Sockstat command

On FreeBSD, we can employ sockstat command to list both open Internet and UNIXdomain sockets: 

  1. # sockstat
  2. USER     COMMAND    PID   FD PROTO  LOCAL ADDRESS         FOREIGN ADDRESS
  3. root     sshd       45768 3  tcp4   192.168.80.129:22     192.168.80.1:60803
  4. root     sshd       22144 3  tcp4   192.168.80.129:22     192.168.80.1:54834
  5. root     sshd       19097 3  tcp4   192.168.80.129:22     192.168.80.1:58174
  6. smmsp    sendmail   662   3  dgram  -> /var/run/log
  7. root     sendmail   659   3  tcp4   127.0.0.1:25          *:*
  8. root     sendmail   659   4  dgram  -> /var/run/logpriv
  9. root     sshd       656   3  tcp6   *:22                  *:*
  10. root     sshd       656   4  tcp4   *:22                  *:*
  11. ......

We can see the output of sockstat lists which process owns the socket, the file descriptor number of the socket, etc. So it is a really awesome tool to diagnose network related issues.

Reference:
SOCKSTAT(1).