netstat

Netstat is a command-line network utility that displays network connections, routing tables, network interfaces and network protocol statistics.

List all connections.

netstat
netstat -a

List TCP or UDP connections.

netstat -at
netstat -au

List listening TCP or UDP ports.

netstat -lt
netstat -lu

Display statistics.

netstat -s

Display TCP or UDP statistics.

netstat -st
netstat -su

Display connections with process PID.

netstat -o

Displays connections with the executable involved in creating each connection or listening port.

netstat -b

Show kernel's network routing table and information.

netstat -r
netstat -rn