Ethereal (now called Wireshark) is a network analyzer (sniffer), i.e. software that can capture data packets traveling on the network, in a fully transparent manner.
Advantages:
Software essential to any network administrator to diagnose problems with the protocols.
Open Source and free
Works on all OS known even on Windows Mobile
This is the latest version
Rich VoIP analysis
Decryption support for many protocols, including IPsec, ISAKMP, Kerberos, SNMPv3, SSL/TLS, WEP, and WPA/WPA2
