Wireshark Wireshark - 2.1 User Guide

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Wireshark User’s Guide

For Wireshark 2.1

Ulf Lamping <ulf.lamping[AT]web.de>

Richard Sharpe, NS Computer Software and

Services P/L <rsharpe[AT]ns.aus.com>

Ed Warnicke <hagbard[AT]physics.rutgers.edu>

Wireshark User’s Guide: For Wireshark 2.1

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.

Preface ............................................................................................................................. ix

1. Foreword ............................................................................................................... ix

2. Who should read this document? ............................................................................... ix

3. Acknowledgements ................................................................................................. ix

4. About this document ................................................................................................ x

5. Where to get the latest copy of this document? ............................................................. x

6. Providing feedback about this document ...................................................................... x

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 dissectors ............................................................................. 2

1.1.7. Open Source Software ................................................................................. 2

1.1.8. What Wireshark is not ................................................................................. 2

1.2. System Requirements ............................................................................................. 3

1.2.1. Microsoft Windows .................................................................................... 3

1.2.2. UNIX / Linux ............................................................................................ 3

1.3. Where to get Wireshark ......................................................................................... 4

1.4. A brief history of Wireshark ................................................................................... 4

1.5. Development and maintenance of Wireshark .............................................................. 5

1.6. Reporting problems and getting help ........................................................................ 5

1.6.1. Website ..................................................................................................... 6

1.6.2. Wiki ......................................................................................................... 6

1.6.3. Q&A Site .................................................................................................. 6

1.6.4. FAQ ......................................................................................................... 6

1.6.5. Mailing Lists ............................................................................................. 6

1.6.6. Reporting Problems .................................................................................... 7

1.6.7. Reporting Crashes on UNIX/Linux platforms .................................................. 7

1.6.8. Reporting Crashes on Windows platforms ....................................................... 8

2. Building and Installing Wireshark ...................................................................................... 9

2.1. Introduction ......................................................................................................... 9

2.2. Obtaining the source and binary distributions ............................................................. 9

2.3. Installing Wireshark under Windows ........................................................................ 9

2.3.1. Installation Components ............................................................................. 10

2.3.2. Additional Tasks ....................................................................................... 10

2.3.3. Install Location ......................................................................................... 10

2.3.4. Installing WinPcap .................................................................................... 11

2.3.5. Windows installer command line options ...................................................... 11

2.3.6. Manual WinPcap Installation ...................................................................... 11

2.3.7. Update Wireshark ..................................................................................... 11

2.3.8. Update WinPcap ....................................................................................... 12

2.3.9. Uninstall Wireshark ................................................................................... 12

2.3.10. Uninstall WinPcap ................................................................................... 12

2.4. Installing Wireshark under OS X ........................................................................... 12

2.5. Building Wireshark from source under UNIX ........................................................... 12

2.6. Installing the binaries under UNIX ......................................................................... 13

2.6.1. Installing from RPM’s under Red Hat and alike ............................................. 13

2.6.2. Installing from deb’s under Debian, Ubuntu and other Debian derivatives ............ 13

2.6.3. Installing from portage under Gentoo Linux ................................................... 14

2.6.4. Installing from packages under FreeBSD ....................................................... 14

2.7. Troubleshooting during the install on Unix .............................................................. 14

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2.8. Building from source under Windows ..................................................................... 14

3. User Interface ............................................................................................................... 15

3.1. Introduction ........................................................................................................ 15

3.2. Start Wireshark ................................................................................................... 15

3.3. The Main window ............................................................................................... 15

3.3.1. Main Window Navigation .......................................................................... 16

3.4. The Menu .......................................................................................................... 17

3.5. The “File” menu ................................................................................................. 18

3.6. The “Edit” menu ................................................................................................. 20

3.7. The “View” menu ............................................................................................... 22

3.8. The “Go” menu .................................................................................................. 26

3.9. The “Capture” menu ............................................................................................ 27

3.10. The “Analyze” menu .......................................................................................... 28

3.11. The “Statistics” menu ......................................................................................... 30

3.12. The “Telephony” menu ....................................................................................... 31

3.13. The “Tools” menu ............................................................................................. 32

3.14. The “Internals” menu ......................................................................................... 33

3.15. The “Help” menu .............................................................................................. 33

3.16. The “Main” toolbar ............................................................................................ 34

3.17. The “Filter” toolbar ............................................................................................ 38

3.18. The “Packet List” pane ....................................................................................... 39

3.19. The “Packet Details” pane ................................................................................... 40

3.20. The “Packet Bytes” pane .................................................................................... 40

3.21. The Statusbar .................................................................................................... 41

4. Capturing Live Network Data .......................................................................................... 43

4.1. Introduction ........................................................................................................ 43

4.2. Prerequisites ....................................................................................................... 43

4.3. Start Capturing .................................................................................................... 43

4.4. The “Capture Interfaces” dialog box ....................................................................... 44

4.5. The “Capture Options” dialog box .......................................................................... 45

4.5.1. Capture frame .......................................................................................... 45

4.5.2. Capture File(s) frame ................................................................................. 46

4.5.3. Stop Capture… frame ................................................................................ 47

4.5.4. Display Options frame ............................................................................... 47

4.5.5. Name Resolution frame ............................................................................. 47

4.5.6. Buttons ................................................................................................... 48

4.6. The “Edit Interface Settings” dialog box .................................................................. 48

4.7. The “Compile Results” dialog box ......................................................................... 49

4.8. The “Add New Interfaces” dialog box .................................................................... 49

4.8.1. Add or remove pipes ................................................................................. 50

4.8.2. Add or hide local interfaces ........................................................................ 50

4.8.3. Add or hide remote interfaces ..................................................................... 50

4.9. The “Remote Capture Interfaces” dialog box ............................................................ 50

4.9.1. Remote Capture Interfaces .......................................................................... 51

4.9.2. Remote Capture Settings ............................................................................ 51

4.10. The “Interface Details” dialog box ........................................................................ 52

4.11. Capture files and file modes ................................................................................ 52

4.12. Link-layer header type ........................................................................................ 53

4.13. Filtering while capturing ..................................................................................... 54

4.13.1. Automatic Remote Traffic Filtering ............................................................ 55

4.14. While a Capture is running … ............................................................................. 56

4.14.1. Stop the running capture ........................................................................... 56

4.14.2. Restart a running capture .......................................................................... 56

5. File Input, Output, and Printing ........................................................................................ 58

Wireshark User’s Guide

5.1. Introduction ........................................................................................................ 58

5.2. Open capture files ............................................................................................... 58

5.2.1. The “Open Capture File” dialog box ............................................................ 58

5.2.2. Input File Formats .................................................................................... 59

5.3. Saving captured packets ....................................................................................... 61

5.3.1. The “Save Capture File As” dialog box ........................................................ 61

5.3.2. Output File Formats .................................................................................. 62

5.4. Merging capture files ........................................................................................... 63

5.4.1. The “Merge with Capture File” dialog box .................................................... 63

5.5. Import hex dump ................................................................................................. 64

5.5.1. The “Import from Hex Dump” dialog box ..................................................... 64

5.6. File Sets ............................................................................................................ 65

5.6.1. The “List Files” dialog box ........................................................................ 66

5.7. Exporting data .................................................................................................... 66

5.7.1. The “Export as Plain Text File” dialog box ................................................... 67

5.7.2. The “Export as PostScript File” dialog box .................................................... 67

5.7.3. The "Export as CSV (Comma Separated Values) File" dialog box ...................... 67

5.7.4. The "Export as C Arrays (packet bytes) file" dialog box ................................... 68

5.7.5. The "Export as PSML File" dialog box ......................................................... 68

5.7.6. The "Export as PDML File" dialog box ........................................................ 68

5.7.7. The "Export selected packet bytes" dialog box ............................................... 68

5.7.8. The "Export Objects" dialog box ................................................................. 69

5.8. Printing packets .................................................................................................. 69

5.8.1. The “Print” dialog box ............................................................................... 69

5.9. The “Packet Range” frame .................................................................................... 70

5.10. The Packet Format frame .................................................................................... 71

6. Working with captured packets ........................................................................................ 72

6.1. Viewing packets you have captured ........................................................................ 72

6.2. Pop-up menus ..................................................................................................... 72

6.2.1. Pop-up menu of the “Packet List” column header ........................................... 72

6.2.2. Pop-up menu of the “Packet List” pane ......................................................... 73

6.2.3. Pop-up menu of the “Packet Details” pane .................................................... 75

6.3. Filtering packets while viewing .............................................................................. 78

6.4. Building display filter expressions .......................................................................... 79

6.4.1. Display filter fields ................................................................................... 79

6.4.2. Comparing values ..................................................................................... 79

6.4.3. Combining expressions .............................................................................. 80

6.4.4. Membership Operator. ............................................................................... 82

6.4.5. A common mistake ................................................................................... 82

6.5. The “Filter Expression” dialog box ......................................................................... 82

6.6. Defining and saving filters .................................................................................... 83

6.7. Defining and saving filter macros ........................................................................... 84

6.8. Finding packets ................................................................................................... 84

6.8.1. The “Find Packet” dialog box ..................................................................... 84

6.8.2. The “Find Next” command ......................................................................... 85

6.8.3. The “Find Previous” command .................................................................... 85

6.9. Go to a specific packet ......................................................................................... 85

6.9.1. The “Go Back” command .......................................................................... 85

6.9.2. The “Go Forward” command ...................................................................... 85

6.9.3. The “Go to Packet” dialog box .................................................................... 85

6.9.4. The “Go to Corresponding Packet” command ................................................ 86

6.9.5. The “Go to First Packet” command .............................................................. 86

6.9.6. The “Go to Last Packet” command .............................................................. 86

6.10. Marking packets ................................................................................................ 86

Wireshark User’s Guide

6.11. Ignoring packets ................................................................................................ 86

6.12. Time display formats and time references .............................................................. 87

6.12.1. Packet time referencing ............................................................................ 87

7. Advanced Topics ........................................................................................................... 89

7.1. Introduction ........................................................................................................ 89

7.2. Following TCP streams ........................................................................................ 89

7.2.1. The “Follow TCP Stream” dialog box .......................................................... 89

7.3. Expert Information .............................................................................................. 90

7.3.1. Expert Info Entries .................................................................................... 90

7.3.2. “Expert Info” dialog .................................................................................. 91

7.3.3. “Colorized” Protocol Details Tree ................................................................ 92

7.3.4. “Expert” Packet List Column (optional) ........................................................ 92

7.4. Time Stamps ...................................................................................................... 92

7.4.1. Wireshark internals ................................................................................... 92

7.4.2. Capture file formats .................................................................................. 93

7.4.3. Accuracy ................................................................................................. 93

7.5. Time Zones ........................................................................................................ 93

7.5.1. Set your computer’s time correctly! .............................................................. 94

7.5.2. Wireshark and Time Zones ......................................................................... 95

7.6. Packet Reassembly .............................................................................................. 96

7.6.1. What is it? ............................................................................................... 96

7.6.2. How Wireshark handles it .......................................................................... 96

7.7. Name Resolution ................................................................................................. 97

7.7.1. Name Resolution drawbacks ....................................................................... 97

7.7.2. Ethernet name resolution (MAC layer) .......................................................... 97

7.7.3. IP name resolution (network layer) .............................................................. 98

7.7.4. TCP/UDP port name resolution (transport layer) ............................................. 98

7.8. Checksums ......................................................................................................... 98

7.8.1. Wireshark checksum validation ................................................................... 99

7.8.2. Checksum offloading ................................................................................. 99

8. Statistics ..................................................................................................................... 101

8.1. Introduction ...................................................................................................... 101

8.2. The Summary window ........................................................................................ 101

8.3. The "Protocol Hierarchy" window ........................................................................ 102

8.4. Conversations .................................................................................................... 102

8.4.1. The “Conversations” window .................................................................... 103

8.5. Endpoints ......................................................................................................... 103

8.5.1. The "Endpoints" window .......................................................................... 104

8.6. The "IO Graphs" window .................................................................................... 105

8.7. Service Response Time ....................................................................................... 106

8.7.1. The "Service Response Time DCE-RPC" window ......................................... 106

8.8. Compare two capture files ................................................................................... 106

8.9. WLAN Traffic Statistics ..................................................................................... 107

8.10. The protocol specific statistics windows ............................................................... 108

9. Telephony ................................................................................................................... 109

9.1. Introduction ...................................................................................................... 109

9.2. RTP Analysis .................................................................................................... 109

9.3. IAX2 Analysis .................................................................................................. 109

9.4. VoIP Calls ........................................................................................................ 109

9.5. LTE MAC Traffic Statistics ................................................................................ 109

9.6. LTE RLC Traffic Statistics .................................................................................. 110

9.7. The protocol specific statistics windows ................................................................ 110

10. Customizing Wireshark ............................................................................................... 111

10.1. Introduction ..................................................................................................... 111

Wireshark User’s Guide

10.2. Start Wireshark from the command line ............................................................... 111

10.3. Packet colorization ........................................................................................... 117

10.4. Control Protocol dissection ................................................................................ 118

10.4.1. The “Enabled Protocols” dialog box .......................................................... 118

10.4.2. User Specified Decodes .......................................................................... 119

10.4.3. Show User Specified Decodes ................................................................. 120

10.5. Preferences ..................................................................................................... 120

10.5.1. Interface Options ................................................................................... 120

10.6. Configuration Profiles ....................................................................................... 121

10.7. User Table ...................................................................................................... 123

10.8. Display Filter Macros ....................................................................................... 123

10.9. ESS Category Attributes .................................................................................... 123

10.10. GeoIP Database Paths ..................................................................................... 123

10.11. IKEv2 decryption table .................................................................................... 124

10.12. Object Identifiers ............................................................................................ 124

10.13. PRES Users Context List ................................................................................. 125

10.14. SCCP users Table ........................................................................................... 125

10.15. SMI (MIB and PIB) Modules ........................................................................... 125

10.16. SMI (MIB and PIB) Paths ............................................................................... 125

10.17. SNMP Enterprise Specific Trap Types ............................................................... 126

10.18. SNMP users Table .......................................................................................... 126

10.19. Tektronix K12xx/15 RF5 protocols Table ........................................................... 126

10.20. User DLTs protocol table ................................................................................ 127

A. Wireshark Messages .................................................................................................... 128

A.1. Packet List Messages ......................................................................................... 128

A.1.1. [Malformed Packet] ................................................................................ 128

A.1.2. [Packet size limited during capture] ........................................................... 128

A.2. Packet Details Messages .................................................................................... 128

A.2.1. [Response in frame: 123] ......................................................................... 128

A.2.2. [Request in frame: 123] ........................................................................... 129

A.2.3. [Time from request: 0.123 seconds] ........................................................... 129

A.2.4. [Stream setup by PROTOCOL (frame 123)] ................................................ 129

B. Files and Folders ......................................................................................................... 130

B.1. Capture Files .................................................................................................... 130

B.1.1. Libpcap File Contents ............................................................................. 130

B.1.2. Not Saved in the Capture File ................................................................... 130

B.2. Configuration Files and Folders ........................................................................... 131

B.2.1. Protocol help configuration ....................................................................... 135

B.3. Windows folders ............................................................................................... 136

B.3.1. Windows profiles .................................................................................... 136

B.3.2. Windows roaming profiles ....................................................................... 137

B.3.3. Windows temporary folder ....................................................................... 137

C. Protocols and Protocol Fields ........................................................................................ 138

D. Related command line tools .......................................................................................... 139

D.1. Introduction ..................................................................................................... 139

D.2. tshark: Terminal-based Wireshark ........................................................................ 139

D.3. tcpdump: Capturing with tcpdump for viewing with Wireshark ................................ 141

D.4. dumpcap: Capturing with dumpcap for viewing with Wireshark ............................... 141

D.5. capinfos: Print information about capture files ........................................................ 142

D.6. rawshark: Dump and analyze network traffic. ........................................................ 143

D.7. editcap: Edit capture files ................................................................................... 144

D.8. mergecap: Merging multiple capture files into one .................................................. 149

D.9. text2pcap: Converting ASCII hexdumps to network captures ..................................... 150

D.10. reordercap: Reorder a capture file ...................................................................... 152

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11. This Document’s License (GPL) ................................................................................... 153

viii

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.

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 https://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.

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.

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.8, “mergecap: Merging multiple capture

files into one” is derived.

Preface

• Ashok Narayanan from whose text2pcap man page Section D.9, “text2pcap: Converting ASCII

hexdumps to network captures” is derived.

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 was originally written in DocBook/XML and converted to AsciiDoc by Gerald Combs. You will find some specially marked parts in this book:

This is a warning

You should pay attention to a warning, 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 are helpful for your everyday work using Wireshark.

