EtherApe is cool

We all probably know Ethereal, a GPL'ed network sniffer that must not be missed in any network administrator's toolkit, and which is packaged by fellow Belgian Debian Developer Frederic Peeters. When trying to decipher obscure network problems, it often helps to have a look at what actually goes over the wire, and see whether anything is out of the ordinary.

Such an approach works reliably well if you have a general idea of what the problem is, and what you should be looking for. If you do not, then looking at the thousands of packages in your sniff log may not be the ideal way to find the solution.

Tune in EtherApe, which is also packaged.

EtherApe gives you a graphical representation of the network traffic it sees, allowing you to quickly track where the problems are. It uses libpcap to sniff the network, but can also work on files. That specific feature makes it extremely interesting -- you can go to a customer's network, let Ethereal sniff away and store the sniffer's results to a file, and analyze that file with both Ethereal and EtherApe to find out what the heck is going on.