Wireshark is a free and open-source packet analyzer. It is used for network troubleshooting, analysis, software and communications protocol development, and education. Originally named Ethereal, in May 2006 the project was renamed Wireshark due to trademark issues.[4]
Wireshark is cross-platform, using the GTK+ widget toolkit to implement its user interface, and using pcap to capture packets; it runs on various Unix-like operating systems including Linux, OS X, BSD, and Solaris, and on Microsoft Windows. There is also a terminal-based (non-GUI) version called TShark. Wireshark, and the other programs distributed with it such as TShark, are free software, released under the terms of the GNU General Public License.
Contents [hide]
1 Functionality
2 History
3 Features
4 Security
5 Notes
6 References
7 External links
[edit]Functionality
Wireshark is very similar to tcpdump, but has a graphical front-end, plus some integrated sorting and filtering options.
Wireshark allows the user to put network interface controllers that support promiscuous mode into that mode, in order to see all traffic visible on that interface, not just traffic addressed to one of the interface's configured addresses and broadcast/multicast traffic. However, when capturing with a packet analyzer in promiscuous mode on a port on a network switch, not all of the traffic traveling through the switch will necessarily be sent to the port on which the capture is being done, so capturing in promiscuous mode will not necessarily be sufficient to see all traffic on the network. Port mirroring or various network taps extend capture to any point on net; simple passive taps are extremely resistant to malware tampering.
On Linux, BSD, and OS X, with libpcap 1.0.0 or later, Wireshark 1.4 and later can also put wireless network interface controllers into monitor mode.
[edit]History
In the late 1990s, Gerald Combs, a computer science graduate of the University of Missouri–Kansas City, was working for a small Internet service provider. The commercial protocol analysis products at the time were priced around $1500[5] and did not run on the company's primary platforms (Solaris and Linux), so Gerald began writing Ethereal and released the first version around 1998.[6] The Ethereal trademark is owned by Network Integration Services.
In May 2006, Combs accepted a job with CACE Technologies. Combs still held copyright on most of Ethereal's source code (and the rest was re-distributable under the GNU GPL), so he used the contents of the Ethereal Subversion repository as the basis for the Wireshark repository. However, he did not own the Ethereal trademark, so he changed the name to Wireshark.[7] In 2010 Riverbed Technology purchased CACE[8] and took over as the primary sponsor of Wireshark. Ethereal development has ceased, and an Ethereal security advisory recommended switching to Wireshark.[9]
Wireshark has won several industry awards over the years,[10] including eWeek,[11] InfoWorld,[12][13] and PC Magazine.[14] It is also the top-rated packet sniffer in the Insecure.Org network security tools survey[15] and was the SourceForge Project of the Month in August 2010.[16]
Combs continues to maintain the overall code of Wireshark and issue releases of new versions of the software. The product website lists over 600 additional contributing authors.
[edit]Features
Wireshark is software that "understands" the structure of different networking protocols. Thus, it is able to display the encapsulation and the fields along with their meanings of different packets specified by different networking protocols. Wireshark uses pcap to capture packets, so it can only capture the packets on the types of networks that pcap supports.
Data can be captured "from the wire" from a live network connection or read from a file that recorded already-captured packets.
Live data can be read from a number of types of network, including Ethernet, IEEE 802.11, PPP, and loopback.
Captured network data can be browsed via a GUI, or via the terminal (command line) version of the utility, TShark.
Captured files can be programmatically edited or converted via command-line switches to the "editcap" program.
Data display can be refined using a display filter.
Plug-ins can be created for dissecting new protocols.
VoIP calls in the captured traffic can be detected. If encoded in a compatible encoding, the media flow can even be played.
Raw USB traffic can be captured.[17]
Wireshark's native network trace file format is the libpcap format supported by libpcap and WinPcap, so it can exchange files of captured network traces with other applications using the same format, including tcpdump and CA NetMaster. It can also read captures from other network analyzers, such as snoop, Network General's Sniffer, and Microsoft Network Monitor.
[edit]Security
Capturing raw network traffic from an interface requires elevated privileges on some platforms. For this reason, older versions of Ethereal/Wireshark and tethereal/TShark often ran with superuser privileges. Taking into account the huge number of protocol dissectors that are called when traffic is captured, this can pose a serious security risk given the possibility of a bug in a dissector. Due to the rather large number of vulnerabilities in the past (of which many have allowed remote code execution) and developers' doubts for better future development, OpenBSD removed Ethereal from its ports tree prior to OpenBSD 3.6.[18]
Elevated privileges are not needed for all of the operations. For example, an alternative is to run tcpdump, or the dumpcap utility that comes with Wireshark, with superuser privileges to capture packets into a file, and later analyze the packets by running Wireshark with restricted privileges. To make near real time analysis, each captured file may be merged by mergecap into growing file processed by Wireshark. On wireless networks, it is possible to use the Aircrack wireless security tools to capture IEEE 802.11 frames and read the resulting dump files with Wireshark.
As of Wireshark 0.99.7, Wireshark and TShark run dumpcap to do traffic capture. On platforms where special privileges are needed to capture traffic, only dumpcap needs to be set up to run with those special privileges: neither Wireshark nor TShark need to run with special privileges, and neither of them should be run with special privileges.
