Checking ports with netcat

checking tcp ports

~% nc -vz 192.168.1.1 80

examplehostname [192.168.1.1] 80 (http) open

~% nc -vz 192.168.1.1 80

examplehostname [192.168.1.1] 80 (http) : Connection refused ~

checking udp ports

~% nc -vzu 192.168.1.1 53

examplehostname [192.168.1.1] 53 (domain) open

~% nc -vzu 192.168.1.1 54

examplehostname [192.168.1.1] 54 (?) : Connection refused

portscan

for i in {1..1024}; do nc -vz -w 1 192.168.1.1 $i; done