os: xubuntu 24.04
firewall: ufw
torrent program: transmission
On transmission I opened port 51401
On a terminal I executed sudo ufw allow 51401, which opens both tcp and udp ports for both ipv4 and ipv6. This is called forwarding, right?
I’m following https://github.com/transmission/transmission/blob/main/docs/Port-Forwarding-Guide.md but apparently I still don’t get it
ETA: thanks for your input, issue has been solved
No, you need to forward from your router as well.
Internet -> router -> machine -> firewall
You’ve only allowed the firewall on this machine to allow that port through. Forward that port from your router to your machine’s IP and port as well.
turns out this was the right answer all along
then how come I’ve always torrented without editing the router?
I’ve used privoxy, can that be the reason?
You can still torrent without forwarding a port, for example by only making outgoing connections. But that may limit your speed, and figuring out forwarding should help.
Your client may have set a UPnP request that your router respects…hard to say. You didn’t post any router config info, so it’s hard to say what your environment looks like or was previously working. UPnP is frowned upon for security reasons, so it’s best to just forward if in doubt.
I was still figuring out the right commands but thanks for your input
It seems like that port needs to be accessible from the public Internet. Your local computer probably has at least one more firewall between it and the Internet, running on your router. You need to also forward the port on your router, which is what it says in the second half of the guide.
Check if your ISP uses CGNAT for IPv4. If so, then you’re out of luck and IPv4 pretty forwarding will never work.
See if your router has an external IP in the CGNAT 100.64.0.0/10 range.
If you have IPv6 you can add a firewall rule to your router to allow the forwarding port through and at least have other IPv6 peers connect.
