net-analyzer/

wireshark

Wireshark is the world's foremost network protocol analyzer, and is the de facto (and often de jure) standard across many industries and educational institutions. Wireshark has a rich feature set which includes 1) deep inspection of hundreds of protocols, with more being added all the time, 2) live capture and offline analysis, 3) standard three-pane packet browser, 4) captured network data can be browsed via a GUI, or via the TTY-mode TShark utility, 5) the most powerful display filters in the industry, 6) rich VoIP analysis, 7) read/write many different capture file formats: tcpdump (libpcap), Catapult DCT2000, Cisco Secure IDS iplog, Microsoft Network Monitor, Network General Sniffer® (compressed and uncompressed), Sniffer® Pro, and NetXray®, Network Instruments Observer, Novell LANalyzer, RADCOM WAN/LAN Analyzer, Shomiti/Finisar Surveyor, Tektronix K12xx, Visual Networks Visual UpTime, WildPackets EtherPeek/TokenPeek/AiroPeek, and many others, 8) capture files compressed with gzip can be decompressed on the fly, 9) live data can be read from Ethernet, IEEE 802.11, PPP/HDLC, ATM, Bluetooth, USB, Token Ring, Frame Relay, FDDI, and others, 10) decryption support for many protocols, including IPsec, ISAKMP, Kerberos, SNMPv3, SSL/TLS, WEP, and WPA/WPA2, 11) coloring rules can be applied to the packet list for quick, intuitive analysis, 12) output can be exported to XML, PostScript®, CSV, or plain text.

GPL-2

Sam James