[josh@enigma ~]$ nmap irc.freenode.net

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2015-10-24 13:22 MDT
Warning: Hostname irc.freenode.net resolves to 16 IPs. Using 91.217.189.42.
Interesting ports on sinisalo.freenode.net (91.217.189.42):
Not shown: 1674 closed ports
PORT     STATE SERVICE
22/tcp   open  ssh
6666/tcp open  irc-serv
6667/tcp open  irc
7000/tcp open  afs3-fileserver
7070/tcp open  realserver
8000/tcp open  http-alt