Connect to Port

Running service in TCP port

netstat -nltp

Scan open ports

nmap <host>

nmap -p <port> <host>

nmap -p 1-65535 <host>

Connect to a port

telnet <host> <port>

ncat -vz <host> <port>

nc -vz <host> <port>

nc -vz -w3 <host> <port>