Wireshark

Wireshark is a tool for revealing the content of network communications by analyzing the protocols involved in this process and the data packets intercepted by the various devices installed in the system. A hexadecimal display at the bottom details the contents of each captured data packet.

The extensive filtering system included with Wireshark allows some data packets to be selected and others to be discarded. Capture is performed in real time, but analysis can be done offline and scanned using the program's own interface, TTY or TShark (command line tool included with Wireshark).

Wireshark can extract compressed data files on the fly using GZip and decode secure protocols such as IPsec, ISAKMP, Kerberos, SSL/TLS, or WPA/WPA2. It can also process VoIP.

Wireshark is compatible with many devices and networks: Ethernet, IEEE 802.11, ATM, Bluetooth, Bluetooth, USB, Token Ring, and Frame Relay, among others. In addition, it supports various capture file formats: tcpdump, catapult DCT2000, Cisco Secure IDS iplog, Microsoft Network Monitor, Network General Sniffer, and so on.

You can export the information captured by the program to XML, PostScript, CSV, and plain text formats.