Netcat

Manual man nc

Port Scanning

scan a single port

nc -v -w 2 z 192.168.56.1 22

scan multiple ports

nc -v -w 2 z 192.168.56.1 22 80

scan range of ports

nc -v -w 2 z 192.168.56.1 20-25

nc -v -n 192.168.56.110 80