Wireshark 0.99.5 User Guide
Wireshark User's Guide
21443 for Wireshark 0.99.5
Ulf Lamping,
Richard Sharpe, NS Computer Software and Services P/L
Ed Warnicke,
Wireshark User's Guide: 21443
for Wireshark 0.99.5
by Ulf Lamping, Richard Sharpe, and Ed Warnicke
Copyright © 2004-2007 Ulf Lamping Richard Sharpe Ed Warnicke
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU General Public License,
Version 2 or any later version published by the Free Software Foundation.
All logos and trademarks in this document are property of their respective owner.
Table of Contents
Preface ............................................................................................................. viii
1. Foreword .............................................................................................. viii
2. Who should read this document? ................................................................. ix
3. Acknowledgements .................................................................................... x
4. About this document ................................................................................. xi
5. Where to get the latest copy of this document? .............................................. xii
6. Providing feedback about this document ..................................................... xiii
1. Introduction ...................................................................................................... 1
1.1. What is Wireshark? ................................................................................. 1
1.1.1. Some intended purposes ................................................................. 1
1.1.2. Features ...................................................................................... 1
1.1.3. Live capture from many different network media ................................ 2
1.1.4. Import files from many other capture programs .................................. 2
1.1.5. Export files for many other capture programs ..................................... 2
1.1.6. Many protocol decoders ................................................................. 2
1.1.7. Open Source Software ................................................................... 2
1.1.8. What Wireshark is not ................................................................... 3
1.2. System Requirements ............................................................................... 4
1.2.1. General Remarks .......................................................................... 4
1.2.2. Microsoft Windows ....................................................................... 4
1.2.3. Unix / Linux ................................................................................ 5
1.3. Where to get Wireshark? .......................................................................... 6
1.4. A brief history of Wireshark ...................................................................... 7
1.5. Development and maintenance of Wireshark ................................................ 8
1.6. Reporting problems and getting help ........................................................... 9
1.6.1. Website ...................................................................................... 9
1.6.2. Wiki ........................................................................................... 9
1.6.3. FAQ ........................................................................................... 9
1.6.4. Mailing Lists ............................................................................... 9
1.6.5. Reporting Problems ......................................................................10
1.6.6. Reporting Crashes on UNIX/Linux platforms ....................................10
1.6.7. Reporting Crashes on Windows platforms ........................................11
2. Building and Installing Wireshark ........................................................................13
2.1. Introduction ..........................................................................................13
2.2. Obtaining the source and binary distributions ...............................................14
2.3. Before you build Wireshark under UNIX ....................................................15
2.4. Building Wireshark from source under UNIX ..............................................17
2.5. Installing the binaries under UNIX ............................................................18
2.5.1. Installing from rpm's under RedHat and alike ....................................18
2.5.2. Installing from deb's under Debian ..................................................18
2.5.3. Installing from portage under Gentoo Linux ......................................18
2.5.4. Installing from packages under FreeBSD ..........................................18
2.6. Troubleshooting during the install on Unix ..................................................19
2.7. Building from source under Windows ........................................................20
2.8. Installing Wireshark under Windows .........................................................21
2.8.1. Install Wireshark .........................................................................21
2.8.2. Manual WinPcap Installation .........................................................23
2.8.3. Update Wireshark ........................................................................23
2.8.4. Update WinPcap ..........................................................................23
2.8.5. Uninstall Wireshark .....................................................................23
2.8.6. Uninstall WinPcap .......................................................................24
3. User Interface ..................................................................................................26
3.1. Introduction ..........................................................................................26
3.2. Start Wireshark ......................................................................................27
3.3. The Main window ..................................................................................28
3.3.1. Main Window Navigation .............................................................29
3.4. The Menu .............................................................................................30
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3.5. The "File" menu .....................................................................................31
3.6. The "Edit" menu ....................................................................................34
3.7. The "View" menu ...................................................................................36
3.8. The "Go" menu ......................................................................................40
3.9. The "Capture" menu ...............................................................................42
3.10. The "Analyze" menu .............................................................................44
3.11. The "Statistics" menu ............................................................................46
3.12. The "Help" menu ..................................................................................48
3.13. The "Main" toolbar ...............................................................................50
3.14. The "Filter" toolbar ...............................................................................53
3.15. The "Packet List" pane ..........................................................................54
3.16. The "Packet Details" pane ......................................................................55
3.17. The "Packet Bytes" pane ........................................................................56
3.18. The Statusbar .......................................................................................57
4. Capturing Live Network Data .............................................................................59
