Nmap
From Linuxintro
nmap allows you to find out what network ports are open on your system:
itchy:~ # nmap localhost Starting Nmap 4.75 ( http://nmap.org ) at 2009-04-06 23:38 EDT Warning: Hostname localhost resolves to 2 IPs. Using 127.0.0.1. Interesting ports on localhost (127.0.0.1): Not shown: 996 closed ports PORT STATE SERVICE 22/tcp open ssh 25/tcp open smtp 111/tcp open rpcbind 631/tcp open ipp Nmap done: 1 IP address (1 host up) scanned in 0.28 seconds
Scan all ports
nmap -sS -O -PI -PT 192.168.0.0/24
To scan all ports -p 1-65535
