Firewall-Settings for Syncthing?

Hi, I use syncthing to sync my Linux-Desktop-computer to a Linux-Notebook and a Windows-Notebook. Both Linux machines sync well with the Windows-computer. However the two linux machines won’t sync with each other unless I switch off the local firewall on one of them. On both linux machines I opened port 22000 for TCP and port 21025 for UDP, as recommended in However still I have to switch off one of the firewalls to make the linux computer recognise each other. I did not change the settings of the syncthing default ports. What else do I have to do to enable syncing between the two lnux computers?

Hope you can help me, Joern

Is the 22000 port opened for both directions (in and out)?

Yes, the port is open in both directions. Actually the opensuse firewall only blocks incoming traffic. No outgoing packets are blocked at all.

I think it’s todo with the broadcasts/multicasts for local discovery, make sure the firewall permits them too.

I think that is true. As soon as the Syncthing connection is established between the two computers I can reenable the firewall and Syncthing keeps working.

However I have no idea what settings I have to change to enable the broadcasts or multicasts. Anybody got an idea what the relevant settings are on the opensuse firewall?

Allowing incoming UDP packets to port 21025 should be enough. Maybe there’s an earlier rule to block broadcasts or packets not destined for a local IP or something.

Thanks for the 21025. I had it set up as 21027 so it wasn’t working except when the firewall was stopped. Port 21027/UDP (for discovery broadcasts

Is there a reason you are running an old version?
This port changed with v0.12 which is why it is listed as 21027 in the docs.