.1. Bluetooth Devices window 10.4. Bluetooth HCI SummaryThe Bluetooth HCI Summary window displays the summary for the captured Host Controller Interface (HCI) layer packets. This window allows users to apply filters and choose to display information about specific interfaces or devices. Figure 10.2. Bluetooth HCI Summary window 10.5. WLAN TrafficStatistics about captured WLAN traffic. This can be found under the menu and summarizes the wireless network traffic found in the capture. Probe requests will be merged into an existing network if the SSID matches. Figure 10.3. The “WLAN Traffic Statistics” window Each row in the list shows the statistical values for exactly one wireless network. Name resolution will be done if selected in the window and if it is active for the MAC layer. Only show existing networks will exclude probe requests with a SSID not matching any network from the list. The Copy button will copy the list values to the clipboard in CSV (Comma Separated Values) format.
Chapter 11. Customizing Wireshark11.1. IntroductionWireshark’s default behavior will usually suit your needs pretty well. However, as you become more familiar with Wireshark, it can be customized in various ways to suit your needs even better. In this chapter we explore:
11.2. Start Wireshark from the command lineYou can start Wireshark from the command line, but it can also be started from most Window managers as well. In this section we will look at starting it from the command line. Wireshark supports a large number of command line parameters. To see what they are, simply enter the command wireshark -h and the help information shown in Help information available from Wireshark (or something similar) should be printed. Help information available from Wireshark. Wireshark 4.1.0 (v4.1.0rc0-55-gccf720d95daf) Interactively dump and analyze network traffic. See https://www.wireshark.org for more information. Usage: wireshark [options] ... [ <infile> ] Capture interface: -i <interface>, --interface <interface> name or idx of interface (def: first non-loopback) -f <capture filter> packet filter in libpcap filter syntax -s <snaplen>, --snapshot-length <snaplen> packet snapshot length (def: appropriate maximum) -p, --no-promiscuous-mode don't capture in promiscuous mode -k start capturing immediately (def: do nothing) -S update packet display when new packets are captured -l turn on automatic scrolling while -S is in use -I, --monitor-mode capture in monitor mode, if available -B <buffer size>, --buffer-size <buffer size> size of kernel buffer (def: 2MB) -y <link type>, --linktype <link type> link layer type (def: first appropriate) --time-stamp-type <type> timestamp method for interface -D, --list-interfaces print list of interfaces and exit -L, --list-data-link-types print list of link-layer types of iface and exit --list-time-stamp-types print list of timestamp types for iface and exit Capture stop conditions: -c <packet count> stop after n packets (def: infinite) -a <autostop cond.> ..., --autostop <autostop cond.> ... duration:NUM - stop after NUM seconds filesize:NUM - stop this file after NUM KB files:NUM - stop after NUM files packets:NUM - stop after NUM packets Capture output: -b <ringbuffer opt.> ..., --ring-buffer <ringbuffer opt.> duration:NUM - switch to next file after NUM secs filesize:NUM - switch to next file after NUM KB files:NUM - ringbuffer: replace after NUM files packets:NUM - switch to next file after NUM packets interval:NUM - switch to next file when the time is an exact multiple of NUM secs Input file: -r <infile>, --read-file <infile> set the filename to read from (no pipes or stdin!) Processing: -R <read filter>, --read-filter <read filter> packet filter in Wireshark display filter syntax -n disable all name resolutions (def: all enabled) -N <name resolve flags> enable specific name resolution(s): "mnNtdv" -d <layer_type>==<selector>,<decode_as_protocol> ... "Decode As", see the man page for details Example: tcp.port==8888,http --enable-protocol <proto_name> enable dissection of proto_name --disable-protocol <proto_name> disable dissection of proto_name --enable-heuristic <short_name> enable dissection of heuristic protocol --disable-heuristic <short_name> disable dissection of heuristic protocol User interface: -C <config profile> start with specified configuration profile -H hide the capture info dialog during packet capture -Y <display filter>, --display-filter <display filter> start with the given display filter -g <packet number> go to specified packet number after "-r" -J <jump filter> jump to the first packet matching the (display) filter -j search backwards for a matching packet after "-J" -t a|ad|adoy|d|dd|e|r|u|ud|udoy format of time stamps (def: r: rel. to first) -u s|hms output format of seconds (def: s: seconds) -X <key>:<value> eXtension options, see man page for details -z <statistics> show various statistics, see man page for details Output: -w <outfile|-> set the output filename (or '-' for stdout) --capture-comment <comment> add a capture file comment, if supported --temp-dir <directory> write temporary files to this directory (default: /tmp) Diagnostic output: --log-level <level> sets the active log level ("critical", "warning", etc.) --log-fatal <level> sets level to abort the program ("critical" or "warning") --log-domains <[!]list> comma separated list of the active log domains --log-debug <[!]list> comma separated list of domains with "debug" level --log-noisy <[!]list> comma separated list of domains with "noisy" level --log-file <path> file to output messages to (in addition to stderr) Miscellaneous: -h, --help display this help and exit -v, --version display version info and exit -P <key>:<path> persconf:path - personal configuration files persdata:path - personal data files -o <name>:<value> ... override preference or recent setting -K <keytab> keytab file to use for kerberos decryption --display <X display> X display to use --fullscreen start Wireshark in full screen We will examine each of the command line options in turn. The first thing to notice is that issuing the command -a <capture autostop condition>, --autostop <capture autostop condition> Specify a criterion that specifies when Wireshark is to stop writing to a capture file. The criterion is of the form test:value, where test is one of: duration:value Stop writing to a capture file after value of seconds have elapsed. filesize:value Stop writing to a capture file after it reaches a size of value kilobytes (where a kilobyte is 1000 bytes, not 1024 bytes). If this option is used together with the -b option, Wireshark will stop writing to the current capture file and switch to the next one if filesize is reached. files:value Stop writing to capture files after value number of files were written. packets:value Stop writing to a capture file after value number of packets were written. -b <capture ring buffer option>If a maximum capture file size was specified, this option causes Wireshark to run in “ring buffer” mode, with the specified number of files. In “ring buffer” mode, Wireshark will write to several capture files. Their name is based on the number of the file and on the creation date and time. When the first capture file fills up Wireshark will switch to writing to the next file, and so on. With the files option it’s also possible to form a “ring buffer.” This will fill up new files until the number of files specified, at which point the data in the first file will be discarded so a new file can be written. If the optional duration is specified, Wireshark will also switch to the next file when the specified number of seconds has elapsed even if the current file is not completely filled up. duration:value Switch to the next file after value seconds have elapsed, even if the current file is not completely filled up. filesize:value Switch to the next file after it reaches a size of value kilobytes (where a kilobyte is 1000 bytes, not 1024 bytes). files:value Begin again with the first file after value number of files were written (form a ring buffer). packets:value Switch to the next file after value number of packets were written, even if the current file is not completely filled up. interval:value Switch to the next file when the time is an exact multiple of value seconds. -B <capture buffer size>, --buffer-size <capture buffer size> Set capture buffer size (in MB, default is 2MB). This is used by the capture driver to buffer packet data until that data can be written to disk. If you encounter packet drops while capturing, try to increase this size. Not supported on some platforms. -C <config profile> Start with the specified configuration profile. -c <capture packet count> This option specifies the maximum number of packets to capture when capturing live data. It would be used in conjunction with the-k option. --capture-comment <comment> Add the comment string to the capture file, if supported by the file format. -d <layer_type>==<selector>,<decode_as_protocol> "Decode As", see
Section 11.4.2, “User Specified Decodes” for details. Example: tcp.port==8888,http -D, --list-interfacesPrint a list of the interfaces on which Wireshark can capture, then exit. For each network interface, a number and an interface name, possibly followed by a text description of the interface, is printed. The interface
name or the number can be supplied to the This can be useful on systems that don’t have a command to list them (e.g., Windows systems, or UNIX systems lacking Note that “can capture” means that Wireshark was able to open that device to do a live capture. If, on your system, a program doing a network capture must be run from an
account with special privileges, then, if Wireshark is run with the Set the name of the network interface or pipe to use for live packet capture. Network
interface names should match one of the names listed in If no interface is specified, Wireshark searches the list of interfaces, choosing the first non-loopback interface if there are any non-loopback interfaces, and choosing the first loopback interface if there are no non-loopback interfaces; if there are no interfaces, Wireshark reports an error and doesn’t start the capture. Pipe names should be either the name of a FIFO (named pipe) or “-” to read data from the standard input. Data read from pipes must be in standard libpcap format. -J <jump filter> After reading in a capture file using the-r flag, jump to the first packet which matches the filter expression. The filter
expression is in display filter format. If an exact match cannot be found the first packet afterwards is selected. -I, --monitor-mode Capture wireless packets in monitor mode if available. -j Use this option after the -J option to search backwards for a first packet to go to. -k The -k option specifies that Wireshark should start capturing packets immediately. This option
requires the use of the -i parameter to specify the interface that packet capture will occur from. -K <keytab file> Use the specified file for Kerberos decryption. -l This option turns on automatic scrolling if the packet list pane is being updated automatically as packets arrive during a capture (as specified by the -S flag). -L, --list-data-link-types List the data link
types supported by the interface and exit. --list-time-stamp-types List timestamp types configurable for the interface and exit. -m <font> This option sets the name of the font used for most text displayed by Wireshark. -n Disable network object name resolution (such as hostname, TCP and UDP port names). -N <name resolving flags> Turns on name resolving for particular types of addresses and port numbers. The argument is a string that may contain the following letters: N Use external name resolver. d Enable name resolution from captured DNS packets. m Enable MAC address resolution. n Enable network address resolution. t Enable transport layer port number resolution. v Enable VLAN ID resolution. -o <preference or recent settings>Sets a preference or recent value, overriding the default value and any value read from a preference or recent file. The argument to the flag is a string of the form prefname:value, where prefname is the name of the preference (which is the same name that would appear in the An example of setting a single preference would be: wireshark -o mgcp.display_dissect_tree:TRUE An example of setting multiple preferences would be: wireshark -o mgcp.display_dissect_tree:TRUE -o mgcp.udp.callagent_port:2627 You can get a list of all available preference strings from the preferences file. See Appendix B, Files and Folders for details. User access tables can be overridden using “uat,” followed by the UAT file name and a valid record for the file: wireshark -o "uat:user_dlts:\"User 0 (DLT=147)\",\"http\",\"0\",\"\",\"0\",\"\"" The example above would dissect packets with a libpcap data link type 147 as HTTP, just as if you had configured it in the DLT_USER protocol preferences. -p, --no-promiscuous-mode Don’t put the interface into promiscuous mode. Note that the interface might be in promiscuous mode for some other reason. Hence,-p cannot be used to ensure that the only traffic that is captured is traffic sent to or from the machine on which Wireshark is running, broadcast traffic, and multicast traffic to addresses received by that machine. -P <path setting>Special path settings usually detected automatically. This is used for special cases, e.g., starting Wireshark from a known location on an USB stick. The criterion is of the form key:path, where key is one of: persconf:path Path of personal configuration files, like the preferences files. persdata:path Path of personal data files, it’s the folder initially opened. After the initialization, the recent file will keep the folder last used. -r <infile>, --read-file <infile> This option provides the name of a capture file for Wireshark to read and display. This capture file can be in one of the formats Wireshark understands. -R <read (display) filter>, --read-filter <read (display) filter> This option specifies a display filter to be applied when reading packets from a capture file. The syntax of this filter is that of the display filters discussed in Section 6.3, “Filtering Packets While Viewing”. Packets not matching the filter are discarded. -s <capture snapshot length>, --snapshot-length <capture snapshot length> This option specifies the snapshot length to use when capturing packets. Wireshark will only capture snaplen bytes of data for each packet. -S This option specifies that Wireshark will display packets as it captures them. This is done by capturing in one process and displaying them in a separate process. This is the same as “Update list of packets in real time” in the “Capture Options” dialog box. -t <time stamp format>This option sets the format of packet timestamps that are displayed in the packet list window. The format can be one of: r Relative, which specifies timestamps are displayed relative to the first packet captured. a Absolute, which specifies that actual times be displayed for all packets. ad Absolute with date, which specifies that actual dates and times be displayed for all packets. adoy Absolute with YYYY/DOY date, which specifies that actual dates and times be displayed for all packets. d Delta, which specifies that timestamps are relative to the previous packet. dd: Delta, which specifies that timestamps are relative to the previous displayed packet. e Epoch, which specifies that timestamps are seconds since epoch (Jan 1, 1970 00:00:00) u Absolute, which specifies that actual times be displayed for all packets in UTC. ud Absolute with date, which specifies that actual dates and times be displayed for all packets in UTC. udoy Absolute with YYYY/DOY date, which specifies that actual dates and times be displayed for all packets in UTC. -u <s | hms> Show timesamps as seconds (“s”, the default) or hours, minutes, and seconds (“hms”) -v, --version This option requests Wireshark to print out its version information and exit. -w <savefile> This option sets the name of the file to be used to save captured packets. This can be '-' for stdout. -y <capture link type>, --link-type <capture like types> If a capture is started from the command line with-k , set the data link type to use while capturing packets. The values reported by
-L are the values that can be used. --time-stamp-type <type> If a capture is started from the command line with -k , set the time stamp type to use while capturing packets. The values reported by --list-time-stamp-types are the values that can be used. -X <eXtension option>Specify an option to be passed to a Wireshark/TShark module. The eXtension option is in the form extension_key:value, where extension_key can be: lua_script:<lua_script_filename> Tells Wireshark to load the given script in addition to the default Lua scripts. lua_script[num]:argument Tells Wireshark to pass the given argument to the lua script identified by num, which is the number indexed order of the lua_script command. For example, if only one script was loaded with 11.3. Packet colorizationA very useful mechanism available in Wireshark is packet colorization. You can set up Wireshark so that it will colorize packets according to a display filter. This allows you to emphasize the packets you might be interested in. You can find a lot of coloring rule examples at the Wireshark Wiki Coloring Rules page at https://gitlab.com/wireshark/wireshark/wikis/ColoringRules. There are two types of coloring rules in Wireshark: temporary rules that are only in effect until you quit the program, and permanent rules that are saved in a preference file so that they are available the next time you run Wireshark. Temporary rules can be added by selecting a packet and pressing the Ctrl key together with one of the number keys. This will create a coloring rule based on the currently selected conversation. It will try to create a conversation filter based on TCP first, then UDP, then IP and at last Ethernet. Temporary filters can also be created by selecting the → menu items when right-clicking in the packet detail pane. To permanently colorize packets, select → . Wireshark will display the “Coloring Rules” dialog box as shown in Figure 11.1, “The “Coloring Rules” dialog box”. Figure 11.1. The “Coloring Rules” dialog box If this is the first time using the Coloring Rules dialog and you’re using the default configuration profile you should see the default rules, shown above.
You can create a new rule by clicking on the + button. You can delete one or more rules by clicking the - button. The “copy” button will duplicate a rule. You can edit a rule by double-clicking on its name or filter. In Figure 11.1, “The “Coloring Rules” dialog box” the name of the rule “Checksum Errors” is being edited. Clicking on the Foreground and Background buttons will open a color chooser (Figure 11.2, “A color chooser”) for the foreground (text) and background colors respectively. Figure 11.2. A color chooser The color chooser appearance depends on your operating system. The macOS color picker is shown. Select the color you desire for the selected packets and click OK. Figure 11.3, “Using color filters with Wireshark” shows an example of several color filters being used in Wireshark. Note that the frame detail shows that the “Bad TCP” rule was applied, along with the matching filter. Figure 11.3. Using color filters with Wireshark 11.4. Control Protocol dissectionThe user can control how protocols are dissected. Each protocol has its own dissector, so dissecting a complete packet will typically involve several dissectors. As Wireshark tries to find the right dissector for each packet (using static “routes” and heuristics “guessing”), it might choose the wrong dissector in your specific case. For example, Wireshark won’t know if you use a common protocol on an uncommon TCP port, e.g., using HTTP on TCP port 800 instead of the standard port 80. There are two ways to control the relations between protocol dissectors: disable a protocol dissector completely or temporarily divert the way Wireshark calls the dissectors. 11.4.1. The “Enabled Protocols” dialog boxThe Enabled Protocols dialog box lets you enable or disable specific protocols. Most protocols are enabled by default. When a protocol is disabled, Wireshark stops processing a packet whenever that protocol is encountered.
To enable or disable protocols select → . Wireshark will pop up the “Enabled Protocols” dialog box as shown in Figure 11.4, “The “Enabled Protocols” dialog box”. Figure 11.4. The “Enabled Protocols” dialog box To disable or enable a protocol, simply click the checkbox using the mouse. Note that typing a few letters of the protocol name in the search box will limit the list to those protocols that contain these letters. You can choose from the following actions: Enable All Enable all protocols in the list. Disable All Disable all protocols in the list. Invert Toggle the state of all protocols in the list. OK Save and apply the changes and close the dialog box, see Appendix B, Files and Folders for details. Cancel Cancel the changes and close the dialog box. 11.4.2. User Specified DecodesThe “Decode As” functionality lets you temporarily divert specific protocol dissections. This might be useful for example, if you do some uncommon experiments on your network. Decode As is accessed by selecting the → . Wireshark will pop up the “Decode As” dialog box as shown in Figure 11.5, “The “Decode As” dialog box”. Figure 11.5. The “Decode As” dialog box In this dialog you are able to edit entries by means of the edit buttons on the left. You can also pop up this dialog box from the context menu in the packet list or packet details. It will then contain a new line based on the currently selected packet. These settings will be lost if you quit Wireshark or change profile unless you save the entries. + Add new entry for selected packet - Remove the selected entry. Copy Copy the selected entry. Clear Clear the list of user specified decodes. OK Apply the user specified decodes and close the dialog box. Save Save and apply the user specified decodes and close the dialog box. Cancel Cancel the changes and close the dialog box. 11.5. PreferencesThere are a number of preferences you can set. Simply select the → ( → on macOS) and Wireshark will pop up the Preferences dialog box as shown in Figure 11.6, “The preferences dialog box”, with the “User Interface” page as default. On the left side is a tree where you can select the page to be shown.
