Sniffit

In the course of checking that a cups server was secure when passing login info I ran sniffit on my Ubuntu box. It turns out you are well-advised to read the docs in /usr/share/doc/sniffit/ rather than restricting yourself to the manpage as the latter document is sparse on details. It turns out that the program will log data to a file even though one doesn't explicitly specify this behaviour from the command line. To put it in other words, you start it up thinking it will dump it's output to stdout and it doesn't. It turns out that the -R option allows one to specify a single output file. If one tails this file in another window one gets the desired behavour of sending to stdout. -- WalterTautz - 16 Jun 2006

Ethereal / Wireshark

Wireshark used to be ethereal, until the author left for another company. Now there's an ethereal, but there's also a wireshark. You want wireshark. It's ported to lots of platforms, including Windows and Mac OS X. They have commandline equivalents too (tethereal, twireshark).

tcpdump

You can't live without it, trust me.