Wireshark is a network packet analyzer. A network packet analyzer will try to capture network packets and tries to display that packet data as detailed as possible. You could think of a network packet analyzer as a measuring device used to examine what's going on inside a network cable, just like a voltmeter is used by an electrician to examine what's going on 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, all that has changed. Wireshark is perhaps one of the best open source packet analyzers available today.

Here are some examples people use Wireshark for: network administrators use it to troubleshoot network problems network security engineers use it to examine security problems developers use it to debug protocol implementations people use it to learn network protocol internals Beside these examples, Wireshark can be helpful in many other situations too.

The following are some of the many features Wireshark provides: Available for UNIX and Windows. Capture live packet data from a network interface. Display packets with very detailed protocol information. Open and Save packet data captured. Import and Export packet data from and to a lot of other capture programs. Filter packets on many criteria. Search for packets on many criteria. Colorize packet display based on filters. Create various statistics. ... and a lot more! However, to really appreciate its power, you have to start using it. shows Wireshark having captured some packets and waiting for you to examine them.

Wireshark can capture traffic from many different network media types - and despite its name - including wireless LAN as well. Which media types are supported, depends on many things like the operating system you are using. An overview of the supported media types can be found at: .

Wireshark can open packets captured from a large number of other capture programs. For a list of input formats see .

Wireshark can save packets captured in a large number of formats of other capture programs. For a list of output formats see .

There are protocol decoders (or dissectors, as they are known in Wireshark) for a great many protocols: see .

Wireshark 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!

Here are some things Wireshark does not provide: Wireshark isn't an intrusion detection system. It will not warn you when someone does strange things on your network that he/she isn't allowed to do. However, if strange things happen, Wireshark might help you figure out what is really going on. Wireshark will not manipulate things on the network, it will only "measure" things from it. Wireshark doesn't send packets on the network or do other active things (except for name resolutions, but even that can be disabled).

What you'll need to get Wireshark up and running ...

The values below are the minimum requirements and only "rules of thumb" for use on a moderately used network Working with a busy network can easily produce huge memory and disk space usage! For example: Capturing on a fully saturated 100MBit/s Ethernet will produce ~ 750MBytes/min! Having a fast processor, lots of memory and disk space is a good idea in that case. If Wireshark is running out of memory it crashes, see: for details and workarounds Wireshark won't benefit much from Multiprocessor/Hyperthread systems as time consuming tasks like filtering packets are single threaded. No rule is without exception: during an "Update list of packets in real time" capture, capturing traffic runs in one process and dissecting and displaying packets runs in another process - which should benefit from two processors.

Windows 2000, XP Home, XP Pro, XP Tablet PC, XP Media Center, Server 2003, Vista or Windows 2008 (XP Pro recommended) 32-bit Pentium or alike (recommended: 400MHz or greater), 64-bit processors in WoW64 emulation - see remarks below 128MB RAM system memory (recommended: 256MBytes or more) 75MB available disk space (plus size of user's capture files, e.g. 100MB extra) 800*600 (1280*1024 or higher recommended) resolution with at least 65536 (16bit) colors (256 colors should work if Wireshark is installed with the "legacy GTK1" selection of the Wireshark 1.0.x releases) A supported network card for capturing: Ethernet: any card supported by Windows should do WLAN: see the MicroLogix support list, no capturing of 802.11 headers and non-data frames Other media: See Remarks: Older Windows versions are no longer supported because of three reasons: None of the developers actively use those systems any longer which makes support difficult. The libraries Wireshark depends on (GTK, WinPCap, ...) are also dropping support for these systems. Microsoft also dropped support for these systems. Windows 95, 98 and ME will no longer work with Wireshark. The last known version to work was Ethereal 0.99.0 (which includes WinPcap 3.1). You can get it from . According to this bug report, you may need to install Ethereal 0.10.0 on some systems. BTW: Microsoft no longer supports 98/ME since July 11, 2006! Windows NT 4.0 will no longer work with Wireshark. The last known version to work was Wireshark 0.99.4 (which includes WinPcap 3.1), you still can get it from: . BTW: Microsoft no longer supports NT 4.0 since December 31, 2005! Windows CE and the embedded (NT/XP) versions are not supported! 64-bit processors run Wireshark in 32 bit emulation (called WoW64), at least WinPcap 4.0 is required for that Multi monitor setups are supported but may behave a bit strangely

Wireshark currently runs on most UNIX platforms. The system requirements should be comparable to the Windows values listed above. Binary packages are available for at least the following platforms: Apple Mac OS X Debian GNU/Linux FreeBSD Gentoo Linux HP-UX Mandriva Linux NetBSD OpenPKG Red Hat Fedora/Enterprise Linux rPath Linux Sun Solaris/i386 Sun Solaris/Sparc If a binary package is not available for your platform, you should download the source and try to build it. Please report your experiences to &WiresharkDevMailList; .

