Here I will post some basic examples:
1. Scan all hosts in a given network for specific open port
– This will scan network 192.168.0.1 /24 for open port 10000 (which belongs to WebMin)
# --open options tells nmap, to print ONLY OPEN ports nmap --open -p 10000 192.168.0.1/24
2. Scan all ports on given host
nmap -v 192.168.0.1