5. Where to get the latest copy of this document?

The latest copy of this documentation can always be found at https://www.wireshark.org/docs/.

6. Providing feedback about this document

Should you have any feedback about this document, please send it to the authors through wireshark-

dev[AT]wireshark.org.

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.

• Open files containing packet data captured with tcpdump/WinDump, Wireshark, and a number of other

packet capture programs.

• Import packets from text files containing hex dumps of packet data.

• Display packets with very detailed protocol information.

• Save packet data captured.

• Export some or all packets in a number of capture file formats.

• Filter packets on many criteria.

• Search for packets on many criteria.

• Colorize packet display based on filters.

Introduction

• 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 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 media

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 https://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 dissectors

There are protocol dissectors (or decoders, as they are known in other products) for a great many protocols: see Appendix C, Protocols and Protocol Fields.

1.1.7. Open Source Software

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!

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).

Introduction

1.2. System Requirements

The 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.

Busy networks mean large captures

Working with a busy network can easily produce huge capture files. Capturing on a gigabit or even 100 megabit network can produce hundreds of megabytes of capture data in a short time. A fast processor, lots of memory and disk space is always a good idea.

If Wireshark runs out of memory it will crash. See https://wiki.wireshark.org/KnownBugs/OutOfMemory for details and workarounds.

Although Wireshark captures packets using a separate process the main interface is single-threaded and won’t benefit much from multi-core systems.

1.2.1. Microsoft Windows

• The current version of Wireshark should support any version of Windows that is still within its extended

support lifetime. At the time of writing this includes Windows 10, 8, 7, Vista, Server 2016, Server 2012,

Server 2008 R2, and Server 2008.

• Any modern 64-bit AMD64/x86-64 or 32-bit x86 processor.

• 400 MB available RAM. Larger capture files require more RAM.

• 300 MB available disk space. Capture files require additional disk space.

• 1024×768 (1280×1024 or higher recommended) resolution with at least 16 bit color. 8 bit color should

work but user experience will be degraded. Power users will find multiple monitors useful.

• A supported network card for capturing

• Ethernet. Any card supported by Windows should work. See the wiki pages on Ethernet capture and

offloading for issues that may affect your environment.

• 802.11. See the Wireshark wiki page. Capturing raw 802.11 information may be difficult without special equipment.

• Other media. See https://wiki.wireshark.org/CaptureSetup/NetworkMedia

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).

Wireshark 1.12 was the last release branch to support Windows Server 2003. Wireshark 1.10 was the last branch to officially support Windows XP. See the Wireshark release lifecycle page for more details.

1.2.2. UNIX / Linux

Wireshark runs on most UNIX and UNIX-like platforms including OS X and Linux. The system requirements should be comparable to the Windows values listed above.

Introduction

Binary packages are available for most Unices and Linux distributions including the following platforms:

• Apple OS X

• Debian GNU/Linux

• FreeBSD

• Gentoo Linux

• HP-UX

• Mandriva Linux

• NetBSD

• OpenPKG

• Red Hat Enterprise/Fedora Linux

• Sun Solaris/i386

• Sun Solaris/SPARC

• Canonical Ubuntu

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 Wireshark

You 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 OS X installers are signed by the Wireshark Foundation.

A new Wireshark version typically becomes available each month or two.

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”.

1.4. A brief history of Wireshark

In 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.

Introduction

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 or 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:

1. 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.

2. 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.

3. 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: https://www.wireshark.org/download.html.

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 https://www.wireshark.org/.

1.6.2. Wiki

The Wireshark Wiki at https://wiki.wireshark.org/ 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, 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. Q&A Site

The Wireshark Q&A site at https://ask.wireshark.org/ offers a resource where questions and answers come together. You have the option to search what questions were asked before and what answers were given by people who knew about the issue. Answers are graded, so you can pick out the best ones easily. If your question hasn’t been discussed before you can post one yourself.

Introduction

1.6.4. FAQ

The Frequently Asked Questions lists often asked questions and their corresponding answers.

Read the FAQ

Before sending any mail to the mailing lists below, be sure to read the FAQ. It will often answer any questions 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: 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 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 building

usually appear about every 4-8 weeks.

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: 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.

The lists are archived

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.

1.6.6. Reporting Problems

Note

Before reporting any problems, please make sure you have installed the latest version of Wireshark.

When reporting problems with Wireshark please supply the following information:

1. The version number of Wireshark and the dependent libraries linked with it, such as Qt or GLib. You can obtain this from Wireshark’s about box or the command wireshark -v.

Introduction

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.

Don’t send large files

Do not send large files (> 1 MB) 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 capture files to the mailing lists be sure they don’t contain any sensitive or confidential information like passwords or personally identifiable information (PII).

1.6.7. Reporting Crashes on UNIX/Linux platforms

When 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.

Introduction

Mail backtrace.txt to wireshark-dev[AT]wireshark.org.

1.6.8. Reporting Crashes on Windows platforms

The Windows distributions don’t contain the symbol files (.pdb) because they are very large. You can download them separately at https://www.wireshark.org/download/win32/all-versions and https://

www.wireshark.org/download/win64/all-versions

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 first install it. If you are running Windows or OS X 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 ship 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 following are the general steps you would use:

1. Download the relevant package for your needs, e.g. source or binary distribution.

2. Compile the source into a binary if needed. This may involve building and/or installing other necessary packages.

3. Install the binaries into their final destinations.

2.2. Obtaining the source and binary distributions

You can obtain both source and binary distributions from the Wireshark web site: https://

www.wireshark.org/. Select the download link and then select the desired binary or source package.

Download all required files

If you are building Wireshark from source you will 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.

2.3. Installing Wireshark under Windows

Windows installers contain the platform and version, e.g. Wireshark-winxx-2.1.x.exe. The Wireshark installer includes WinPcap which is required for packet capture.

Simply download the Wireshark installer from: https://www.wireshark.org/download.html and execute it. Official packages are signed by the Wireshark Foundation. You can choose to install several optional

Building and Installing Wireshark

components and select the location of the installed package. The default settings are recommended for most users.

2.3.1. Installation Components

On the Choose Components page of the installer you can select from the following:

• Wireshark - The network protocol analyzer that we all know and mostly love.

• TShark - A command-line network protocol analyzer. If you haven’t tried it you should.

• Wireshark 1 Legacy - The old (GTK+) user interface in case you need it.

• Plugins & Extensions - Extras for the Wireshark and TShark dissection engines

• Dissector Plugins - Plugins with some extended dissections.

• Tree Statistics Plugins - Extended statistics.

• Mate - Meta Analysis and Tracing Engine - User configurable extension(s) of the display filter

engine, see https://wiki.wireshark.org/Mate for details.

• SNMP MIBs - SNMP MIBs for a more detailed SNMP dissection.

• Tools - Additional command line tools to work with capture files

• Editcap - Reads a capture file and writes some or all of the packets into another capture file.

• Text2Pcap - Reads in an ASCII hex dump and writes the data into a pcap capture file.

• Reordercap - Reorders a capture file by timestamp.

• Mergecap - Combines multiple saved capture files into a single output file.

• Capinfos - Provides information on capture files.

• Rawshark - Raw packet filter.

• User’s Guide - Local installation of the User’s Guide. The Help buttons on most dialogs will require

an internet connection to show help pages if the User’s Guide is not installed locally.

2.3.2. Additional Tasks

• Start Menu Shortcuts - Add some start menu shortcuts.

• Desktop Icon - Add a Wireshark icon to the desktop.

• Quick Launch Icon - add a Wireshark icon to the Explorer quick launch toolbar.

• Associate file extensions to Wireshark - Associate standard network trace files to Wireshark.

2.3.3. Install Location

By default Wireshark installs into %ProgramFiles%\Wireshark on 32-bit Windows and %ProgramFiles64%\Wireshark on 64-bit Windows. This expands to C:\Program Files \Wireshark on most systems.

Building and Installing Wireshark

2.3.4. Installing WinPcap

The Wireshark installer contains the latest WinPcap installer. If you don’t have WinPcap 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 WinPcap will be installed. If you don’t wish to do this or if you wish to reinstall WinPcap you can check the Install WinPcap box as needed.

For more information about WinPcap see https://www.winpcap.org/ and https://wiki.wireshark.org/

WinPcap.

2.3.5. Windows installer command line options

For special cases, there are some command line parameters available:

• /S runs the installer or uninstaller silently with default values. The silent installer will not install

WinPCap.

• /desktopicon installation of the desktop icon, =yes - force installation, =no - don’t install,

otherwise use default settings. This option can be useful for a silent installer.

• /quicklaunchicon installation of the quick launch icon, =yes - force installation, =no - don’t

install, otherwise use default settings.

• /D sets the default installation directory ($INSTDIR), overriding InstallDir and InstallDirRegKey. It

must be the last parameter used in the command line and must not contain any quotes even if the path contains spaces.

• /NCRC disables the CRC check. We recommend against using this flag.

Example:

> Wireshark-win64-wireshark-2.0.5.exe /NCRC /S /desktopicon=yes /quicklaunchicon=no /D=C:\Program Files\Foo

Running the installer without any parameters shows the normal interactive installer.

2.3.6. Manual WinPcap Installation

As mentioned above, the Wireshark installer takes care of installing WinPcap. The following is only necessary if you want to use a different version than the one included in the Wireshark installer, e.g. because a new WinPcap version was released.

Additional WinPcap versions (including newer alpha or beta releases) can be downloaded from the main WinPcap site: https://www.winpcap.org/. The Installer for Windows supports modern Windows operating systems.

2.3.7. Update Wireshark

By default the offical Windows package 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 subcribe to the wireshark-announce mailing list. 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 start the installer exe. A reboot is usually not required and all your personal settings remain unchanged.

Building and Installing Wireshark

2.3.8. Update WinPcap

New versions of WinPcap are less frequently available. You will find WinPcap update instructions the WinPcap web site at https://www.winpcap.org/. You may have to reboot your machine after installing a new WinPcap version.

2.3.9. Uninstall Wireshark

You 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 WinPcap. WinPcap is left installed by default in case other programs need it.

2.3.10. Uninstall WinPcap

You can uninstall WinPcap independently of Wireshark using the WinPcap entry in the Programs and Features control panel. Remember that if you uninstall WinPcap you won’t be able to capture anything

with Wireshark.

2.4. Installing Wireshark under OS X

The official OS X packages are distributed as disk images (.dmg) containing the application installer. To install Wireshark simply open the disk image and run the enclosed installer.

The installer package includes Wireshark, its related command line utilities, and a launch daemon that adjusts capture permissions at system startup. See the included Read me first file for more details.

2.5. Building Wireshark from source under UNIX

Building Wireshark requires the proper build environment including a compiler and many supporting libraries. See the Developer’s Guide at https://www.wireshark.org/docs/ for more information.

Use the following general steps to build Wireshark from source under UNIX or Linux:

1. Unpack the source from its compressed tar file. If you are using Linux or your version of UNIX uses GNU tar you can use the following command:

$ tar xaf wireshark-2.0.5.tar.bz2

In other cases you will have to use the following commands:

$ bzip2 -d wireshark-2.0.5.tar.bz2 $ tar xf wireshark-2.0.5.tar

2. Change directory to the Wireshark source directory.

$ cd wireshark-2.0.5

3. Configure your source so it will build correctly for your version of UNIX. You can do this with the following command:

Building and Installing Wireshark

$ ./configure

If this step fails you will have to rectify the problems and rerun configure. Troubleshooting hints are provided in Section 2.7, “Troubleshooting during the install on Unix”.

4. Build the sources.

$ make

5. Install the software in its final destination.

$ make install

Once you have installed Wireshark with make install above, you should be able to run it by entering wireshark.

2.6. Installing the binaries under UNIX

In 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 RPM’s under Red Hat and alike

Building RPMs from Wireshark’s source code results in several packages (most distributions follow the same system):

• The wireshark package contains the core Wireshark libraries and command-line tools.

• The wireshark-qt package contains the Qt-based GUI.

• The wireshark-gtk (formerly wireshark-gnome) package contains the legacy Gtk+ based GUI.

Many distributions use yum or a similar package management tool to make installation of software (including its dependencies) easier. If your distribution uses yum, use the following command to install Wireshark together with the Qt GUI:

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 deb’s under Debian, Ubuntu and other Debian derivatives

If you can just install from the repository then use

$ aptitude install wireshark

Aptitude should take care of all of the dependency issues for you. Use the following command to install downloaded Wireshark deb’s under Debian:

Building and Installing Wireshark

$ dpkg -i wireshark-common_2.0.5.0-1_i386.deb wireshark_wireshark-2.0.5.0-1_i386.deb

dpkg doesn’t take care of all dependencies, but reports what’s missing.

Capturing requires privileges

By installing Wireshark packages non-root users won’t gain rights automatically to capture packets. To allow non-root users to capture packets follow the procedure described in /usr/

share/doc/wireshark-common/README.Debian

2.6.3. Installing from portage under Gentoo Linux

Use the following command to install Wireshark under Gentoo Linux with all of the extra features:

$ USE="adns gtk ipv6 portaudio snmp ssl kerberos threads selinux" emerge wireshark

2.6.4. Installing from packages under FreeBSD

Use 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.

2.7. Troubleshooting during the install on Unix

A number of errors can occur during the installation process. Some hints on solving these are provided here. If the configure stage fails you will need to find out why. You can check the file config.log in

the source directory to find out what failed. The last few lines of this file should help in determining the problem.

The standard problems are that you do not have a required development package on your system or that the development package isn’t new enough. Note that installing a library package isn’t enough. You need to install its development package as well. configure will also fail if you do not have libpcap (at least the required include files) on your system.

If you cannot determine what the problems are, send an email to the wireshark-dev mailing list explaining your problem. Include the output from config.log and anything else you think is relevant such as a trace of the make stage.

2.8. Building from source under Windows

We strongly recommended that you use the binary installer for Windows unless you want to start developing Wireshark on the Windows platform.

For further information how to build Wireshark for Windows from the sources see the Developer’s Guide at https://www.wireshark.org/docs/

You may also want to have a look at the Development Wiki (https://wiki.wireshark.org/Development) for the latest available development documentation.

Chapter 3. User Interface

3.1. Introduction

By now you have installed Wireshark and are most likely keen to get started capturing your first packets. In the next chapters we will explore:

• How the Wireshark user interface works

• How to capture packets in Wireshark

• How to view packets in Wireshark

• How to filter packets in Wireshark

• … and many other things!

3.2. Start Wireshark

You can start Wireshark from your shell or window manager.

Power user tip

When starting Wireshark it’s possible to specify optional settings using the command line. See Section 10.2, “Start Wireshark from the command line” for details.

In the following chapters a lot of screenshots from Wireshark will be shown. 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 window

Let’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.

1. The menu (see Section 3.4, “The Menu”) is used to start actions.

2. The main toolbar (see Section 3.16, “The “Main” toolbar”) provides quick access to frequently used items from the menu.

3. The filter toolbar (see Section 3.17, “The “Filter” toolbar”) provides a way to directly manipulate the currently used display filter (see Section 6.3, “Filtering packets while viewing”).

4. The packet list pane (see Section 3.18, “The “Packet List” pane”) displays a summary of each packet captured. By clicking on packets in this pane you control what is displayed in the other two panes.

User Interface

5. The packet details pane (see Section 3.19, “The “Packet Details” pane”) displays the packet selected in the packet list pane in more detail.

6. The packet bytes pane (see Section 3.20, “The “Packet Bytes” pane”) displays the data from the packet selected in the packet list pane, and highlights the field selected in the packet details pane.

7. The statusbar (see Section 3.21, “The Statusbar”) shows some detailed information about the current program state and the captured data.

Tip

The layout of the main window can be customized by changing preference settings. See

Section 10.5, “Preferences” for details!

3.3.1. Main Window Navigation

Packet 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 3.5, “Go menu

items” for additional navigation keystrokes.

Table 3.1. Keyboard Navigation

Accelerator Description Tab, Shift+Tab Move between screen elements, e.g. from the

toolbars to the packet list to the packet detail.

Down Move to the next packet or detail item. Up Move to the previous packet or detail item. Ctrl+Down, F8 Move to the next packet, even if the packet list

isn’t focused.

Ctrl+Up, F7 Move to the previous packet, even if the packet list

isn’t focused.

Ctrl+. Move to the next packet of the conversation (TCP,

UDP or IP)

Ctrl+, Move to the previous packet of the conversation

(TCP, UDP or IP)

Left In the packet detail, closes the selected tree item. If

it’s already closed, jumps to the parent node.

Right In the packet detail, opens the selected tree item. Shift+Right In the packet detail, opens the selected tree item

and all of its subtrees.

