What is Wireshark?

Combs continues to maintain the overall code of Wireshark and to issue releases of new versions of the software. On Linux, BSD, and macOS, with libpcap 1.0.0 or later, Wireshark 1.4 and later can also put wireless network interface controllers into monitor mode. Wireshark is also widely used in cybersecurity to detect suspicious network activity, including packet sniffing and intrusion attempts. Wireshark is very similar to tcpdump, but has a graphical front-end and integrated sorting and filtering options. Wireshark, and the other programs distributed with it such as TShark, are free software, released under the terms of the GNU General Public License version 2 or any later version.

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This is really the same question as a previous one; see the response to that question. If not, then see the main Npcap page – check the “Patches, Bug Reports, Questions, Suggestions, etc” section. If you disable network address-to-name translation – for example, by turning off the “Enable network name resolution” option in the “Capture Options” dialog box for starting a network capture – the lookups of the address won’t be done, which may speed up the process of reading the capture file after the capture is stopped. You will have to determine whether your OS needs to be so configured and, if so, can be so configured, configure it if necessary and possible, and make whatever changes to libpcap and the packet capture program you’re using are necessary, if any, to support capturing the FCS of a frame. You will have to determine whether your OS needs to be so configured and, if so, can be so configured, configure it if necessary and possible, and make whatever changes to libpcap and the packet capture program you’re using are necessary, if any, to support capturing those packets.

• More advanced setups may use managed switches, mirror ports, or dedicated capture devices.
• If it does, you should ask whoever supplied the driver for the interface (the vendor, or the supplier of the OS you’re running on your machine) whether it supports promiscuous mode with that network interface.
• TCP segments that start with the middle of a Yahoo Messenger packet that takes more than one TCP segment will not be recognized as Yahoo Messenger packets (even if the TCP segment also contains the beginning of another Yahoo Messenger packet).
• As of Wireshark 0.8.16, such a mechanism exists; if you select a UDP or TCP packet, the right mouse button menu will have a “Decode As…​” menu item, which will pop up a dialog box letting you specify that the source port, the destination port, or both the source and destination ports of the packet should be dissected as some particular protocol.
• If this occurs, please let the Wireshark developers know at wireshark-; be sure to send us a copy of that trace file if it’s small and contains non-sensitive data.
• If not, this may just be a problem with promiscuous sniffing, either due to running on a switched network or a dual-speed hub, or due to problems with the interface not supporting promiscuous mode; see the response to this earlier question.

1.2. Features

Users can apply filters to view specific streams of data or analyze how different devices communicate. The third panel in the Wireshark UI shows the raw data of a packet in hexadecimal and ASCII format for further analysis. The tool breaks down the packet into layers in OSI or TCP/IP layers and can be expanded into fields showing ports, flags, TTL values, and more. Wireshark UI consists of three different panes that display data from captured packets.

Developer Documentation

• There are many tutorials and videos that show you how to use Wireshark for specific purposes.
• Note also that on the Linksys Web site, they say that their auto-sensing hubs “broadcast the 10Mb packets to the port that operate at 10Mb only and broadcast the 100Mb packets to the ports that operate at 100Mb only”, which would indicate that if you sniff on a 10Mb port, you will not see traffic coming sent to a 100Mb port, and vice versa.
• The capture filter syntax used by libpcap can be found in the tcpdump(8) man page.
• Otherwise, on Windows, see the response to this question and, on a UNIX-flavored OS, see the response to this question.
• This site is built for people who want to understand packet captures, protocol behavior, and real network traffic in a clearer, more practical way.
• Yes, if, for example, you mean “I work for a commercial organization; can I use Wireshark to capture and analyze network traffic in our company’s networks or in our customer’s networks?”
• This means that you should disable name resolution when capturing in monitor mode; otherwise, when Wireshark (or TShark, or tcpdump) tries to display IP addresses as host names, it will probably block for a long time trying to resolve the name because it will not be able to communicate with any DNS or NIS servers.

That makes it easier to understand what happened on the network instead of guessing. Learn how to choose an interface, start a live capture, and inspect the traffic that appears in real time. Build practical packet analysis and troubleshooting knowledge that supports networking and infrastructure career growth. It can also support people exploring network engineering careers and building stronger troubleshooting skills. This site is built for people who want to understand packet captures, protocol behavior, and real network traffic in a clearer, more practical way.
If this is the case on your system, there’s probably a separate package named “wireshark-qt”. Many distributions have separate Wireshark packages, one for non-GUI components such as TShark, editcap, dumpcap, etc. and one for the GUI. Each major release branch of Wireshark supports the versions of Windows that are within their product lifecycle at the time of the “.0” release for that branch. Support for particular capture file formats is added to Wireshark as a result of people contributing that support; no formal plans for adding support for particular capture file formats in particular future releases exist. Support for particular protocols is added to Wireshark as a result of people contributing that support; no formal plans for adding support for particular protocols in particular future releases exist.

