nmap 127.0.0.1

Starting Nmap 4.20 ( http://insecure.org ) at 2007-09-26 03:14 CEST
Interesting ports on localhost.localdomain (127.0.0.1):
Not shown: 1693 closed ports
PORT     STATE SERVICE
80/tcp   open  http
139/tcp  open  netbios-ssn
445/tcp  open  microsoft-ds
6000/tcp open  X11

Nmap finished: 1 IP address (1 host up) scanned in 0.148 seconds