Ctrl+Right In the packet detail, opens all tree items. Ctrl+Left In the packet detail, closes all tree items. Backspace In the packet detail, jumps to the parent node. Return, Enter In the packet detail, toggles the selected tree item.

Help → About Wireshark → Keyboard Shortcuts 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 Menu

Wireshark’s main menu is located either at the top of the main window (Windows, Linux) or at the top of your main screen (OS X). An example is shown in Figure 3.2, “The Menu”.

Note

Some menu items will be disabled (greyed out( if the corresponding feature isn’t available. For example, you cannot save a capture file if you haven’t captured or loaded any packets.

Figure 3.2. The Menu

The main menu contains the following items: File This menu contains items to open and merge capture files, save, print, or export

Edit This menu contains items to find a packet, time reference or mark one or more packets,

User Interface

capture files in whole or in part, and to quit the Wireshark application. See Section 3.5,

“The “File” menu”.

handle configuration profiles, and set your preferences; (cut, copy, and paste are not presently implemented). See Section 3.6, “The “Edit” menu”.

View 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”.

Go This menu contains items to go to a specific packet. See Section 3.8, “The “Go”

menu”.

Capture This menu allows you to start and stop captures and to edit capture filters. See

Section 3.9, “The “Capture” menu”.

Analyze 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”.

Statistics 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”.

Telephony 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”. Wireless The items in this menu show Bluetooth and IEEE 802.11 wireless statistics. Tools This menu contains various tools available in Wireshark, such as creating Firewall

ACL Rules. See Section 3.13, “The “Tools” menu”. Help 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.

Shortcuts make life easier

Most common menu items have keyboard shortcuts. For example, you can press the Control (or Strg in German) and the K keys together to open the “Capture Options” dialog.

3.5. The “File” menu

The 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

Menu Item Accelerator Description

Open… Ctrl+O This shows the file open dialog

Open Recent This lets you open recently

Merge… This menu item lets you merge

Import from Hex Dump… This menu item brings up the

Close Ctrl+W This menu item closes the current

Save Ctrl+S This menu item saves the current

User Interface

box that allows you to load a capture file for viewing. It is discussed in more detail in

Section 5.2.1, “The “Open Capture File” dialog box”.

opened capture files. Clicking on one of the submenu items will open the corresponding capture file directly.

a capture file into the currently loaded one. It is discussed in more detail in Section 5.4,

“Merging capture files”.

import file dialog box that allows you to import a text file containing a hex dump into a new temporary capture. It is discussed in more detail in

Section 5.5, “Import hex dump”.

capture. If you haven’t saved the capture, you will be asked to do so first (this can be disabled by a preference setting).

capture. If you have not set a default capture file name (perhaps with the -w <capfile> option), Wireshark pops up the Save Capture File As dialog box (which is discussed further

User Interface

Menu Item Accelerator Description

in Section 5.3.1, “The “Save

Capture File As” dialog box”).

If you have already saved the current capture, this menu item will be greyed out.

You cannot save a live capture while the capture is in progress. You must stop the capture in order to save.

Save As… Shift+Ctrl+S This menu item allows you to

save the current capture file to whatever file you would like. It pops up the Save Capture File As dialog box (which is discussed further in Section 5.3.1, “The

“Save Capture File As” dialog box”).

File Set → List Files

File Set → Next File

File Set → Previous File

Export Specified Packets… This menu item allows you

Export Packet Dissections… Ctrl+H These menu items allow you

This menu item allows you to show a list of files in a file set. It pops up the Wireshark List File Set dialog box (which is discussed further in Section 5.6,

“File Sets”).

If the currently loaded file is part of a file set, jump to the next file in the set. If it isn’t part of a file set or just the last file in that set, this item is greyed out.

If the currently loaded file is part of a file set, jump to the previous file in the set. If it isn’t part of a file set or just the first file in that set, this item is greyed out.

to export all (or some) of the packets in the capture file to file. It pops up the Wireshark Export dialog box (which is discussed further in Section 5.7, “Exporting

data”).

to export the currently selected bytes in the packet bytes pane to a text file file in a number of formats including plain, CSV, and XML. It is discussed further in Section 5.7.7, “The "Export

User Interface

Menu Item Accelerator Description

selected packet bytes" dialog box”.

Export Objects These menu items allow you to

export captured DICOM, HTTP, SMB, or TFTP objects into local files. It pops up a corresponding object list (which is discussed further in Section 5.7.8, “The

"Export Objects" dialog box”)

Print… Ctrl+P This menu item allows you to

print all (or some) of the packets in the capture file. It pops up the Wireshark Print dialog box (which is discussed further in

Section 5.8, “Printing packets”).

Quit Ctrl+Q This menu item allows you to

quit from Wireshark. Wireshark will ask to save your capture file if you haven’t previously saved it (this can be disabled by a preference setting).

3.6. The “Edit” menu

The 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

Menu Item Accelerator Description

Copy These menu items will copy

Find Packet… Ctrl+F This menu item brings up a

Find Next Ctrl+N This menu item tries to find the

Find Previous Ctrl+B This menu item tries to find the

the packet list, packet detail, or properties of the currently selected packet to the clipboard.

toolbar that allows you to find a packet by many criteria. There is further information on finding packets in Section 6.8, “Finding

packets”.

next packet matching the settings from “Find Packet…”.

previous packet matching the settings from “Find Packet…”.

User Interface

Menu Item Accelerator Description

Mark/Unmark Packet Ctrl+M This menu item marks the

currently selected packet. See

Section 6.10, “Marking packets”

for details.

Mark All Displayed Packets Shift+Ctrl+M This menu item marks all

displayed packets.

Unmark All Displayed Packets Ctrl+Alt+M This menu item unmarks all

displayed packets.

Next Mark Shift+Alt+N Find the next marked packet. Previous Mark Shift+Alt+B Find the previous marked packet. Ignore/Unignore Packet Ctrl+D This menu item marks the

currently selected packet as ignored. See Section 6.11,

“Ignoring packets” for details.

Ignore All Displayed Shift+Ctrl+D This menu item marks all

displayed packets as ignored.

Unignore All Displayed Ctrl+Alt+D This menu item unmarks all

ignored packets.

Set/Unset Time Reference Ctrl+T This menu item set a time

reference on the currently selected packet. See

Section 6.12.1, “Packet time referencing” for more

information about the time referenced packets.

Unset All Time References Ctrl+Alt+T This menu item removes all time

references on the packets.

Next Time Reference Ctrl+Alt+N This menu item tries to find the

next time referenced packet.

Previous Time Reference Ctrl+Alt+B This menu item tries to find the

previous time referenced packet.

Time Shift Ctrl+Shift+T This will show the Time Shift

dialog, which allows you to adjust the timestamps of some or all packets.

Packet Comment… This will let you add a comment

to a single packet. Note that the ability to save packet comments depends on your file format. E.g. pcapng supports comments, pcap does not.

Configuration Profiles… Shift+Ctrl+A This menu item brings up

a dialog box for handling configuration profiles. More detail is provided in Section 10.6,

“Configuration Profiles”.

Menu Item Accelerator Description Preferences… Shift+Ctrl+P or Cmd+ (OS X) This menu item brings up a

3.7. The “View” menu

The Wireshark View menu contains the fields shown in Table 3.4, “View menu items”.

Figure 3.5. The “View” Menu

User Interface

dialog box that allows you to set preferences for many parameters that control Wireshark. You can also save your preferences so Wireshark will use them the next time you start it. More detail is provided in Section 10.5,

“Preferences”.

Table 3.4. View menu items

Menu Item Accelerator Description

Main Toolbar This menu item hides or

shows the main toolbar, see

Section 3.16, “The “Main” toolbar”.

Filter Toolbar This menu item hides or

shows the filter toolbar, see

Section 3.17, “The “Filter” toolbar”.

Wireless Toolbar This menu item hides or shows

the wireless toolbar. May not be present on some platforms.

Statusbar This menu item hides or shows

the statusbar, see Section 3.21,

“The Statusbar”.

Packet List This menu item hides or

shows the packet list pane, see

Section 3.18, “The “Packet List” pane”.

Packet Details This menu item hides or shows

the packet details pane, see

Section 3.19, “The “Packet Details” pane”.

Packet Bytes This menu item hides or shows

the packet bytes pane, see

Section 3.20, “The “Packet Bytes” pane”.

User Interface

Menu Item Accelerator Description

Time Display Format → Date and Time of Day: 1970-01-01 01:02:03.123456

Time Display Format → Time of Day: 01:02:03.123456

Time Display Format → Seconds Since Epoch (1970-01-01):

1234567890.123456

Time Display Format → Seconds Since Beginning of Capture:

123.123456

Time Display Format → Seconds Since Previous Captured Packet:

1.123456

Time Display Format → Seconds Since Previous Displayed Packet:

1.123456

Time Display Format → Automatic (File Format Precision)

Selecting this tells Wireshark to display the time stamps in date and time of day format, see Section 6.12, “Time display

formats and time references”.

The fields "Time of Day", "Date and Time of Day", "Seconds Since Beginning of Capture", "Seconds Since Previous Captured Packet" and "Seconds Since Previous Displayed Packet" are mutually exclusive.

Selecting this tells Wireshark to display time stamps in time of day format, see Section 6.12,

“Time display formats and time references”.

Selecting this tells Wireshark to display time stamps in seconds since 1970-01-01 00:00:00, see

Section 6.12, “Time display formats and time references”.

Selecting this tells Wireshark to display time stamps in seconds since beginning of capture format, see Section 6.12,

“Time display formats and time references”.

Selecting this tells Wireshark to display time stamps in seconds since previous captured packet format, see Section 6.12,

“Time display formats and time references”.

Selecting this tells Wireshark to display time stamps in seconds since previous displayed packet format, see Section 6.12,

“Time display formats and time references”.

Selecting this tells Wireshark to display time stamps with the precision given by the capture file format used, see

Section 6.12, “Time display formats and time references”.

User Interface

Menu Item Accelerator Description

The fields "Automatic", "Seconds" and "…seconds" are mutually exclusive.

Time Display Format → Seconds: 0

Time Display Format → … seconds: 0….

Time Display Format → Display Seconds with hours and minutes

Name Resolution → Resolve Name

Name Resolution → Enable for MAC Layer

Name Resolution → Enable for Network Layer

Name Resolution → Enable for Transport Layer

Colorize Packet List This item allows you to control

Selecting this tells Wireshark to display time stamps with a precision of one second, see

Section 6.12, “Time display formats and time references”.

Selecting this tells Wireshark to display time stamps with a precision of one second, decisecond, centisecond, millisecond, microsecond or nanosecond, see Section 6.12,

“Time display formats and time references”.

Selecting this tells Wireshark to display time stamps in seconds, with hours and minutes.

This item allows you to trigger a name resolve of the current packet only, see Section 7.7,

“Name Resolution”.

This item allows you to control whether or not Wireshark translates MAC addresses into names, see Section 7.7, “Name

Resolution”.

This item allows you to control whether or not Wireshark translates network addresses into names, see Section 7.7, “Name

Resolution”.

This item allows you to control whether or not Wireshark translates transport addresses into names, see Section 7.7, “Name

Resolution”.

whether or not Wireshark should colorize the packet list.

Enabling colorization will slow down the display of new packets while capturing / loading capture files.

Auto Scroll in Live Capture This item allows you to specify

that Wireshark should scroll the packet list pane as new packets

User Interface

Menu Item Accelerator Description

come in, so you are always looking at the last packet. If you do not specify this, Wireshark simply adds new packets onto the end of the list, but does not scroll the packet list pane.

Zoom In Ctrl++ Zoom into the packet data

(increase the font size).

Zoom Out Ctrl+- Zoom out of the packet data

(decrease the font size).

Normal Size Ctrl+= Set zoom level back to 100% (set

font size back to normal).

Resize All Columns Shift+Ctrl+R Resize all column widths so the

content will fit into it. Resizing may take a significant

amount of time, especially if a large capture file is loaded.

Displayed Columns This menu items folds out with

a list of all configured columns. These columns can now be shown or hidden in the packet list.

Expand Subtrees Shift+

Collapse Subtrees Shift+

Expand All Ctrl+

Collapse All Ctrl+

Colorize Conversation This menu item brings up a

→

←

→

←

This menu item expands the currently selected subtree in the packet details tree.

This menu item collapses the currently selected subtree in the packet details tree.

Wireshark keeps a list of all the protocol subtrees that are expanded, and uses it to ensure that the correct subtrees are expanded when you display a packet. This menu item expands all subtrees in all packets in the capture.

This menu item collapses the tree view of all packets in the capture list.

submenu that allows you to color packets in the packet list pane based on the addresses of the currently selected packet. This makes it easy to distinguish packets belonging to different

User Interface

Menu Item Accelerator Description

conversations. Section 10.3,

“Packet colorization”.

Colorize Conversation → Color 1-10

Colorize Conversation → Reset coloring

Colorize Conversation → New Coloring Rule…

Coloring Rules… This menu item brings up a

Show Packet in New Window This menu item brings up the

Reload Ctrl+R This menu item allows you to

These menu items enable one of the ten temporary color filters based on the currently selected conversation.

This menu item clears all temporary coloring rules.

This menu item opens a dialog window in which a new permanent coloring rule can be created based on the currently selected conversation.

dialog box that allows you to color packets in the packet list pane according to filter expressions you choose. It can be very useful for spotting certain types of packets, see Section 10.3, “Packet

colorization”.

selected packet in a separate window. The separate window shows only the tree view and byte view panes.

reload the current capture file.

3.8. The “Go” menu

The Wireshark Go menu contains the fields shown in Table 3.5, “Go menu items”.

Figure 3.6. The “Go” Menu

Table 3.5. Go menu items

Menu Item Accelerator Description

Back Alt+

Forward Alt+

←

→

Jump to the recently visited packet in the packet history, much like the page history in a web browser.

Jump to the next visited packet in the packet history, much like the page history in a web browser.

User Interface

Menu Item Accelerator Description

Go to Packet… Ctrl+G Bring up a window frame that

allows you to specify a packet number, and then goes to that packet. See Section 6.9, “Go to a

specific packet” for details.

Go to Corresponding Packet Go to the corresponding packet

of the currently selected protocol field. If the selected field doesn’t correspond to a packet, this item is greyed out.

Previous Packet Ctrl+

Next Packet Ctrl+

First Packet Ctrl+Home Jump to the first packet of the

Last Packet Ctrl+End Jump to the last packet of the

Previous Packet In Conversation Ctrl+, Move to the previous packet

Next Packet In Conversation Ctrl+. Move to the next packet in the

↑

↓

Move to the previous packet in the list. This can be used to move to the previous packet even if the packet list doesn’t have keyboard focus.

Move to the next packet in the list. This can be used to move to the previous packet even if the packet list doesn’t have keyboard focus.

capture file.

in the current conversation. This can be used to move to the previous packet even if the packet list doesn’t have keyboard focus.

current conversation. This can be used to move to the previous packet even if the packet list doesn’t have keyboard focus.

3.9. The “Capture” menu

The Wireshark Capture menu contains the fields shown in Table 3.6, “Capture menu items”.

Figure 3.7. The “Capture” Menu

Table 3.6. Capture menu items

Menu Item Accelerator Description

Interfaces… Ctrl+I This menu item brings up a

dialog box that shows what’s

User Interface

Menu Item Accelerator Description

going on at the network interfaces Wireshark knows of, see Section 4.4, “The “Capture

Interfaces” dialog box”) .

Options… Ctrl+K This menu item brings up the

Capture Options dialog box (discussed further in Section 4.5,

“The “Capture Options” dialog box”) and allows you to start

capturing packets.

Start Ctrl+E Immediately start capturing

packets with the same settings than the last time.

Stop Ctrl+E This menu item stops the

currently running capture, see

Section 4.14.1, “Stop the running capture”) .

Restart Ctrl+R This menu item stops the

currently running capture and starts again with the same options, this is just for convenience.

Capture Filters… This menu item brings up a

dialog box that allows you to create and edit capture filters. You can name filters, and you can save them for future use. More detail on this subject is provided in Section 6.6,

“Defining and saving filters”

3.10. The “Analyze” menu

The Wireshark Analyze menu contains the fields shown in Table 3.7, “Analyze menu items”.

Figure 3.8. The “Analyze” Menu

Table 3.7. Analyze menu items

Menu Item Accelerator Description

Display Filters… This menu item brings up a

dialog box that allows you to create and edit display filters. You can name filters, and you can save them for future use. More detail on this subject is provided in Section 6.6,

“Defining and saving filters”

User Interface

Menu Item Accelerator Description

Display Filter Macros… This menu item brings up a

dialog box that allows you to create and edit display filter macros. You can name filter macros, and you can save them for future use. More detail on this subject is provided in

Section 6.7, “Defining and saving filter macros”

Apply as Column This menu item adds the selected

protocol item in the packet details pane as a column to the packet list.