Figure 11.6. The preferences dialog box Wireshark supports quite a few protocols, which is reflected in the long list of entries in the “Protocols” pane. You can jump to the preferences for a specific protocol by expanding “Protocols” and quickly typing the first few letters of the protocol name. The “Advanced” pane will let you view and edit all of Wireshark’s preferences, similar to about:config and chrome:flags in the Firefox and Chrome web browsers. Figure 11.7. Advanced preferences You can search for a preference by typing text into the “Search” entry. You can also pass preference names to Wireshark and TShark on the command line. For example, the gui.prepend_window_title can be used to differentiate between different instances of Wireshark: $ wireshark -o "gui.prepend_window_title:Internal Network" & $ wireshark -o "gui.prepend_window_title:External Network" & 11.6. Configuration ProfilesConfiguration Profiles can be used to configure and use more than one set of preferences and configurations. Select the → menu item or press Shift+Ctrl+A or Shift+⌘+A (macOS) and Wireshark will pop up the Configuration Profiles dialog box as shown in Figure 11.8, “The configuration profiles dialog box”. It is also possible to click in the “Profile” part of the statusbar to popup a menu with available Configuration Profiles (Figure 3.23, “The Statusbar with a configuration profile menu”). Configuration files stored in each profile include:
All other configurations are stored in the personal configuration folder and are common to all profiles. Figure 11.8. The configuration profiles dialog box Search for profile … The list of profiles can be filtered by entering part of the profile’s name into the search box. Type selection Profiles can be filtered between displaying "All profiles", "Personal profiles" and "Global profiles"
11.8. Display Filter MacrosDisplay Filter Macros are a mechanism to create shortcuts for complex filters. For example, defining a display filter macro named tcp_conv whose text is (ip.src == $1 and ip.dst == $2 and tcp.srcport == $3 and tcp.dstport == $4) or (ip.src == $2 and ip.dst == $1 and tcp.srcport == $4 and tcp.dstport == $3) would allow to use a display filter like ${tcp_conv:10.1.1.2;10.1.1.3;1200;1400} instead of typing the whole filter. Display Filter Macros can be managed with a user table, as described in Section 11.7, “User Table”, by selecting → from the menu. The User Table has the following fields: Name The name of the macro. Text The replacement text for the macro it uses $1, $2, $3, … as the input arguments. 11.9. ESS Category AttributesWireshark uses this table to map ESS Security Category attributes to textual representations. The values to put in this table are usually found in an XML SPIF, which is used for defining security labels. This table is a user table, as described in Section 11.7, “User Table”, with the following fields: Tag Set An Object Identifier representing the Category Tag Set. Value The value (Label And Cert Value) representing the Category. Name The textual representation for the value. 11.10. MaxMind Database PathsIf your copy of Wireshark supports MaxMind’s MaxMindDB library, you can use their databases to match IP addresses to countries, cites, autonomous system numbers, and other bits of information. Some databases are available at no cost for registered users, while others require a licensing fee. See the MaxMind web site for more information. The configuration for the MaxMind database is a user table, as described in Section 11.7, “User Table”, with the following fields: Database pathname This specifies a directory containing MaxMind data files. Any files ending with .mmdb will be automatically loaded. The locations for your data files are up to you, but Previous versions of Wireshark supported MaxMind’s original GeoIP Legacy database format. They were configured similar to MaxMindDB files above, except GeoIP files must begin with Geo and end with .dat. They are no longer supported and MaxMind stopped distributing GeoLite Legacy databases in April 2018. 11.11. IKEv2 decryption tableWireshark can decrypt Encrypted Payloads of IKEv2 (Internet Key Exchange version 2) packets if necessary information is provided. Note that you can decrypt only IKEv2 packets with this feature. If you want to decrypt IKEv1 packets or ESP packets, use Log Filename setting under ISAKMP protocol preference or settings under ESP protocol preference respectively. This is handled by a user table, as described in Section 11.7, “User Table”, with the following fields: Initiator’s SPI Initiator’s SPI of the IKE_SA. This field takes hexadecimal string without “0x” prefix and the length must be 16 hex chars (represents 8 octets). Responder’s SPI Responder’s SPI of the IKE_SA. This field takes hexadecimal string without “0x” prefix and the length must be 16 hex chars (represents 8 octets). SK_ei Key used to encrypt/decrypt IKEv2 packets from initiator to responder. This field takes hexadecimal string without “0x” prefix and its length must meet the requirement of the encryption algorithm selected. SK_er Key used to encrypt/decrypt IKEv2 packets from responder to initiator. This field takes hexadecimal string without “0x” prefix and its length must meet the requirement of the encryption algorithm selected. Encryption Algorithm Encryption algorithm of the IKE_SA. SK_ai Key used to calculate Integrity Checksum Data for IKEv2 packets from responder to initiator. This field takes hexadecimal string without “0x” prefix and its length must meet the requirement of the integrity algorithm selected. SK_ar Key used to calculate Integrity Checksum Data for IKEv2 packets from initiator to responder. This field takes hexadecimal string without “0x” prefix and its length must meet the requirement of the integrity algorithm selected. Integrity Algorithm Integrity algorithm of the IKE_SA. 11.12. Object IdentifiersMany protocols that use ASN.1 use Object Identifiers (OIDs) to uniquely identify certain pieces of information. In many cases, they are used in an extension mechanism so that new object identifiers (and associated values) may be defined without needing to change the base standard. While Wireshark has knowledge about many of the OIDs and the syntax of their associated values, the extensibility means that other values may be encountered. Wireshark uses this table to allow the user to define the name and syntax of Object Identifiers that Wireshark does not know about (for example, a privately defined X.400 extension). It also allows the user to override the name and syntax of Object Identifiers that Wireshark does know about (e.g., changing the name “id-at-countryName” to just “c”). This table is a user table, as described in Section 11.7, “User Table”, with the following fields: OID The string representation of the Object Identifier e.g., “2.5.4.6”. Name The name that should be displayed by Wireshark when the Object Identifier is dissected e.g., (“c”); Syntax The syntax of the value associated with the Object Identifier. This must be one of the syntaxes that Wireshark already knows about (e.g., “PrintableString”). 11.13. PRES Users Context ListWireshark uses this table to map a presentation context identifier to a given object identifier when the capture does not contain a PRES package with a presentation context definition list for the conversation. This table is a user table, as described in Section 11.7, “User Table”, with the following fields: Context Id An Integer representing the presentation context identifier for which this association is valid. Syntax Name OID The object identifier representing the abstract syntax name, which defines the protocol that is carried over this association. 11.14. SCCP users TableWireshark uses this table to map specific protocols to a certain DPC/SSN combination for SCCP. This table is a user table, as described in Section 11.7, “User Table”, with the following fields: Network Indicator An Integer representing the network indicator for which this association is valid. Called DPCs A range of integers representing the dpcs for which this association is valid. Called SSNs A range of integers representing the ssns for which this association is valid. User protocol The protocol that is carried over this association 11.15. SMI (MIB and PIB) ModulesIf your copy of Wireshark supports libSMI, you can specify a list of MIB and PIB modules here. The COPS and SNMP dissectors can use them to resolve OIDs. Module name The name of the module, e.g., IF-MIB. 11.16. SMI (MIB and PIB) PathsIf your copy of Wireshark supports libSMI, you can specify one or more paths to MIB and PIB modules here. Directory name A module directory, e.g., 11.17. SNMP Enterprise Specific Trap TypesWireshark uses this table to map specific-trap values to user defined descriptions in a Trap PDU. The description is shown in the packet details specific-trap element. This table is a user table, as described in Section 11.7, “User Table”, with the following fields: Enterprise OID The object identifier representing the object generating the trap. Trap Id An Integer representing the specific-trap code. Description The description to show in the packet details. 11.18. SNMP users TableWireshark uses this table to verify authentication and to decrypt encrypted SNMPv3 packets. This table is a user table, as described in Section 11.7, “User Table”, with the following fields: Engine ID If given this entry will be used only for packets whose engine id is this. This field takes a hexadecimal string in the form 0102030405. Username This is the userName. When a single user has more than one password for different SNMP-engines the first entry to match both is taken, if you need a catch all engine-id (empty) that entry should be the last one. Authentication model Which auth model to use (either “MD5” or “SHA1”). Password The authentication password. Use \xDD for unprintable characters. A hexadecimal password must be entered as a sequence of \xDD characters. For example, the hex password 010203040506 must be entered as \x01\x02\x03\x04\x05\x06. The \ character must be treated as an unprintable character, i.e., it must be entered as \x5C or \x5c. Privacy protocol Which encryption algorithm to use (either “DES” or “AES”). Privacy password The privacy password. Use \xDD for unprintable characters. A hexadecimal password must be entered as a sequence of \xDD characters. For example, the hex password 010203040506 must be entered as \x01\x02\x03\x04\x05\x06. The \ character must be treated as an unprintable character, i.e., it must be entered as \x5C or \x5c. 11.19. Tektronix K12xx/15 RF5 protocols TableThe Tektronix K12xx/15 rf5 file format uses helper files (*.stk) to identify the various protocols that are used by a certain interface. Wireshark doesn’t read these stk files, it uses a table that helps it identify which lowest layer protocol to use. Stk file to protocol matching is handled by a user table, as described in Section 11.7, “User Table”, with the following fields: Match string A partial match for an stk filename, the first match wins, so if you have a specific case and a general one the specific one must appear first in the list. Protocol This is the name of the encapsulating protocol (the lowest layer in the packet data) it can be either just the name of the protocol (e.g., mtp2, eth_withoutfcs, sscf-nni ) or the name of the encapsulation protocol and the “application” protocol over it separated by a colon (e.g., sscop:sscf-nni, sscop:alcap, sscop:nbap, …) 11.20. User DLTs protocol tableWhen a pcap file uses one of the user DLTs (147 to 162) Wireshark uses this table to know which protocol(s) to use for each user DLT. This table is a user table, as described in Section 11.7, “User Table”, with the following fields: DLT One of the user dlts. Payload protocol This is the name of the payload protocol (the lowest layer in the packet data). (e.g., “eth” for ethernet, “ip” for IPv4) Header size If there is a header protocol (before the payload protocol) this tells which size this header is. A value of 0 disables the header protocol. Header protocol The name of the header protocol to be used (uses “data” as default). Trailer size If there is a trailer protocol (after the payload protocol) this tells which size this trailer is. A value of 0 disables the trailer protocol. Trailer protocol The name of the trailer protocol to be used (uses “data” as default). 11.21. Protobuf Search PathsThe binary wire format of Protocol Buffers (Protobuf) messages are not self-described protocol. For example, the You can specify protobuf search paths at the Protobuf protocol preferences. For example, if you defined a proto file with path The configuration for the protobuf search paths is a user table, as described in Section 11.7, “User Table”, with the following fields: Protobuf source directory This specifies a directory containing protobuf source files. For example, 11.22. Protobuf UDP Message TypesIf the payload of UDP on certain ports is Protobuf encoding, Wireshark use this table to know which Protobuf message type should be used to parsing the data on the specified UDP port(s). The configuration for UDP Port(s) to Protobuf message type maps is a user table, as described in Section 11.7, “User Table”, with the following fields: UDP Ports The range of UDP ports. The format may be "8000" or "8000,8008-8088,9080". Message Type The Protobuf message type as which the data on the specified udp port(s) should be parsed. The message type is allowed to be empty, that means let Protobuf to dissect the data on specified UDP ports as normal wire type without precise definitions. Tips: You can create your own dissector to call Protobuf dissector. If your dissector is written in C language, you can pass the message type to Protobuf dissector by "message," message_type_name For example: message,helloworld.HelloRequest the Chapter 12. MATE12.1. IntroductionMATE: Meta Analysis and Tracing Engine What is MATE? Well, to keep it very short, with MATE you can create user configurable extension(s) of the display filter engine. MATE’s goal is to enable users to filter frames based on information extracted from related frames or information on how frames relate to each other. MATE was written to help troubleshooting gateways and other systems where a "use" involves more protocols. However, MATE can be used as well to analyze other issues regarding an interaction between packets like response times, incompleteness of transactions, presence/absence of certain attributes in a group of PDUs and more. MATE is a Wireshark plugin that allows the user to specify how different frames are related to each other. To do so, MATE extracts data from the frames' tree and then, using that information, tries to group the frames based on how MATE is configured. Once the PDUs are related, MATE will create a "protocol" tree with fields the user can filter with. The fields will be almost the same for all the related frames, so one can filter a complete session spanning several frames containing more protocols based on an attribute appearing in some related frame. Other than that MATE allows to filter frames based on response times, number of PDUs in a group and a lot more. So far MATE has been used to:
12.2. Getting StartedThese are the steps to try out MATE:
If anything went well, your packet details might look something like this: 12.3. MATE Manual12.3.1. IntroductionMATE creates a filterable tree based on information contained in frames that share some relationship with information obtained from other frames. The way these relationships are made is described in a configuration file. The configuration file tells MATE what makes a PDU and how to relate it to other PDUs. MATE analyzes each frame to extract relevant information from the "protocol" tree of that frame. The extracted information is contained in MATE PDUs; these contain a list of relevant attributes taken from the tree. From now on, I will use the term "PDU" to refer to the objects created by MATE containing the relevant information extracted from the frame; I’ll use "frame" to refer to the "raw" information extracted by the various dissectors that pre-analyzed the frame. For every PDU, MATE checks if it belongs to an existing "Group of PDUs" (Gop). If it does, it assigns the PDU to that Gop and moves any new relevant attributes to the Gop’s attribute list. How and when do PDUs belong to Gops is described in the configuration file as well. Every time a Gop is assigned a new PDU, MATE will check if it matches the conditions to make it belong to a "Group of Groups" (Gog). Naturally the conditions that make a Gop belong to a Gog are taken from the configuration file as well. Once MATE is done analyzing the frame it will be able to create a "protocol" tree for each frame based on the PDUs, the Gops they belong to and naturally any Gogs the former belongs to. How to tell MATE what to extract, how to group it and then how to relate those groups is made using AVPs and AVPLs. Information in MATE is contained in Attribute/Value Pairs (AVPs). AVPs are made of two strings: the name and the value. AVPs are used in the configuration and there they have an operator as well. There are various ways AVPs can be matched against each other using those operators. AVPs are grouped into AVP Lists (AVPLs). PDUs, Gops and Gogs have an AVPL each. Their AVPLs will be matched in various ways against others coming from the configuration file. MATE will be instructed how to extract AVPs from frames in order to create a PDU with an AVPL. It will be instructed as well, how to match that AVPL against the AVPLs of other similar PDUs in order to relate them. In MATE the relationship between PDUs is a Gop, it has an AVPL as well. MATE will be configured with other AVPLs to operate against the Gop’s AVPL to relate Gops together into Gogs. A good understanding on how AVPs and AVPLs work is fundamental to understand how MATE works. 12.3.2. Attribute Value PairsInformation used by MATE to relate different frames is contained in Attribute/ Value Pairs (AVPs). AVPs are made of two strings - the name and the value. When AVPs are used in the configuration, an operator is defined as well. There are various ways AVPs can be matched against each other using those operators. avp_name="avp's value" another_name= "1234 is the value" The name is a string used to refer to a "kind" of an AVP. Two AVPs won’t match unless their names are identical. You should not use uppercase characters in names, or names that start with “.” or “_”. Capitalized names are reserved for configuration parameters (we’ll call them keywords); nothing forbids you from using capitalized strings for other things as well but it probably would be confusing. I’ll avoid using capitalized words for anything but the keywords in this document, the reference manual, the examples and the base library. Names that start with a “.” would be very confusing as well because in the old grammar, AVPL transformations use names starting with a “.” to indicate they belong to the replacement AVPL. The value is a string that is either set in the configuration (for configuration AVPs) or by Wireshark while extracting interesting fields from a frame’s tree. The values extracted from fields use the same representation as they do in filter strings except that no quotes are used. The name can contain only alphanumeric characters, "_", and ".". The name ends with an operator. The value will be dealt with as a string even if it is a number. If there are any spaces in the value, the value must be between quotes "". ip_addr=10.10.10.11, tcp_port=1234, binary_data=01:23:45:67:89:ab:cd:ef, parameter12=0x23aa, parameter_with_spaces="this value has spaces" The way two AVPs with the same name might match is described by the operator. Remember two AVPs won’t match unless their names are identical. In MATE, match operations are always made between the AVPs extracted from frames (called data AVPs) and the configuration’s AVPs. Currently defined MATE’s AVP match operators are:
12.3.3. AVP listsAn AVPL is a set of diverse AVPs that can be matched against other AVPLs. Every PDU, Gop and Gog has an AVPL that contains the information regarding it. The rules that MATE uses to group Pdus and Gops are AVPL operations. There will never be two identical AVPs in a given AVPL. However, we can have more than one AVP with the same name in an AVPL as long as their values are different. Some AVPL examples: ( addr=10.20.30.40, addr=192.168.0.1, tcp_port=21, tcp_port=32534, user_cmd=PORT, data_port=12344, data_addr=192.168.0.1 ) ( addr=10.20.30.40, addr=192.168.0.1, channel_id=22:23, message_type=Setup, calling_number=1244556673 ) ( addr=10.20.30.40, addr=192.168.0.1, ses_id=01:23:45:67:89:ab:cd:ef ) ( user_id=pippo, calling_number=1244556673, assigned_ip=10.23.22.123 ) In MATE there are two types of AVPLs:
Data AVPLs can be operated against operation AVPLs in various ways:
12.3.4. MATE AnalysisMATE’s analysis of a frame is performed in three phases:
