On the current market, there are many packet analyzers, but the vast majority of them can only be used from a command-line terminal because they don't have a graphic user interface (GUI), something that makes them more complicated to use.

Packetyzer is a sniffer, based on Ethereal, with a very practical graphic interface, thanks to which detecting and analyzing problems in any network will be a lot easier. The program is capable of capturing data from any network adapter available in the system.

Main features

• Decoding of more than 700 protocols (IEEE 802.11, IEEE 802.11 wireless LAN and 802.1q Virtual LAN, among many others).
• Detailed packet captures.
• Packet filtering by IP or protocol.
• Compatibility with the majority of market standards (Novell's LANalyzer, Cisco Secure IDS iplog, NetXray, AIX's iptrace, WildPackets, EtherPeek and AiroPeek).

If you're looking for a program to sniff packets and analyze them, that offers a practical graphical interface, and that's totally free, you should try out Packetyzer.