Apply as Filter → …

Prepare a Filter → …

Enabled Protocols… Shift+Ctrl+E This menu item allows the

Decode As… This menu item allows the user

User Specified Decodes… This menu item allows the user

Follow TCP Stream This menu item brings up a

These menu items will change the current display filter and apply the changed filter immediately. Depending on the chosen menu item, the current display filter string will be replaced or appended to by the selected protocol field in the packet details pane.

These menu items will change the current display filter but won’t apply the changed filter. Depending on the chosen menu item, the current display filter string will be replaced or appended to by the selected protocol field in the packet details pane.

user to enable/disable protocol dissectors, see Section 10.4.1,

“The “Enabled Protocols” dialog box”

to force Wireshark to decode certain packets as a particular protocol, see Section 10.4.2,

“User Specified Decodes”

to force Wireshark to decode certain packets as a particular protocol, see Section 10.4.3,

“Show User Specified Decodes”

separate window and displays all the TCP segments captured

User Interface

Menu Item Accelerator Description

that are on the same TCP connection as a selected packet, see Section 7.2, “Following TCP

streams”

Follow UDP Stream Same functionality as “Follow

TCP Stream” but for UDP streams.

Follow SSL Stream Same functionality as “Follow

TCP Stream” but for SSL streams. See the wiki page on

SSL for instructions on providing

SSL keys.

Expert Info Open a dialog showing some

expert information about the captured packets. The amount of information will depend on the protocol and varies from very detailed to non-existent. XXX add a new section about this and link from here

Conversation Filter → …

In this menu you will find conversation filter for various protocols.

3.11. The “Statistics” menu

The Wireshark Statistics menu contains the fields shown in Table 3.8, “Statistics menu items”.

Figure 3.9. The “Statistics” Menu

All menu items will bring up a new window showing specific statistical information.

Table 3.8. Statistics menu items

Menu Item Accelerator Description

Summary Show information about the data

Protocol Hierarchy Display a hierarchical tree

Conversations Display a list of conversations

Endpoints Display a list of endpoints

captured, see Section 8.2, “The

Summary window”.

of protocol statistics, see

Section 8.3, “The "Protocol Hierarchy" window”.

(traffic between two endpoints), see Section 8.4.1, “The

“Conversations” window”.

(traffic to/from an address), see

User Interface

Menu Item Accelerator Description

Section 8.5.1, “The "Endpoints" window”.

Packet Lengths… See Section 8.10, “The protocol

specific statistics windows”

IO Graphs Display user specified graphs

(e.g. the number of packets in the course of time), see Section 8.6,

“The "IO Graphs" window”.

Service Response Time Display the time between a

request and the corresponding response, see Section 8.7,

“Service Response Time”.

ANCP See Section 8.10, “The protocol

specific statistics windows”

Colledtd… See Section 8.10, “The protocol

specific statistics windows”

Compare… See Section 8.10, “The protocol

specific statistics windows”

Flow Graph… See Section 8.10, “The protocol

specific statistics windows”

HTTP HTTP request/response statistics,

see Section 8.10, “The protocol

specific statistics windows”

IP Addresses… See Section 8.10, “The protocol

specific statistics windows”

IP Destinations… See Section 8.10, “The protocol

specific statistics windows”

IP Protocol Types… See Section 8.10, “The protocol

specific statistics windows”

ONC-RPC Programs See Section 8.10, “The protocol

specific statistics windows”

Sametime See Section 8.10, “The protocol

specific statistics windows”

TCP Stream Graph See Section 8.10, “The protocol

specific statistics windows”

UDP Multicast Streams See Section 8.10, “The protocol

specific statistics windows”

WLAN Traffic See Section 8.9, “WLAN Traffic

Statistics”

BOOTP-DHCP See Section 8.10, “The protocol

specific statistics windows”

3.12. The “Telephony” menu

The Wireshark Telephony menu contains the fields shown in Table 3.9, “Telephony menu items”.

User Interface

Figure 3.10. The “Telephony” Menu

All menu items will bring up a new window showing specific telephony related statistical information.

Table 3.9. Telephony menu items

Menu Item Accelerator Description

IAX2 See Section 9.7, “The protocol

specific statistics windows”

SMPP Operations… See Section 9.7, “The protocol

specific statistics windows”

SCTP See Section 9.7, “The protocol

specific statistics windows”

ANSI See Section 9.7, “The protocol

specific statistics windows”

GSM See Section 9.7, “The protocol

specific statistics windows”

H.225… See Section 9.7, “The protocol

specific statistics windows”

ISUP Messages… See Section 9.7, “The protocol

specific statistics windows”

LTE See Section 9.5, “LTE MAC

Traffic Statistics”

MTP3 See Section 9.7, “The protocol

specific statistics windows”

RTP See Section 9.2, “RTP Analysis” SIP… See Section 9.7, “The protocol

specific statistics windows”

UCP Messages… See Section 9.7, “The protocol

specific statistics windows”

VoIP Calls… See Section 9.4, “VoIP Calls” WAP-WSP… See Section 9.7, “The protocol

specific statistics windows”

3.13. The “Tools” menu

The Wireshark Tools menu contains the fields shown in Table 3.10, “Tools menu items”.

Figure 3.11. The “Tools” Menu

Table 3.10. Tools menu items

Menu Item Accelerator Description

Firewall ACL Rules This allows you to create

command-line ACL rules for

User Interface

Menu Item Accelerator Description

Lua These options allow you to

3.14. The “Internals” menu

many different firewall products,

including Cisco IOS, Linux

Netfilter (iptables), OpenBSD

pf and Windows Firewall

(via netsh). Rules for MAC

addresses, IPv4 addresses, TCP

and UDP ports, and IPv4+port

combinations are supported.

It is assumed that the rules will

be applied to an outside interface.

work with the Lua interpreter

optionally build into Wireshark.

See the “Lua Support in

Wireshark” in the Wireshark

Developer’s Guide.

The Wireshark Internals menu contains the fields shown in Table 3.11, “Help menu items”.

Figure 3.12. The “Internals” Menu

Table 3.11. Help menu items

Menu Item Accelerator Description

Dissector tables This menu item brings up a

Supported Protocols (slow!) This menu item brings up

3.15. The “Help” menu

The Wireshark Help menu contains the fields shown in Table 3.12, “Help menu items”.

Figure 3.13. The “Help” Menu

dialog box showing the tables

with subdissector relationships.

a dialog box showing the

supported protocols and protocol

fields.

Table 3.12. Help menu items

Menu Item Accelerator Description

Contents F1 This menu item brings up a basic

help system.

User Interface

Menu Item Accelerator Description

Manual Pages → …

Website This menu item starts a

FAQ’s This menu item starts a Web

Downloads This menu item starts a

Wiki This menu item starts a Web

Sample Captures This menu item starts a

About Wireshark This menu item brings up

This menu item starts a Web

browser showing one of the

locally installed html manual

pages.

Web browser showing the

webpage from: https://

www.wireshark.org/.

browser showing various FAQ’s.

Web browser showing the

downloads from: https://

www.wireshark.org/.

browser showing the front page

from: https://wiki.wireshark.org/.

Web browser showing the

sample captures from: https://

wiki.wireshark.org/.

an information window that

provides various detailed

information items on Wireshark,

such as how it’s build, the

plugins loaded, the used folders,

…

Note

Opening a Web browser might be unsupported in your version of Wireshark. If this is the case the corresponding menu items will be hidden.

If calling a Web browser fails on your machine, nothing happens, or the browser starts but no page is shown, have a look at the web browser setting in the preferences dialog.

3.16. The “Main” toolbar

The 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 even more packet data.

As in the menu, only the items useful in the current program state will be available. The others will be greyed out (e.g. you cannot save a capture file if you haven’t loaded one).

Figure 3.14. The “Main” toolbar

Table 3.13. Main toolbar items

User Interface

Toolbar Icon Toolbar Item Corresponding Menu

Item

Interfaces…

Options…

Start

Stop

Restart

Open…

Save As…

Capture → Interfaces…

Capture → Options…

Capture → Start

Capture → Stop

Capture → Restart

File → Open…

File → Save As…

Description

This item brings up the Capture Interfaces List dialog box (discussed further in Section 4.3,

“Start Capturing”).

This item brings up the Capture Options dialog box (discussed further in Section 4.3, “Start

Capturing”) and allows

you to start capturing packets.

This item starts capturing packets with the options form the last time.

This item stops the currently running live capture process

Section 4.3, “Start Capturing”).

This item stops the currently running live capture process and restarts it again, for convenience.

This item brings up the file open dialog box that allows you to load a capture file for viewing. It is discussed in more detail in Section 5.2.1,

“The “Open Capture File” dialog box”.

This item allows you to save the current capture file to whatever file you would like. It pops up the Save Capture File As dialog box (which is discussed further in

Section 5.3.1, “The “Save Capture File As” dialog box”).

If you currently have a temporary capture file,

User Interface

Toolbar Icon Toolbar Item Corresponding Menu

Item

Reload

Print…

Find Packet…

Go Back

Go Forward

Go to Packet…

Go To First Packet

Go To Last Packet

Colorize

Auto Scroll in Live Capture

File → Close

View → Reload

File → Print…

Edit → Find Packet…

Go → Go Back

Go → Go Forward

Go → Go to Packet…

Go → First Packet

Go → Last Packet

View → Colorize

View → Auto Scroll in Live Capture

Description

the Save icon will be shown instead.

This item closes the current capture. If you have not saved the capture, you will be asked to save it first.

This item allows you to reload the current capture file.

This item allows you to print all (or some of) the packets in the capture file. It pops up the Wireshark Print dialog box (which is discussed further in

Section 5.8, “Printing packets”).

This item brings up a dialog box that allows you to find a packet. There is further information on finding packets in Section 6.8,

“Finding packets”.

This item jumps back in the packet history.

This item jumps forward in the packet history.

This item brings up a dialog box that allows you to specify a packet number to go to that packet.

This item jumps to the first packet of the capture file.

This item jumps to the last packet of the capture file.

Colorize the packet list (or not).

Auto scroll packet list while doing a live capture (or not).

User Interface

Toolbar Icon Toolbar Item Corresponding Menu

Item

Zoom In

Zoom Out

Normal Size

Resize Columns

Capture Filters…

Display Filters…

Coloring Rules…

Preferences…

View → Zoom In

View → Zoom Out

View → Normal Size

View → Resize Columns

Capture → Capture Filters…

Analyze → Display Filters…

View → Coloring Rules…

Edit → Preferences

Description

Zoom into the packet data (increase the font size).

Zoom out of the packet data (decrease the font size).

Set zoom level back to 100%.

Resize columns, so the content fits into them.

This item brings up a dialog box that allows you to create and edit capture filters. You can name filters, and you can save them for future use. More detail on this subject is provided in

Section 6.6, “Defining and saving filters”.

This item brings up a dialog box that allows you to create and edit display filters. You can name filters, and you can save them for future use. More detail on this subject is provided in

Section 6.6, “Defining and saving filters”.

This item brings up a dialog box that allows you to color packets in the packet list pane according to filter expressions you choose. It can be very useful for spotting certain types of packets. More detail on this subject is provided in Section 10.3, “Packet

colorization”.

This item brings up a dialog box that allows you to set preferences for many parameters that control Wireshark. You can also save

User Interface

Toolbar Icon Toolbar Item Corresponding Menu

Help

3.17. The “Filter” toolbar

The 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 3.14. Filter toolbar items

Toolbar Icon Toolbar Item Description

Filter: Brings up the filter construction

Filter input The area to enter or edit

Item

Help → Contents

Description

your preferences so Wireshark will use them the next time you start it. More detail is provided in Section 10.5,

“Preferences”

This item brings up help dialog box.

dialog, described in Figure 6.8,

“The “Capture Filters” and

“Display Filters” dialog boxes”.

a display filter string, see

Section 6.4, “Building display

filter expressions”. A syntax

check of your filter string is

done while you are typing. The

background will turn red if you

enter an incomplete or invalid

string, and will become green

when you enter a valid string.

You can click on the pull down

arrow to select a previously-

entered filter string from a list.

The entries in the pull down list

will remain available even after a

program restart.

After you’ve changed something

in this field, don’t forget to press

the Apply button (or the Enter/

Return key), to apply this filter

string to the display.

This field is also where the

current filter in effect is

displayed.

User Interface

Toolbar Icon Toolbar Item Description

Expression… The middle button labeled "Add

Clear Reset the current display filter

Apply Apply the current value in the

3.18. The “Packet List” pane

The packet list pane displays all the packets in the current capture file.

Expression…" opens a dialog

box that lets you edit a display

filter from a list of protocol

fields, described in Section 6.5,

“The “Filter Expression” dialog

box”

and clears the edit area.

edit area as the new display filter.

Applying a display filter on large

capture files might take quite a

long time.

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 a lot of different columns available. Which columns are displayed can be selected by preference settings, see Section 10.5, “Preferences”.

The default columns will show:

• No. The number of the packet in the capture file. This number won’t change, even if a display filter is used.

• Time The timestamp of the packet. The presentation format of this timestamp can be changed, see

Section 6.12, “Time display formats and time references”.

• Source The address where this packet is coming from.

• Destination The address where this packet is going to.

• Protocol The protocol name in a short (perhaps abbreviated) version.

• Info Additional information about the packet content.

User Interface

There is a context menu (right mouse click) available, see details in Figure 6.4, “Pop-up menu of the

“Packet List” pane”.

3.19. The “Packet Details” pane

The 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 protocols and fields of the packet are displayed using 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 are specially displayed.

• Generated fields Wireshark itself will generate additional protocol fields which are surrounded by brackets. The information in these fields is derived from the known context to other packets in the capture file. For example, Wireshark is doing a sequence/acknowledge analysis of each TCP stream, which is displayed in the [SEQ/ACK analysis] fields of the TCP protocol.

• Links If Wireshark detected a relationship to another packet in the capture file, it will generate a link to that packet. Links are underlined and displayed in blue. If double-clicked, Wireshark jumps to the corresponding packet.

3.20. The “Packet Bytes” pane

The 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

As usual for a hexdump, the left side shows the offset in the packet data, in the middle the packet data is shown in a hexadecimal representation and on the right the corresponding ASCII characters (or . if not appropriate) are displayed.

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 7.6, “Packet Reassembly”. In this case there are some additional tabs shown at the bottom of the pane to let you select the page you want to see.

Figure 3.19. The “Packet Bytes” pane with tabs

Note

The additional pages might contain data picked from multiple packets.

The context menu (right mouse click) of the tab labels will show a list of all available pages. This can be helpful if the size in the pane is too small for all the tab labels.

3.21. The Statusbar

The statusbar displays informational messages. In general, the left side will show context related information, the middle part will show the current number

of packets, and the right side will show the selected configuration profile. Drag the handles between the text areas to change the size.

Figure 3.20. The initial Statusbar

This statusbar is shown while no capture file is loaded, e.g. when Wireshark is started.

Figure 3.21. The Statusbar with a loaded capture file

• The colorized bullet on the left shows the highest expert info level found in the currently loaded capture file. Hovering the mouse over this icon will show a textual description of the expert info level, and clicking the icon will bring up the Expert Infos dialog box. For a detailed description of expert info, see Section 7.3, “Expert Information”.

User Interface

• The left side shows information about the capture file, its name, its size and the elapsed time while it was being captured.

• The middle part 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

• 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 packets are ignored)

• The right side shows the selected configuration profile. Clicking in 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 3.22. The Statusbar with a configuration profile menu

For a detailed description of configuration profiles, see Section 10.6, “Configuration Profiles”.

Figure 3.23. The Statusbar with a selected protocol field

User Interface

This is displayed if you have selected a protocol field from the “Packet Details” pane.

Tip

The value between the brackets (in this example arp.opcode) can be used as a display filter string, representing the selected protocol field.

Figure 3.24. The Statusbar with a display filter message

This is displayed if you are trying to use a display filter which may have unexpected results. For a detailed description, see Section 6.4.5, “A common mistake”.

Chapter 4. Capturing Live Network Data

4.1. Introduction

Capturing live network data is one of the major features of Wireshark. The Wireshark capture engine provides the following features:

• Capture from different kinds of network hardware such as Ethernet or 802.11.

• Stop the capture on different triggers such as the amount of captured data, elapsed time, or the number of packets.

• Simultaneously show decoded packets while Wireshark is capturing.

• Filter packets, reducing the amount of data to be captured. See Section 4.13, “Filtering while capturing”.

• Save packets in multiple files while doing a long term capture, optionally rotating through a fixed number of files (a “ringbuffer”). See Section 4.11, “Capture files and file modes”.