The extraction and matching logic comes from MATE’s configuration; MATE’s configuration file is declared by the mate.config preference. By default it is an empty string which means: do not configure MATE. The config file tells MATE what to look for in frames; How to make PDUs out of it; How will PDUs be related to other similar PDUs into Gops; And how Gops relate into Gogs. The MATE configuration file is a list of declarations. There are 4 types of declarations: Transform, Pdu, Gop and Gog. 12.3.4.1. Mate’s PDU’sMATE will look in the tree of every frame to see if there is useful data to extract, and if there is, it will create one or more PDU objects containing the useful information. The first part of MATE’s analysis is the "PDU extraction"; there are various "Actions" that are used to instruct MATE what has to be extracted from the current frame’s tree into MATE’s PDUs. 12.3.4.1.1. PDU data extractionMATE will make a Pdu for each different proto field of Proto type present in the frame. MATE will fetch from the field’s tree those fields that are defined in the Section 12.8.1, “Pdsu’s configuration actions” declaration whose initial offset in the frame is within the boundaries of the current Proto and those of the given Transport and Payload statements. Pdu dns_pdu Proto dns Transport ip { Extract addr From ip.addr; Extract dns_id From dns.id; Extract dns_resp From dns.flags.response; }; MATE will make a Pdu for each different proto field of Proto type present in the frame. MATE will fetch from the field’s tree those fields that are defined in the Section 12.8.1, “Pdsu’s configuration actions” AVPL whose initial offset in the frame is within the boundaries of the current Proto and those of the various assigned Transports. Once MATE has found a Proto field for which to create a Pdu from the frame it will move backwards in the frame looking for the respective Transport fields. After that it will create AVPs named as each of those given in the rest of the AVPL for every instance of the fields declared as its values. Sometimes we need information from more than one Transport protocol. In that case MATE will check the frame looking backwards to look for the various Transport protocols in the given stack. MATE will choose only the closest transport boundary per "protocol" in the frame. This way we’ll have all Pdus for every Proto that appears in a frame match its relative transports. Pdu isup_pdu Proto isup Transport mtp3/ip { Extract m3pc From mtp3.dpc; Extract m3pc From mtp3.opc; Extract cic From isup.cic; Extract addr From ip.addr; Extract isup_msg From isup.message_type; }; This allows to assign the right Transport to the Pdu avoiding duplicate transport protocol entries (in case of tunneled ip over ip for example). Pdu ftp_pdu Proto ftp Transport tcp/ip { Extract addr From ip.addr; Extract port From tcp.port; Extract ftp_cmd From ftp.command; }; Other than the mandatory Transport there is also an optional Payload statement, which works pretty much as Transport but refers to elements after the Proto's range. It is useful in those cases where the payload protocol might not appear in a Pdu but nevertheless the Pdu belongs to the same category. Pdu mmse_over_http_pdu Proto http Transport tcp/ip { Payload mmse; Extract addr From ip.addr; Extract port From tcp.port; Extract method From http.request.method; Extract content From http.content_type; Extract http_rq From http.request; Extract resp From http.response.code; Extract host From http.host; Extract trx From mmse.transaction_id; Extract msg_type From mmse.message_type; Extract notify_status From mmse.status; Extract send_status From mmse.response_status; }; 12.3.4.1.2. Conditions on which to create PDUsThere might be cases in which we won’t want MATE to create a PDU unless some of its extracted attributes meet or do not meet some criteria. For that we use the Criteria statements of the Pdu declarations. Pdu isup_pdu Proto isup Transport mtp3/ip { ... // MATE will create isup_pdu PDUs only when there is not a point code '1234' Criteria Reject Strict (m3pc=1234); }; Pdu ftp_pdu Proto ftp Transport tcp/ip { ... // MATE will create ftp_pdu PDUs only when they go to port 21 of our ftp_server Criteria Accept Strict (addr=10.10.10.10, port=21); }; The Criteria statement is given an action (Accept or Reject), a match mode (Strict, Loose or Every) and an AVPL against which to match the currently extracted one. 12.3.4.1.3. Transforming the attributes of a PDUOnce the fields have been extracted into the Pdu’s AVPL, MATE will apply any declared transformation to it. The way transforms are applied and how they work is described later on. However, it’s useful to know that once the AVPL for the Pdu is created, it may be transformed before being analyzed. That way we can massage the data to simplify the analysis. 12.3.4.1.4. MATE’s PDU treeEvery successfully created Pdu will add a MATE tree to the frame dissection. If the Pdu is not related to any Gop, the tree for the Pdu will contain just the Pdu’s info, if it is assigned to a Gop, the tree will also contain the Gop items, and the same applies for the Gog level. mate dns_pdu:1 dns_pdu: 1 dns_pdu time: 3.750000 dns_pdu Attributes dns_resp: 0 dns_id: 36012 addr: 10.194.4.11 addr: 10.194.24.35 The Pdu’s tree contains some filterable fields
12.3.4.2. Grouping Pdus together (Gop)Once MATE has created the Pdus it passes to the Pdu analysis phase. During the PDU analysis phase MATE will try to group Pdus of the same type into 'Groups of Pdus' (aka *Gop*s) and copy some AVPs from the Pdu’s AVPL to the Gop’s AVPL. 12.3.4.2.1. What can belong to a GopGiven a Pdu, the first thing MATE will do is to check if there is any Gop declaration in the configuration for the given Pdu type. If so, it will use its Match AVPL to match it against the Pdu’s AVPL; if they don’t match, the analysis phase is done. If there is a match, the AVPL is the Gop’s candidate key which will be used to search the Gop’s index for the Gop to which to assign the current PDU. If there is no such Gop and this Pdu does not match the Start criteria of a Gop declaration for the Pdu type, the Pdu will remain unassigned and only the analysis phase will be done. Gop ftp_ses On ftp_pdu Match (addr, addr, port, port); Gop dns_req On dns_pdu Match (addr, addr, dns_id); Gop isup_leg On isup_pdu Match (m3pc, m3pc, cic); 12.3.4.2.2. Start of a GopIf there was a match, the candidate key will be used to search the Gop’s index to see if there is already a Gop matching the Gop’s key the same way. If there is such a match in the Gops collection, and the PDU doesn’t match the Start AVPL for its kind, the PDU will be assigned to the matching Gop. If it is a Start match, MATE will check whether or not that Gop has been already stopped. If the Gop has been stopped, a new Gop will be created and will replace the old one in the Gop’s index. Gop ftp_ses On ftp_pdu Match (addr, addr, port, port) { Start (ftp_cmd=USER); }; Gop dns_req On dns_pdu Match (addr, addr, dns_id) { Start (dns_resp=0); }; Gop isup_leg On isup_pdu Match (m3pc, m3pc, cic) { Start (isup_msg=1); }; If no Start is given for a Gop, a Pdu whose AVPL matches an existing Gog’s key will act as the start of a Gop. 12.3.4.2.3. What goes into the Gop’s AVPLOnce we know a Gop exists and the Pdu has been assigned to it, MATE will copy into the Gop’s AVPL all the attributes matching the key plus any AVPs of the Pdu’s AVPL matching the Extra AVPL. Gop ftp_ses On ftp_pdu Match (addr, addr, port, port) { Start (ftp_cmd=USER); Extra (pasv_prt, pasv_addr); }; Gop isup_leg On isup_pdu Match (m3pc, m3pc, cic) { Start (isup_msg=1); Extra (calling, called); }; 12.3.4.2.4. End of a GopOnce the Pdu has been assigned to the Gop, MATE will check whether or not the Pdu matches the Stop, if it happens, MATE will mark the Gop as stopped. Even after stopped, a Gop may get assigned new Pdus matching its key, unless such Pdu matches Start. If it does, MATE will instead create a new Gop starting with that Pdu. Gop ftp_ses On ftp_pdu Match (addr, addr, port, port) { Start (ftp_cmd=USER); Stop (ftp_cmd=QUIT); // The response to the QUIT command will be assigned to the same Gop Extra (pasv_prt, pasv_addr); }; Gop dns_req On dns_pdu Match (addr, addr, dns_id) { Start (dns_resp=0); Stop (dns_resp=1); }; Gop isup_leg On isup_pdu Match (m3pc, m3pc, cic) { Start (isup_msg=1); // IAM Stop (isup_msg=16); // RLC Extra (calling, called); }; If no Stop criterium is stated for a given Gop, the Gop will be stopped as soon as it is created. However, as with any other Gop, Pdus matching the Gop’s key will still be assigned to the Gop unless they match a Start condition, in which case a new Gop using the same key will be created. 12.3.4.3. Gop’s treeFor every frame containing a Pdu that belongs to a Gop, MATE will create a tree for that Gop. The example below represents the tree created by the dns_pdu and dns_req examples. ... mate dns_pdu:6->dns_req:1 dns_pdu: 6 dns_pdu time: 2.103063 dns_pdu time since beginning of Gop: 2.103063 dns_req: 1 dns_req Attributes dns_id: 36012 addr: 10.194.4.11 addr: 10.194.24.35 dns_req Times dns_req start time: 0.000000 dns_req hold time: 2.103063 dns_req duration: 2.103063 dns_req number of PDUs: 2 Start PDU: in frame 1 Stop PDU: in frame 6 (2.103063 : 2.103063) dns_pdu Attributes dns_resp: 1 dns_id: 36012 addr: 10.194.4.11 addr: 10.194.24.35 Other than the pdu’s tree, this one contains information regarding the relationship between the Pdus that belong to the Gop. That way we have:
12.3.4.3.1. Gop’s timersNote that there are two "timers" for a Gop:
So:
12.3.4.4. Grouping Gops together (Gog)When Gops are created, or whenever their AVPL changes, Gops are (re)analyzed to check if they match an existent group of groups (Gog) or can create a new one. The Gop analysis is divided into two phases. In the first phase, the still unassigned Gop is checked to verify whether it belongs to an already existing Gog or may create a new one. The second phase eventually checks the Gog and registers its keys in the Gogs index. There are several reasons for the author to believe that this feature needs to be reimplemented, so probably there will be deep changes in the way this is done in the near future. This section of the documentation reflects the version of MATE as of Wireshark 0.10.9; in future releases this will change. 12.3.4.4.1. Declaring a Group Of GroupsThe first thing we have to do configuring a Gog is to tell MATE that it exists. Gog web_use { ... }; 12.3.4.4.2. Telling MATE what could be a Gog memberThen we have to tell MATE what to look for a match in the candidate Gops. Gog web_use { Member http_ses (host); Member dns_req (host); }; 12.3.4.4.3. Getting interesting data into the GopMost often, also other attributes than those used for matching would be interesting. In order to copy from Gop to Gog other interesting attributes, we might use Extra like we do for Gops. Gog web_use { ... Extra (cookie); }; 12.3.4.4.4. Gog’s treemate http_pdu:4->http_req:2->http_use:1 http_pdu: 4 http_pdu time: 1.309847 http_pdu time since beginning of Gop: 0.218930 http_req: 2 ... (the gop's tree for http_req: 2) .. http_use: 1 http_use Attributes host: www.example.com http_use Times http_use start time: 0.000000 http_use duration: 1.309847 number of GOPs: 3 dns_req: 1 ... (the gop's tree for dns_req: 1) .. http_req: 1 ... (the gop's tree for http_req: 1) .. http_req of current frame: 2 We can filter on:
12.3.4.5. AVPL TransformsA Transform is a sequence of Match rules optionally completed with modification of the match result by an additional AVPL. Such modification may be an Insert (merge) or a Replace. Transforms can be used as helpers to manipulate an item’s AVPL before it is processed further. They come to be very helpful in several cases. 12.3.4.5.1. SyntaxAVPL Transformations are declared in the following way: Transform name { Match [Strict|Every|Loose] match_avpl [Insert|Replace] modify_avpl ; ... }; The name is the handle to the AVPL transformation. It is used to refer to the transform when invoking it later. The Match declarations instruct MATE what and how to match against the data AVPL and how to modify the data AVPL if the match succeeds. They will be executed in the order they appear in the config file whenever they are invoked. The optional match mode qualifier (Strict, Every, or Loose) is used to choose the match mode as explained above; Strict is a default value which may be omitted. The optional modification mode qualifier instructs MATE how the modify AVPL should be used:
The modify_avpl may be an empty one; this comes useful in some cases for both Insert and Replace modification modes. Examples: Transform insert_name_and { Match Strict (host=10.10.10.10, port=2345) Insert (name=JohnDoe); }; adds name=JohnDoe to the data AVPL if it contains host=10.10.10.10 and port=2345 Transform insert_name_or { Match Loose (host=10.10.10.10, port=2345) Insert (name=JohnDoe); }; adds name=JohnDoe to the data AVPL if it contains host=10.10.10.10 or port=2345 Transform replace_ip_address { Match (host=10.10.10.10) Replace (host=192.168.10.10); }; replaces the original host=10.10.10.10 by host=192.168.10.10 Transform add_ip_address { Match (host=10.10.10.10) (host=192.168.10.10); }; adds (inserts) host=192.168.10.10 to the AVPL, keeping the original host=10.10.10.10 in it too Transform replace_may_be_surprising { Match Loose (a=aaaa, b=bbbb) Replace (c=cccc, d=dddd); }; gives the following results:
12.3.4.5.2. UsageOnce declared, Transforms can be added to the declarations of PDUs, Gops or Gogs. This is done by adding the Transform name_list statement to the declaration: Pdu my_proto_pdu Proto my_proto Transport ip { Extract addr From ip.addr; ... Transform my_pdu_transform[, other_pdu_transform[, yet_another_pdu_transform]]; };
12.3.4.6. Operation
MATE’s Transforms can be used for many different things, like: 12.3.4.6.1. Multiple Start/Stop conditions for a GopUsing Transforms we can add more than one start or stop condition to a Gop. Transform start_cond { Match (attr1=aaa,attr2=bbb) (msg_type=start); Match (attr3=www,attr2=bbb) (msg_type=start); Match (attr5^a) (msg_type=stop); Match (attr6$z) (msg_type=stop); }; Pdu pdu ... { ... Transform start_cond; } Gop gop ... { Start (msg_type=start); Stop (msg_type=stop); ... } 12.3.4.6.2. Marking Gops and Gogs to filter them easilyTransform marks { Match (addr=10.10.10.10, user=john) (john_at_host); Match (addr=10.10.10.10, user=tom) (tom_at_host); } ... Gop my_gop ... { ... Transform marks; } After that we can use a display filter mate.gop.john_at_host or mate.gop.tom_at_host 12.3.4.6.3. Adding direction knowledge to MATETransform direction_as_text { Match (src=192.168.0.2, dst=192.168.0.3) Replace (direction=from_2_to_3); Match (src=192.168.0.3, dst=192.168.0.2) Replace (direction=from_3_to_2); }; Pdu my_pdu Proto my_proto Transport tcp/ip { Extract src From ip.src; Extract dst From ip.dst; Extract addr From ip.addr; Extract port From tcp.port; Extract start From tcp.flags.syn; Extract stop From tcp.flags.fin; Extract stop From tcp.flags.rst; Transform direction_as_text; } Gop my_gop On my_pdu Match (addr,addr,port,port) { ... Extra (direction); } 12.3.4.6.4. NATNAT can create problems when tracing, but we can easily work around it by Transforming the NATed IP address and the Ethernet address of the router into the non-NAT address: Transform denat { Match (addr=192.168.0.5, ether=01:02:03:04:05:06) Replace (addr=123.45.67.89); Match (addr=192.168.0.6, ether=01:02:03:04:05:06) Replace (addr=123.45.67.90); Match (addr=192.168.0.7, ether=01:02:03:04:05:06) Replace (addr=123.45.67.91); } Pdu my_pdu Proto my_proto transport tcp/ip/eth { Extract ether From eth.addr; Extract addr From ip.addr; Extract port From tcp.port; Transform denat; } 12.3.5. About MATEMATE was originally written by Luis Ontanon, a Telecommunications systems troubleshooter, as a way to save time filtering out the packets of a single call from huge capture files using just the calling number. Later he used the time he had saved to make it flexible enough to work with protocols other than the ones he was directly involved with. 12.4. MATE’s configuration tutorialWe’ll show a MATE configuration that first creates Gops for every DNS and HTTP request, then it ties the Gops together in a Gop based on the host. Finally, we’ll separate into different Gogs request coming from different users. With this MATE configuration loaded we can:
The complete config file is available on the Wireshark Wiki: https://gitlab.com/wireshark/wireshark/-/wikis/Mate/Tutorial Note: This example uses dns.qry.name which is defined since Wireshark version 0.10.9. Supposing you have a mate plugin already installed you can test it with the current Wireshark version. 12.4.1. A Gop for DNS requestsFirst we’ll tell MATE how to create a Gop for each DNS request/response. MATE needs to know what makes a DNS PDU. We describe it this using a Pdu declaration: Pdu dns_pdu Proto dns Transport ip { Extract addr From ip.addr; Extract dns_id From dns.id; Extract dns_resp From dns.flags.response; }; Using Proto dns we tell MATE to create Pdus every time it finds dns. Using Transport ip we inform MATE that some of the fields we are interested are in the ip part of the frame. Finally, we tell MATE to import ip.addr as addr, dns.id as dns_id and dns.flags.response as dns_resp. Once we’ve told MATE how to extract dns_pdus we’ll tell it how to match requests and responses and group them into a Gop. For this we’ll use a Gop declaration to define the Gop, and then, Start and Stop statements to tell it when the Gop starts and ends. Gop dns_req On dns_pdu Match (addr,addr,dns_id) { Start (dns_resp=0); Stop (dns_resp=1); }; Using the Gop declaration we tell MATE that the Name of the Gop is dns_req, that dns_pdus can become members of the Gop, and what is the key used to match the Pdus to the Gop. The key for this Gop is "addr, addr, dns_id". That means that in order to belong to the same Gop, dns_pdus have to have both addresses and the request id identical. We then instruct MATE that a dns_req starts whenever a dns_pdu matches "dns_resp=0" and that it stops when another dns_pdu matches "dns_resp=1". At this point, if we open a capture file using this configuration, we are able to use a display filter mate.dns_req.Time > 1 to see only the packets of DNS requests that take more than one second to complete. We can use a display filter mate.dns_req && ! mate.dns_req.Time to find requests for which no response was given. mate.xxx.Time is set only for Gops that have being stopped. 12.4.2. A Gop for HTTP requestsThis other example creates a Gop for every HTTP request. Pdu http_pdu Proto http Transport tcp/ip { Extract addr From ip.addr; Extract port From tcp.port; Extract http_rq From http.request.method; Extract http_rs From http.response; DiscardPduData true; }; Gop http_req On http_pdu Match (addr, addr, port, port) { Start (http_rq); Stop (http_rs); }; So, if we open a capture using this configuration
You have to know that mate.xxx.Time gives the time in seconds between the pdu matching the GopStart and the Pdu matching the GopStop (yes, you can create timers using this!). On the other hand, mate.xxx.Duration gives you the time passed between the GopStart and the last pdu assigned to that Gop regardless whether it is a stop or not. After the GopStop, Pdus matching the Gop’s Key will still be assigned to the same Gop as far as they don’t match the GopStart, in which case a new Gop with the same key will be created. 12.4.3. Getting DNS and HTTP together into a GogWe’ll tie together to a single Gog all the http packets belonging to requests and responses to a certain host and the dns request and response used to resolve its domain name using the Pdu and Gop definitions of the previous examples To be able to group DNS and HTTP requests together, we need to import into the Pdus and Gops some part of information that both those protocols share. Once the Pdus and Gops have been defined, we can use Extract (for Pdus) and Extract (for Gops) statements to tell MATE what other protocol fields are to be added to Pdus' and Gops' AVPLs. We add the following statements to the appropriate declarations: Extract host From http.host; // to Pdu http_pdu as the last Extract in the list Extra (host); // to Gop http_req after the Stop Extract host From dns.qry.name; // to Pdu dns_pdu as the last Extract in the list Extra (host); // to Gop dns_req after the Stop Here we’ve told MATE to import http.host into http_pdu and dns.qry.name into dns_pdu as host. We also have to tell MATE to copy the host attribute from the Pdus to the Gops, we do this using Extra. Once we have all the data we need in Pdus and Gops, we tell MATE what makes different Gops belong to a certain Gog. Gog http_use { Member http_req (host); Member dns_req (host); Expiration 0.75; }; Using the Gog declaration, we tell MATE to define a Gog type Named http_use whose expiration is 0.75 seconds after all the Gops that belong to it had been stopped. After that time, an eventual new Gop with the same key match will create a new Gog instead of been added to the previous Gog. Using the Member statements, we tell MATE that http_req*s with the same *host belong to the same Gog, same thing for *dns_req*s. So far we have instructed mate to group every packet related to sessions towards a certain host. At this point if we open a capture file and:
12.4.4. Separating requests from multiple users"Houston: we’ve had a problem here." This configuration works fine if used for captures taken at the client’s side but deeper in the network we’d got a real mess. Requests from many users get mixed together into http_uses. Gogs are created and stopped almost randomly (depending on the timing in which Gops start and stop). How do we get requests from individual users separated from each other? MATE has a tool that can be used to resolve this kind of grouping issues. This tool are the Transforms. Once defined, they can be applied against Pdus, Gops and Gogs and they might replace or insert more attributes based on what’s there. We’ll use them to create an attribute named client, using which we’ll separate different requests. For DNS we need the ip.src of the request moved into the Gop only from the DNS request. So we first tell MATE to import ip.src as client: Extract client From ip.src; Next, we tell MATE to replace ( dns_resp=1, client ) with just dns_resp=1 in the Pdu. That way, we’ll keep the attribute client only in the DNS request Pdus (i.e., packets coming from the client).To do so, we have to add a Transform declaration (in this case, with just one clause) before the Pdu declaration which uses it: Transform rm_client_from_dns_resp { Match (dns_resp=1, client) Replace (dns_resp=1); }; Next, we invoke the transform by adding the following line after the Extract list of the dns_pdu Pdu: Transform rm_client_from_dns_resp; HTTP is a little trickier. We have to remove the attribute carrying ip.src from both the response and the "continuations" of the response, but as there is nothing to filter on for the continuations, we have to add a fake attribute first. And then we have to remove client when the fake attribute appears. This is possible due to the fact that the Match clauses in the Transform are executed one by one until one of them succeeds. First, we declare another two Transforms: Transform rm_client_from_http_resp1 { Match (http_rq); //first match wins so the request won't get the not_rq attribute inserted Match Every (addr) Insert (not_rq); //this line won't be evaluated if the first one matched so not_rq won't be inserted to requests }; Transform rm_client_from_http_resp2 { Match (not_rq, client) Replace (); //replace "client and not_rq" with nothing (will happen only in the response and eventual parts of it) }; Next, we add another Extract statement to the http_pdu declaration, and apply both Transforms declared above in a proper order: Extract client From ip.src; Transform rm_client_from_http_resp1, rm_client_from_http_resp2; In MATE, all the Transform_s listed for an item will be evaluated, while inside a single _Transform, the evaluation will stop at the first successful Match clause. That’s why we first just match http_rq to get out of the first sequence before adding the not_rq attribute. Then we apply the second Transform which removes both not_rq and client if both are there. Yes, _Transform_s are cumbersome, but they are very useful. Once we got all what we need in the Pdus, we have to tell MATE to copy the attribute client from the Pdus to the respective Gops, by adding client to Extra lists of both Gop declarations: Extra (host, client); On top of that, we need to modify the old declarations of Gop key to new ones that include both client and host. So we change the Gog Member declarations the following way: Member http_req (host, client); Member dns_req (host, client); Now we got it, every "usage" gets its own Gog. 12.5. MATE configuration examplesThe following is a collection of various configuration examples for MATE. Many of them are useless because the "conversations" facility does a better job. Anyway they are meant to help users understanding how to configure MATE. 12.5.1. TCP sessionThe following example creates a GoP out of every TCP session. Pdu tcp_pdu Proto tcp Transport ip { Extract addr From ip.addr; Extract port From tcp.port; Extract tcp_start From tcp.flags.syn; Extract tcp_stop From tcp.flags.reset; Extract tcp_stop From tcp.flags.fin; }; Gop tcp_ses On tcp_pdu Match (addr, addr, port, port) { Start (tcp_start=1); Stop (tcp_stop=1); }; Done; This probably would do fine in 99.9% of the cases but 10.0.0.1:20→10.0.0.2:22 and 10.0.0.1:22→10.0.0.2:20 would both fall into the same gop if they happen to overlap in time.
