What should I do if I run a server that I’ve configured to run on a blocked port?

If you’ve configured a server on your network to run on a port number you’ve chosen yourself, and the port is listed in the Blocked Ports list above, then you will need to reconfigure your system to run on a port that isn’t on the block list shown above.

We also recommend you choose a port number that is not used by a widely used service, as this may cause issues with your server’s connectivity.

A list of ports and the services they’re used by is available at Wikipedia’s List of TCP and UDP port numbers page.