There a couple of ways to find out.
1) Using telnet to find if port is open on a remote/localhost using the command as:
telnet hostname portnumber
If a port is open then there would be some output on the terminal other wise it would say connection refused or something similar message.
mvohra@livrona:~$ telnet developerfeed.com 2201
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
2) Using netstat to find out if the port is open.
netstat -na | grep portnumber
mvohra@livrona:~$ netstat -na | grep 2201
tcp 0 0 0.0.0.0:2201 0.0.0.0:* LISTEN
mvohra@livrona:~$
If a process is listening on a port it would show up in the grep with the word LISTEN.