4.1. Introduction ..........................................................................................59
4.2. Prerequisites ..........................................................................................60
4.3. Start Capturing ......................................................................................61
4.4. The "Capture Interfaces" dialog box ...........................................................62
4.5. The "Capture Options" dialog box .............................................................64
4.5.1. Capture frame .............................................................................64
4.5.2. Capture File(s) frame ....................................................................66
4.5.3. Stop Capture... frame ....................................................................66
4.5.4. Display Options frame ..................................................................67
4.5.5. Name Resolution frame ................................................................67
4.5.6. Buttons ......................................................................................67
4.6. Capture files and file modes .....................................................................68
4.7. Link-layer header type ............................................................................70
4.8. Filtering while capturing ..........................................................................71
4.8.1. Automatic Remote Traffic Filtering .................................................72
4.9. While a Capture is running ... ...................................................................74
4.9.1. Stop the running capture ...............................................................74
4.9.2. Restart a running capture ...............................................................75
5. File Input / Output and Printing ...........................................................................77
5.1. Introduction ..........................................................................................77
5.2. Open capture files ..................................................................................78
5.2.1. The "Open Capture File" dialog box ................................................78
5.2.2. Input File Formats ........................................................................80
5.3. Saving captured packets ..........................................................................82
5.3.1. The "Save Capture File As" dialog box ............................................82
5.3.2. Output File Formats .....................................................................84
5.4. Merging capture files ..............................................................................86
5.4.1. The "Merge with Capture File" dialog box ........................................86
5.5. File Sets ...............................................................................................88
5.5.1. The "List Files" dialog box ............................................................88
5.6. Exporting data .......................................................................................90
5.6.1. The "Export as Plain Text File" dialog box .......................................90
5.6.2. The "Export as PostScript File" dialog box .......................................90
5.6.3. The "Export as CSV (Comma Separated Values) File" dialog box .........91
5.6.4. The "Export as PSML File" dialog box ............................................91
5.6.5. The "Export as PDML File" dialog box ............................................92
5.6.6. The "Export selected packet bytes" dialog box ...................................93
5.6.7. The "Export Objects" dialog box .....................................................94
5.7. Printing packets .....................................................................................96
5.7.1. The "Print" dialog box ..................................................................96
5.8. The Packet Range frame ..........................................................................98
5.9. The Packet Format frame .........................................................................99
6. Working with captured packets ..........................................................................101
6.1. Viewing packets you have captured ......................................................... 101
6.2. Pop-up menus ...................................................................................... 103
6.2.1. Pop-up menu of the "Packet List" pane .......................................... 103
6.2.2. Pop-up menu of the "Packet Details" pane ......................................105
6.3. Filtering packets while viewing ...............................................................108
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6.4. Building display filter expressions ........................................................... 110
6.4.1. Display filter fields ....................................................................110
6.4.2. Comparing values ...................................................................... 110
6.4.3. Combining expressions ............................................................... 111
6.4.4. A common mistake .................................................................... 113
6.5. The "Filter Expression" dialog box ..........................................................114
6.6. Defining and saving filters ..................................................................... 116
6.7. Finding packets ....................................................................................118
6.7.1. The "Find Packet" dialog box ....................................................... 118
6.7.2. The "Find Next" command .......................................................... 119
6.7.3. The "Find Previous" command ..................................................... 119
6.8. Go to a specific packet .......................................................................... 120
6.8.1. The "Go Back" command ............................................................ 120
6.8.2. The "Go Forward" command .......................................................120
6.8.3. The "Go to Packet" dialog box ..................................................... 120
6.8.4. The "Go to Corresponding Packet" command .................................. 120
6.8.5. The "Go to First Packet" command ............................................... 120
6.8.6. The "Go to Last Packet" command ................................................ 120
6.9. Marking packets ...................................................................................121
6.10. Time display formats and time references ................................................ 122
6.10.1. Packet time referencing ............................................................. 122
7. Advanced Topics ............................................................................................ 125
7.1. Introduction ........................................................................................125
7.2. Following TCP streams .........................................................................126
7.2.1. The "Follow TCP Stream" dialog box ............................................ 126
7.3. Time Stamps ....................................................................................... 128
7.3.1. Wireshark internals .................................................................... 128
7.3.2. Capture file formats ................................................................... 128
7.3.3. Accuracy .................................................................................. 128
7.4. Time Zones .........................................................................................130
7.4.1. Set your computer's time correct! .................................................. 131
7.4.2. Wireshark and Time Zones .......................................................... 131
