Port Forwarding FAQ

Why do I see a red dot and "Port is closed"?

You haven't port forwarded correctly. Port forwarding opens a port in your firewall or router so that incoming connections from the outside world can be made with Transmission. If the port is forwarded, other people in the torrent can see you, thus increasing your potential number of connections, which more importantly, may increase the speed of your download.

When do I need to Port Forward?

If you share your internet connection with a router, or if your broadband modem is a router itself, then you will need to forward Transmission's port by following the instructions below. In addition, if you have enabled the Mac OS X firewall, you will need to open a port in that too. See below for details.

How do I Port Forward?

Keep in mind that many DSL modems also function as routers, and hence port forwarding as per above may still be necessary, even though your computer is directly connected to the modem.

How do I know if I've done it right?

  1. Open Transmission.
  2. Go to Preferences >> Advanced.
  3. Check the notification next to 'Incoming TCP Port'.