Wireshark 1.4.6

Ever since Wireshark come on the scene it was adopted as the #1 LAN sniffer for security demonstrations, says me. You don't have to believe all the hype and can go back to your console screen logging hours at the page down key. Wireshark for Windows is the best choice for capturing LAN traffic. Download Wireshark Here.

Wireshark is extremely easy to use and even a novice can start capturing data on the network. Wireshark features a very rich system to let you edit and resend packets over the network. You can set it to stop capturing after 'x' amount of packets which can be VERY handy for testing application bugs. You can control the size of capture log files and even use multiple files to log your captures too.