How do I change the port BitTorrent uses?
Open the Options, click Network. You can change the port in the box next to “Port used for incoming connections.” However, it takes a restart of BitTorrent to take effect. Make sure you do not run two clients with the same port! You can choose to have BitTorrent use a different port each time you start the client, but this will not work if you are using Port Forwarding to forward a particular port.