Finding what Applications use what Port

If you need to know what applications are using what ports simply follow these instructions.

1) Open the command prompt.

2) Type “netstat -ano” without the quotes.

-a: Displays all active TCP connections and the TCP and UDP ports on which the computer is listening.
-n: Displays active TCP connections, however, addresses and port numbers are expressed numerically and no attempt is made to determine names.
-o: Displays active TCP connections and includes the process ID (PID) for each connection. You can find the application based on the PID on the Processes tab in Windows Task Manager. This parameter can be combined with -a-n, and -o.

3) Open the Windows Task Manager and look for the process ID or PID and compare to the results listed in the command prompt.

– note:  If the PID information is not listed in the Windows Task Manager window, Click on the “View” menu and select  the “Select Columns” option.  Make sure there is a check mark beside the PID (process ID) option.

Sample netstat -ano

Sample netstat -ano

For more information about the netstat command, please reference http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/netstat.mspx?mfr=true