[CentOS] Show IP Traffic on a port

Wed May 21 01:18:16 UTC 2008
Les Mikesell <lesmikesell at gmail.com>

Joseph L. Casale wrote:
> I am trying to determine the root of an issue I am having.
> How can I watch traffic destined to a specific port on my CentOS 5.1
> box to see if its even hitting it? It would be udp traffic.

Use wireshark if you are logged in with a gui.  In text mode use 
tcpdump.  In either you can specify a filter with protocol, source 
and/or destination addresses and port number.  Something like
tcpdump -i eth0 udp
might be enough if you don't have a lot of traffic or
tcpdump -i eth0 udp and port portnumber
to narrow it down more.

   Les Mikesell
    lesmikesell at gmail.com