• Simultaneously capture from multiple network interfaces.

The capture engine still lacks the following features:

• Stop capturing (or perform some other action) depending on the captured data.

4.2. Prerequisites

Setting up Wireshark to capture packets for the first time can be tricky. A comprehensive guide “How To setup a Capture” is available at https://wiki.wireshark.org/CaptureSetup.

Here are some common pitfalls:

• You may need special privileges to start a live capture.

• You need to choose the right network interface to capture packet data from.

• You need to capture at the right place in the network to see the traffic you want to see.

If you have any problems setting up your capture environment you should have a look at the guide mentioned above.

4.3. Start Capturing

The following methods can be used to start capturing packets with Wireshark:

• You can double-click on an interface in the main window.

• You can get an overview of the available interfaces using the “Capture Interfaces” dialog box (Capture → Options…). See Figure 4.1, “The “Capture Interfaces” dialog box on Microsoft Windows” or

Figure 4.2, “The “Capture Interfaces” dialog box on Unix/Linux” for more information. You can start

a capture from this dialog box using the Start button.

Capturing Live Network Data

•

You can immediately start a capture using your current settings by selecting Capture → Start or by cliking the first toolbar button.

• If you already know the name of the capture interface you can start Wireshark from the command line:

$ wireshark -i eth0 -k

This will start Wireshark capturing on interface eth0. More details can be found at Section 10.2, “Start

Wireshark from the command line”.

4.4. The “Capture Interfaces” dialog box

When you select Capture → Options… from the main menu Wireshark pops up the “Capture Interfaces” dialog box as shown in Figure 4.1, “The “Capture Interfaces” dialog box on Microsoft Windows” or

Figure 4.2, “The “Capture Interfaces” dialog box on Unix/Linux”.

Both you and your OS can hide interfaces

This dialog box will only show the local interfaces Wireshark can access. It will also hide interfaces marked as hidden in Section 10.5.1, “Interface Options”. As Wireshark might not be able to detect all local interfaces and it cannot detect the remote interfaces available there could be more capture interfaces available than listed.

It is possible to select more than one interface and capture from them simultaneously.

Figure 4.1. The “Capture Interfaces” dialog box on Microsoft Windows

Figure 4.2. The “Capture Interfaces” dialog box on Unix/Linux

Device (Unix/Linux only) The interface device name.

Description The interface description provided by the operating system, or the

user defined comment added in Section 10.5.1, “Interface Options”.

IP The first IP address Wireshark could find for this interface. You can

click on the address to cycle through other addresses assigned to it, if available. If no address could be found “none” will be displayed.

Packets The number of packets captured from this interface, since this

dialog was opened. Will be greyed out, if no packet was captured in the last second.

Packets/s Number of packets captured in the last second. Will be greyed out,

if no packet was captured in the last second.

Stop Stop a currently running capture.

Start Start a capture on all selected interfaces immediately, using the

settings from the last capture or the default settings, if no options have been set.

Capturing Live Network Data

Options Open the Capture Options dialog with the marked interfaces

selected. See Section 4.5, “The “Capture Options” dialog box”.

Details (Microsoft Windows only) Open a dialog with detailed information about the interface. See

Section 4.10, “The “Interface Details” dialog box”.

Help Show this help page.

Close Close this dialog box.

4.5. The “Capture Options” dialog box

When you select Capture → Options… (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” dialog box”.

Figure 4.3. The “Capture Options” dialog box

Tip

If you are unsure which options to choose in this dialog box just try keeping the defaults as this should work well in many cases.

4.5.1. Capture frame

The table shows the settings for all available interfaces:

• The name of the interface and its IP addresses. If no address could be resolved from the system, “none” will be shown.

Note

Loopback interfaces are not available on Windows platforms.

• The link-layer header type.

• The information whether promicuous mode is enabled or disabled.

• The maximum amount of data that will be captured for each packet. The default value is set to the 65535 bytes.

• The size of the kernel buffer that is reserved to keep the captured packets.

• The information whether packets will be captured in monitor mode (Unix/Linux only).

• The chosen capture filter.

By marking the checkboxes in the first column the interfaces are selected to be captured from. By doubleclicking on an interface the “Edit Interface Settings” dialog box as shown in Figure 4.4, “The “Edit

Interface Settings” dialog box” will be opened.

Capture on all interfaces As Wireshark can capture on multiple interfaces it is possible to

choose to capture on all available interfaces.

Capturing Live Network Data

Capture all packets in promiscuous mode

Capture Filter This field allows you to specify a capture filter for all interfaces

Compile selected BPFs This button allows you to compile the capture filter into BPF code

This checkbox allows you to specify that Wireshark should put all interfaces in promiscuous mode when capturing.

that are currently selected. Once a filter has been entered in this field, the newly selected interfaces will inherit the filter. Capture filters are discussed in more details in Section 4.13, “Filtering while

capturing”. It defaults to empty, or no filter.

You can also click on the Capture Filter button and Wireshark will bring up the Capture Filters dialog box and allow you to create and/or select a filter. Please see Section 6.6, “Defining and saving

filters”

and pop up a window showing you the resulting pseudo code. This can help in understanding the working of the capture filter you created. The Compile Selected BPFs button leads you to Figure 4.5,

“The “Compile Results” dialog box”.

Tip

Linux power user tip

The execution of BPFs can be sped up on Linux by turning on BPF JIT by executing

$ echo 1 >/proc/sys/net/core/bpf_jit_enable

if it is not enabled already. To make the change persistent you can use sysfsutils.

Manage Interfaces The Manage Interfaces button opens the Figure 4.6, “The “Add New

Interfaces” dialog box” where pipes can be defined, local interfaces

scanned or hidden, or remote interfaces added (Windows only).

4.5.2. Capture File(s) frame

An explanation about capture file usage can be found in Section 4.11, “Capture files and file modes”.

File This field allows you to specify the file name that will be used for

the capture file. This field is left blank by default. If the field is left blank, the capture data will be stored in a temporary file. See

Section 4.11, “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.

Use multiple files Instead of using a single file Wireshark will automatically switch

to a new one if a specific trigger condition is reached.

Use pcap-ng format This checkbox allows you to specify that Wireshark saves the

captured packets in pcap-ng format. This next generation capture file format is currently in development. If more than one interface is chosen for capturing, this checkbox is set by default. See https://

wiki.wireshark.org/Development/PcapNg for more details on pcap-

ng.

Capturing Live Network Data

Next file every n megabyte(s) Multiple files only. Switch to the next file after the given number

of byte(s)/kilobyte(s)/megabyte(s)/gigabyte(s) have been captured.

Next file every n minute(s) Multiple files only: Switch to the next file after the given number

of second(s)/minutes(s)/hours(s)/days(s) have elapsed.

Ring buffer with n files Multiple files only: Form a ring buffer of the capture files with the

given number of files.

Stop capture after n file(s) Multiple files only: Stop capturing after switching to the next file

the given number of times.

4.5.3. Stop Capture… frame

… after n packet(s) Stop capturing after the given number of packets have been

captured.

… after n megabytes(s) Stop capturing after the given number of byte(s)/kilobyte(s)/

megabyte(s)/gigabyte(s) have been captured. This option is greyed out if “Use multiple files” is selected.

… after n minute(s) Stop capturing after the given number of second(s)/minutes(s)/

hours(s)/days(s) have elapsed.

4.5.4. Display Options frame

Update list of packets in real time This option allows you to specify that Wireshark should update the

packet list pane in real time. If you do not specify this, Wireshark does 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.

Automatic scrolling in live capture This option allows you to specify that Wireshark should scroll the

packet list pane as new packets come in, so you are always looking at the last packet. If you do not specify this Wireshark simply adds new packets onto the end of the list but does not scroll the packet list pane. This option is greyed out if “Update list of packets in real time” is disabled.

Hide capture info dialog If this option is checked, the capture info dialog described in

Section 4.14, “While a Capture is running …” will be hidden.

4.5.5. Name Resolution frame

Enable MAC name resolution This option allows you to control whether or not Wireshark

translates MAC addresses into names. See Section 7.7, “Name

Resolution”.

Enable network name resolution This option allows you to control whether or not Wireshark

translates network addresses into names. See Section 7.7, “Name

Resolution”.

Enable transport name resolution This option allows you to control whether or not Wireshark

translates transport addresses into protocols. See Section 7.7,

“Name Resolution”.

Capturing Live Network Data

4.5.6. Buttons

Once you have set the values you desire and have selected the options you need, simply click on Start to commence the capture or Cancel to cancel the capture.

If you start a capture, Wireshark allows you to stop capturing when you have enough packets captured, for details see Section 4.14, “While a Capture is running …”.

4.6. The “Edit Interface Settings” dialog box

If you double-click on an interface in Figure 4.3, “The “Capture Options” dialog box” the following dialog box pops up.

Figure 4.4. The “Edit Interface Settings” dialog box

You can set the following fields in this dialog box: IP address The IP address(es) of the selected interface. If no address could be

resolved from the system “none” will be shown.

Link-layer header type Unless you are in the rare situation that requires this keep the default

setting. For a detailed description. See Section 4.12, “Link-layer

header type”

Wireless settings (Windows only) Here you can set the settings for wireless capture using the AirPCap

adapter. For a detailed description see the AirPCap Users Guide.

Remote settings (Windows only) Here you can set the settings for remote capture. For a detailed

description see Section 4.9, “The “Remote Capture Interfaces”

dialog box”

Capture packets in promiscuous mode

This checkbox allows you to specify that Wireshark should put the interface in promiscuous mode when capturing. If you do not specify this Wireshark will only capture the packets going to or from your computer (not all packets on your LAN segment).

Note

If some other process has put the interface in promiscuous mode you may be capturing in promiscuous mode even if you turn off this option.

Even in promiscuous mode you still won’t necessarily see all packets on your LAN segment. See the Wireshark FAQ for more information.

Limit each packet to n bytes This field allows you to specify the maximum amount of data that

will be captured for each packet, and is sometimes referred to as the snaplen. If disabled the value is set to the maximum 65535 which will be sufficient for most protocols. Some rules of thumb:

• If you are unsure just keep the default value.

• If you don’t need or don’t want all of the data in a packet - for example, if you only need the link-layer, IP, and TCP headers you might want to choose a small snapshot length, as less CPU

Capturing Live Network Data

time is required for copying packets, less buffer space is required for packets, and thus perhaps fewer packets will be dropped if traffic is very heavy.

• If you don’t capture all of the data in a packet you might find that the packet data you want is in the part that’s dropped or that reassembly isn’t possible as the data required for reassembly is missing.

Buffer size: n megabyte(s) Enter the buffer size to be used while capturing. This is the size of

the kernel buffer which will keep the captured packets, until they are written to disk. If you encounter packet drops, try increasing this value.

Capture packets in monitor mode (Unix/Linux only)

This checkbox allows you to setup the Wireless interface to capture all traffic it can receive, not just the traffic on the BSS to which it is associated, which can happen even when you set promiscuous mode. Also it might be necessary to turn this option on in order to see IEEE 802.11 headers and/or radio information from the captured frames.

Note

In monitor mode the adapter might disassociate itself from the network it was associated to.

Capture Filter This field allows you to specify a capture filter. Capture filters are discussed in

more details in Section 4.13, “Filtering while capturing”. It defaults to empty, or no filter.

You can also click on the Capture Filter button and Wireshark will bring up the “Capture Filters” dialog box and allow you to create and/or select a filter. Please see Section 6.6, “Defining and saving filters”

Compile BPF This button allows you to compile the capture filter into BPF code and pop up a

window showing you the resulting pseudo code. This can help in understanding the working of the capture filter you created.

4.7. The “Compile Results” dialog box

This figure shows the compile results of the selected interfaces.

Figure 4.5. The “Compile Results” dialog box

In the left window the interface names are listed. The results of an individual interface are shown in the right window when it is selected.

4.8. The “Add New Interfaces” dialog box

As a central point to manage interfaces this dialog box consists of three tabs to add or remove interfaces.

Figure 4.6. The “Add New Interfaces” dialog box

Capturing Live Network Data

4.8.1. Add or remove pipes

Figure 4.7. The “Add New Interfaces - Pipes” dialog box

To successfully add a pipe, this pipe must have already been created. Click the New button and type the name of the pipe including its path. Alternatively, the Browse button can be used to locate the pipe. With the Save button the pipe is added to the list of available interfaces. Afterwards, other pipes can be added.

To remove a pipe from the list of interfaces it first has to be selected. Then click the Delete button.

4.8.2. Add or hide local interfaces

Figure 4.8. The “Add New Interfaces - Local Interfaces” dialog box

The tab “Local Interfaces” contains a list of available local interfaces, including the hidden ones, which are not shown in the other lists.

If a new local interface is added, for example, a wireless interface has been activated, it is not automatically added to the list to prevent the constant scanning for a change in the list of available interfaces. To renew the list a rescan can be done.

One way to hide an interface is to change the preferences. If the “Hide” checkbox is activated and the Apply button clicked, the interface will not be seen in the lists of the “Capture Interfaces” dialog box any more. The changes are also saved in the preferences file.

4.8.3. Add or hide remote interfaces

Figure 4.9. The “Add New Interfaces - Remote Interfaces” dialog box

In this tab interfaces on remote hosts can be added. One or more of these interfaces can be hidden. In contrast to the local interfaces they are not saved in the preferences file.

To remove a host including all its interfaces from the list, it has to be selected. Then click the Delete button. For a detailed description see Section 4.9, “The “Remote Capture Interfaces” dialog box”

4.9. The “Remote Capture Interfaces” dialog box

Besides doing capture on local interfaces Wireshark is capable of reaching out across the network to a so called capture daemon or service processes to receive captured data from.

Microsoft Windows only

This dialog and capability is only available on Microsoft Windows. On Linux/Unix you can achieve the same effect (securely) through an SSH tunnel.

Capturing Live Network Data

The Remote Packet Capture Protocol service must first be running on the target platform before Wireshark can connect to it. The easiest way is to install WinPcap from https://www.winpcap.org/install/ on the target. Once installation is completed go to the Services control panel, find the Remote Packet Capture Protocol service and start it.

Note

Make sure you have outside access to port 2002 on the target platform. This is the port where the Remote Packet Capture Protocol service can be reached by default.

To access the Remote Capture Interfaces dialog use the “Add New Interfaces - Remote” dialog. See

Figure 4.9, “The “Add New Interfaces - Remote Interfaces” dialog box” and select Add.

4.9.1. Remote Capture Interfaces

Figure 4.10. The “Remote Capture Interfaces” dialog box

You have to set the following parameters in this dialog:

Host Enter 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 open 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. Configuring the target platform like this makes it insecure.

Password authentication This is the normal way of connecting to a target platform. Set

the credentials needed to connect to the Remote Packet Capture Protocol service.

4.9.2. Remote Capture Settings

The remote capture can be further fine tuned to match your situation. The Remote Settings button in

Figure 4.4, “The “Edit Interface Settings” dialog box” gives you this option. It pops up the dialog shown

in Figure 4.11, “The “Remote Capture Settings” dialog box”.

Figure 4.11. The “Remote Capture Settings” dialog box

You can set the following parameters in this dialog:

Do not capture own RPCAP traffic This option sets a capture filter so that the traffic flowing back

from the Remote Packet Capture Protocol service to Wireshark isn’t captured as well and also send back. The recursion in this saturates the link with duplicate traffic.

Capturing Live Network Data

You only should switch this off when capturing on an interface other than the interface connecting back to Wireshark.

Use UDP for data transfer Remote capture control and data flows over a TCP connection. This

option allows you to choose an UDP stream for data transfer.

Sampling option None This option instructs the Remote Packet Capture Protocol service

to send back all captured packets which have passed the capture filter. This is usually not a problem on a remote capture session with sufficient bandwidth.

Sampling option 1 of x packets This option limits the Remote Packet Capture Protocol service to

send only a sub sampling of the captured data, in terms of number of packets. This allows capture over a narrow band remote capture session of a higher bandwidth interface.

Sampling option 1 every x milliseconds

This option limits the Remote Packet Capture Protocol service to send only a sub sampling of the captured data in terms of time. This allows capture over a narrow band capture session of a higher bandwidth interface.

4.10. The “Interface Details” dialog box

When you select Details from the Capture Interface menu, Wireshark pops up the “Interface Details” dialog box as shown in Figure 4.12, “The “Interface Details” dialog box”. This dialog shows various characteristics and statistics for the selected interface.

Microsoft Windows only

This dialog is only available on Microsoft Windows

Figure 4.12. The “Interface Details” dialog box

4.11. Capture files and file modes

While 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 the capture file(s) the user specified.

Different modes of operation are available when saving this packet data to the capture file(s).

