I want to monitor the UDP packets being received by my server for debugging purposes.

Is there a good, reasonably easy to use traffic dumper program that works from the UNIX command line? I'd prefer for it to print the UDP packets in human readable form (not hexadecimal).

You might want to look at Snort (http://snort.sourcefire.com) or Demarc (http://www.demarc.com).

Snort is a packet sniffer, but it runs agains a set of rules and dumps packets that match the rules. It's really a network intrusion detection system, but it might work for you.

Demarc is a front end to snort, with a bunch of other useful features.

Frank