nmap command…

Again here’s a reminder about the nmap command. I needed the command to tell what a udp port or a tcp port, was being used for. To test a listening UDP port, simply use nmap as follows:

# nmap -p [port] -sU -P0 [host name | ip address]

# nmap -p 123 -sU -P0 example.com

# nmap -p 123 -sU -P0

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 (
4000/udp closed icqNmap run completed — 1 IP address (1 host up) scanned in 0.057 seconds