Wireshark( Ethereal) is a free and open-source packet analyzer, used for network troubleshooting, analysis, software and communications protocol development, and education.
Some excellent features include Deep inspection of hundreds of protocols, Live capture and offline analysis, standard three-pane packet browser, Rich VoIP analysis, decryption support for many protocols, including IPsec, ISAKMP, Kerberos, SNMPv3, SSL/TLS, WEP, and WPA/WPA2, can be exported to XML, PostScript®, CSV, or plain text.....
Some excellent features include Deep inspection of hundreds of protocols, Live capture and offline analysis, standard three-pane packet browser, Rich VoIP analysis, decryption support for many protocols, including IPsec, ISAKMP, Kerberos, SNMPv3, SSL/TLS, WEP, and WPA/WPA2, can be exported to XML, PostScript®, CSV, or plain text.....
IDs: C, Communications, Developer Tools, GNU GPL, Open Source, Wireshark, Wireshark 1.6.0 RC1