12.5.2. a Gog for a complete FTP sessionThis configuration allows to tie a complete passive ftp session (including the data transfer) in a single Gog. Pdu ftp_pdu Proto ftp Transport tcp/ip { Extract ftp_addr From ip.addr; Extract ftp_port From tcp.port; Extract ftp_resp From ftp.response.code; Extract ftp_req From ftp.request.command; Extract server_addr From ftp.passive.ip; Extract server_port From ftp.passive.port; LastPdu; }; Pdu ftp_data_pdu Proto ftp-data Transport tcp/ip{ Extract server_addr From ip.src; Extract server_port From tcp.srcport; }; Gop ftp_data On ftp_data_pdu (server_addr, server_port) { Start (server_addr); }; Gop ftp_ctl On ftp_pdu (ftp_addr, ftp_addr, ftp_port, ftp_port) { Start (ftp_resp=220); Stop (ftp_resp=221); Extra (server_addr, server_port); }; Gog ftp_ses { Member ftp_ctl (ftp_addr, ftp_addr, ftp_port, ftp_port); Member ftp_data (server_addr, server_port); }; Done; Note: not having anything to distinguish between ftp-data packets makes this config to create one Gop for every ftp-data packet instead of each transfer. Pre-started Gops would avoid this. 12.5.3. using RADIUS to filter SMTP traffic of a specific userSpying on people, in addition to being immoral, is illegal in many countries. This is an example meant to explain how to do it not an invitation to do so. It’s up to the police to do this kind of job when there is a good reason to do so. Pdu radius_pdu On radius Transport udp/ip { Extract addr From ip.addr; Extract port From udp.port; Extract radius_id From radius.id; Extract radius_code From radius.code; Extract user_ip From radius.framed_addr; Extract username From radius.username; } Gop radius_req On radius_pdu (radius_id, addr, addr, port, port) { Start (radius_code {1|4|7} ); Stop (radius_code {2|3|5|8|9} ); Extra (user_ip, username); } // we define the smtp traffic we want to filter Pdu user_smtp Proto smtp Transport tcp/ip { Extract user_ip From ip.addr; Extract smtp_port From tcp.port; Extract tcp_start From tcp.flags.syn; Extract tcp_stop From tcp.flags.reset; } Gop user_smtp_ses On user_smtp (user_ip, user_ip, smtp_port!25) { Start (tcp_start=1); Stop (tcp_stop=1); } // with the following group of groups we'll group together the radius and the smtp // we set a long expiration to avoid the session expire on long pauses. Gog user_mail { Expiration 1800; Member radius_req (user_ip); Member user_smtp_ses (user_ip); Extra (username); } Done; Filtering the capture file with mate.user_mail.username == "theuser" will filter the radius packets and smtp traffic for "theuser". 12.5.4. H323 CallsThis configuration will create a Gog out of every call. Pdu q931 Proto q931 Transport ip { Extract addr From ip.addr; Extract call_ref From q931.call_ref; Extract q931_msg From q931.message_type; Extract calling From q931.calling_party_number.digits; Extract called From q931.called_party_number.digits; Extract guid From h225.guid; Extract q931_cause From q931.cause_value; }; Gop q931_leg On q931 Match (addr, addr, call_ref) { Start (q931_msg=5); Stop (q931_msg=90); Extra (calling, called, guid, q931_cause); }; Pdu ras Proto h225.RasMessage Transport ip { Extract addr From ip.addr; Extract ras_sn From h225.requestSeqNum; Extract ras_msg From h225.RasMessage; Extract guid From h225.guid; }; Gop ras_req On ras Match (addr, addr, ras_sn) { Start (ras_msg {0|3|6|9|12|15|18|21|26|30} ); Stop (ras_msg {1|2|4|5|7|8|10|11|13|14|16|17|19|20|22|24|27|28|29|31}); Extra (guid); }; Gog call { Member ras_req (guid); Member q931_leg (guid); Extra (called,calling,q931_cause); }; Done; with this we can:
12.5.5. MMSWith this example, all the components of an MMS send or receive will be tied into a single Gog. Note that this example uses the Payload clause because MMS delivery uses MMSE over either HTTP or WSP. As it is not possible to relate the retrieve request to a response by the means of MMSE only (the request is just an HTTP GET without any MMSE), a Gop is made of HTTP Pdus but MMSE data need to be extracted from the bodies. ## WARNING: this example has been blindly translated from the "old" MATE syntax ## and it has been verified that Wireshark accepts it. However, it has not been ## tested against any capture file due to lack of the latter. Transform rm_client_from_http_resp1 { Match (http_rq); Match Every (addr) Insert (not_rq); }; Transform rm_client_from_http_resp2 { Match (not_rq,ue) Replace (); }; Pdu mmse_over_http_pdu Proto http Transport tcp/ip { Payload mmse; Extract addr From ip.addr; Extract port From tcp.port; Extract http_rq From http.request; Extract content From http.content_type; Extract resp From http.response.code; Extract method From http.request.method; Extract host From http.host; Extract content From http.content_type; Extract trx From mmse.transaction_id; Extract msg_type From mmse.message_type; Extract notify_status From mmse.status; Extract send_status From mmse.response_status; Transform rm_client_from_http_resp1, rm_client_from_http_resp2; }; Gop mmse_over_http On mmse_over_http_pdu Match (addr, addr, port, port) { Start (http_rq); Stop (http_rs); Extra (host, ue, resp, notify_status, send_status, trx); }; Transform mms_start { Match Loose() Insert (mms_start); }; Pdu mmse_over_wsp_pdu Proto wsp Transport ip { Payload mmse; Extract trx From mmse.transaction_id; Extract msg_type From mmse.message_type; Extract notify_status From mmse.status; Extract send_status From mmse.response_status; Transform mms_start; }; Gop mmse_over_wsp On mmse_over_wsp_pdu Match (trx) { Start (mms_start); Stop (never); Extra (ue, notify_status, send_status); }; Gog mms { Member mmse_over_http (trx); Member mmse_over_wsp (trx); Extra (ue, notify_status, send_status, resp, host, trx); Expiration 60.0; }; 12.6. MATE’s configuration libraryThe MATE library (will) contains GoP definitions for several protocols. Library protocols are included in your MATE config using: _Action=Include; Lib=proto_name;_. For Every protocol with a library entry, we’ll find defined what from the PDU is needed to create a GoP for that protocol, eventually any criteria and the very essential GoP definition (i.e., GopDef, GopStart and GopStop).
12.6.1. General use protocols12.6.1.1. TCPIt will create a GoP for every TCP session, If it is used it should be the last one in the list. And every other proto on top of TCP should be declared with Stop=TRUE; so the a TCP PDU is not created where we got already one going on. Action=PduDef; Name=tcp_pdu; Proto=tcp; Transport=ip; addr=ip.addr; port=tcp.port; tcp_start=tcp.flags.syn; tcp_stop=tcp.flags.fin; tcp_stop=tcp.flags.reset; Action=GopDef; Name=tcp_session; On=tcp_pdu; addr; addr; port; port; Action=GopStart; For=tcp_session; tcp_start=1; Action=GopStop; For=tcp_session; tcp_stop=1;
12.6.1.2. DNSwill create a GoP containing every request and its response (eventually retransmissions too). Action=PduDef; Name=dns_pdu; Proto=dns; Transport=udp/ip; addr=ip.addr; port=udp.port; dns_id=dns.id; dns_rsp=dns.flags.response; Action=GopDef; Name=dns_req; On=dns_pdu; addr; addr; port!53; dns_id; Action=GopStart; For=dns_req; dns_rsp=0; Action=GopStop; For=dns_req; dns_rsp=1; 12.6.1.3. RADIUSA Gop for every transaction. Action=PduDef; Name=radius_pdu; Proto=radius; Transport=udp/ip; addr=ip.addr; port=udp.port; radius_id=radius.id; radius_code=radius.code; Action=GopDef; Name=radius_req; On=radius_pdu; radius_id; addr; addr; port; port; Action=GopStart; For=radius_req; radius_code|1|4|7; Action=GopStop; For=radius_req; radius_code|2|3|5|8|9; 12.6.1.4. RTSPAction=PduDef; Name=rtsp_pdu; Proto=rtsp; Transport=tcp/ip; addr=ip.addr; port=tcp.port; rtsp_method=rtsp.method; Action=PduExtra; For=rtsp_pdu; rtsp_ses=rtsp.session; rtsp_url=rtsp.url; Action=GopDef; Name=rtsp_ses; On=rtsp_pdu; addr; addr; port; port; Action=GopStart; For=rtsp_ses; rtsp_method=DESCRIBE; Action=GopStop; For=rtsp_ses; rtsp_method=TEARDOWN; Action=GopExtra; For=rtsp_ses; rtsp_ses; rtsp_url; 12.6.2. VoIP/TelephonyMost protocol definitions here will create one Gop for every Call Leg unless stated. 12.6.2.1. ISUPAction=PduDef; Name=isup_pdu; Proto=isup; Transport=mtp3; mtp3pc=mtp3.dpc; mtp3pc=mtp3.opc; cic=isup.cic; isup_msg=isup.message_type; Action=GopDef; Name=isup_leg; On=isup_pdu; ShowPduTree=TRUE; mtp3pc; mtp3pc; cic; Action=GopStart; For=isup_leg; isup_msg=1; Action=GopStop; For=isup_leg; isup_msg=16; 12.6.2.2. Q931Action=PduDef; Name=q931_pdu; Proto=q931; Stop=TRUE; Transport=tcp/ip; addr=ip.addr; call_ref=q931.call_ref; q931_msg=q931.message_type; Action=GopDef; Name=q931_leg; On=q931_pdu; addr; addr; call_ref; Action=GopStart; For=q931_leg; q931_msg=5; Action=GopStop; For=q931_leg; q931_msg=90; 12.6.2.3. H225 RASAction=PduDef; Name=ras_pdu; Proto=h225.RasMessage; Transport=udp/ip; addr=ip.addr; ras_sn=h225.RequestSeqNum; ras_msg=h225.RasMessage; Action=PduExtra; For=ras_pdu; guid=h225.guid; Action=GopDef; Name=ras_leg; On=ras_pdu; addr; addr; ras_sn; Action=GopStart; For=ras_leg; ras_msg|0|3|6|9|12|15|18|21|26|30; Action=GopStop; For=ras_leg; ras_msg|1|2|4|5|7|8|10|11|13|14|16|17|19|20|22|24|27|28|29|31; Action=GopExtra; For=ras_leg; guid; 12.6.2.4. SIPAction=PduDef; Proto=sip_pdu; Transport=tcp/ip; addr=ip.addr; port=tcp.port; sip_method=sip.Method; sip_callid=sip.Call-ID; calling=sdp.owner.username; Action=GopDef; Name=sip_leg; On=sip_pdu; addr; addr; port; port; Action=GopStart; For=sip; sip_method=INVITE; Action=GopStop; For=sip; sip_method=BYE; 12.6.2.5. MEGACOWill create a Gop out of every transaction. To "tie" them to your call’s GoG use: Action=GogKey; Name=your_call; On=mgc_tr; addr!mgc_addr; megaco_ctx; Action=PduDef; Name=mgc_pdu; Proto=megaco; Transport=ip; addr=ip.addr; megaco_ctx=megaco.context; megaco_trx=megaco.transid; megaco_msg=megaco.transaction; term=megaco.termid; Action=GopDef; Name=mgc_tr; On=mgc_pdu; addr; addr; megaco_trx; Action=GopStart; For=mgc_tr; megaco_msg|Request|Notify; Action=GopStop; For=mgc_tr; megaco_msg=Reply; Action=GopExtra; For=mgc_tr; term^DS1; megaco_ctx!Choose one; 12.7. MATE’s reference manual12.7.1. Attribute Value PairsMATE uses AVPs for almost everything: to keep the data it has extracted from the frames' trees as well as to keep the elements of the configuration. These "pairs" (actually tuples) are made of a name, a value and, in case of configuration AVPs, an operator. Names and values are strings. AVPs with operators other than '=' are used only in the configuration and are used for matching AVPs of Pdus, GoPs and GoGs in the analysis phase. 12.7.1.1. NameThe name is a string used to refer to a class of AVPs. Two attributes won’t match unless their names are identical. Capitalized names are reserved for keywords (you can use them for your elements if you want but I think it’s not the case). MATE attribute names can be used in Wireshark’s display filters the same way like names of protocol fields provided by dissectors, but they are not just references to (or aliases of) protocol fields. 12.7.1.2. ValueThe value is a string. It is either set in the configuration (for configuration AVPs) or by MATE while extracting interesting fields from a dissection tree and/or manipulating them later. The values extracted from fields use the same representation as they do in filter strings. 12.7.1.3. OperatorsCurrently only match operators are defined (there are plans to (re)add transform attributes but some internal issues have to be solved before that). The match operations are always performed between two operands: the value of an AVP stated in the configuration and the value of an AVP (or several AVPs with the same name) extracted from packet data (called "data AVPs"). It is not possible to match data AVPs to each other. The defined match operators are:
12.7.1.3.1. Equal AVP OperatorThis operator tests whether the values of the operator and the operand AVP are equal. Example attrib=aaa matches attrib=aaa attrib=aaa does not match attrib=bbb
12.7.1.3.2. Not equal AVP operatorThis operator matches if the value strings of two AVPs are not equal. Example attrib=aaa matches attrib!bbb attrib=aaa does not match attrib!aaa 12.7.1.3.3. "One of" AVP operatorThe "one of" operator matches if the data AVP value is equal to one of the values listed in the "one of" AVP. Example attrib=1 matches attrib{1|2|3} attrib=2 matches attrib{1|2|3} attrib=4 does not match attrib{1|2|3} 12.7.1.3.4. "Starts with" AVP operatorThe "starts with" operator matches if the first characters of the data AVP value are identical to the configuration AVP value. Example attrib=abcd matches attrib^abc attrib=abc matches attrib^abc attrib=ab does not match attrib^abc attrib=abcd does not match attrib^bcd attrib=abc does not match attrib^abcd 12.7.1.3.5. "Ends with" operatorThe ends with operator will match if the last bytes of the data AVP value are equal to the configuration AVP value. Example attrib=wxyz matches attrib$xyz attrib=yz does not match attrib$xyz attrib=abc…wxyz does not match attrib$abc 12.7.1.3.6. Contains operatorThe "contains" operator will match if the data AVP value contains a string identical to the configuration AVP value. Example attrib=abcde matches attrib~bcd attrib=abcde matches attrib~abc attrib=abcde matches attrib~cde attrib=abcde does not match attrib~xyz
12.7.1.3.7. "Lower than" operatorThe "lower than" operator will match if the data AVP value is semantically lower than the configuration AVP value. Example attrib=abc matches attrib<bcd attrib=1 matches attrib<2 but beware: attrib=10 does not match attrib<9 attrib=bcd does not match attrib<abc attrib=bcd does not match attrib<bcd BUGS It should check whether the values are numbers and compare them numerically 12.7.1.3.8. "Higher than" operatorThe "higher than" operator will match if the data AVP value is semantically higher than the configuration AVP value. Examples attrib=bcd matches attrib>abc attrib=3 matches attrib>2 but beware: attrib=9 does not match attrib>10 attrib=abc does not match attrib>bcd attrib=abc does not match attrib>abc BUGS It should check whether the values are numbers and compare them numerically 12.7.1.3.9. Exists operatorThe exists operator will always match as far as the two operands have the same name. Examples attrib=abc matches attrib? attrib=abc matches attrib (this is just an alternative notation of the previous example) obviously attrib=abc does not match other_attrib?
