How to view which port an application is running on under Linux?

To find out which port an application is running on in Linux, you can use several commands:

• ss -tulpn — shows all listening TCP and UDP ports with processes.
• netstat -tulpn — similar, but may require installing the net-tools package.
• lsof -i -P -n | grep LISTEN — shows processes listening on ports.

For example, the command:

ss -tulpn | grep <process_name>

will help find the ports used by a specific application. If the process PID is known, you can use:

lsof -p <PID> -a -i

This will help precisely identify which ports your application is using.