Ernest L. Williams Jr. wrote:
I don't know which ports modern IM/chat software uses, but these will make for a good start:Hi
Which port does one block to stop all AIM and chat room related network
activity from going in or out?
[bevan@vyvyn ~]$ grep irc /etc/services irc 194/tcp # Internet Relay Chat irc 194/udp ircs 994/tcp ircs 994/udp ircd 6667/tcp # Internet Relay Chat ircd 6667/udp # Internet Relay Chat
Of course, if you can, it's easier and better to block all ports that you aren't actively using.