12.7.2. Attribute/Value Pair List (AVPL)Pdus, GoPs and GoGs use an AVPL to contain the tracing information. An AVPL is an unsorted set of AVPs that can be matched against other AVPLs. 12.7.2.1. Operations between AVPLsThere are three types of match operations that can be performed between AVPLs. The Pdu’s/GoP’s/GoG’s AVPL will be always one of the operands; the AVPL operator (match type) and the second operand AVPL will always come from the configuration. Note that a diverse AVP match operator may be specified for each AVP in the configuration AVPL. An AVPL match operation returns a result AVPL. In Transforms, the result AVPL may be replaced by another AVPL. The replacement means that the existing data AVPs are dropped and the replacement AVPL from the configuration is Merged to the data AVPL of the Pdu/GoP/GoG.
12.7.2.1.1. Loose MatchA loose match between AVPLs succeeds if at least one of the data AVPs matches at least one of the configuration AVPs. Its result AVPL contains all the data AVPs that matched. Loose matches are used in Extra operations against the Pdu's AVPL to merge the result into Gop's AVPL, and against Gop's AVPL to merge the result into Gog's AVPL. They may also be used in Criteria and Transforms.
Loose Match Examples (attr_a=aaa, attr_b=bbb, attr_c=xxx) Match Loose (attr_a?, attr_c?) =⇒ (attr_a=aaa, attr_c=xxx) (attr_a=aaa, attr_b=bbb, attr_c=xxx) Match Loose (attr_a?, attr_c=ccc) =⇒ (attr_a=aaa) (attr_a=aaa, attr_b=bbb, attr_c=xxx) Match Loose (attr_a=xxx; attr_c=ccc) =⇒ No Match! 12.7.2.1.2. Every MatchAn "every" match between AVPLs succeeds if none of the configuration’s AVPs that have a counterpart in the data AVPL fails to match. Its result AVPL contains all the data AVPs that matched. These may only be used in Criteria and Transforms.
"Every" Match Examples (attr_a=aaa, attr_b=bbb, attr_c=xxx) Match Every (attr_a?, attr_c?) =⇒ (attr_a=aaa, attr_c=xxx) (attr_a=aaa, attr_b=bbb, attr_c=xxx) Match Every (attr_a?, attr_c?, attr_d=ddd) =⇒ (attr_a=aaa, attr_c=xxx) (attr_a=aaa, attr_b=bbb, attr_c=xxx) Match Every (attr_a?, attr_c=ccc) =⇒ No Match! (attr_a=aaa; attr_b=bbb; attr_c=xxx) Match Every (attr_a=xxx, attr_c=ccc) =⇒ No Match! 12.7.2.1.3. Strict MatchA Strict match between AVPLs succeeds if and only if every AVP in the configuration AVPL has at least one counterpart in the data AVPL and none of the AVP matches fails. The result AVPL contains all the data AVPs that matched. These are used between Gop keys (key AVPLs) and Pdu AVPLs. They may also be used in Criteria and Transforms. Examples (attr_a=aaa, attr_b=bbb, attr_c=xxx) Match Strict (attr_a?, attr_c=xxx) =⇒ (attr_a=aaa, attr_c=xxx) (attr_a=aaa, attr_b=bbb, attr_c=xxx, attr_c=yyy) Match Strict (attr_a?, attr_c?) =⇒ (attr_a=aaa, attr_c=xxx, attr_c=yyy) (attr_a=aaa, attr_b=bbb, attr_c=xxx) Match Strict (attr_a?, attr_c=ccc) =⇒ No Match! (attr_a=aaa, attr_b=bbb, attr_c=xxx) Match Strict (attr_a?, attr_c?, attr_d?) =⇒ No Match! 12.7.2.1.4. AVPL MergeAn AVPL may be merged into another one. That would add to the latter every AVP from the former that does not already exist there. This operation is done
Examples (attr_a=aaa, attr_b=bbb) Merge (attr_a=aaa, attr_c=xxx) former becomes (attr_a=aaa, attr_b=bbb, attr_c=xxx) (attr_a=aaa, attr_b=bbb) Merge (attr_a=aaa, attr_a=xxx) former becomes (attr_a=aaa, attr_a=xxx, attr_b=bbb) (attr_a=aaa, attr_b=bbb) Merge (attr_c=xxx, attr_d=ddd) former becomes (attr_a=aaa, attr_b=bbb, attr_c=xxx, attr_d=ddd) 12.7.2.1.5. TransformsA Transform is a sequence of Match rules optionally followed by an instruction how to modify the match result using an additional AVPL. Such modification may be an Insert (merge) or a Replace. The syntax is as follows: Transform name { Match [Strict|Every|Loose] match_avpl [[Insert|Replace] modify_avpl] ; // may occur multiple times, at least once }; For examples of Transforms, check the Manual page. TODO: migrate the examples here? The list of Match rules inside a Transform is processed top to bottom; the processing ends as soon as either a Match rule succeeds or all have been tried in vain. Transforms can be used as helpers to manipulate an item’s AVPL before the item is processed further. An item declaration may contain a Transform clause indicating a list of previously declared Transforms. Regardless whether the individual transforms succeed or fail, the list is always executed completely and in the order given, i.e., left to right. In MATE configuration file, a Transform must be declared before declaring any item which uses it. 12.8. Configuration AVPLs12.8.1. Pdsu’s configuration actionsThe following configuration AVPLs deal with PDU creation and data extraction. 12.8.1.1. Pdu declaration block headerIn each frame of the capture, MATE will look for source proto_name's PDUs in the order in which the declarations appear in its configuration and will create Pdus of every type it can from that frame, unless specifically instructed that some Pdu type is the last one to be looked for in the frame. If told so for a given type, MATE will extract all Pdus of that type and the previously declared types it finds in the frame but not those declared later. The complete declaration of a Pdu looks as below; the mandatory order of the diverse clauses is as shown. Pdu name Proto proto_name Transport proto1[/proto2/proto3[/...]]] { Payload proto; //optional, no default value Extract attribute From proto.field ; //may occur multiple times, at least once Transform (transform1[, transform2[, ...]]); //optional Criteria [{Accept|Reject}] [{Strict|Every|Loose} match_avpl]; DropUnassigned {true|false}; //optional, default=false DiscardPduData {true|false}; //optional, default=false LastExtracted {true|false}; //optional, default=false }; 12.8.1.2. Pdu nameThe name is a mandatory attribute of a Pdu declaration. It is chosen arbitrarily, except that each name may only be used once in MATE’s configuration, regardless the class of an item it is used for. The name is used to distinguish between different types of Pdus, Gops, and Gogs. The name is also used as part of the filterable fields' names related to this type of Pdu which MATE creates. However, several Pdu declarations may share the same name. In such case, all of them are created from each source PDU matching their Proto, Transport, and Payload clauses, while the bodies of their declarations may be totally different from each other. Together with the Accept (or Reject) clauses, this feature is useful when it is necessary to build the Pdu’s AVPL from different sets of source fields depending on contents (or mere presence) of other source fields. 12.8.1.2.1. Proto and Transport clausesEvery instance of the protocol proto_name PDU in a frame will generate one Pdu with the AVPs extracted from fields that are in the proto_name's range and/or the ranges of underlying protocols specified by the Transport list. It is a mandatory attribute of a Pdu declaration. The proto_name is the name of the protocol as used in Wireshark display filter. The Pdu’s Proto, and its Transport list of protocols separated by / tell MATE which fields of a frame can get into the Pdu’s AVPL. In order that MATE would extract an attribute from a frame’s protocol tree, the area representing the field in the hex display of the frame must be within the area of either the Proto or its relative Transport s. Transport s are chosen moving backwards from the protocol area, in the order they are given. Proto http Transport tcp/ip does what you’d expect it to - it selects the nearest tcp range that precedes the current http range, and the nearest ip range that precedes that tcp range. If there is another ip range before the nearest one (e.g., in case of IP tunneling), that one is not going to be selected. Transport tcp/ip/ip that "logically" should select the encapsulating IP header too doesn’t work so far. Once we’ve selected the Proto and Transport ranges, MATE will fetch those protocol fields belonging to them whose extraction is declared using the Extract clauses for the Pdu type. The Transport list is also mandatory, if you actually don’t want to use any transport protocol, use Transport mate. (This didn’t work until 0.10.9). 12.8.1.2.2. Payload clauseOther than the Pdu’s Proto and its Transport protocols, there is also a Payload attribute to tell MATE from which ranges of Proto's payload to extract fields of a frame into the Pdu. In order to extract an attribute from a frame’s tree the highlighted area of the field in the hex display must be within the area of the Proto's relative payload(s). Payload s are chosen moving forward from the protocol area, in the order they are given. Proto http Transport tcp/ip Payload mmse will select the first mmse range after the current http range. Once we’ve selected the Payload ranges, MATE will fetch those protocol fields belonging to them whose extraction is declared using the Extract clauses for the Pdu type. 12.8.1.2.3. Extract clauseEach Extract clause tells MATE which protocol field value to extract as an AVP value and what string to use as the AVP name. The protocol fields are referred to using the names used in Wireshark display filters. If there is more than one such protocol field in the frame, each instance that fulfills the criteria stated above is extracted into its own AVP. The AVP names may be chosen arbitrarily, but to be able to match values originally coming from different Pdus (e.g., hostname from DNS query and a hostname from HTTP GET request) later in the analysis, identical AVP names must be assigned to them and the dissectors must provide the field values in identical format (which is not always the case). 12.8.1.2.4. Transform clauseThe Transform clause specifies a list of previously declared Transform s to be performed on the Pdu’s AVPL after all protocol fields have been extracted to it. The list is always executed completely, left to right. On the contrary, the list of Match clauses inside each individual Transform is executed only until the first match succeeds. 12.8.1.2.5. Criteria clauseThis clause tells MATE whether to use the Pdu for analysis. It specifies a match AVPL, an AVPL match type (Strict, Every, or Loose) and the action to be performed (Accept or Reject) if the match succeeds. Once every attribute has been extracted and eventual transform list has been executed, and if the Criteria clause is present, the Pdu’s AVPL is matched against the match AVPL; if the match succeeds, the action specified is executed, i.e., the Pdu is accepted or rejected. The default behaviors used if the respective keywords are omitted are Strict and Accept. Accordingly, if the clause is omitted, all Pdus are accepted. 12.8.1.2.6. DropUnassigned clauseIf set to TRUE, MATE will destroy the Pdu if it cannot assign it to a Gop. If set to FALSE (the default if not given), MATE will keep them. 12.8.1.2.7. DiscardPduData clauseIf set to TRUE, MATE will delete the Pdu’s AVPL once it has analyzed it and eventually extracted some AVPs from it into the Gop’s AVPL. This is useful to save memory (of which MATE uses a lot). If set to FALSE (the default if not given), MATE will keep the Pdu attributes. 12.8.1.2.8. LastExtracted clauseIf set to FALSE (the default if not given), MATE will continue to look for Pdus of other types in the frame. If set to TRUE, it will not try to create Pdus of other types from the current frame, yet it will continue to try for the current type. 12.8.1.3. Gop’s configuration actions12.8.1.3.1. Gop declaration block headerDeclares a Gop type and its prematch candidate key. Gop name On pduname Match key { Start match_avpl; // optional Stop match_avpl; // optional Extra match_avpl; // optional Transform transform_list; // optional Expiration time; // optional IdleTimeout time; // optional Lifetime time; // optional DropUnassigned [TRUE|FALSE]; //optional ShowTree [NoTree|PduTree|FrameTree|BasicTree]; //optional ShowTimes [TRUE|FALSE]; //optional, default TRUE }; 12.8.1.3.2. Gop nameThe name is a mandatory attribute of a Gop declaration. It is chosen arbitrarily, except that each name may only be used once in MATE’s configuration, regardless the class of an item it is used for. The name is used to distinguish between different types of Pdus, Gops, and Gogs. The name is also used as part of the filterable fields' names related to this type of Gop which MATE creates. 12.8.1.3.3. On clauseThe name of Pdus which this type of Gop is supposed to be groupping. It is mandatory. 12.8.1.3.4. Match clauseDefines what AVPs form up the key part of the Gop’s AVPL (the Gop’s key AVPL or simply the Gop’s key). All Pdus matching the key AVPL of an active Gop are assigned to that Gop; a Pdu which contains the AVPs whose attribute names are listed in the Gop’s key AVPL, but they do not strictly match any active Gop’s key AVPL, will create a new Gop (unless a Start clause is given). When a Gop is created, the elements of its key AVPL are copied from the creating Pdu. 12.8.1.3.5. Start clauseIf given, it tells MATE what match_avpl must a Pdu’s AVPL match, in addition to matching the Gop’s key, in order to start a Gop. If not given, any Pdu whose AVPL matches the Gop’s key AVPL will act as a start for a Gop. The Pdu’s AVPs matching the match_avpl are not automatically copied into the Gop’s AVPL. 12.8.1.3.6. Stop clauseIf given, it tells MATE what match_avpl must a Pdu’s AVPL match, in addition to matching the Gop’s key, in order to stop a Gop. If omitted, the Gop is "auto-stopped" - that is, the Gop is marked as stopped as soon as it is created. The Pdu’s AVPs matching the match_avpl are not automatically copied into the Gop’s AVPL. 12.8.1.3.7. Extra clauseIf given, tells MATE which AVPs from the Pdu’s AVPL are to be copied into the Gop’s AVPL in addition to the Gop’s key. 12.8.1.3.8. Transform clauseThe Transform clause specifies a list of previously declared Transform s to be performed on the Gop’s AVPL after the AVPs from each new Pdu, specified by the key AVPL and the Extra clause’s match_avpl, have been merged into it. The list is always executed completely, left to right. On the contrary, the list of Match clauses inside each individual Transform is executed only until the first match succeeds. 12.8.1.3.9. Expiration clauseA (floating) number of seconds after a Gop is Stop ped during which further Pdus matching the Stop ped Gop’s key but not the Start condition will still be assigned to that Gop. The default value of zero has an actual meaning of infinity, as it disables this timer, so all Pdus matching the Stop ped Gop’s key will be assigned to that Gop unless they match the Start condition. 12.8.1.3.10. IdleTimeout clauseA (floating) number of seconds elapsed from the last Pdu assigned to the Gop after which the Gop will be considered released. The default value of zero has an actual meaning of infinity, as it disables this timer, so the Gop won’t be released even if no Pdus arrive - unless the Lifetime timer expires. 12.8.1.3.11. Lifetime clauseA (floating) of seconds after the Gop Start after which the Gop will be considered released regardless anything else. The default value of zero has an actual meaning of infinity. 12.8.1.3.12. DropUnassigned clauseWhether or not a Gop that has not being assigned to any Gog should be discarded. If TRUE, the Gop is discarded right after creation. If FALSE, the default, the unassigned Gop is kept. Setting it to TRUE helps save memory and speed up filtering. 12.8.1.3.13. TreeMode clauseControls the display of Pdus subtree of the Gop:
12.8.1.3.14. ShowTimes clauseWhether or not to show the times subtree of the Gop. If TRUE, the default, the subtree with the timers is added to the Gop’s tree. If FALSE, the subtree is suppressed. 12.8.1.4. Gog’s configuration actions12.8.1.4.1. Gop declaration block headerDeclares a Gog type and its prematch candidate key. Gog name { Member gopname (key); // mandatory, at least one Extra match_avpl; // optional Transform transform_list; // optional Expiration time; // optional, default 2.0 GopTree [NoTree|PduTree|FrameTree|BasicTree]; // optional ShowTimes [TRUE|FALSE]; // optional, default TRUE }; 12.8.1.4.2. Gop nameThe name is a mandatory attribute of a Gog declaration. It is chosen arbitrarily, except that each name may only be used once in MATE’s configuration, regardless the class of an item it is used for. The name is used to distinguish between different types of Pdus, Gops, and Gogs. The name is also used as part of the filterable fields' names related to this type of Gop which MATE creates. 12.8.1.4.3. Member clauseDefines the key AVPL for the Gog individually for each Gop type gopname. All gopname type Gops whose key AVPL matches the corresponding key AVPL of an active Gog are assigned to that Gog; a Gop which contains the AVPs whose attribute names are listed in the Gog’s corresponding key AVPL, but they do not strictly match any active Gog’s key AVPL, will create a new Gog. When a Gog is created, the elements of its key AVPL are copied from the creating Gop. Although the key AVPLs are specified separately for each of the Member gopname s, in most cases they are identical, as the very purpose of a Gog is to group together Gops made of Pdus of different types. 12.8.1.4.4. Extra clauseIf given, tells MATE which AVPs from any of the Gop’s AVPL are to be copied into the Gog’s AVPL in addition to the Gog’s key. 12.8.1.4.5. Expiration clauseA (floating) number of seconds after all the Gops assigned to a Gog have been released during which new Gops matching any of the session keys should still be assigned to the existing Gog instead of creating a new one. Its value can range from 0.0 to infinite. Defaults to 2.0 seconds. 12.8.1.4.6. Transform clauseThe Transform clause specifies a list of previously declared Transform s to be performed on the Gog’s AVPL after the AVPs from each new Gop, specified by the key AVPL and the Extra clause’s match_avpl, have been merged into it. The list is always executed completely, left to right. On the contrary, the list of Match clauses inside each individual Transform is executed only until the first match succeeds. 12.8.1.4.7. TreeMode clauseControls the display of Gops subtree of the Gog:
12.8.1.4.8. ShowTimes clauseWhether or not to show the times subtree of the Gog. If TRUE, the default, the subtree with the timers is added to the Gog’s tree. If FALSE, the subtree is suppressed. 12.8.1.5. Settings Config AVPLThe Settings config element is used to pass to MATE various operational parameters. the possible parameters are 12.8.1.5.1. GogExpirationHow long in seconds after all the gops assigned to a gog have been released new gops matching any of the session keys should create a new gog instead of being assigned to the previous one. Its value can range from 0.0 to infinite. Defaults to 2.0 seconds. 12.8.1.5.2. DiscardPduDataWhether or not the AVPL of every Pdu should be deleted after it was being processed (saves memory). It can be either TRUE or FALSE. Defaults to TRUE. Setting it to FALSE can save you from a headache if your config does not work. 12.8.1.5.3. DiscardUnassignedPduWhether Pdus should be deleted if they are not assigned to any Gop. It can be either TRUE or FALSE. Defaults to FALSE. Set it to TRUE to save memory if unassigned Pdus are useless. 12.8.1.5.4. DiscardUnassignedGopWhether GoPs should be deleted if they are not assigned to any session. It can be either TRUE or FALSE. Defaults to FALSE. Setting it to TRUE saves memory. 12.8.1.5.5. ShowPduTree12.8.1.5.6. ShowGopTimes12.8.1.6. Debugging StuffThe following settings are used to debug MATE and its configuration. All levels are integers ranging from 0 (print only errors) to 9 (flood me with junk), defaulting to 0. 12.8.1.6.1. Debug declaration block header
Debug { Filename "path/name"; //optional, no default value Level [0-9]; //optional, generic debug level Pdu Level [0-9]; //optional, specific debug level for Pdu handling Gop Level [0-9]; //optional, specific debug level for Gop handling Gog Level [0-9]; //optional, specific debug level for Gog handling }; 12.8.1.6.2. Filename clauseThe {{{path/name}}} is a full path to the file to which debug output is to be written. Non-existent file will be created, existing file will be overwritten at each opening of a capture file. If the statement is missing, debug messages are written to console, which means they are invisible on Windows. 12.8.1.6.3. Level clauseSets the level of debugging for generic debug messages. It is an integer ranging from 0 (print only errors) to 9 (flood me with junk). 12.8.1.6.4. Pdu Level clauseSets the level of debugging for messages regarding Pdu creation. It is an integer ranging from 0 (print only errors) to 9 (flood me with junk). 12.8.1.6.5. Gop Level clauseSets the level of debugging for messages regarding Pdu analysis (that is how do they fit into ?GoPs). It is an integer ranging from 0 (print only errors) to 9 (flood me with junk). 12.8.1.6.6. Gog Level clauseSets the level of debugging for messages regarding GoP analysis (that is how do they fit into ?GoGs). It is an integer ranging from 0 (print only errors) to 9 (flood me with junk). 12.8.1.6.7. Settings ExampleAction=Settings; SessionExpiration=3.5; DiscardPduData=FALSE; 12.8.1.7. Action=IncludeWill include a file to the configuration. Action=Include; {Filename=filename;|Lib=libname;} 12.8.1.7.1. FilenameThe filename of the file to include. If it does not begin with '/' it will look for the file in the current path. 12.8.1.7.2. LibThe name of the lib config to include. will look for libname.mate in wiresharks_dir/matelib. 12.8.1.7.3. Include ExampleAction=Include; Filename=rtsp.mate; This will include the file called "rtsp.mate" into the current config. Appendix A. Wireshark MessagesWireshark provides you with additional information generated out of the plain packet data or it may need to indicate dissection problems. Messages generated by Wireshark are usually placed in square brackets (“[]”). A.1. Packet List MessagesThese messages might appear in the packet list. A.1.1. [Malformed Packet]Malformed packet means that the protocol dissector can’t dissect the contents of the packet any further. There can be various reasons:
Any of the above is possible. You’ll have to look into the specific situation to determine the reason. You could disable the dissector by disabling the protocol on the Analyze menu and check how Wireshark displays the packet then. You could (if it’s TCP) enable reassembly for TCP and the specific dissector (if possible) in the Edit|Preferences menu. You could check the packet contents yourself by reading the packet bytes and comparing it to the protocol specification. This could reveal a dissector bug. Or you could find out that the packet is indeed wrong. A.1.2. [Packet size limited during capture]The packet size was limited during capture, see “Limit each packet to n bytes” at the Section 4.5, “The “Capture Options” Dialog Box”. While dissecting, the current protocol dissector was simply running out of packet bytes and had to give up. There’s nothing else you can do now, except to repeat the whole capture process again with a higher (or no) packet size limitation. A.2. Packet Details MessagesThese messages might appear in the packet details. A.2.1. [Response in frame: 123]The current packet is the request of a detected request/response pair. You can directly jump to the corresponding response packet by double clicking on the message. A.2.2. [Request in frame: 123]Same as “Response in frame: 123” above, but the other way round. A.2.3. [Time from request: 0.123 seconds]The time between the request and the response packets. A.2.4. [Stream setup by PROTOCOL (frame 123)]The session control protocol (SDP, H225, etc.) message which signaled the creation of this session. You can directly jump to the corresponding packet by double clicking on this message. Appendix B. Files and FoldersB.1. Capture FilesTo understand which information will remain available after the captured packets are saved to a capture file, it’s helpful to know a bit about the capture file contents. Wireshark uses the pcapng file format as the default format to save captured packets. It is very flexible but other tools may not support it. Wireshark also supports the libpcap file format. This is a much simpler format and is well established. However, it has some drawbacks: it’s not extensible and lacks some information that would be really helpful (e.g., being able to add a comment to a packet such as “the problems start here” would be really nice). In addition to the libpcap format, Wireshark supports several different capture file formats. However, the problems described above also applies for these formats. B.1.1. Libpcap File ContentsAt the start of each libpcap capture file some basic information is stored like a magic number to identify the libpcap file format. The most interesting information of this file start is the link layer type (Ethernet, 802.11, MPLS, etc.). The following data is saved for each packet:
A detailed description of the libpcap file format can be found at https://gitlab.com/wireshark/wireshark/-/wikis/Development/LibpcapFileFormat B.1.2. Not Saved in the Capture FileYou should also know the things that are not saved in capture files:
B.2. Configuration File and Plugin FoldersTo match the different policies for Unix-like systems and Windows, and different policies used on different Unix-like systems, the folders containing configuration files and plugins are different on different platforms. We indicate the location of the top-level folders under which configuration files and plugins are stored here, giving them placeholder names independent of their actual location, and use those names later when giving the location of the folders for configuration files and plugins.
