Troubleshooting With Netstat

netstat (Network Statistics) is useful to query the state of your network connections. It is available for Linux, Windows and MacOS.

Verify your application is listening on the correct port

Run netstat from the console of your server. Useful command switches are:

-u : Show UDP sockets

-p : Show the PID and name of the program to which each socket belongs.

-l : Show only listening sockets.

-n : Show numeric addresses.

-t : Show TCP sockets

Example:

$ netstat -uplnt



Active Internet connections (only servers)

Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name

tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      1491/sshd

tcp6       0      0 :::22                   :::*                    LISTEN      1491/sshd

udp        0      0 127.0.0.1:323           0.0.0.0:*                           655/chronyd

udp        0      0 0.0.0.0:68              0.0.0.0:*                           1312/dhclient

udp6       0      0 ::1:323                 :::*                                655/chronyd

Review this information to verify your application is listening on the correct local address and socket. Please provide this information to support if you submit a ticket for further debugging.