Difference between revisions of "Wireshark"

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[[File:Wireshark_Capture.jpg|thumb|Capture Filter]]
[[File:Wireshark_Capture.jpg|thumb|Capture Filter]]
The '''Capture Filter''' is set before starting a packet capture and cannot be modified during the capture. It is more limited than the display filter and used to reduce the size of raw capture data. The filter can be entered, as seen in Figure 'Capture Filter', in the text-field above the interfaces before the capturing is started.
The '''Capture Filter''' is set before starting a packet capture and cannot be modified during the capture. It is more limited than the display filter and used to reduce the size of raw capture data. The filter can be entered in the text-field above the interfaces before the capturing is started.
The Capture Filter has an own syntax described below. It only supports combinations of the listed primitives. An example is shown in figure 'Capture Filter'. The filter captures only packets which source IP address is 192.168.0.1 and the TCP port 23
 
Protocol selection  [tcp|udp]
IP address          [src|dst] [host]
Port number        [port]
Operations          [and|or] [less|greater] [not]


== References ==
== References ==

Revision as of 14:48, 15 January 2021

Summary

Wireshark is one of the most famous network protocol analyzers. It is a powerful multi platform open source tool, that can analyze network traffic on all possible network interfaces, like Ethernet, Wi-Fi, Bluetooth, local Loopback and VMware Adapters and even USB. The Wireshark project was founded 1998 by Gerald Combs, under the name of 'Ethernal' and gets continuously further developed by volunteers, network professionals and enthusiasts around the globe. Version 1.0 was released in 2008. Before, only expensive and proprietary solutions were available. Today Wireshark provides a wide set of features including:

  • Capturing network traffic
  • Filter and visualise the traffic
  • Safe and open captured traffic in files
  • Import and export other capture file formats

Therefore Wireshark is used to troubleshoot network problems, examine network security, test network applications and for educational purposes.

The application is free to download from the Wireshark website and is published under the GNU General Public License. A wizard leads trough the installation process. Npcap has to be installed to capture network traffic, additionally USBpcap can be installed, to capture USB traffic. Npcap is a packet sniffing driver copyrighted by the Nmap Project.

Functionality

Start screen

After starting the Wireshark application, it automatically scans for all available interfaces. In Figure 'Start screen' you can see the listed interfaces with a preview of the network traffic.

By clicking on 'Aufzeichnen' or 'Capture' above the interface list, the interface menu opens. The first tab shows the interfaces including their MAC Addresses, which helps identifying the right one. Also Pipes and remote interfaces can be configured. The second tab shows the output options. Here you can save the captures automatically in files, according to different rules. The third tab offers additional options for display and name resolution.

Capture and Display Filter

The capture process starts by double clicking a interface or select one and click on the blue fin icon in the menu bar.

Capture Filter

The Capture Filter is set before starting a packet capture and cannot be modified during the capture. It is more limited than the display filter and used to reduce the size of raw capture data. The filter can be entered in the text-field above the interfaces before the capturing is started. The Capture Filter has an own syntax described below. It only supports combinations of the listed primitives. An example is shown in figure 'Capture Filter'. The filter captures only packets which source IP address is 192.168.0.1 and the TCP port 23

Protocol selection [tcp|udp] IP address [src|dst] [host] Port number [port] Operations [and|or] [less|greater] [not]

References