nmap

Linux

Commands

nmap 192.168.10.1                       scan a host
nmap 192.168.10.1/24                    scan a subnet
nmap 192.168.10.1-50                    scan a range

nmap 192.168.10.1  -sV                  daemon version detection
nmap 192.168.10.1  -O --osscan-guess    OS detection