B.2.1. Folders on Windows%APPDATA% is the personal application data folder, e.g.: C:\Users\username\AppData\Roaming\Wireshark (details can be found at: Section B.5.1, “Windows profiles”). WIRESHARK is the Wireshark program folder, e.g.: C:\Program Files\Wireshark. B.2.2. Folders on Unix-like systems$XDG_CONFIG_HOME is the folder for user-specific configuration files. It’s usually $HOME/.config, where $HOME is the user’s home folder, which is usually something such as /home/username, or /Users/username on macOS. If you are using macOS and you are running a copy of Wireshark installed as an application bundle, APPDIR is the top-level directory of the Wireshark application bundle, which will typically be /Applications/Wireshark.app. Otherwise, INSTALLDIR is the top-level directory under
which reside the subdirectories in which components of Wireshark are installed. This will typically be B.3. Configuration FilesWireshark uses a number of configuration files while it is running. Some of these reside in the personal configuration folder and are used to maintain information between runs of Wireshark, while some of them are maintained in system areas. The content format of the configuration files is the same on all platforms. On Windows:
On Unix-like systems:
Table B.1. Configuration files overview
File contentscfilters This file contains all the capture filters that you have defined and saved. It consists of one or more lines, where each line has the following format: "<filter name>" <filter string> At program start, if there is a cfilters file in the personal configuration folder, it is read. If there isn’t a cfilters file in the personal configuration folder, then, if there is a cfilters file in the global configuration folder, it is read. When you press the Save button in the “Capture Filters” dialog box, all the current capture filters are written to the personal capture filters file. colorfiltersThis file contains all the color filters that you have defined and saved. It consists of one or more lines, where each line has the following format: @<filter name>@<filter string>@[<bg RGB(16-bit)>][<fg RGB(16-bit)>] At program start, if there is a colorfilters file in the personal configuration folder, it is read. If there isn’t a colorfilters file in the personal configuration folder, then, if there is a colorfilters file in the global configuration folder, it is read. When you press the Save button in the “Coloring Rules” dialog box, all the current color filters are written to the personal color filters file. dfilter_buttonsThis file contains all the display filter buttons that you have defined and saved. It consists of one or more lines, where each line has the following format: "TRUE/FALSE","<button label>","<filter string>","<comment string>" where the first field is TRUE if the button is enabled (shown). At program start, if there is a dfilter_buttons file in the personal configuration folder, it is read. If there isn’t a dfilter_buttons file in the personal configuration folder, then, if there is a dfilter_buttons file in the global configuration folder, it is read. When you save any changes to the filter buttons, all the current display filter buttons are written to the personal display filter buttons file. dfilter_macrosThis file contains all the display filter macros that you have defined and saved. It consists of one or more lines, where each line has the following format: "<macro name>" <filter string> At program start, if there is a dfilter_macros file in the personal configuration folder, it is read. If there isn’t a dfilter_macros file in the personal configuration folder, then, if there is a dfilter_macros file in the global configuration folder, it is read. When you press the Save button in the "Display Filter Macros" dialog box, all the current display filter macros are written to the personal display filter macros file. More information about Display Filter Macros is available in Section 11.8, “Display Filter Macros” dfiltersThis file contains all the display filters that you have defined and saved. It consists of one or more lines, where each line has the following format: "<filter name>" <filter string> At program start, if there is a dfilters file in the personal configuration folder, it is read. If there isn’t a dfilters file in the personal configuration folder, then, if there is a dfilters file in the global configuration folder, it is read. When you press the Save button in the “Display Filters” dialog box, all the current display filters are written to the personal display filters file. disabled_protosEach line in this file specifies a disabled protocol name. The following are some examples: tcp udp At program start, if there is a disabled_protos file in the global configuration folder, it is read first. Then, if there is a disabled_protos file in the personal configuration folder, that is read; if there is an entry for a protocol set in both files, the setting in the personal disabled protocols file overrides the setting in the global disabled protocols file. When you press the Save button in the “Enabled Protocols” dialog box, the current set of disabled protocols is written to the personal disabled protocols file. ethersWhen Wireshark is trying to translate a hardware MAC address to a name, it consults the ethers file in the personal configuration folder first. If the address is not found in that file, Wireshark consults the ethers file in the system configuration folder. This file has the same format as the /etc/ethers file on some Unix-like systems. Each line in these files consists of one hardware address and name separated by whitespace. The digits of hardware addresses are separated by colons (:), dashes (-) or periods(.). The following are some examples: ff-ff-ff-ff-ff-ff Broadcast c0-00-ff-ff-ff-ff TR_broadcast 00.2b.08.93.4b.a1 Freds_machine The settings from this file are read in when a MAC address is to be translated to a name, and never written by Wireshark. hostsWireshark uses the entries in the hosts files to translate IPv4 and IPv6 addresses into names. At program start, if there is a hosts file in the global configuration folder, it is read first. Then, if there is a hosts file in the personal configuration folder, that is read; if there is an entry for a given IP address in both files, the setting in the personal hosts file overrides the entry in the global hosts file. This file has the same format as the usual /etc/hosts file on Unix systems. An example is: # Comments must be prepended by the # sign! 192.168.0.1 homeserver The settings from this file are read in at program start and never written by Wireshark. ipxnetsWhen Wireshark is trying to translate an IPX network number to a name, it consults the ipxnets file in the personal configuration folder first. If the address is not found in that file, Wireshark consults the ipxnets file in the system configuration folder. An example is: C0.A8.2C.00 HR c0-a8-1c-00 CEO 00:00:BE:EF IT_Server1 110f FileServer3 The settings from this file are read in when an IPX network number is to be translated to a name, and never written by Wireshark. manufAt program start, if there is a manuf file in the global configuration folder, it is read. The entries in this file are used to translate MAC address prefixes into short and long manufacturer names. Each line consists of a MAC address prefix followed by an abbreviated manufacturer name and the full manufacturer name. Prefixes 24 bits long by default and may be followed by an optional length. Note that this is not the same format as the ethers file. Examples are: 00:00:01 Xerox Xerox Corporation 00:50:C2:00:30:00/36 Microsof Microsoft The settings from this file are read in at program start and never written by Wireshark. preferencesThis file contains your Wireshark preferences, including defaults for capturing and displaying packets. It is a simple text file containing statements of the form: variable: value At program start, if there is a preferences file in the global configuration folder, it is read first. Then, if there is a preferences file in the personal configuration folder, that is read; if there is a preference set in both files, the setting in the personal preferences file overrides the setting in the global preference file. If you press the Save button in the “Preferences” dialog box, all the current settings are written to the personal preferences file. recentThis file contains GUI settings that are specific to the current profile, such as column widths and toolbar visibility. It is a simple text file containing statements of the form: variable: value It is read at program start and written when preferences are saved and at program exit. It is also written and read whenever you switch to a different profile. recent_commonThis file contains common GUI settings, such as recently opened capture files, recently used filters, and window geometries. It is a simple text file containing statements of the form: variable: value It is read at program start and written when preferences are saved and at program exit. servicesWireshark uses the services files to translate port numbers into names. At program start, if there is a services file in the global configuration folder, it is read first. Then, if there is a services file in the personal configuration folder, that is read; if there is an entry for a given port number in both files, the setting in the personal hosts file overrides the entry in the global hosts file. An example is: mydns 5045/udp # My own Domain Name Server mydns 5045/tcp # My own Domain Name Server The settings from these files are read in at program start and never written by Wireshark. ss7pcsWireshark uses the ss7pcs file to translate SS7 point codes to node names. At program start, if there is a ss7pcs file in the personal configuration folder, it is read. Each line in this file consists of one network indicator followed by a dash followed by a point code in decimal and a node name separated by whitespace or tab. An example is: 2-1234 MyPointCode1 The settings from this file are read in at program start and never written by Wireshark. subnetsWireshark uses the subnets files to translate an IPv4 address into a subnet name. If no exact match from a hosts file or from DNS is found, Wireshark will attempt a partial match for the subnet of the address. At program start, if there is a subnets file in the personal configuration folder, it is read first. Then, if there is a subnets file in the global configuration folder, that is read; if there is a preference set in both files, the setting in the global preferences file overrides the setting in the personal preference file. Each line in one of these files consists of an IPv4 address, a subnet mask length separated only by a “/” and a name separated by whitespace. While the address must be a full IPv4 address, any values beyond the mask length are subsequently ignored. An example is: # Comments must be prepended by the # sign! 192.168.0.0/24 ws_test_network A partially matched name will be printed as “subnet-name.remaining-address”. For example, “192.168.0.1” under the subnet above would be printed as “ws_test_network.1”; if the mask length above had been 16 rather than 24, the printed address would be “ws_test_network.0.1”. The settings from these files are read in at program start and never written by Wireshark. vlansWireshark uses the vlans file to translate VLAN tag IDs into names. If there is a vlans file in the currently active profile folder, it is used. Otherwise, the vlans file in the personal configuration folder is used. Each line in this file consists of one VLAN tag ID and a describing name separated by whitespace or tab. An example is: 123 Server-LAN 2049 HR-Client-LAN The settings from this file are read in at program start or when changing the active profile and are never written by Wireshark. B.4. Plugin foldersWireshark supports plugins for various purposes. Plugins can either be scripts written in Lua or code written in C or C++ and compiled to machine code. Wireshark looks for plugins in both a personal plugin folder and a global plugin folder. Lua plugins are stored in the plugin folders; compiled plugins are stored in subfolders of the plugin folders, with the subfolder name being the Wireshark minor version number (X.Y). There is another hierarchical level for each Wireshark plugin type (libwireshark, libwiretap and codecs). So for example the location for a libwireshark plugin foo.so (foo.dll on Windows) would be PLUGINDIR/X.Y/epan (libwireshark used to be called libepan; the other folder names are codecs and wiretap). On Windows:
On Unix-like systems:
B.5. Windows foldersHere you will find some details about the folders used in Wireshark on different Windows versions. As already mentioned, you can find the currently used folders in the “About Wireshark” dialog. B.5.1. Windows profilesWindows uses some special directories to store user configuration files which define the “user profile”. This can be confusing, as the default directory location changed from Windows version to version and might also be different for English and internationalized versions of Windows.
The following guides you to the right place where to look for Wireshark’s profile data. Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Vista, and associated server editions C:\Users\username\AppData\Roaming\Wireshark. Windows XP and Windows Server 2003 [1] C:\Documents and Settings\username\Application Data. “Documents and Settings” and “Application Data” might be internationalized. B.5.2. Windows roaming profilesSome larger Windows environments use roaming profiles. If this is the case the configurations of all programs you use won’t be saved on your local hard drive. They will be stored on the domain server instead. Your settings will travel with you from computer to computer with one exception. The “Local Settings” folder in your profile data (typically something like: C:\Documents and Settings\username\Local Settings) will not be transferred to the domain server. This is the default for temporary capture files. B.5.3. Windows temporary folderWireshark uses the folder which is set by the TMPDIR or TEMP environment variable. This variable will be set by the Windows installer. Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Vista, and associated server editions C:\Users\username\AppData\Local\TempWindows XP and Windows Server 2003 [1] C:\Documents and Settings\username\Local Settings\Temp Appendix C. Protocols and Protocol FieldsWireshark distinguishes between protocols (e.g., tcp) and protocol fields (e.g., tcp.port). A comprehensive list of all protocols and protocol fields can be found in the “Display Filter Reference” at https://www.wireshark.org/docs/dfref/ Appendix D. Related command line toolsD.1. IntroductionWireshark comes with an array of command line tools which can be helpful for packet analysis. Some of these tools are described in this chapter. You can find more information about all of Wireshark’s command line tools on the web site. D.2. tshark: Terminal-based WiresharkTShark is a terminal oriented version of Wireshark designed for capturing and displaying packets when an interactive user interface isn’t necessary or available. It supports the same options as Help information available from
TShark (Wireshark) 4.1.0 (v4.1.0rc0-55-gccf720d95daf) Dump and analyze network traffic. See https://www.wireshark.org for more information. Usage: tshark [options] ... Capture interface: -i <interface>, --interface <interface> name or idx of interface (def: first non-loopback) -f <capture filter> packet filter in libpcap filter syntax -s <snaplen>, --snapshot-length <snaplen> packet snapshot length (def: appropriate maximum) -p, --no-promiscuous-mode don't capture in promiscuous mode -I, --monitor-mode capture in monitor mode, if available -B <buffer size>, --buffer-size <buffer size> size of kernel buffer (def: 2MB) -y <link type>, --linktype <link type> link layer type (def: first appropriate) --time-stamp-type <type> timestamp method for interface -D, --list-interfaces print list of interfaces and exit -L, --list-data-link-types print list of link-layer types of iface and exit --list-time-stamp-types print list of timestamp types for iface and exit Capture stop conditions: -c <packet count> stop after n packets (def: infinite) -a <autostop cond.> ..., --autostop <autostop cond.> ... duration:NUM - stop after NUM seconds filesize:NUM - stop this file after NUM KB files:NUM - stop after NUM files packets:NUM - stop after NUM packets Capture output: -b <ringbuffer opt.> ..., --ring-buffer <ringbuffer opt.> duration:NUM - switch to next file after NUM secs filesize:NUM - switch to next file after NUM KB files:NUM - ringbuffer: replace after NUM files packets:NUM - switch to next file after NUM packets interval:NUM - switch to next file when the time is an exact multiple of NUM secs Input file: -r <infile>, --read-file <infile> set the filename to read from (or '-' for stdin) Processing: -2 perform a two-pass analysis -M <packet count> perform session auto reset -R <read filter>, --read-filter <read filter> packet Read filter in Wireshark display filter syntax (requires -2) -Y <display filter>, --display-filter <display filter> packet displaY filter in Wireshark display filter syntax -n disable all name resolutions (def: "mNd" enabled, or as set in preferences) -N <name resolve flags> enable specific name resolution(s): "mnNtdv" -d <layer_type>==<selector>,<decode_as_protocol> ... "Decode As", see the man page for details Example: tcp.port==8888,http -H <hosts file> read a list of entries from a hosts file, which will then be written to a capture file. (Implies -W n) --enable-protocol <proto_name> enable dissection of proto_name --disable-protocol <proto_name> disable dissection of proto_name --enable-heuristic <short_name> enable dissection of heuristic protocol --disable-heuristic <short_name> disable dissection of heuristic protocol Output: -w <outfile|-> write packets to a pcapng-format file named "outfile" (or '-' for stdout) --capture-comment <comment> add a capture file comment, if supported -C <config profile> start with specified configuration profile -F <output file type> set the output file type, default is pcapng an empty "-F" option will list the file types -V add output of packet tree (Packet Details) -O <protocols> Only show packet details of these protocols, comma separated -P, --print print packet summary even when writing to a file -S <separator> the line separator to print between packets -x add output of hex and ASCII dump (Packet Bytes) --hexdump <hexoption> add hexdump, set options for data source and ASCII dump all dump all data sources (-x default) frames dump only frame data source ascii include ASCII dump text (-x default) delimit delimit ASCII dump text with '|' characters noascii exclude ASCII dump text help display help for --hexdump and exit -T pdml|ps|psml|json|jsonraw|ek|tabs|text|fields|? format of text output (def: text) -j <protocolfilter> protocols layers filter if -T ek|pdml|json selected (e.g. "ip ip.flags text", filter does not expand child nodes, unless child is specified also in the filter) -J <protocolfilter> top level protocol filter if -T ek|pdml|json selected (e.g. "http tcp", filter which expands all child nodes) -e <field> field to print if -Tfields selected (e.g. tcp.port, _ws.col.Info) this option can be repeated to print multiple fields -E<fieldsoption>=<value> set options for output when -Tfields selected: bom=y|n print a UTF-8 BOM header=y|n switch headers on and off separator=/t|/s|<char> select tab, space, printable character as separator occurrence=f|l|a print first, last or all occurrences of each field aggregator=,|/s|<char> select comma, space, printable character as aggregator quote=d|s|n select double, single, no quotes for values -t a|ad|adoy|d|dd|e|r|u|ud|udoy output format of time stamps (def: r: rel. to first) -u s|hms output format of seconds (def: s: seconds) -l flush standard output after each packet -q be more quiet on stdout (e.g. when using statistics) -Q only log true errors to stderr (quieter than -q) -g enable group read access on the output file(s) -W n Save extra information in the file, if supported. n = write network address resolution information -X <key>:<value> eXtension options, see the man page for details -U tap_name PDUs export mode, see the man page for details -z <statistics> various statistics, see the man page for details --export-objects <protocol>,<destdir> save exported objects for a protocol to a directory named "destdir" --export-tls-session-keys <keyfile> export TLS Session Keys to a file named "keyfile" --color color output text similarly to the Wireshark GUI, requires a terminal with 24-bit color support Also supplies color attributes to pdml and psml formats (Note that attributes are nonstandard) --no-duplicate-keys If -T json is specified, merge duplicate keys in an object into a single key with as value a json array containing all values --elastic-mapping-filter <protocols> If -G elastic-mapping is specified, put only the specified protocols within the mapping file --temp-dir <directory> write temporary files to this directory (default: /tmp) Diagnostic output: --log-level <level> sets the active log level ("critical", "warning", etc.) --log-fatal <level> sets level to abort the program ("critical" or "warning") --log-domains <[!]list> comma separated list of the active log domains --log-debug <[!]list> comma separated list of domains with "debug" level --log-noisy <[!]list> comma separated list of domains with "noisy" level --log-file <path> file to output messages to (in addition to stderr) Miscellaneous: -h, --help display this help and exit -v, --version display version info and exit -o <name>:<value> ... override preference setting -K <keytab> keytab file to use for kerberos decryption -G [report] dump one of several available reports and exit default report="fields" use "-G help" for more help Dumpcap can benefit from an enabled BPF JIT compiler if available. You might want to enable it by executing: "echo 1 > /proc/sys/net/core/bpf_jit_enable" Note that this can make your system less secure! D.3. tcpdump: Capturing with “tcpdump” for viewing with WiresharkIt’s often more useful to capture packets using Older versions of $ tcpdump -i <interface> -s 65535 -w <file> You will have to specify the correct interface and the name of a file to save into. In addition, you will have to terminate the capture with ^C when you believe you have captured enough packets.