Tip

Working with large files (several hundred MB) can be quite slow. If you plan to do a long term capture or capturing from a high traffic network, think about using one of the “Multiple files” options. This will spread the captured packets over several smaller files which can be much more pleasant to work with.

Using Multiple files 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

Capturing Live Network Data

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

“File” option “Use multiple

files” option

- - - Single temporary

foo.cap - - Single named file foo.cap foo.cap x - Multiple files,

foo.cap x x Multiple files, ring

Single temporary file A temporary file will be created and used (this is the default).

Single named file A single capture file will be used. If you want to place the new

Multiple files, continuous Like the “Single named file” mode, but a new file is created and

“Ring buffer with n files” option

After capturing is stopped this file can be saved later under a user specified name.

capture file in a specific folder choose this mode.

used after reaching one of the multiple file switch conditions (one of the “Next file every …” values).

Mode Resulting

filename(s) used

wiresharkXXXXXX

file

continuous

buffer

(where XXXXXX is a unique number)

foo_00001_20100205110102.cap, foo_00002_20100205110318.cap, …

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.

4.12. Link-layer header type

In most cases you won’t have to modify link-layer header type. Some exceaptions 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

Capturing Live Network Data

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 LLCencapsulated 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”.

4.13. Filtering while capturing

Wireshark uses the libpcap filter language for capture filters. A brief overview of the syntax follows. Complete documentation can be found in the pcap-filter man page. You can find a lot of Capture Filter examples at https://wiki.wireshark.org/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” dialog box”.

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

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

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

Capturing Live Network Data

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>}]

[tcp|udp] [src|dst] port <port> This primitive allows you to filter on TCP and UDP port numbers.

less|greater <length> This primitive allows you to filter on packets whose length was less

ip|ether proto <protocol> This primitive allows you to filter on the specified protocol at either

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.

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.

than or equal to the specified length, or greater than or equal to the specified length, respectively.

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 http://www.tcpdump.org/manpages/pcap-filter.7.html for more details.

4.13.1. Automatic Remote Traffic Filtering

If 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:

SSH_CONNECTION (ssh) <remote IP> <remote port> <local IP> <local port>

SSH_CLIENT (ssh) <remote IP> <remote port> <local port>

Capturing Live Network Data

REMOTEHOST (tcsh, others?) <remote name> DISPLAY (x11) [remote name]:<display num> SESSIONNAME (terminal server) <remote name>

On Windows it asks the operating system if it’s running in a Remote Desktop Services environment.

4.14. While a Capture is running …

While a capture is running, the following dialog box is shown:

Figure 4.13. The “Capture Info” dialog box

This dialog box will inform you about the number of captured packets and the time since the capture was started. The selection of which protocols are counted cannot be changed.

Tip

This “Capture Info” dialog box can be hidden using the “Hide capture info dialog” option in the Capture Options dialog box.

4.14.1. Stop the running capture

A running capture session will be stopped in one of the following ways:

1. Using the button:[Stop[ button from the “Capture Info” dialog box.

Note

The “Capture Info” dialog box might be hidden if the “Hide capture info dialog” option is used.

Using the Capture → Stop menu item.

2. Using the Stop toolbar button.

3. Pressing Ctrl+E.

4. The capture will be automatically stopped if one of the Stop Conditions is met, e.g. the maximum amount of data was captured.

4.14.2. Restart a running capture

A 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:

Using the Capture → Restart menu item.

Capturing Live Network Data

2. Using the Restart toolbar button.

Chapter 5. File Input, Output, and Printing

5.1. Introduction

This chapter will describe input and output of capture data.

• Open capture files in various capture file formats

• Save/Export capture files in various capture file formats

• Merge capture files together

• Import text files containing hex dumps of packets

• Print packets

5.2. Open capture files

Wireshark can read in previously saved capture files. To read them, simply select the File → Open 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”.

It’s convenient to use drag-and-drop

You can open a file by simply dragging it in your file manager and dropping it onto Wireshark’s main window. However, drag-and-drop may not be available in all desktop environments.

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 box

The “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 behaviour on all systems:

• Select files and directories.

• Click the Open or OK button to accept your selected file and open it.

• Click the Cancel button to go back to Wireshark and not load a capture file.

File Input, Output, and Printing

Wireshark extensions to the standard behaviour of these dialogs:

• View file preview information such as the filesize and the number of packets in a selected a capture file.

• Specify a display filter with the Filter button and filter field. This filter will be used when opening the

new file. The text field background becomes green for a valid filter string and red for an invalid one. Clicking on the Filter button causes Wireshark to pop up the “Filters” dialog box (which is discussed further in Section 6.3, “Filtering packets while viewing”).

• Specify which type of name resolution is to be performed for all packets by clicking on one of the “…

name resolution” check buttons. Details about name resolution can be found in Section 7.7, “Name

Resolution”.

Save a lot of time loading huge capture files

You can change the display filter and name resolution settings later while viewing the packets. However, loading huge capture files can take a significant amount of extra time if these settings are changed later, so in such situations it can be a good idea to set at least the filter in advance here.

Figure 5.1. “Open” on Microsoft Windows

This is the common Windows file open dialog - plus some Wireshark extensions.

Specific for this dialog:

• The Help button will lead you to this section of this “User’s Guide”.

Figure 5.2. “Open” - Linux and UNIX

This is the common Gimp/GNOME file open dialog plus some Wireshark extensions.

Specific for this dialog:

• The + button allows you to add a directory selected in the right-hand pane to the favorites list on the

left. These changes are persistent.

• The - button allows you to remove a selected directory from the list. Some items (such as “Desktop”)

cannot be removed from the favorites list.

• If Wireshark doesn’t recognize the selected file as a capture file it will grey out the Open button.

5.2.2. Input File Formats

The following file formats from other capture tools can be opened by Wireshark:

• pcapng. A flexible, etensible successor to the libpcap format. Wireshark 1.8 and later save files as pcapng

by default. Versions prior to 1.8 used libpcap.

• libpcap. The default format used by the libpcap packet capture library. Used by tcpdump, _Snort, Nmap,

Ntop, and many other tools.

File Input, Output, and Printing

• Oracle (previously Sun) snoop and atmsnoop

• Finisar (previously Shomiti) Surveyor captures

• Microsoft Network Monitor captures

• Novell LANalyzer captures

• AIX iptrace captures

• Cinco Networks NetXray captures

• Network Associates Windows-based Sniffer and Sniffer Pro captures

• Network General/Network Associates DOS-based Sniffer (compressed or uncompressed) captures

• AG Group/WildPackets/Savvius EtherPeek/TokenPeek/AiroPeek/EtherHelp/PacketGrabber captures

• RADCOM’s WAN/LAN Analyzer captures

• Network Instruments Observer version 9 captures

• Lucent/Ascend router debug output

• HP-UX’s nettl

• Toshiba’s ISDN routers dump output

• ISDN4BSD i4btrace utility

• traces from the EyeSDN USB S0

• IPLog format from the Cisco Secure Intrusion Detection System

• pppd logs (pppdump format)

• the output from VMS’s TCPIPtrace/TCPtrace/UCX$TRACE utilities

• the text output from the DBS Etherwatch VMS utility

• Visual Networks' Visual UpTime traffic capture

• the output from CoSine L2 debug

• the output from Accellent’s 5Views LAN agents

• Endace Measurement Systems' ERF format captures

• Linux Bluez Bluetooth stack hcidump -w traces

• Catapult DCT2000 .out files

• Gammu generated text output from Nokia DCT3 phones in Netmonitor mode

• IBM Series (OS/400) Comm traces (ASCII & UNICODE)

• Juniper Netscreen snoop captures

File Input, Output, and Printing

• Symbian OS btsnoop captures

• Tamosoft CommView captures

• Textronix K12xx 32bit .rf5 format captures

• Textronix K12 text file format captures

• Apple PacketLogger captures

• Captures from Aethra Telecommunications' PC108 software for their test instruments

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 packets

You can save captured packets simply by using the File → Save As… menu item. 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 box

The “Save Capture File As” dialog box allows you to save the current capture to a file. The following sections show some examples of this dialog box. The appearance of this dialog depends on the system. However, the functionality should be the same across systems.

Figure 5.3. “Save” on Microsoft Windows

This is the common Windows file save dialog with some additional Wireshark extensions.

Specific behavior for this dialog:

• If available, the “Help” button will lead you to this section of this "User’s Guide".

• If you don’t provide a file extension to the filename (e.g. .pcap) Wireshark will append the standard

file extension for that file format.

Figure 5.4. “Save” on Linux and UNIX

This is the common Gimp/GNOME file save dialog with additional Wireshark extensions.

Specific for this dialog:

• Clicking on the + at "Browse for other folders" will allow you to browse files and folders in your file

system.

File Input, Output, and Printing

With this dialog box, you can perform the following actions:

1. Type in the name of the file you wish to save the captured packets in, as a standard file name in your file system.

2. Select the directory to save the file into.

3. Select the range of the packets to be saved. See Section 5.9, “The “Packet Range” frame”.

4. Specify the format of the saved capture file by clicking on the File type drop down box. You can choose from the types described in Section 5.3.2, “Output File Formats”.

Some capture formats may not be available depending on the packet types captured.

Wireshark can convert file formats

You can convert capture files from one format to another by reading in a capture file and writing it out using a different format.

1. Click the Save or OK button to accept your selected file and save to it. If Wireshark has a problem saving the captured packets to the file you specified it will display an error dialog box. After clicking OK on that error dialog box you can try again.

2. Click on the Cancel button to go back to Wireshark without saving any packets.

5.3.2. Output File Formats

Wireshark 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.

Different file formats have different time stamp accuracies

Saving from the currently used file format to a different format may reduce the time stamp accuracy; see the Section 7.4, “Time Stamps” for details.

The following file formats can be saved by Wireshark (with the known file extensions):

• pcapng (*.pcapng). A flexible, etensible successor to the libpcap format. Wireshark 1.8 and later save

files as pcapng by default. Versions prior to 1.8 used libpcap.

• libpcap, tcpdump and various other tools using tcpdump’s capture format (*.pcap,*.cap,*.dmp)

• Accellent 5Views (*.5vw)

• HP-UX’s nettl (*.TRC0,*.TRC1)

• Microsoft Network Monitor - NetMon (*.cap)

• Network Associates Sniffer - DOS (*.cap,*.enc,*.trc,*fdc,*.syc)

• Network Associates Sniffer - Windows (*.cap)

• Network Instruments Observer version 9 (*.bfr)

• Novell LANalyzer (*.tr1)

File Input, Output, and Printing

• Oracle (previously Sun) snoop (*.snoop,*.cap)

• Visual Networks Visual UpTime traffic (*.*)

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 ;-)

Third party protocol analyzers may require specific file extensions

Wireshark examines a file’s contents to determine its type. Some other protocol analyzers only look at a filename extensions. For example, you might need to use the .cap extension in order to open a file using Sniffer.

5.4. Merging capture files

Sometimes 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:

•

Use the File → Merge menu to open the “Merge” dialog. See Section 5.4.1, “The “Merge with Capture

File” dialog box”. This menu item will be disabled unless you have loaded a capture file.

• Use drag-and-drop to drop multiple files on the main window. Wireshark will try to merge the packets

in chronological order from the dropped files into a newly created temporary file. If you drop only a single file it will simply replace the existing capture.

• Use the mergecap tool, a command line tool to merge capture files. This tool provides the most options

to merge capture files. See Section D.8, “mergecap: Merging multiple capture files into one” for details.

5.4.1. The “Merge with Capture File” dialog box

This dialog box let 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”.

Specific controls of this merge dialog are: Prepend packets to existing file Prepend the packets from the selected file before the currently

loaded packets.

Merge packets chronologically Merge both the packets from the selected and currently loaded file

in chronological order.

Append packets to existing file Append the packets from the selected file after the currently loaded

packets.

Figure 5.5. “Merge” on Microsoft Windows

File Input, Output, and Printing

This is the common Windows file open dialog with additional Wireshark extensions.

Figure 5.6. “Merge” on Linux and UNIX

This is the common Gimp/GNOME file open dialog with additional Wireshark extensions.

5.5. Import hex dump

Wireshark can read in an ASCII 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.

Wireshark understands a hexdump of the form generated by od -Ax -tx1 -v. In other words, each byte is individually displayed and surrounded with a space. Each line begins with an offset describing the position in the file. The offset is a hex number (can also be octal or decimal), of more than two hex digits. Here is a sample dump that can be imported:

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. Byte and 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 are 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. If not the first packet is timestamped with the current time the import takes place. Multiple packets are read in with timestamps differing by one microsecond each. 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.)

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 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. Wireshark also allows the user to read in dumps of application-level data, by inserting dummy L2, L3 and L4 headers before each packet. The user can elect to insert Ethernet headers, Ethernet and IP, or Ethernet, IP and UDP/TCP/SCTP headers before each packet. This allows Wireshark or any other full-packet decoder to handle these dumps.

5.5.1. The “Import from Hex Dump” dialog box

This dialog box lets you select a text file, containing a hex dump of packet data, to be imported and set import parameters.

File Input, Output, and Printing

Figure 5.7. The “Import from Hex Dump” dialog

Specific controls of this import dialog are split in two sections:

Input Determine which input file has to be imported and how it is to be interpreted.

Import Determine how the data is to be imported.

The input parameters are as follows:

Filename / Browse Enter the name of the text file to import. You can use Browse to browse

for a file.

Offsets Select the radix of the offsets given in the text file to import. This is usually

hexadecimal, but decimal and octal are also supported.

Date/Time Tick this checkbox if there are timestamps associated with the frames in

the text file to import you would like to use. Otherwise the current time is used for timestamping the frames.

Format This is the format specifier used to parse the timestamps in the text

file to import. It uses a simple syntax to describe the format of the timestamps, using %H for hours, %M for minutes, %S for seconds, etc. The straightforward HH:MM:SS format is covered by %T. For a full definition of the syntax look for strptime(3).

The import parameters are as follows:

Encapsulation type Here you can select which type of frames you are importing. This all

Dummy header When Ethernet encapsulation is selected you have to option to prepend

Maximum frame length You may not be interested in the full frames from the text file, just

Once all input and import parameters are setup click OK to start the import. If your current data wasn’t saved before you will be asked to save it first.

When completed there will be a new capture file loaded with the frames imported from the text file.

5.6. File Sets

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 headers to the frames to import. These headers can provide artificial Ethernet, IP, UDP or TCP or SCTP headers and SCTP data chunks. When selecting a type of dummy header the applicable entries are enabled, others are grayed out and default values are used.

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 65535 bytes.

When using the "Multiple Files" option while doing a capture (see: Section 4.11, “Capture files and file

modes”), the capture data is spread over several capture files, called a file set.

File Input, Output, and Printing

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.

How does Wireshark detect the files of a file set?

A filename in a file set uses the format Prefix_Number_DateTimeSuffix which might look something like test_00001_20060420183910.pcap. All files of a file set share the same prefix (e.g. “test”) and suffix (e.g. “.pcap”) and a varying middle part.

To find the files of a file set, Wireshark scans the directory where the currently loaded file resides and checks for files matching the filename pattern (prefix and suffix) of the currently loaded file.

This simple mechanism usually works well but has its drawbacks. If several file sets were captured with the same prefix and suffix, Wireshark will detect them as a single file set. If files were renamed or spread over several directories the mechanism will fail to find all files of a set.

The following features in the File → File Set submenu are available to work with file sets in a convenient way:

• The “List Files” dialog box will list the files Wireshark has recognized as being part of the current file set.

• Next File closes the current and opens the next file in the file set.

• Previous File closes the current and opens the previous file in the file set.

5.6.1. The “List Files” dialog box

Figure 5.8. 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 data

Wireshark provides several ways and formats to export packet data. This section describes general ways to export data from the main Wireshark application. There are more specialized functions to export specific data which are described elsewhere.

File Input, Output, and Printing

5.7.1. The “Export as Plain Text File” dialog box

Export packet data into a plain ASCII text file, much like the format used to print packets.

Tip

If you would like to be able to import any previously exported packets from a plain text file it is recommended that you:

• Add the “Absolute date and time” column.

• Temporarily hide all other columns.

•

Disable the Edit → Preferences → Protocols → Data “Show not dissected data on new Packet Bytes pane” preference. More details are provided in Section 10.5, “Preferences”

• Include the packet summary line.

• Exclude column headings.

• Exclude packet details.

• Include the packet bytes.

Figure 5.9. The “Export as Plain Text File” dialog box

• The “Export to file:” frame chooses the file to export the packet data to.

• The “Packet Range” frame is described in Section 5.9, “The “Packet Range” frame”.

