ss flags & options

-t

Show TCP sockets only.

ss -t

-u

Show UDP sockets only.

ss -u

-l

Show only listening sockets.

ss -l

ss -lt

-n

Show numeric addresses and ports instead of resolving names.

ss -n

-p

Show the process using each socket.

sudo ss -p

sudo ss -tlnp

-a

Show all sockets (listening and non-listening).

ss -a

ss -ta

-s

Print summary statistics.

ss -s

-tulnp

Common combo: show all listening TCP/UDP sockets with process info.

sudo ss -tulnp

state

Filter sockets by connection state.

ss state established

ss -t state time-wait