D.4. dumpcap: Capturing with “dumpcap” for viewing with WiresharkDumpcap is a network traffic dump tool. It captures packet data from a live network and writes the packets to a file. Dumpcap’s native capture file format is pcapng, which is also the format used by Wireshark. By default, Dumpcap uses the pcap library to capture traffic from the first available network interface and writes the received raw packet data, along with the packets’ time stamps into a pcapng file. The capture filter syntax follows the rules of the pcap library. For more information on Help information available from Dumpcap (Wireshark) 4.1.0 (v4.1.0rc0-55-gccf720d95daf) Capture network packets and dump them into a pcapng or pcap file. See https://www.wireshark.org for more information. Usage: dumpcap [options] ... Capture interface: -i <interface>, --interface <interface> name or idx of interface (def: first non-loopback), or for remote capturing, use one of these formats: rpcap://<host>/<interface> [email protected]<host>:<port> --ifname <name> name to use in the capture file for a pipe from which we're capturing --ifdescr <description> description to use in the capture file for a pipe from which we're capturing -f <capture filter> packet filter in libpcap filter syntax -s <snaplen>, --snapshot-length <snaplen> packet snapshot length (def: appropriate maximum) -p, --no-promiscuous-mode don't capture in promiscuous mode -I, --monitor-mode capture in monitor mode, if available -B <buffer size>, --buffer-size <buffer size> size of kernel buffer in MiB (def: 2MiB) -y <link type>, --linktype <link type> link layer type (def: first appropriate) --time-stamp-type <type> timestamp method for interface -D, --list-interfaces print list of interfaces and exit -L, --list-data-link-types print list of link-layer types of iface and exit --list-time-stamp-types print list of timestamp types for iface and exit -d print generated BPF code for capture filter -k <freq>,[<type>],[<center_freq1>],[<center_freq2>] set channel on wifi interface -S print statistics for each interface once per second -M for -D, -L, and -S, produce machine-readable output Stop conditions: -c <packet count> stop after n packets (def: infinite) -a <autostop cond.> ..., --autostop <autostop cond.> ... duration:NUM - stop after NUM seconds filesize:NUM - stop this file after NUM kB files:NUM - stop after NUM files packets:NUM - stop after NUM packets Output (files): -w <filename> name of file to save (def: tempfile) -g enable group read access on the output file(s) -b <ringbuffer opt.> ..., --ring-buffer <ringbuffer opt.> duration:NUM - switch to next file after NUM secs filesize:NUM - switch to next file after NUM kB files:NUM - ringbuffer: replace after NUM files packets:NUM - ringbuffer: replace after NUM packets interval:NUM - switch to next file when the time is an exact multiple of NUM secs printname:FILE - print filename to FILE when written (can use 'stdout' or 'stderr') -n use pcapng format instead of pcap (default) -P use libpcap format instead of pcapng --capture-comment <comment> add a capture comment to the output file (only for pcapng) --temp-dir <directory> write temporary files to this directory (default: /tmp) Diagnostic output: --log-level <level> sets the active log level ("critical", "warning", etc.) --log-fatal <level> sets level to abort the program ("critical" or "warning") --log-domains <[!]list> comma separated list of the active log domains --log-debug <[!]list> comma separated list of domains with "debug" level --log-noisy <[!]list> comma separated list of domains with "noisy" level --log-file <path> file to output messages to (in addition to stderr) Miscellaneous: -N <packet_limit> maximum number of packets buffered within dumpcap -C <byte_limit> maximum number of bytes used for buffering packets within dumpcap -t use a separate thread per interface -q don't report packet capture counts -v, --version print version information and exit -h, --help display this help and exit Dumpcap can benefit from an enabled BPF JIT compiler if available. You might want to enable it by executing: "echo 1 > /proc/sys/net/core/bpf_jit_enable" Note that this can make your system less secure! Example: dumpcap -i eth0 -a duration:60 -w output.pcapng "Capture packets from interface eth0 until 60s passed into output.pcapng" Use Ctrl-C to stop capturing at any time. D.5. capinfos: Print information about capture files
Help information available from Capinfos (Wireshark) 4.1.0 (v4.1.0rc0-55-gccf720d95daf) Print various information (infos) about capture files. See https://www.wireshark.org for more information. Usage: capinfos [options] <infile> ... General infos: -t display the capture file type -E display the capture file encapsulation -I display the capture file interface information -F display additional capture file information -H display the SHA256, RIPEMD160, and SHA1 hashes of the file -k display the capture comment Size infos: -c display the number of packets -s display the size of the file (in bytes) -d display the total length of all packets (in bytes) -l display the packet size limit (snapshot length) Time infos: -u display the capture duration (in seconds) -a display the capture start time -e display the capture end time -o display the capture file chronological status (True/False) -S display start and end times as seconds Statistic infos: -y display average data rate (in bytes/sec) -i display average data rate (in bits/sec) -z display average packet size (in bytes) -x display average packet rate (in packets/sec) Metadata infos: -n display number of resolved IPv4 and IPv6 addresses -D display number of decryption secrets Output format: -L generate long report (default) -T generate table report -M display machine-readable values in long reports Table report options: -R generate header record (default) -r do not generate header record -B separate infos with TAB character (default) -m separate infos with comma (,) character -b separate infos with SPACE character -N do not quote infos (default) -q quote infos with single quotes (') -Q quote infos with double quotes (") Miscellaneous: -h, --help display this help and exit -v, --version display version info and exit -C cancel processing if file open fails (default is to continue) -A generate all infos (default) -K disable displaying the capture comment Options are processed from left to right order with later options superseding or adding to earlier options. If no options are given the default is to display all infos in long report output format. D.6. rawshark: Dump and analyze network traffic.Rawshark reads a stream of packets from a file or pipe, and prints a line describing its output, followed by a set of matching fields for each packet on stdout. For more information on Help information available from Rawshark (Wireshark) 4.1.0 (v4.1.0rc0-55-gccf720d95daf) Dump and analyze network traffic. See https://www.wireshark.org for more information. Usage: rawshark [options] ... Input file: -r <infile> set the pipe or file name to read from Processing: -d <encap:linktype>|<proto:protoname> packet encapsulation or protocol -F <field> field to display -m virtual memory limit, in bytes -n disable all name resolution (def: all enabled) -N <name resolve flags> enable specific name resolution(s): "mnNtdv" -p use the system's packet header format (which may have 64-bit timestamps) -R <read filter> packet filter in Wireshark display filter syntax -s skip PCAP header on input Output: -l flush output after each packet -S format string for fields (%D - name, %S - stringval, %N numval) -t ad|a|r|d|dd|e output format of time stamps (def: r: rel. to first) Diagnostic output: --log-level <level> sets the active log level ("critical", "warning", etc.) --log-fatal <level> sets level to abort the program ("critical" or "warning") --log-domains <[!]list> comma separated list of the active log domains --log-debug <[!]list> comma separated list of domains with "debug" level --log-noisy <[!]list> comma separated list of domains with "noisy" level --log-file <path> file to output messages to (in addition to stderr) Miscellaneous: -h display this help and exit -o <name>:<value> ... override preference setting -v display version info and exit D.7. editcap: Edit capture files
Help information available from editcap. Editcap (Wireshark) 4.1.0 (v4.1.0rc0-55-gccf720d95daf) Edit and/or translate the format of capture files. See https://www.wireshark.org for more information. Usage: editcap [options] ... <infile> <outfile> [ <packet#>[-<packet#>] ... ] <infile> and <outfile> must both be present; use '-' for stdin or stdout. A single packet or a range of packets can be selected. Packet selection: -r keep the selected packets; default is to delete them. -A <start time> only read packets whose timestamp is after (or equal to) the given time. -B <stop time> only read packets whose timestamp is before the given time. Time format for -A/-B options is YYYY-MM-DDThh:mm:ss[.nnnnnnnnn][Z|+-hh:mm] Unix epoch timestamps are also supported. Duplicate packet removal: --novlan remove vlan info from packets before checking for duplicates. -d remove packet if duplicate (window == 5). -D <dup window> remove packet if duplicate; configurable <dup window>. Valid <dup window> values are 0 to 1000000. NOTE: A <dup window> of 0 with -V (verbose option) is useful to print MD5 hashes. -w <dup time window> remove packet if duplicate packet is found EQUAL TO OR LESS THAN <dup time window> prior to current packet. A <dup time window> is specified in relative seconds (e.g. 0.000001). NOTE: The use of the 'Duplicate packet removal' options with other editcap options except -V may not always work as expected. Specifically the -r, -t or -S options will very likely NOT have the desired effect if combined with the -d, -D or -w. --skip-radiotap-header skip radiotap header when checking for packet duplicates. Useful when processing packets captured by multiple radios on the same channel in the vicinity of each other. Packet manipulation: -s <snaplen> truncate each packet to max. <snaplen> bytes of data. -C [offset:]<choplen> chop each packet by <choplen> bytes. Positive values chop at the packet beginning, negative values at the packet end. If an optional offset precedes the length, then the bytes chopped will be offset from that value. Positive offsets are from the packet beginning, negative offsets are from the packet end. You can use this option more than once, allowing up to 2 chopping regions within a packet provided that at least 1 choplen is positive and at least 1 is negative. -L adjust the frame (i.e. reported) length when chopping and/or snapping. -t <time adjustment> adjust the timestamp of each packet. <time adjustment> is in relative seconds (e.g. -0.5). -S <strict adjustment> adjust timestamp of packets if necessary to ensure strict chronological increasing order. The <strict adjustment> is specified in relative seconds with values of 0 or 0.000001 being the most reasonable. A negative adjustment value will modify timestamps so that each packet's delta time is the absolute value of the adjustment specified. A value of -0 will set all packets to the timestamp of the first packet. -E <error probability> set the probability (between 0.0 and 1.0 incl.) that a particular packet byte will be randomly changed. -o <change offset> When used in conjunction with -E, skip some bytes from the beginning of the packet. This allows one to preserve some bytes, in order to have some headers untouched. --seed <seed> When used in conjunction with -E, set the seed to use for the pseudo-random number generator. This allows one to repeat a particular sequence of errors. -I <bytes to ignore> ignore the specified number of bytes at the beginning of the frame during MD5 hash calculation, unless the frame is too short, then the full frame is used. Useful to remove duplicated packets taken on several routers (different mac addresses for example). e.g. -I 26 in case of Ether/IP will ignore ether(14) and IP header(20 - 4(src ip) - 4(dst ip)). -a <framenum>:<comment> Add or replace comment for given frame number Output File(s): -c <packets per file> split the packet output to different files based on uniform packet counts with a maximum of <packets per file> each. -i <seconds per file> split the packet output to different files based on uniform time intervals with a maximum of <seconds per file> each. -F <capture type> set the output file type; default is pcapng. An empty "-F" option will list the file types. -T <encap type> set the output file encapsulation type; default is the same as the input file. An empty "-T" option will list the encapsulation types. --inject-secrets <type>,<file> Insert decryption secrets from <file>. List supported secret types with "--inject-secrets help". --discard-all-secrets Discard all decryption secrets from the input file when writing the output file. Does not discard secrets added by "--inject-secrets" in the same command line. --capture-comment <comment> Add a capture file comment, if supported. --discard-capture-comment Discard capture file comments from the input file when writing the output file. Does not discard comments added by "--capture-comment" in the same command line. Miscellaneous: -h, --help display this help and exit. -V verbose output. If -V is used with any of the 'Duplicate Packet Removal' options (-d, -D or -w) then Packet lengths and MD5 hashes are printed to standard-error. -v, --version print version information and exit. Capture file types available from editcap: The available capture file types for the "-F" flag are: pcap - Wireshark/tcpdump/... - pcap pcapng - Wireshark/... - pcapng 5views - InfoVista 5View capture btsnoop - Symbian OS btsnoop commview-ncf - TamoSoft CommView NCF commview-ncfx - TamoSoft CommView NCFX dct2000 - Catapult DCT2000 trace (.out format) erf - Endace ERF capture eyesdn - EyeSDN USB S0/E1 ISDN trace format k12text - K12 text file lanalyzer - Novell LANalyzer logcat - Android Logcat Binary format logcat-brief - Android Logcat Brief text format logcat-long - Android Logcat Long text format logcat-process - Android Logcat Process text format logcat-tag - Android Logcat Tag text format logcat-thread - Android Logcat Thread text format logcat-threadtime - Android Logcat Threadtime text format logcat-time - Android Logcat Time text format modpcap - Modified tcpdump - pcap netmon1 - Microsoft NetMon 1.x netmon2 - Microsoft NetMon 2.x nettl - HP-UX nettl trace ngsniffer - Sniffer (DOS) ngwsniffer_1_1 - NetXray, Sniffer (Windows) 1.1 ngwsniffer_2_0 - Sniffer (Windows) 2.00x nokiapcap - Nokia tcpdump - pcap nsecpcap - Wireshark/tcpdump/... - nanosecond pcap nstrace10 - NetScaler Trace (Version 1.0) nstrace20 - NetScaler Trace (Version 2.0) nstrace30 - NetScaler Trace (Version 3.0) nstrace35 - NetScaler Trace (Version 3.5) observer - Viavi Observer rf5 - Tektronix K12xx 32-bit .rf5 format rh6_1pcap - RedHat 6.1 tcpdump - pcap snoop - Sun snoop suse6_3pcap - SuSE 6.3 tcpdump - pcap visual - Visual Networks traffic capture Encapsulation types available from editcap: The available encapsulation types for the "-T" flag are: ap1394 - Apple IP-over-IEEE 1394 arcnet - ARCNET arcnet_linux - Linux ARCNET ascend - Lucent/Ascend access equipment atm-pdus - ATM PDUs atm-pdus-untruncated - ATM PDUs - untruncated atm-rfc1483 - RFC 1483 ATM auerlog - Auerswald Log autosardlt - AUTOSAR DLT ax25 - Amateur Radio AX.25 ax25-kiss - AX.25 with KISS header bacnet-ms-tp - BACnet MS/TP bacnet-ms-tp-with-direction - BACnet MS/TP with Directional Info ber - ASN.1 Basic Encoding Rules bluetooth-bredr-bb-rf - Bluetooth BR/EDR Baseband RF bluetooth-h4 - Bluetooth H4 bluetooth-h4-linux - Bluetooth H4 with linux header bluetooth-hci - Bluetooth without transport layer bluetooth-le-ll - Bluetooth Low Energy Link Layer bluetooth-le-ll-rf - Bluetooth Low Energy Link Layer RF bluetooth-linux-monitor - Bluetooth Linux Monitor can20b - Controller Area Network 2.0B chdlc - Cisco HDLC chdlc-with-direction - Cisco HDLC with Directional Info cosine - CoSine L2 debug log dbus - D-Bus dct2000 - Catapult DCT2000 docsis - Data Over Cable Service Interface Specification docsis31_xra31 - DOCSIS with Excentis XRA pseudo-header dpauxmon - DisplayPort AUX channel with Unigraf pseudo-header dpnss_link - Digital Private Signalling System No 1 Link Layer dvbci - DVB-CI (Common Interface) ebhscr - Elektrobit High Speed Capture and Replay enc - OpenBSD enc(4) encapsulating interface epon - Ethernet Passive Optical Network erf - Extensible Record Format eri_enb_log - Ericsson eNode-B raw log ether - Ethernet ether-mpacket - IEEE 802.3br mPackets ether-nettl - Ethernet with nettl headers etw - Event Tracing for Windows messages fc2 - Fibre Channel FC-2 fc2sof - Fibre Channel FC-2 With Frame Delimiter fddi - FDDI fddi-nettl - FDDI with nettl headers fddi-swapped - FDDI with bit-swapped MAC addresses flexray - FlexRay frelay - Frame Relay frelay-with-direction - Frame Relay with Directional Info gcom-serial - GCOM Serial gcom-tie1 - GCOM TIE1 gfp-f - ITU-T G.7041/Y.1303 Generic Framing Procedure Frame-mapped mode gfp-t - ITU-T G.7041/Y.1303 Generic Framing Procedure Transparent mode gprs-llc - GPRS LLC gsm_um - GSM Um Interface hhdlc - HiPath HDLC i2c-linux - I2C with Linux-specific pseudo-header ieee-802-11 - IEEE 802.11 Wireless LAN ieee-802-11-avs - IEEE 802.11 plus AVS radio header ieee-802-11-netmon - IEEE 802.11 plus Network Monitor radio header ieee-802-11-prism - IEEE 802.11 plus Prism II monitor mode radio header ieee-802-11-radio - IEEE 802.11 Wireless LAN with radio information ieee-802-11-radiotap - IEEE 802.11 plus radiotap radio header ieee-802-16-mac-cps - IEEE 802.16 MAC Common Part Sublayer infiniband - InfiniBand ios - Cisco IOS internal ip-ib - IP over IB ip-over-fc - RFC 2625 IP-over-Fibre Channel ip-over-ib - IP over InfiniBand ipfix - RFC 5655/RFC 5101 IPFIX ipmb-kontron - Intelligent Platform Management Bus with Kontron pseudo-header ipmi-trace - IPMI Trace Data Collection ipnet - Solaris IPNET irda - IrDA isdn - ISDN iso14443 - ISO 14443 contactless smartcard standards ixveriwave - IxVeriWave header and stats block jfif - JPEG/JFIF json - JavaScript Object Notation juniper-atm1 - Juniper ATM1 juniper-atm2 - Juniper ATM2 juniper-chdlc - Juniper C-HDLC juniper-ether - Juniper Ethernet juniper-frelay - Juniper Frame-Relay juniper-ggsn - Juniper GGSN juniper-mlfr - Juniper MLFR juniper-mlppp - Juniper MLPPP juniper-ppp - Juniper PPP juniper-pppoe - Juniper PPPoE juniper-st - Juniper Secure Tunnel Information juniper-svcs - Juniper Services juniper-vn - Juniper VN juniper-vp - Juniper Voice PIC k12 - K12 protocol analyzer lapb - LAPB lapd - LAPD layer1-event - EyeSDN Layer 1 event lin - Local Interconnect Network linux-atm-clip - Linux ATM CLIP linux-lapd - LAPD with Linux pseudo-header linux-sll - Linux cooked-mode capture v1 linux-sll2 - Linux cooked-mode capture v2 log_3GPP - 3GPP Phone Log logcat - Android Logcat Binary format logcat_brief - Android Logcat Brief text format logcat_long - Android Logcat Long text format logcat_process - Android Logcat Process text format logcat_tag - Android Logcat Tag text format logcat_thread - Android Logcat Thread text format logcat_threadtime - Android Logcat Threadtime text format logcat_time - Android Logcat Time text format loop - OpenBSD loopback loratap - LoRaTap ltalk - Localtalk message_analyzer_wfp_capture2_v4 - Message Analyzer WFP Capture2 v4 message_analyzer_wfp_capture2_v6 - Message Analyzer WFP Capture2 v6 message_analyzer_wfp_capture_auth_v4 - Message Analyzer WFP Capture Auth v4 message_analyzer_wfp_capture_auth_v6 - Message Analyzer WFP Capture Auth v6 message_analyzer_wfp_capture_v4 - Message Analyzer WFP Capture v4 message_analyzer_wfp_capture_v6 - Message Analyzer WFP Capture v6 mime - MIME most - Media Oriented Systems Transport mp2ts - ISO/IEC 13818-1 MPEG2-TS mp4 - MP4 files mpeg - MPEG mtp2 - SS7 MTP2 mtp2-with-phdr - MTP2 with pseudoheader mtp3 - SS7 MTP3 mux27010 - MUX27010 netanalyzer - Hilscher netANALYZER netanalyzer-transparent - Hilscher netANALYZER-Transparent netlink - Linux Netlink netmon_event - Network Monitor Network Event netmon_filter - Network Monitor Filter netmon_header - Network Monitor Header netmon_network_info - Network Monitor Network Info nfc-llcp - NFC LLCP nflog - NFLOG nordic_ble - nRF Sniffer for Bluetooth LE nstrace10 - NetScaler Encapsulation 1.0 of Ethernet nstrace20 - NetScaler Encapsulation 2.0 of Ethernet nstrace30 - NetScaler Encapsulation 3.0 of Ethernet nstrace35 - NetScaler Encapsulation 3.5 of Ethernet null - NULL/Loopback packetlogger - Apple Bluetooth PacketLogger pflog - OpenBSD PF Firewall logs pflog-old - OpenBSD PF Firewall logs, pre-3.4 pktap - Apple PKTAP ppi - Per-Packet Information header ppp - PPP ppp-with-direction - PPP with Directional Info pppoes - PPP-over-Ethernet session raw-icmp-nettl - Raw ICMP with nettl headers raw-icmpv6-nettl - Raw ICMPv6 with nettl headers raw-telnet-nettl - Raw telnet with nettl headers rawip - Raw IP rawip-nettl - Raw IP with nettl headers rawip4 - Raw IPv4 rawip6 - Raw IPv6 redback - Redback SmartEdge rfc7468 - RFC 7468 file rtac-serial - RTAC serial-line ruby_marshal - Ruby marshal object s4607 - STANAG 4607 s5066-dpdu - STANAG 5066 Data Transfer Sublayer PDUs(D_PDU) sccp - SS7 SCCP sctp - SCTP sdh - SDH sdjournal - systemd journal sdlc - SDLC sita-wan - SITA WAN packets slip - SLIP socketcan - SocketCAN symantec - Symantec Enterprise Firewall tnef - Transport-Neutral Encapsulation Format tr - Token Ring tr-nettl - Token Ring with nettl headers tzsp - Tazmen sniffer protocol unknown - Unknown unknown-nettl - Unknown link-layer type with nettl headers usb-20 - USB 2.0/1.1/1.0 packets usb-20-full - Full-Speed USB 2.0/1.1/1.0 packets usb-20-high - High-Speed USB 2.0 packets usb-20-low - Low-Speed USB 2.0/1.1/1.0 packets usb-darwin - USB packets with Darwin (macOS, etc.) headers usb-freebsd - USB packets with FreeBSD header usb-linux - USB packets with Linux header usb-linux-mmap - USB packets with Linux header and padding usb-usbpcap - USB packets with USBPcap header user0 - USER 0 user1 - USER 1 user2 - USER 2 user3 - USER 3 user4 - USER 4 user5 - USER 5 user6 - USER 6 user7 - USER 7 user8 - USER 8 user9 - USER 9 user10 - USER 10 user11 - USER 11 user12 - USER 12 user13 - USER 13 user14 - USER 14 user15 - USER 15 v5-ef - V5 Envelope Function vpp - Vector Packet Processing graph dispatch trace vsock - Linux vsock whdlc - Wellfleet HDLC wireshark-upper-pdu - Wireshark Upper PDU export wpan - IEEE 802.15.4 Wireless PAN wpan-nofcs - IEEE 802.15.4 Wireless PAN with FCS not present wpan-nonask-phy - IEEE 802.15.4 Wireless PAN non-ASK PHY wpan-tap - IEEE 802.15.4 Wireless with TAP pseudo-header x2e-serial - X2E serial line capture x2e-xoraya - X2E Xoraya x25-nettl - X.25 with nettl headers xeth - Xerox 3MB Ethernet zbncp - ZBOSS NCP zwave-serial - Z-Wave Serial API packets D.8. mergecap: Merging multiple capture files into oneMergecap is a program that combines multiple saved capture files into a single output file specified by the By default, Mergecap writes all of the packets in the input capture files to a pcapng file.
The Packets from the input files are merged in chronological order
based on each frame’s timestamp, unless the If the If the For more information on Help information available from Mergecap (Wireshark) 4.1.0 (v4.1.0rc0-55-gccf720d95daf) Merge two or more capture files into one. See https://www.wireshark.org for more information. Usage: mergecap [options] -w <outfile>|- <infile> [<infile> ...] Output: -a concatenate rather than merge files. default is to merge based on frame timestamps. -s <snaplen> truncate packets to <snaplen> bytes of data. -w <outfile>|- set the output filename to <outfile> or '-' for stdout. -F <capture type> set the output file type; default is pcapng. an empty "-F" option will list the file types. -I <IDB merge mode> set the merge mode for Interface Description Blocks; default is 'all'. an empty "-I" option will list the merge modes. Miscellaneous: -h, --help display this help and exit. -V verbose output. -v, --version print version information and exit. A simple example merging Simple example of using mergecap. $ mergecap -w outfile.pcapng dhcp-capture.pcapng imap-1.pcapng D.9. text2pcap: Converting ASCII hexdumps to network capturesThere may be some occasions when you wish to convert a hex dump of some network traffic into a capture file.
000000 00 e0 1e a7 05 6f 00 10 ........ 000008 5a a0 b9 12 08 00 46 00 ........ 000010 03 68 00 00 00 00 0a 2e ........ 000018 ee 33 0f 19 08 7f 0f 19 ........ 000020 03 80 94 04 00 00 10 01 ........ 000028 16 a2 0a 00 03 50 00 0c ........ 000030 01 01 0f 19 03 80 11 01 ........ There is no limit on the width or number of bytes per line. Also the text dump at the end of the line is ignored. Bytes/hex numbers can be uppercase or lowercase. Any text before the offset is ignored, including email forwarding characters “>”. Any lines of text between the bytestring
lines is ignored. The offsets are used to track the bytes, so offsets must be correct. Any line which has only bytes without a leading offset is ignored. An offset is recognized as being a hex number longer than two characters. Any text after the bytes is ignored (e.g., the character dump). Any hex numbers in this text are also ignored. An offset of zero is indicative of starting a new packet, so a single text file with a series of hexdumps can be converted into a packet capture with multiple
packets. Packets may be preceded by a timestamp. These are interpreted according to the format given on the command line. If not, the first packet is timestamped with the current time the conversion takes place. Multiple packets are written with timestamps differing by one microsecond each. In general, short of these restrictions, There are a couple of other special features to note. Any line where the first non-whitespace character is “#” will be ignored as a comment. Any line beginning with #TEXT2PCAP is a directive and options can be inserted after this command to be processed by
For more information on Help information available from text2pcap. Text2pcap (Wireshark) 4.1.0 (v4.1.0rc0-198-ga48298a93a39) Generate a capture file from an ASCII hexdump of packets. See https://www.wireshark.org for more information. Usage: text2pcap [options] <infile> <outfile> where <infile> specifies input filename (use - for standard input) <outfile> specifies output filename (use - for standard output) Input: -o hex|oct|dec|none parse offsets as (h)ex, (o)ctal, (d)ecimal, or (n)one; default is hex. -t <timefmt> treat the text before the packet as a date/time code; <timefmt> is a format string supported by strptime, with an optional %f descriptor for fractional seconds. Example: The time "10:15:14.5476" has the format code "%H:%M:%S.%f" The special format string ISO supports ISO-8601 times. NOTE: Date/time fields from the current date/time are used as the default for unspecified fields. -D the text before the packet starts with an I or an O, indicating that the packet is inbound or outbound. This is used when generating dummy headers if the output format supports it (e.g. pcapng). -a enable ASCII text dump identification. The start of the ASCII text dump can be identified and excluded from the packet data, even if it looks like a HEX dump. NOTE: Do not enable it if the input file does not contain the ASCII text dump. -r <regex> enable regex mode. Scan the input using <regex>, a Perl compatible regular expression matching a single packet. Named capturing subgroups are used to identify fields: <data> (mand.), and <time>, <dir>, and <seqno> (opt.) The time field format is taken from the -t option Example: -r '^(?<dir>[<>])\s(?<time>\d+:\d\d:\d\d.\d+)\s(?<data>[0-9a-fA-F]+)$' could match a file with lines like > 0:00:00.265620 a130368b000000080060 < 0:00:00.295459 a2010800000000000000000800000000 -b 2|8|16|64 encoding base (radix) of the packet data in regex mode (def: 16: hexadecimal) No effect in hexdump mode. Output: -F <capture type> set the output file type; default is pcapng. an empty "-F" option will list the file types. -E <encap type> set the output file encapsulation type; default is ether (Ethernet). An empty "-E" option will list the encapsulation types. -l <typenum> set the output file encapsulation type via link-layer type number; default is 1 (Ethernet). See https://www.tcpdump.org/linktypes.html for a list of numbers. Example: -l 7 for ARCNet packets. -m <max-packet> max packet length in output; default is 262144 -N <intf-name> assign name to the interface in the pcapng file. Prepend dummy header: -e <l3pid> prepend dummy Ethernet II header with specified L3PID (in HEX). Example: -e 0x806 to specify an ARP packet. -i <proto> prepend dummy IP header with specified IP protocol (in DECIMAL). Automatically prepends Ethernet header as well if link-layer type is Ethernet. Example: -i 46 -4 <srcip>,<destip> prepend dummy IPv4 header with specified dest and source address. Example: -4 10.0.0.1,10.0.0.2 -6 <srcip>,<destip> prepend dummy IPv6 header with specified dest and source address. Example: -6 2001:db8::b3ff:fe1e:8329,2001:0db8:85a3::8a2e:0370:7334 -u <srcp>,<destp> prepend dummy UDP header with specified source and destination ports (in DECIMAL). Automatically prepends Ethernet & IP headers as well. Example: -u 1000,69 to make the packets look like TFTP/UDP packets. -T <srcp>,<destp> prepend dummy TCP header with specified source and destination ports (in DECIMAL). Automatically prepends Ethernet & IP headers as well. Example: -T 50,60 -s <srcp>,<dstp>,<tag> prepend dummy SCTP header with specified source/dest ports and verification tag (in DECIMAL). Automatically prepends Ethernet & IP headers as well. Example: -s 30,40,34 -S <srcp>,<dstp>,<ppi> prepend dummy SCTP header with specified source/dest ports and verification tag 0. Automatically prepends a dummy SCTP DATA chunk header with payload protocol identifier ppi. Example: -S 30,40,34 -P <dissector> prepend EXPORTED_PDU header with specified dissector as the payload DISSECTOR_NAME tag. Automatically sets link type to Upper PDU Export. EXPORTED_PDU payload defaults to "data" otherwise. Diagnostic output: --log-level <level> sets the active log level ("critical", "warning", etc.) --log-fatal <level> sets level to abort the program ("critical" or "warning") --log-domains <[!]list> comma separated list of the active log domains --log-debug <[!]list> comma separated list of domains with "debug" level --log-noisy <[!]list> comma separated list of domains with "noisy" level --log-file <path> file to output messages to (in addition to stderr) Miscellaneous: -h display this help and exit -v print version information and exit -q don't report processed packet counts D.10. reordercap: Reorder a capture file
Help information available from reordercap. Reordercap (Wireshark) 4.1.0 (v4.1.0rc0-55-gccf720d95daf) Reorder timestamps of input file frames into output file. See https://www.wireshark.org for more information. Usage: reordercap [options] <infile> <outfile> Options: -n don't write to output file if the input file is ordered. -h display this help and exit. -v print version information and exit. Chapter 13. This Document’s License (GPL)As with the original license and documentation distributed with Wireshark, this document is covered by the GNU General Public License (GNU GPL). If you haven’t read the GPL before, please do so. It explains all the things that you are allowed to do with this code and documentation. GNU GENERAL PUBLIC LICENSE Version 2, June 1991 Copyright (C) 1989, 1991 Free Software Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Preamble The licenses for most software are designed to take away your freedom to share and change it. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change free software--to make sure the software is free for all its users. This General Public License applies to most of the Free Software Foundation's software and to any other program whose authors commit to using it. (Some other Free Software Foundation software is covered by the GNU Library General Public License instead.) You can apply it to your programs, too. When we speak of free software, we are referring to freedom, not price. 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We protect your rights with two steps: (1) copyright the software, and (2) offer you this license which gives you legal permission to copy, distribute and/or modify the software. Also, for each author's protection and ours, we want to make certain that everyone understands that there is no warranty for this free software. If the software is modified by someone else and passed on, we want its recipients to know that what they have is not the original, so that any problems introduced by others will not reflect on the original authors' reputations. Finally, any free program is threatened constantly by software patents. We wish to avoid the danger that redistributors of a free program will individually obtain patent licenses, in effect making the program proprietary. To prevent this, we have made it clear that any patent must be licensed for everyone's free use or not licensed at all. The precise terms and conditions for copying, distribution and modification follow. 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BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. END OF TERMS AND CONDITIONS How to Apply These Terms to Your New Programs If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms. To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively convey the exclusion of warranty; and each file should have at least the "copyright" line and a pointer to where the full notice is found. <one line to give the program's name and a brief idea of what it does.> Copyright (C) <year> <name of author> This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA Also add information on how to contact you by electronic and paper mail. If the program is interactive, make it output a short notice like this when it starts in an interactive mode: Gnomovision version 69, Copyright (C) year name of author Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details. The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, the commands you use may be called something other than `show w' and `show c'; they could even be mouse-clicks or menu items--whatever suits your program. You should also get your employer (if you work as a programmer) or your school, if any, to sign a "copyright disclaimer" for the program, if necessary. Here is a sample; alter the names: Yoyodyne, Inc., hereby disclaims all copyright interest in the program `Gnomovision' (which makes passes at compilers) written by James Hacker. <signature of Ty Coon>, 1 April 1989 Ty Coon, President of Vice This General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Library General Public License instead of this License. Which of the following answers refers to a secure implementation of a protocol used for synchronizing clocks over a computer network?The Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks.
Which of these protocols use TLS to provide secure communication select two?Which of these protocols use TLS to provide secure communication? TLS, and FTPS is the File Transfer Protocol over TLS. colloquially referenced as SSL.
What are the three protocols which are used in the management of TLS exchanges?There are three main components to what the TLS protocol accomplishes: Encryption, Authentication, and Integrity. Encryption: hides the data being transferred from third parties. Authentication: ensures that the parties exchanging information are who they claim to be.
What are the two main protocols of TLS?According to the protocol specification, TLS is composed of two layers: the TLS record protocol and the TLS handshake protocol.
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