• The “Packet Details” frame is described in Section 5.10, “The Packet Format frame”.

5.7.2. The “Export as PostScript File” dialog box

Figure 5.10. The "Export as PostScript File" dialog box

• Export to file: frame chooses the file to export the packet data to.

• The Packet Range frame is described in Section 5.9, “The “Packet Range” frame”.

• The Packet Details frame is described in Section 5.10, “The Packet Format frame”.

5.7.3. The "Export as CSV (Comma Separated Values) File" dialog box

Export packet summary into CSV, used e.g. by spreadsheet programs to im-/export data.

• Export to file: frame chooses the file to export the packet data to.

• The Packet Range frame is described in Section 5.9, “The “Packet Range” frame”.

File Input, Output, and Printing

5.7.4. The "Export as C Arrays (packet bytes) file" dialog box

Export packet bytes into C arrays so you can import the stream data into your own C program.

• Export to file: frame chooses the file to export the packet data to.

• The Packet Range frame is described in Section 5.9, “The “Packet Range” frame”.

5.7.5. The "Export as PSML File" dialog box

Export packet data into PSML. This is an XML based format including only the packet summary. The PSML file specification is available at: http://www.nbee.org/doku.php?id=netpdl:psml_specification.

Figure 5.11. The "Export as PSML File" dialog box

• Export to file: frame chooses the file to export the packet data to.

• The Packet Range frame is described in Section 5.9, “The “Packet Range” frame”.

There’s no such thing as a packet details frame for PSML export, as the packet format is defined by the PSML specification.

5.7.6. The "Export as PDML File" dialog box

Export packet data into PDML. This is an XML based format including the packet details. The PDML file specification is available at: http://www.nbee.org/doku.php?id=netpdl:pdml_specification.

Note

The PDML specification is not officially released and Wireshark’s implementation of it is still in an early beta state, so please expect changes in future Wireshark versions.

Figure 5.12. The "Export as PDML File" dialog box

• Export to file: frame chooses the file to export the packet data to.

• The Packet Range frame is described in Section 5.9, “The “Packet Range” frame”.

There’s no such thing as a packet details frame for PDML export, as the packet format is defined by the PDML specification.

5.7.7. The "Export selected packet bytes" dialog box

Export the bytes selected in the "Packet Bytes" pane into a raw binary file.

Figure 5.13. The "Export Selected Packet Bytes" dialog box

File Input, Output, and Printing

• Name: the filename to export the packet data to.

• The Save in folder: field lets you select the folder to save to (from some predefined folders).

• Browse for other folders provides a flexible way to choose a folder.

5.7.8. The "Export Objects" dialog box

This feature scans through HTTP streams in the currently open capture file or running capture and takes reassembled objects such as HTML documents, image files, executables and anything else that can be transferred over HTTP and lets you save them to 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 with the proper viewer or executed in the case of executables (if it is for the same platform you are running Wireshark on) without any further work on your part. This feature is not available when using GTK2 versions below 2.4.

Figure 5.14. The "Export Objects" dialog box

• Packet num: 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 the object as a response to an HTTP request.

• Content Type: The HTTP content type of this object.

• Bytes: The size of this object in bytes.

• Filename: The final part of the URI (after the last slash). This is typically a filename, but may be a

long complex looking string, which typically indicates that the file was received in response to a HTTP POST request.

• Help: Opens this section in the user’s guide.

• Close: Closes this dialog.

• Save As: 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.

• Save All: Saves all objects in the list using the filename from the filename column. You will be asked

what directory / folder to save them in. If the filename is invalid for the operating system / file system you are running Wireshark on, then an error will appear and that object will not be saved (but all of the others will be).

5.8. Printing packets

To print packets, select the File → Print… menu item. When you do this Wireshark pops up the “Print” dialog box as shown in Figure 5.15, “The “Print” dialog box”.

5.8.1. The “Print” dialog box

Figure 5.15. The “Print” dialog box

File Input, Output, and Printing

The following fields are available in the Print dialog box: Printer

This field contains a pair of mutually exclusive radio buttons:

• Plain Text specifies that the packet print should be in plain text.

• PostScript specifies that the packet print process should use PostScript to generate a better print output on PostScript aware printers.

• Output to file: specifies that printing be done to a file, using the filename entered in the field or selected with the browse button.

This field is where you enter the file to print to if you have selected Print to a file, or you can click the button to browse the filesystem. It is greyed out if Print to a file is not selected.

• Print command specifies that a command be used for printing.

Note!

These Print command fields are not available on windows platforms.

This field specifies the command to use for printing. It is typically lpr. You would change it to specify a particular queue if you need to print to a queue other than the default. An example might be:

$ lpr -Pmypostscript

This field is greyed out if Output to file: is checked above.

Packet Range Select the packets to be printed, see Section 5.9, “The “Packet

Range” frame”

Packet Format Select the output format of the packets to be printed. You can

choose, how each packet is printed, see Figure 5.17, “The “Packet

Format” frame”

5.9. The “Packet Range” frame

The packet range frame is a part of various output related dialog boxes. It provides options to select which packets should be processed by the output function.

Figure 5.16. The “Packet Range” frame

If the Captured button is set (default), all packets from the selected rule will be processed. If the Displayed button is set, only the currently displayed packets are taken into account to the selected rule.

• All packets will process all packets.

• Selected packet only process only the selected packet.

• Marked packets only process only the marked packets.

• From first to last marked packet process the packets from the first to the last marked one.

File Input, Output, and Printing

• Specify a packet range process a user specified range of packets, e.g. specifying 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.

5.10. The Packet Format frame

The packet format frame is a part of various output related dialog boxes. It provides options to select which parts of a packet should be used for the output function.

Figure 5.17. The “Packet Format” frame

• Packet summary line enable the output of the summary line, just as in the “Packet List” pane.

• Packet details enable the output of the packet details tree.

• All collapsed the info from the “Packet Details” pane in “all collapsed” state.

• As displayed the info from the “Packet Details” pane in the current state.

• All expanded the info from the “Packet Details” pane in “all expanded” state.

• Packet bytes enable the output of the packet bytes, just as in the “Packet Bytes” pane.

• Each packet on a new page put each packet on a separate page (e.g. when saving/printing to a text file, this will put a form feed character between the packets).

Chapter 6. Working with captured packets

6.1. Viewing packets you have captured

Once 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 View → Show Packet in New Window. 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:

• Hold down the shift key and double-click on a frame link in the packet details.

• From Table 6.2, “The menu items of the “Packet List” pop-up menu”.

• From Table 6.3, “The menu items of the “Packet Details” pop-up menu”.

6.2. Pop-up menus

You can bring up a pop-up menu over either the “Packet List”, its column header, or “Packet Details” pane by clicking your right mouse button at the corresponding pane.

6.2.1. Pop-up menu of the “Packet List” column header

Figure 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 short description of each item.

Working with captured packets

Table 6.1. The menu items of the “Packet List” column header pop-up menu

Item Identical to main menu’s item: Description

Sort Ascending Sort the packet list in ascending

order based on this column.

Sort Descending Sort the packet list in descending

order based on this column.

No Sort Remove sorting order based on

this column.

Align Left Set left alignment of the values in

this column.

Align Center Set center alignment of the

values in this column.

Align Right Set right alignment of the values

in this column.

Column Preferences… Open the Preferences dialog box

on the column tab.

Resize Column Resize the column to fit the

values.

Rename Column Title Allows you to change the title of

the column header.

Displayed Column View This menu items folds out with

a list of all configured columns. These columns can now be shown or hidden in the packet list.

Hide Column Allows you to hide the column

from the packet list.

Remove Column Allows you to remove the

column from the packet list.

6.2.2. Pop-up menu of the “Packet List” pane

Figure 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

Item Identical to main menu’s item: Description

Mark Packet (toggle) Edit Mark/unmark a packet. Ignore Packet (toggle) Edit Ignore or inspect this packet

while dissecting the capture file.

Set Time Reference (toggle) Edit Set/reset a time reference.

Working with captured packets

Item Identical to main menu’s item: Description

Manually Resolve Address Allows you to enter a name to

resolve for the selected address.

Apply as Filter Analyze Prepare and apply a display filter

based on the currently selected item.

Prepare a Filter Analyze Prepare a display filter based on

the currently selected item.

Conversation Filter This menu item applies a

display filter with the address information from the selected packet. E.g. the IP menu entry will set a filter to show the traffic between the two IP addresses of the current packet. XXX - add a new section describing this better.

Colorize Conversation This menu item uses a

display filter with the address information from the selected packet to build a new colorizing rule.

SCTP Allows you to analyze and

prepare a filter for this SCTP association.

Follow TCP Stream Analyze Allows you to view all the data

on a TCP stream between a pair of nodes.

Follow UDP Stream Analyze Allows you to view all the data

on a UDP datagram stream between a pair of nodes.

Follow SSL Stream Analyze Same as “Follow TCP Stream”

but for SSL. XXX - add a new section describing this better.

Copy/ Summary (Text) Copy the summary fields as

displayed to the clipboard, as tabseparated text.

Copy/ Summary (CSV) Copy the summary fields as

displayed to the clipboard, as comma-separated text.

Copy/ As Filter Prepare a display filter based on

the currently selected item and copy that filter to the clipboard.

Copy/ Bytes (Offset Hex Text) Copy the packet bytes to the

clipboard in hexdump-like format.

Copy/ Bytes (Offset Hex) Copy the packet bytes to the

clipboard in hexdump-like

Working with captured packets

Item Identical to main menu’s item: Description

format, but without the text portion.

Copy/ Bytes (Printable Text Only)

Copy/ Bytes (Hex Stream) Copy the packet bytes to the

Copy/ Bytes (Binary Stream) Copy the packet bytes to the

Decode As… Analyze Change or apply a new relation

Print… File Print packets. Show Packet in New Window View Display the selected packet in a

Copy the packet bytes to the clipboard as ASCII text, excluding non-printable characters.

clipboard as an unpunctuated list of hex digits.

clipboard as raw binary. The data is stored in the clipboard as MIME-type “application/octetstream”.

between two dissectors.

new window.

6.2.3. Pop-up menu of the “Packet Details” pane

Figure 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

Item Identical to main menu’s item: Description

Expand Subtrees View Expand the currently selected

subtree.

Collapse Subtrees View Collapse the currently selected

subtree.

Expand All View Expand all subtrees in all packets

in the capture.

Collapse All View Wireshark keeps a list of all

the protocol subtrees that are expanded, and uses it to ensure that the correct subtrees are expanded when you display a packet. This menu item collapses the tree view of all packets in the capture list.

Apply as Column Use the selected protocol item

to create a new column in the packet list.

Working with captured packets

Item Identical to main menu’s item: Description

Apply as Filter Analyze Prepare and apply a display filter

based on the currently selected item.

Prepare a Filter Analyze Prepare a display filter based on

the currently selected item.

Colorize with Filter This menu item uses a display

filter with the information from the selected protocol item to build a new colorizing rule.

Follow TCP Stream Analyze Allows you to view all the data

on a TCP stream between a pair of nodes.

Follow UDP Stream Analyze Allows you to view all the data

on a UDP datagram stream between a pair of nodes.

Follow SSL Stream Analyze Same as “Follow TCP Stream”

but for SSL. XXX - add a new section describing this better.

Copy/ Description Edit Copy the displayed text of the

selected field to the system clipboard.

Copy/ Fieldname Edit Copy the name of the selected

field to the system clipboard.

Copy/ Value Edit Copy the value of the selected

field to the system clipboard.

Copy/ As Filter Edit Prepare a display filter based on

the currently selected item and copy it to the clipboard.

Copy/ Bytes (Offset Hex Text) Copy the packet bytes to the

clipboard in hexdump-like format; similar to the Packet List Pane command, but copies only the bytes relevant to the selected part of the tree (the bytes selected in the Packet Bytes Pane).

Copy/ Bytes (Offset Hex) Copy the packet bytes to the

clipboard in hexdump-like format, but without the text portion; similar to the Packet List Pane command, but copies only the bytes relevant to the selected part of the tree (the bytes selected in the Packet Bytes Pane).

Copy/ Bytes (Printable Text Only)

Copy the packet bytes to the clipboard as ASCII text, excluding non-printable characters; similar to the Packet

Working with captured packets

Item Identical to main menu’s item: Description

List Pane command, but copies only the bytes relevant to the selected part of the tree (the bytes selected in the Packet Bytes Pane).

Copy/ Bytes (Hex Stream) Copy the packet bytes to the

clipboard as an unpunctuated list of hex digits; similar to the Packet List Pane command, but copies only the bytes relevant to the selected part of the tree (the bytes selected in the Packet Bytes Pane).

Copy/ Bytes (Binary Stream) Copy the packet bytes to

the clipboard as raw binary; similar to the Packet List Pane command, but copies only the bytes relevant to the selected part of the tree (the bytes selected in the Packet Bytes Pane). The data is stored in the clipboard as MIME-type “application/octetstream”.

Export Selected Packet Bytes… File This menu item is the same as

the File menu item of the same name. It allows you to export raw packet bytes to a binary file.

Wiki Protocol Page Show the wiki page

corresponding to the currently selected protocol in your web browser.

Filter Field Reference Show the filter field reference

web page corresponding to the currently selected protocol in your web browser.

Protocol Preferences… The menu item takes you to the

properties dialog and selects the page corresponding to the protocol if there are properties associated with the highlighted field. More information on preferences can be found in

Figure 10.7, “The preferences dialog box”.

Decode As… Analyze Change or apply a new relation

between two dissectors.

Disable Protocol Allows you to temporarily

disable a protocol dissector,

Working with captured packets

Item Identical to main menu’s item: Description

which may be blocking the legitimate dissector.

Resolve Name View Causes a name resolution to

be performed for the selected packet, but NOT every packet in the capture.

Go to Corresponding Packet Go If the selected field has a

corresponding packet, go to it. Corresponding packets will usually be a request/response packet pair or such.

6.3. Filtering packets while viewing

Wireshark has two filtering languages: One used when capturing packets, and one used when displaying packets. In this section we explore that second type of filter: Display filters. The first one has already been dealt with in Section 4.13, “Filtering while capturing”.

Display filters allow you to concentrate on the packets you are interested in while hiding the currently uninteresting ones. They allow you to select packets by:

• Protocol

• The presence of a field

• The values of fields

• A comparison between fields

• … and a lot more!

To select packets based on protocol type, simply type the protocol in which you are interested in the Filter: field in the filter toolbar of the Wireshark window and press enter to initiate the filter. Figure 6.6, “Filtering

on the TCP protocol” shows an example of what happens when you type tcp in the filter field.

Note

All protocol and field names are entered in lowercase. Also, don’t forget to press enter after entering the filter expression.

Figure 6.6. Filtering on the TCP protocol

As you might have noticed, only packets of the TCP protocol are displayed now (e.g. packets 1-10 are hidden). The packet numbering will remain as before, so the first packet shown is now packet number 11.

Note

When using a display filter, all packets remain in the capture file. The display filter only changes the display of the capture file but not its content!

Working with captured packets

You can filter on any protocol that Wireshark understands. You can also filter on any field that a dissector adds to the tree view, but only if the dissector has added an abbreviation for the field. A list of such fields is available in Wireshark in the Add Expression… dialog box. You can find more information on the Add Expression… dialog box in Section 6.5, “The “Filter Expression” dialog box”.

For example, to narrow the packet list pane down to only those packets to or from the IP address

192.168.0.1, use ip.addr==192.168.0.1.

Note

To remove the filter, click on the Clear button to the right of the filter field.

6.4. Building display filter expressions

Wireshark provides a simple but powerful display filter language that allows you to build quite complex filter expressions. You can compare values in packets as well as combine expressions into more specific expressions. The following sections provide more information on doing this.

Tip

You will find a lot of Display Filter examples at the Wireshark Wiki Display Filter page at:

https://wiki.wireshark.org/DisplayFilters.

6.4.1. Display filter fields

Every field in the packet details pane can be used as a filter string, this will result in showing only the packets where this field exists. For example: the filter string: tcp will show all packets containing the tcp protocol.

There is a complete list of all filter fields available through the menu item Help → Supported Protocols in the page “Display Filter Fields” of the “Supported Protocols” dialog.

6.4.2. Comparing values

You can build display filters that compare values using a number of different comparison operators. They are shown in Table 6.4, “Display Filter comparison operators”.

Tip

You can use English and C-like terms in the same way, they can even be mixed in a filter string.

Table 6.4. Display Filter comparison operators

English C-like Description and example

eq == Equal. ip.src==10.0.0.5 ne != Not equal. ip.src!