7.5. Packet Reassembling ............................................................................ 133
7.5.1. What is it? ................................................................................ 133
7.5.2. How Wireshark handles it ........................................................... 133
7.6. Name Resolution .................................................................................. 135
7.6.1. Name Resolution drawbacks ........................................................ 135
7.6.2. Ethernet name resolution (MAC layer) ........................................... 135
7.6.3. IP name resolution (network layer) ................................................ 136
7.6.4. IPX name resolution (network layer) ............................................. 136
7.6.5. TCP/UDP port name resolution (transport layer) .............................. 136
7.7. Checksums ......................................................................................... 137
7.7.1. Wireshark checksum validation .................................................... 137
7.7.2. Checksum offloading .................................................................. 138
8. Statistics .......................................................................................................140
8.1. Introduction ........................................................................................140
8.2. The "Summary" window ........................................................................ 141
8.3. The "Protocol Hierarchy" window ...........................................................143
8.4. Endpoints ........................................................................................... 145
8.4.1. What is an Endpoint? .................................................................. 145
8.4.2. The "Endpoints" window ............................................................. 145
8.4.3. The protocol specific "Endpoint List" windows ...............................146
8.5. Conversations ...................................................................................... 147
8.5.1. What is a Conversation? .............................................................. 147
8.5.2. The "Conversations" window ....................................................... 147
8.5.3. The protocol specific "Conversation List" windows ..........................147
8.6. The "IO Graphs" window ....................................................................... 148
8.7. Service Response Time ......................................................................... 150
8.7.1. The "Service Response Time DCE-RPC" window ............................150
8.8. The protocol specific statistics windows ................................................... 152
9. Customizing Wireshark .................................................................................... 154
9.1. Introduction ........................................................................................154
9.2. Start Wireshark from the command line .................................................... 155
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9.3. Packet colorization ............................................................................... 160
9.4. Control Protocol dissection .................................................................... 163
9.4.1. The "Enabled Protocols" dialog box ..............................................163
9.4.2. User Specified Decodes ..............................................................165
9.4.3. Show User Specified Decodes ...................................................... 166
9.5. Preferences ......................................................................................... 167
9.6. User Table .......................................................................................... 168
9.7. Display Filter Macros ............................................................................ 169
9.8. Tektronics K12xx/15 RF5 protocols Table ................................................170
9.9. User DLTs protocol table ....................................................................... 171
9.10. SNMP users Table .............................................................................. 172
A. Files and Folders ............................................................................................ 174
A.1. Capture Files ......................................................................................174
A.1.1. Libpcap File Contents ................................................................ 174
A.1.2. Not Saved in the Capture File ...................................................... 174
A.2. Configuration Files and Folders ..............................................................176
A.3. Windows folders ................................................................................. 180
A.3.1. Windows profiles ......................................................................180
A.3.2. Windows Vista/XP/2000/NT roaming profiles ................................ 180
A.3.3. Windows temporary folder ......................................................... 180
B. Protocols and Protocol Fields ........................................................................... 183
C. Wireshark Messages ....................................................................................... 184
C.1. Packet List Messages ............................................................................ 184
C.1.1. [Malformed Packet] ................................................................... 184
C.1.2. [Packet size limited during capture] .............................................. 184
C.2. Packet Details Messages ....................................................................... 185
C.2.1. [Response in frame: 123] ............................................................185
C.2.2. [Request in frame: 123] ..............................................................185
C.2.3. [Time from request: 0.123 seconds] .............................................. 185
D. Related command line tools ............................................................................. 187
D.1. Introduction ........................................................................................ 187
D.2. tshark: Terminal-based Wireshark ......................................................... 188
D.3. tcpdump: Capturing with tcpdump for viewing with Wireshark ................... 189
D.4. dumpcap: Capturing with dumpcap for viewing with Wireshark .................. 190
D.5. capinfos: Print information about capture files .......................................... 191
D.6. editcap: Edit capture files ..................................................................... 192
D.7. mergecap: Merging multiple capture files into one .................................... 195
D.8. text2pcap: Converting ASCII hexdumps to network captures ...................... 198
D.9. idl2wrs: Creating dissectors from CORBA IDL files .................................. 201
D.9.1. What is it? ...............................................................................201
D.9.2. Why do this? ............................................................................ 201
D.9.3. How to use idl2wrs ....................................................................201
D.9.4. TODO .................................................................................... 202
D.9.5. Limitations .............................................................................. 203
D.9.6. Notes ......................................................................................203
E. This Document's License (GPL) ........................................................................ 205
vii
Preface
1. Foreword
Wireshark is one of those programs that many network managers would love to be able to use, but
they are often prevented from getting what they would like from Wireshark because of the lack of
documentation.
