Either one of the following commands could show you the process which is running a specific port

• lsof -i :<port>
• netstat -tulpn | grep :<port>

Here is an example on my Ubuntu server.

root@li266-91:~# netstat -tulpn | grep :80
tcp   0   0 0.0.0.0:80   0.0.0.0:*   LISTEN   31024/apache2

Apache is running on port 80.

Done =)

Reference: How do I determine which application is using port 8080?