netstat

Display network-related information such as open connections, open socket ports, etc. See also: lsof for listing network connections, including listening ports. More information: https://keith.github.io/xcode-man-pages/netstat.1.html.

Display the PID and program name listening on a specific protocol:

netstat -p {{protocol}}

Print the routing table and do not resolve IP addresses to hostnames:

netstat -nr

Print the routing table of IPv4 addresses:

netstat -nr -f inet