How do I Port Forward?

If your router supports NAT-PMP, UPnP, or you have Apple AirPort, Transmission can map its port automatically. Most routers manufactured since 2001 have this feature.

  1. Open Transmission.
  2. Go to Preferences → Network, and check 'Automatically map port'.
  3. If you get a green dot and 'Port is Open' then you have successfully port forwarded!
  4. If you get a red dot and the message 'Port is closed', click here.

If you don't have a compatible router, it is simple to forward Transmission's port manually. For instructions click here.

If you don't use a router, and your modem is directly connected to your computer, you'll need to open Transmission's port in the macOS firewall. For instructions click here.

Note: It is highly recommended you enable the macOS firewall if you are not using a router.

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