“Socket statistics” (ss) is a netstat-like tool with slightly nicer formatting. Options:

  • -t — Display TCP sockets
  • -u — Display UDP sockets
  • -l — Display listening sockets (not just established connections)
  • -p — Show the process using the socket (broken?)
  • -n — Show raw port numbers (not named services)

For example, ss -tulpn will produce a nice list of open ports.