Network/Protocol Analyzer for free?
This is very cool … a low-level network analysis tool for free! I have been using Novell’s LANalyzer for years, but it was shelved a couple of years back, and the support of it went away. I don’t believe that I can get a Win2K version of it … let alone a Linux version. Now, I can get something here that will most likely satisfy any of my network troubleshooting and protocol debugging needs …

Ethereal 0.8.17 (Default). GUI network protocol analyzer [freshmeat.net]