Nmap Command

Again here’s a reminder about the nmap command. I needed the command to what was a udp port or a tcp port. To test a listening UDP port, simply use nmap as nmap -p [port] -sU -P0 [host name | ip address]

# nmap -p 123 -sU -P0 nmap -p 123 -sU -P0 123.123.123.123

An example of the output from the command

# nmap -p 4000 -sU -P0 localhost

Starting nmap 3.70 ( http://www.insecure.org/nmap/ ) at 2008-05-20 11:00 EST
Interesting ports on localhost (127.0.0.1):
PORT     STATE  SERVICE
4000/udp closed icq

Nmap run completed — 1 IP address (1 host up) scanned in 0.057 seconds