[[nmap]]
`nmap` - Port Scans
-------------------

`nmap` is designed to allow system administrators to scan large
networks to determine which hosts are up and what services they are
offering. You can use nmap to test your firewall setting, for example
to see if the required ports are open.

.Test Razor port (tcp port 2703):
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# nmap -P0 -sS -p 2703 c301.cloudmark.com

Starting Nmap 5.00 ( http://nmap.org ) at 2012-07-31 11:10 CEST
Interesting ports on c301.cloudmark.com (208.83.137.114):
PORT     STATE SERVICE
2703/tcp open  unknown

Nmap done: 1 IP address (1 host up) scanned in 0.17 seconds
----

See the manual page (`man nmap`) for more information about nmap.