You can get the latest copy of the program from the Wireshark website: &WiresharkDownloadPage;. The website allows you to choose from among several mirrors for downloading. A new Wireshark version will typically become available every 4-8 months. 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 .

In late 1997, Gerald Combs needed a tool for tracking down networking problems and wanted to learn more about networking, so he started writing Ethereal (the former 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, so 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 of Network Appliance 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 Ethereal has become very long since then, and almost all of them started with a protocol that they needed that Ethereal 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.

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). 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: Other people who find your contributions useful will appreciate them, and you will know that you have helped people in the same way that the developers of Wireshark have helped people. The developers of Wireshark might improve your changes even more, as there's always room for improvement. Or they may implement some advanced things on top of your code, which can be useful for yourself too. The maintainers and developers of Wireshark will maintain your code as well, fixing it when API changes or other changes are made, and generally keeping it in tune with what is happening with Wireshark. So if Wireshark is updated (which is done often), you can get a new Wireshark version from the website and your changes will already be included without any effort for you. The Wireshark source code and binary kits for some platforms are all available on the download page of the Wireshark website: &WiresharkDownloadPage;.

If you have problems, or need help with Wireshark, there are several places that may be of interest to you (well, besides this guide of course).

You will find lots of useful information on the Wireshark homepage at &WiresharkWebSite;.

The Wireshark Wiki at &WiresharkWikiPage; provides a wide range of information related to Wireshark and packet capturing in general. You will find a lot of information not part of this user's guide. For example, there is an explanation how to capture on a switched network, an ongoing effort to build a protocol reference and a lot 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 by simply using your web browser.

The "Frequently Asked Questions" will list often asked questions and the corresponding answers. Before sending any mail to the mailing lists below, be sure to read the FAQ, as it will often answer the question(s) you might have. This will save yourself and others a lot of time (keep in mind that a lot of people are subscribed to the mailing lists). 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: &WiresharkFAQPage;. You might prefer this online version, as it's typically more up to date and the HTML format is easier to use.

There are several mailing lists of specific Wireshark topics available: wireshark-announce This mailing list will inform you about new program releases, which usually appear about every 4-8 weeks. wireshark-users This list is for users of Wireshark. People post questions about building and using Wireshark, others (hopefully) provide answers. wireshark-dev This list is for Wireshark developers. If you want to start developing a protocol dissector, join this list. You can subscribe to each of these lists from the Wireshark web site: &WiresharkWebSite;. Simply select the mailing lists link on the left hand side of the site. The lists are archived at the Wireshark web site as well. You can search in the list archives to see if someone asked the same question some time before and maybe already got an answer. That way you don't have to wait until someone answers your question.

Before reporting any problems, please make sure you have installed the latest version of Wireshark. When reporting problems with Wireshark, it is helpful if you supply the following information: The version number of Wireshark and the dependent libraries linked with it, e.g. GTK+, etc. You can obtain this with the command wireshark -v. Information about the platform you run Wireshark on. A detailed description of your problem. If you get an error/warning message, copy the text of that message (and also a few lines before and after it, if there are some), so others may find the place where things go wrong. Please don't give something like: "I get a warning while doing x" as this won't give a good idea where to look at. Do not send large files (>100KB) to the mailing lists, just place a note that further data is available on request. Large files will only annoy a lot of people on the list who are not interested in your specific problem. If required, you will be asked for further data by the persons who really can help you. If you send captured data to the mailing lists, be sure they don't contain any sensitive or confidential information like passwords or such.

When reporting crashes with Wireshark, it is helpful if you supply the traceback information (besides the information mentioned in "Reporting Problems"). You can obtain this traceback information with the following commands: & bt.txt backtrace ^D $ ]]> Type the characters in the first line verbatim! Those are back-tics there! backtrace is a gdb command. You should enter it verbatim after the first line shown above, but it will not be echoed. The ^D (Control-D, that is, press the Control key and the D key together) will cause gdb to exit. This will leave you with a file called bt.txt in the current directory. Include the file with your bug report. If you do not have gdb available, you will have to check out your operating system's debugger. You should mail the traceback to the &WiresharkDevMailList; mailing list.

The Windows distributions don't contain the symbol files (.pdb), because they are very large. For this reason it's not possible to create a meaningful backtrace file from it. You should report your crash just like other problems, using the mechanism described above.