netcat nmap ports Check open ports - client netcat TCP nc -zvw2 192.168.1.1 22 UDP nc -zvw2 -u 192.168.1.1 53 telnet TCP telnet 192.168.1.11 143 nmap TCP nmap -p 10050 192.168.1.1 UDP nmap -sU -p U:5060 192.168.1.1