2.8. ss

ss is a command-line utility that prints statistical information about sockets, allowing administrators to assess device performance over time. By default, ss lists open non-listening TCP sockets that have established connections, but a number of useful options are provided to help administrators filter out statistics about specific sockets.

Red Hat recommends using ss over netstat in Red Hat Enterprise Linux 7.

One common usage is ss -tmpie which displays detailed information (including internal information) about TCP sockets, memory usage, and processes using the socket.

ss is provided by the iproute package. For more information, see the man page:

$ man ss