Linux utility that shows socket statistics. The replacement for netstat in some distros.

Things you can do with ss:

  • Display socket statistics (similar to netstat -s) - e.g. to troubleshoot network issues
  • View TCP and UDP connections, including local and remote addresses and ports
  • Find sockets by protocol (e.g. TCP, UDP, etc.)
  • See sockets associated with a particular process (PID)


Netid values

In the output of ss, Netid means “network protocol identifier”. The following values are seen:

  • tcp - TCP
  • udp - UDP
  • nl - Netlink
  • u_str - Unix stream sockets
  • u_dgr - Unix datagram sockets
  • u_seq - Unix sequenced-packet sockets
  • p_dgr - Packet datagram sockets
  • p_raw - Packet raw sockets


Show all TCP sockets including established connections

ss --tcp --all

Find out what’s listening on a port

ss -ltnp sport = :<portnum>

For example:

$ ss -ltnp sport = :8080
State          Recv-Q         Send-Q     Local Address:Port   Peer Address:Port   Process         
LISTEN         0              100                    *:8080              *:*       users:(("java",pid=449045,fd=46))