This document is part of an effort by the Wireshark team to improve the usability of Wireshark.
We hope that you find it useful, and look forward to your comments.
viii
Preface
2. Who should read this document?
The intended audience of this book is anyone using Wireshark.
This book will explain all the basics and also some of the advanced features that Wireshark
provides. As Wireshark has become a very complex program since the early days, not every feature
of Wireshark 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 http://wiki.wireshark.org
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) users of Wireshark.
ix
3. Acknowledgements
The authors would like to thank the whole Wireshark team for their assistance. In particular, the authors would like to thank:
• Gerald Combs, for initiating the Wireshark project and funding to do this documentation.
• Guy Harris, for many helpful hints and a great deal of patience in reviewing this document.
• Gilbert Ramirez, for general encouragement and helpful hints along the way.
The authors would also like to thank the following people for their helpful feedback on this document:
• Pat Eyler, for his suggestions on improving the example on generating a backtrace.
• Martin Regner, for his various suggestions and corrections.
• Graeme Hewson, for a lot of grammatical corrections.
Preface
The authors would like to acknowledge those man page and README authors for the Wireshark
project from who sections of this document borrow heavily:
• Scott Renfro from whose mergecap man page Section D.7, “mergecap: Merging multiple cap-
ture files into one ” is derived.
• Ashok Narayanan from whose text2pcap man page Section D.8, “text2pcap: Converting ASCII
hexdumps to network captures ” is derived.
• Frank Singleton from whose README.idl2wrs Section D.9, “idl2wrs: Creating dissectors
from CORBA IDL files ” is derived.
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Preface
4. About this document
This 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 is written in DocBook/XML.
You will find some specially marked parts in this book:
This is a warning!
You should pay attention to a warning, as otherwise data loss might occur.
This is a note!
A note will point you to common mistakes and things that might not be obvious.
This is a tip!
Tips will be helpful for your everyday work using Wireshark.
xi
Preface
5. Where to get the latest copy of this document?
The latest copy of this documentation can always be found at: http:/ /www.wireshark.org/ docs/
#usersguide.
xii
Preface
6. Providing feedback about this document
Should you have any feedback about this document, please send them to the authors through wire-
shark-dev[AT]wireshark.org.
xiii
Preface
xiv
Chapter 1. Introduction
1.1. What is Wireshark?
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.
1.1.1. Some intended purposes
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.
1.1.2. Features
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.
Figure 1.1, “ Wireshark captures packets and allows you to examine their content. ” shows Wire-
shark having captured some packets and waiting for you to examine them.
1
Introduction
Figure 1.1. Wireshark captures packets and allows you to examine their
content.
1.1.3. Live capture from many different network media
Wireshark can capture traffic from many different network media types - and despite it's 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: http://
wiki.wireshark.org/CaptureSetup/NetworkMedia.
1.1.4. Import files from many other capture programs
Wireshark can open packets captured from a large number of other 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 programs
Wireshark can save packets captured in a large number of formats of other capture programs. For a
list of output formats see Section 5.3.2, “Output File Formats”.
1.1.6. Many protocol decoders
There are protocol decoders (or dissectors, as they are known in Wireshark) for a great many protocols: see Appendix B, Protocols and Protocol Fields.
