“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.