=10.0.0.5

gt > Greater than. frame.len >

Working with captured packets

English C-like Description and example

lt < Less than. frame.len < 128 ge >= Greater than or equal to.

frame.len ge 0x100

le <= Less than or equal to.

frame.len <= 0x20

In addition, all protocol fields have a type. Table 6.5, “Display Filter Field Types” provides a list of the types and example of how to express them.

Table 6.5. Display Filter Field Types

Type Example

Unsigned integer (8-bit, 16-bit, 24-bit, 32-bit) You can express integers in decimal, octal, or

hexadecimal. The following display filters are equivalent: ---- ip.len le 1500 ip.len le 02734 ip.len

le 0x436 ---Signed integer (8-bit, 16-bit, 24-bit, 32-bit) Boolean A boolean field is present in the protocol decode

only if its value is true. For example, tcp.flags.syn

is present, and thus true, only if the SYN flag is

present in a TCP segment header.

Ethernet address (6 bytes) Separators can be a colon (:), dot (.) or dash (-) and

IPv4 address ip.addr == 192.168.0.1

IPv6 address ipv6.addr == ::1 String (text) http.request.uri == "https://www.wireshark.org/"

6.4.3. Combining expressions

Thus the filter expression tcp.flags.syn will select

only those packets for which this flag exists,

that is, TCP segments where the segment header

contains the SYN flag. Similarly, to find source-

routed token ring packets, use a filter expression of

tr.sr.

can have one or two bytes between separators: ----

eth.dst == ff:ff:ff:ff:ff:ff eth.dst == ff-ff-ff-ff-ff-ff

eth.dst == ffff.ffff.ffff ----

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:

ip.addr == 129.111.0.0/16

You can combine filter expressions in Wireshark using the logical operators shown in Table 6.6, “Display

Filter Logical Operations”

Working with captured packets

Table 6.6. Display Filter Logical Operations

English C-like Description and example

and && Logical AND.

ip.src==10.0.0.5 and tcp.flags.fin

or || Logical OR.

ip.scr==10.0.0.5 or ip.src==192.1.1.1

xor ^^ Logical XOR. tr.dst[0:3]

== 0.6.29 xor tr.src[0:3] == 0.6.29

not ! Logical NOT. not llc […] Substring Operator. Wireshark

allows you to select subsequences 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

Working with captured packets

English C-like Description and example

6.4.4. Membership Operator.

Wireshark allows you to test a field for membership in a set of values or fields. After the field name, use the in operator followed by the set items surrounded by braces {}.

tcp.port in {80 443 8080}

This can be considered a shortcut operator, as the previous expression could have been expressed as:

tcp.port == 80 || tcp.port == 443 || tcp.port == 8080

6.4.5. A common mistake

Using the != operator on combined expressions like eth.addr, ip.addr, tcp.port, and udp.port will probably not work as expected.

Often people use a filter string to display something like ip.addr == 1.2.3.4 which will display all packets containing the IP address 1.2.3.4.

compound ranges as shown above.

Then they use ip.addr != 1.2.3.4 to see all packets not containing the IP address 1.2.3.4 in it. Unfortunately, this does not do the expected.

Instead, that expression will even be true for packets where either source or destination IP address equals

1.2.3.4. The reason for this, is that the expression ip.addr != 1.2.3.4 must be read as “the packet contains a field named ip.addr with a value different from 1.2.3.4”. As an IP datagram contains both a source and a destination address, the expression will evaluate to true whenever at least one of the two addresses differs from 1.2.3.4.

If you want to filter out all packets containing IP datagrams to or from IP address 1.2.3.4, then the correct filter is !(ip.addr == 1.2.3.4) as it reads “show me all the packets for which it is not true that a field named ip.addr exists with a value of 1.2.3.4”, or in other words, “filter out all packets for which there are no occurrences of a field named ip.addr with the value 1.2.3.4”.

6.5. The “Filter Expression” dialog box

When 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 “Filter Expression” dialog box helps with this.

Tip

The “Filter Expression” dialog box is an excellent way to learn how to write Wireshark display filter strings.

Figure 6.7. The “Filter Expression” dialog box

When you first bring up the Filter Expression dialog box you are shown a tree of field names, organized by protocol, and a box for selecting a relation.

Working with captured packets

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

enum’s in C. If the selected protocol field has such values defined, you can choose one of them here.

Range A range of integers or a group of ranges, such as 1-12 or

39-42,98-2000.

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 filters

You can define filters with Wireshark and give them labels for later use. This can save time in remembering and retyping some of the more complex filters you use.

To define a new filter or edit an existing one, select Capture → Capture Filters… or Analyze → Display Filters…. Wireshark will then pop up the Filters dialog as shown in Figure 6.8, “The “Capture Filters”

and “Display Filters” dialog boxes”.

The mechanisms for defining and saving capture filters and display filters are almost identical. Both will be described here but the differences between these two will be marked as such.

Warning

You must use Save to save your filters permanently. OK or Apply will not save the filters and they will be lost when you close Wireshark.

Figure 6.8. The “Capture Filters” and “Display Filters” dialog boxes

New This button adds a new filter to the list of filters. The currently entered values

from Filter name and Filter string will be used. If any of these fields are empty, it will be set to “new”.

Delete This button deletes the selected filter. It will be greyed out, if no filter is

selected.

Working with captured packets

Filter You can select a filter from this list (which will fill in the filter name and filter

string in the fields down at the bottom of the dialog box).

Filter name: You can change the name of the currently selected filter here.

The filter name will only be used in this dialog to identify the filter for your convenience, it will not be used elsewhere. You can add multiple filters with the same name, but this is not very useful.

Filter string: You can change the filter string of the currently selected filter here. Display

Filter only: the string will be syntax checked while you are typing.

Add Expression… Display Filter only: This button brings up the Add Expression dialog box

which assists in building filter strings. You can find more information about the Add Expression dialog in Section 6.5, “The “Filter Expression” dialog

box”

OK Display Filter only: This button applies the selected filter to the current display

and closes the dialog.

Apply Display Filter only: This button applies the selected filter to the current

display, and keeps the dialog open.

Save Save the current settings in this dialog. The file location and format is

explained in Appendix B, Files and Folders.

Close Close this dialog. This will discard unsaved settings.

6.7. Defining and saving filter macros

You can define filter macros with Wireshark and give them labels for later use. This can save time in remembering and retyping some of the more complex filters you use.

6.8. Finding packets

You can easily find packets once you have captured some packets or have read in a previously saved capture file. Simply select the Find Packet… menu item from the Edit menu. Wireshark will pop up the dialog box shown in Figure 6.9, “The “Find Packet” dialog box”.

6.8.1. The “Find Packet” dialog box

Figure 6.9. The “Find Packet” dialog box

You might first select the kind of thing to search for:

• Display filter Simply enter a display filter string into the Filter: field, select a direction, and click on OK. 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

Working with captured packets

For more details on display filters, see Section 6.3, “Filtering packets while viewing”

• Hex Value

Search for a specific byte sequence in the packet data.

For example, use “00:00” to find the next packet including two null bytes in the packet data.

• String

Find a string in the packet data, with various options.

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.

You can choose the search direction:

• Up

Search upwards in the packet list (decreasing packet numbers).

• Down

Search downwards in the packet list (increasing packet numbers).

6.8.2. The “Find Next” command

“Find Next” will continue searching with the same options used in the last “Find Packet”.

6.8.3. The “Find Previous” command

“Find Previous” will do the same thing as “Find Next”, but in the reverse direction.

6.9. Go to a specific packet

You can easily jump to specific packets with one of the menu items in the Go menu.

6.9.1. The “Go Back” command

Go back in the packet history, works much like the page history in current web browsers.

6.9.2. The “Go Forward” command

Go forward in the packet history, works much like the page history in current web browsers.

6.9.3. The “Go to Packet” dialog box

Figure 6.10. The “Go To Packet” dialog box

This dialog box will let you enter a packet number. When you press OK, Wireshark will jump to that packet.

Working with captured packets

6.9.4. The “Go to Corresponding Packet” command

If 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 doubleclick on the field to jump to the corresponding field.

6.9.5. The “Go to First Packet” command

This command will simply jump to the first packet displayed.

6.9.6. The “Go to Last Packet” command

This command will simply jump to the last packet displayed.

6.10. Marking packets

You 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.

The packet marks are not stored in the capture file or anywhere else. All packet marks will be lost when you close the capture file.

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 three functions to manipulate the marked state of a packet:

• Mark packet (toggle) toggles the marked state of a single packet.

• Mark all displayed packets set the mark state of all displayed packets.

• Unmark all packets reset the mark state of all packets.

These mark functions are available from the “Edit” menu, and the “Mark packet (toggle)” function is also available from the pop-up menu of the “Packet List” pane.

6.11. Ignoring packets

You can ignore packets in the “Packet List” pane. Wireshark will then pretend that this packets does not exist in the capture file. An ignored packet will be shown with white background and gray foreground, regardless of the coloring rules set.

The packet ignored marks are not stored in the capture file or anywhere else. All “packet ignored” marks will be lost when you close the capture file.

There are three functions to manipulate the ignored state of a packet:

• Ignore packet (toggle) toggles the ignored state of a single packet.

• Ignore all displayed packets set the ignored state of all displayed packets.

Working with captured packets

• Un-Ignore all packets reset the ignored state of all packets.

These ignore functions are available from the “Edit” menu, and the “Ignore packet (toggle)” function is also available from the pop-up menu of the “Packet List” pane.

6.12. Time display formats and time references

While 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 7.4, “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:

• Date and Time of Day: 1970-01-01 01:02:03.123456 The absolute date and time of the day when the packet was captured.

• Time of Day: 01:02:03.123456 The absolute time of the day when the packet was captured.

• Seconds Since Beginning of Capture: 123.123456 The time relative to the start of the capture file or the first “Time Reference” before this packet (see Section 6.12.1, “Packet time referencing”).

• Seconds Since Previous Captured Packet: 1.123456 The time relative to the previous captured packet.

• Seconds Since Previous Displayed Packet: 1.123456 The time relative to the previous displayed packet.

• Seconds Since Epoch (1970-01-01): 1234567890.123456 The time relative to epoch (midnight UTC of January 1, 1970).

The available precisions (aka. the number of displayed decimal places) are:

• Automatic The timestamp precision of the loaded capture file format will be used (the default).

• Seconds, Deciseconds, Centiseconds, Milliseconds, Microseconds or Nanoseconds The timestamp precision will be forced to the given setting. If the actually available precision is smaller, zeros will be appended. If the precision is larger, the remaining decimal places will be cut off.

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 referencing

The 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 Beginning of

Capture”. If one of the other time display formats are used, time referencing will have no effect (and will make no sense either).

Working with captured packets

To work with time references, choose one of the Time Reference items in the Edit menu or from the popup menu of the “Packet List” pane. See Section 3.6, “The “Edit” menu”.

• Set Time Reference (toggle) Toggles the time reference state of the currently selected packet to on or off.

• Find Next Find the next time referenced packet in the “Packet List” pane.

• Find Previous Find the previous time referenced packet in the “Packet List” pane.

Figure 6.11. 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 Topics

7.1. Introduction

This chapter some of Wireshark’s advanced features.

7.2. Following TCP streams

If you are working with TCP based protocols it can be very helpful to see the data from a TCP stream 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 of that TCP stream. If so, Wireshark’s ability to follow a TCP stream will be useful to you.

Simply select a TCP packet in the packet list of the stream/connection you are interested in and then select the Follow TCP Stream menu item from the Wireshark Tools menu (or use the context menu in the packet list). Wireshark will set an appropriate display filter and pop up a dialog box with all the data from the TCP stream laid out in order, as shown in Figure 7.1, “The “Follow TCP Stream” dialog box”.

Note

Opening the “Follow TCP Stream” installs a display filter to select all the packets in the TCP stream you have selected.

7.2.1. 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. Traffic from A to B is marked in red, while traffic from B to A is marked in blue. If you like, you can change these colors in the “Colors” page if the “Preferences” dialog.

Non-printable characters will be replaced by dots.

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:

1. Save As: Save the stream data in the currently selected format.

2. Print: Print the stream data in the currently selected format.

3. Direction: Choose the stream direction to be displayed (“Entire conversation”, “data from A to B only”

or “data from B to A only”).

4. Filter out this stream: Apply a display filter removing the current TCP stream data from the display.

5. Close: Close this dialog box, leaving the current display filter in effect.

You can choose to view the data in one of the following formats:

Advanced Topics

1. ASCII: In this view you see the data from each direction in ASCII. Obviously best for ASCII based

protocols, e.g. HTTP.

2. EBCDIC: For the big-iron freaks out there.

3. HEX Dump: This allows you to see all the data. This will require a lot of screen space and is best used

with binary protocols.

4. C Arrays: This allows you to import the stream data into your own C program.

5. Raw: 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.

7.3. Expert Information

The expert infos is a kind of log of the anomalies found by Wireshark in a capture file.

The general idea behind the following “Expert Info” is to have a better display of “uncommon” or just notable network behaviour. This way, both novice and expert users will hopefully find probable network problems a lot faster, compared to scanning the packet list “manually” .

Expert infos are only a hint

Take expert infos as a hint what’s worth looking at, but not more. For example, the absence of expert infos doesn’t necessarily mean everything is OK.

The amount of expert infos largely depends on the protocol being used. While some common protocols like TCP/IP will show detailed expert infos, most other protocols currently won’t show any expert infos at all.

The following will first describe the components of a single expert info, then the User Interface.

7.3.1. Expert Info Entries

Each expert info will contain the following things which will be described in detail below.

Table 7.1. Some example expert infos

Packet # Severity Group Protocol Summary

1 Note Sequence TCP Duplicate ACK

2 Chat Sequence TCP Connection reset

8 Note Sequence TCP Keep-Alive 9 Warn Sequence TCP Fast retransmission

(#1)

(RST)

(suspected)

7.3.1.1. Severity

Every expert info has a specific severity level. The following severity levels are used, in parentheses are the colors in which the items will be marked in the GUI:

• Chat (grey): information about usual workflow, e.g. a TCP packet with the SYN flag set

Wireshark Wireshark - 2.1 User Guide

Specifications and Main Features

Frequently Asked Questions

User Manual

Wireshark User’s Guide

Preface

1. Foreword

2. Who should read this document?

3. Acknowledgements

4. About this document

5. Where to get the latest copy of this document?

6. Providing feedback about this document

Chapter 1. Introduction

1.1. What is Wireshark?

1.1.1. Some intended purposes

1.1.2. Features

1.1.3. Live capture from many different network media

1.1.4. Import files from many other capture programs

1.1.5. Export files for many other capture programs

1.1.6. Many protocol dissectors

1.1.7. Open Source Software

1.1.8. What Wireshark is not

1.2. System Requirements

1.2.1. Microsoft Windows

1.2.2. UNIX / Linux

1.3. Where to get Wireshark

1.4. A brief history of Wireshark

1.5. Development and maintenance of Wireshark

1.6. Reporting problems and getting help

1.6.1. Website

1.6.2. Wiki

1.6.3. Q&A Site

1.6.4. FAQ

1.6.5. Mailing Lists

1.6.6. Reporting Problems

1.6.7. Reporting Crashes on UNIX/Linux platforms

1.6.8. Reporting Crashes on Windows platforms

Chapter 2. Building and Installing Wireshark

2.1. Introduction

2.2. Obtaining the source and binary distributions

2.3. Installing Wireshark under Windows

2.3.1. Installation Components

2.3.2. Additional Tasks

2.3.3. Install Location

2.3.4. Installing WinPcap

2.3.5. Windows installer command line options

2.3.6. Manual WinPcap Installation

2.3.7. Update Wireshark

2.3.8. Update WinPcap

2.3.9. Uninstall Wireshark

2.3.10. Uninstall WinPcap

2.4. Installing Wireshark under OS X

2.5. Building Wireshark from source under UNIX

2.6. Installing the binaries under UNIX

2.6.1. Installing from RPM’s under Red Hat and alike

2.6.2. Installing from deb’s under Debian, Ubuntu and other Debian derivatives

2.6.3. Installing from portage under Gentoo Linux

2.6.4. Installing from packages under FreeBSD

2.7. Troubleshooting during the install on Unix

2.8. Building from source under Windows

Chapter 3. User Interface

3.1. Introduction

3.2. Start Wireshark

3.3. The Main window

3.3.1. Main Window Navigation

3.4. The Menu

3.5. The “File” menu

3.6. The “Edit” menu

3.7. The “View” menu

3.8. The “Go” menu

3.9. The “Capture” menu

3.10. The “Analyze” menu

3.11. The “Statistics” menu

3.12. The “Telephony” menu

3.13. The “Tools” menu

3.14. The “Internals” menu

3.15. The “Help” menu

3.16. The “Main” toolbar

3.17. The “Filter” toolbar

3.18. The “Packet List” pane