1.1.7. Open Source Software
2
Introduction
Wireshark is an open source software project, and is released under the GNU General Public Li-
cence (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 not
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).
3
Introduction
1.2. System Requirements
What you'll need to get Wireshark up and running ...
1.2.1. General Remarks
• 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: http://wiki.wireshark.org/KnownBugs/
OutOfMemory 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 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.
1.2.2. Microsoft Windows
• Windows 2000, XP Home, XP Pro, XP Tablet PC, XP Media Center, Server 2003 or Vista (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)
• 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 http://wiki.wireshark.org/CaptureSetup/NetworkMedia
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, ...) 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 still can get it from: http://ethereal.com/
download.html. BTW: Microsoft no longer supports 98/ME since July 11, 2006!
4
• 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: http:/ / prdown-
loads.sourceforge.net/wireshark/wireshark-setup-0.99.4.exe. 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
1.2.3. Unix / Linux
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
Introduction
• 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 wireshark-dev[AT]wireshark.org .
5
Introduction
1.3. Where to get Wireshark?
You can get the latest copy of the program from the Wireshark website: ht-
tp://www.wireshark.org/download.html. The website allows you to choose from among several mir-
rors for downloading.
A new Wireshark version will typically become available every 4-8 weeks.
If you want to be notified about new Wireshark releases, you should subscribe to the wireshark-an-
nounce mailing list. You will find more details in Section 1.6.4, “Mailing Lists”.
6
Introduction
1.4. A brief history of Wireshark
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.
7
Introduction
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 Li-
cence (GPL). All source code is freely available under the GPL. You are welcome to modify Wire-
shark 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: http://www.wireshark.org/download.html.
8
Introduction
1.6. Reporting problems and getting help
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).
1.6.1. Website
You will find lots of useful information on the Wireshark homepage at http://www.wireshark.org.
1.6.2. Wiki
The Wireshark Wiki at http://wiki.wireshark.org 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.
1.6.3. FAQ
The "Frequently Asked Questions" will list often asked questions and the corresponding answers.
Read the FAQ!
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 upcoming dialog.
An online version is available at the Wireshark website: http://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.
1.6.4. Mailing Lists
There are several mailing lists of specific Wireshark topics available:
wireshark-announce This mailing list will inform you about new program releases, which
wireshark-users This list is for users of Wireshark. People post questions about build-
wireshark-dev This list is for Wireshark developers. If you want to start developing a
usually appear about every 4-8 weeks.
ing and using Wireshark, others (hopefully) provide answers.
protocol dissector, join this list.
You can subscribe to each of these lists from the Wireshark web site: http://www.wireshark.org.
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.
Tip!
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.
9
Introduction
1.6.5. Reporting Problems
Note!
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:
1. The version number of Wireshark and the dependent libraries linked with it, eg GTK+, etc.
You can obtain this with the command wireshark -v.
2. Information about the platform you run Wireshark on.
3. A detailed description of your problem.
4. 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.
Don't send large files!
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.
Don't send confidential information!
If you send captured data to the mailing lists, be sure they don't contain any sensitive
or confidential information like passwords or such.
1.6.6. Reporting Crashes on UNIX/Linux platforms
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:
$ gdb `whereis wireshark | cut -f2 -d: | cut -d' ' -f2` core >& bt.txt
backtrace
^D
$
Note
Type the characters in the first line verbatim! Those are back-tics there!
Note
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
10
Introduction
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.
Note
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 wireshark-dev[AT]wireshark.org mailing list.
1.6.7. Reporting Crashes on Windows platforms
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.
11
Introduction
12
Chapter 2. Building and Installing Wireshark
2.1. Introduction
As with all things, there must be a beginning, and so it is with Wireshark. To use Wireshark, you
must:
• Obtain a binary package for your operating system, or
• Obtain the source and build Wireshark for your operating system.
Currently, only two or three Linux distributions ship Wireshark, and they are commonly shipping an
out-of-date version. No other versions of UNIX ship Wireshark so far, and Microsoft does not ship
it with any version of Windows. 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 following are the general steps you would use:
1. Download the relevant package for your needs, e.g. source or binary distribution.
2. Build the source into a binary, if you have downloaded the source.
This may involve building and/or installing other necessary packages.