DNS Behavior

Install Wireshark safely and get set up for packet capture and network troubleshooting. Learn how packets move across networks, how protocols like DNS, TCP, HTTP, and TLS operate, and how packet captures are used to diagnose real-world network problems. Streamline your data collection and vendor risk assessments with UpGuard’s SIG Lite risk-mapped questionnaire.
At least on x86-based machines, Linux can get high-resolution time stamps on newer processors with the Time Stamp Counter (TSC) register; for example, Intel x86 processors, starting with the Pentium Pro, and including all x86 processors since then, have had a TSC, and other vendors probably added the TSC at some point to their families of x86 processors. This is really the same question as the previous one; see the response to that question. In your mail, please give full details of the problem, as described above, and also indicate that the problem occurs with tcpdump not just with Wireshark. If you can capture on the interface with tcpdump, send mail to email protected giving full details of the problem, including If you are having trouble capturing on a particular network interface, and you’ve made sure that (on platforms that require it) you’ve arranged that packet capture support is present, as per the above, first try capturing on that device with tcpdump. You may need to run Wireshark from an account with sufficient privileges to capture packets, such as the super-user account, or may need to give your account sufficient privileges to capture packets.
RTP doesn’t have a standard port number, so 1) doesn’t work; it doesn’t, as far as I know, have any “signature”, so 2) doesn’t work. Whether you will be able to capture in monitor mode depends on the operating system, adapter, and driver you’re using. Even on those that do, monitor mode might not be supported by the operating system or by the drivers for all interfaces. On some platforms, or with some cards, this might require that you capture in monitor mode – promiscuous mode might not be sufficient. This would probably require that you capture in promiscuous mode or in the mode called “monitor mode” or “RFMON mode”. If your distribution has a bug such as this, you may have to run a standard kernel from kernel.org in order to get high-resolution time stamps.
Wireshark can open packet captures from a large number of capture programs. The specific media types supported may be limited by several factors, including your hardware and operating system. However, to really appreciate its power you have to start using it. You can stay informed about new Wireshark releases by subscribing to the wireshark-announce mailing list . Past releases can be found by browsing the all-versions directories under each platform directory. You can download source code packages and Windows installers which are automatically created each time code is checked into the source code repository .

A network protocol analyzer, also referred to as a packet sniffer informally, is used to capture and analyze packets on a network to troubleshoot network behavior for bottlenecks, anomalous performance, and security threats. Wireshark is a leading open source network protocol analyzer that security analysts, network admins, and developers can use to capture and analyze network traffic to improve performance or detect security vulnerabilities. Is your security program benefiting from the full potential of open source innovation? It was released in 2025 and donated to the Wireshark Foundation to build on Wireshark’s legacy. Stratoshark is an open source companion tool for Wireshark that shares the same UI, dissection engine, and filtering code, making it easier for Wireshark users to pick up and learn it quickly. Before running a session, users can also select a capture filter, such as traffic to a single host, port 80 traffic, or TCP.

Display Filter Reference

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. Wireshark is a data capturing program that “understands” the structure (encapsulation) of different networking protocols. Wireshark is cross-platform, using the Qt widget toolkit in current releases to implement its user interface, and using pcap to capture packets; it runs on Linux, macOS, BSD, Solaris, some other Unix-like operating systems, and Microsoft Windows. You can narrow the view using display filters, making it easier to inspect specific conversations or protocols. Any single frame selected in the top pane is further explained in the tool’s middle panel.
The top panel lists frames individually, with key data on a single line. This means that you should disable name resolution when capturing in monitor mode; otherwise, when Wireshark (or TShark, or tcpdump) tries to display IP addresses as host names, it will probably block for a long time trying to resolve the name because it will not be able to communicate with any DNS or NIS servers. Wireshark gets time stamps from libpcap/Npcap, and libpcap/Npcap get them from the OS kernel, so Wireshark – and any other program using libpcap, such as tcpdump – is at the mercy of the time stamping code in the OS for time stamps. You can make that setting the default by selecting “Preferences” from the “Edit” menu, turning off the “Enable network name resolution” option in the “Name resolution” options in the preferences dialog box, and using the “Save” button in that dialog box; note that this will save all your current preference settings. For any particular link-layer network type, unless the OS supplies the FCS of a frame as part of the frame, or can be configured to do so, Wireshark – and other programs that capture raw packets, such as tcpdump – cannot capture the FCS of a frame. Unless the OS always supplies packets with errors such as invalid CRCs to the raw packet capture mechanism, or can be configured to do so, invalid CRCs to the raw packet capture mechanism, Wireshark – and other programs that capture raw packets, such as tcpdump – cannot capture those packets.