3. Install the binaries into their final destinations.
13
Building and Installing Wireshark
2.2. Obtaining the source and binary distributions
You can obtain both source and binary distributions from the Wireshark web site: ht-
tp://www.wireshark.org. Simply select the download link, and then select either the source package
or binary package of your choice from the mirror site closest to you.
Download all required files!
In general, unless you have already downloaded Wireshark before, you will most
likely need to download several source packages if you are building Wireshark from
source. This is covered in more detail below.
Once you have downloaded the relevant files, you can go on to the next step.
Note!
While you will find a number of binary packages available on the Wireshark web site,
you might not find one for your platform, and they often tend to be several versions
behind the current released version, as they are contributed by people who have the
platforms they are built for.
For this reason, you might want to pull down the source distribution and build it, as the
process is relatively simple.
14
Building and Installing Wireshark
2.3. Before you build Wireshark under UNIX
Before you build Wireshark from sources, or install a binary package, you must ensure that you
have the following other packages installed:
• GTK+, The GIMP Tool Kit.
You will also need Glib. Both can be obtained from www.gtk.org
• libpcap, the packet capture software that Wireshark uses.
You can obtain libpcap from www.tcpdump.org
Depending on your system, you may be able to install these from binaries, e.g. RPMs, or you may
need to obtain them in source code form and build them.
If you have downloaded the source for GTK+, the instructions shown in Example 2.1, “Building
GTK+ from source” may provide some help in building it:
Example 2.1. Building GTK+ from source
gzip -dc gtk+-1.2.10.tar.gz | tar xvf <much output removed>
cd gtk+-1.2.10
./configure
<much output removed>
make
<much output removed>
make install
<much output removed>
Note!
You may need to change the version number of gtk+ in Example 2.1, “Building GTK+
from source” to match the version of GTK+ you have downloaded. The directory you
change to will change if the version of GTK+ changes, and in all cases, tar xvf - will
show you the name of the directory you should change to.
Note!
If you use Linux, or have GNU tar installed, you can use tar zxvf gtk+-1.2.10.tar.gz.
It is also possible to use gunzip -c or gzcat rather than gzip -dc on many UNIX systems.
Note!
If you downloaded gtk+ or any other tar file using Windows, you may find your file
called gtk+-1_2_8_tar.gz.
You should consult the GTK+ web site if any errors occur in carrying out the instructions in Ex-
ample 2.1, “Building GTK+ from source”.
If you have downloaded the source to libpcap, the general instructions shown in Example 2.2,
“Building and installing libpcap” will assist in building it. Also, if your operating system does not
support tcpdump, you might also want to download it from the tcpdump web site and install it.
15
Building and Installing Wireshark
Example 2.2. Building and installing libpcap
gzip -dc libpcap-0.9.4.tar.Z | tar xvf <much output removed>
cd libpcap-0.9.4
./configure
<much output removed>
make
<much output removed>
make install
<much output removed>
Note!
The directory you should change to will depend on the version of libpcap you have
downloaded. In all cases, tar xvf - will show you the name of the directory that has
been unpacked.
Under RedHat 6.x and beyond (and distributions based on it, like Mandrake) you can simply install
each of the packages you need from RPMs. Most Linux systems will install GTK+ and GLib in any
case, however, you will probably need to install the devel versions of each of these packages. The
commands shown in Example 2.3, “ Installing required RPMs under RedHat Linux 6.2 and beyond
” will install all the needed RPMs if they are not already installed.
Example 2.3. Installing required RPMs under RedHat Linux 6.2 and beyond
cd /mnt/cdrom/RedHat/RPMS
rpm -ivh glib-1.2.6-3.i386.rpm
rpm -ivh glib-devel-1.2.6-3.i386.rpm
rpm -ivh gtk+-1.2.6-7.i386.rpm
rpm -ivh gtk+-devel-1.2.6-7.i386.rpm
rpm -ivh libpcap-0.4-19.i386.rpm
Note
If you are using a version of RedHat later than 6.2, the required RPMs have most
likely changed. Simply use the correct RPMs from your distribution.
Under Debian you can install Wireshark using apt-get. apt-get will handle any dependency issues
for you. Example 2.4, “Installing debs under Debian” shows how to do this.
Example 2.4. Installing debs under Debian
apt-get install wireshark-dev
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