I am running Syncthing on my homelab using an dynamic DNS service and it worked like a charm for the last couple of years. (syncing phone, laptops, etc. no matter where I was)
Suddenly, I was unable to sync the directories from my university PC with my instance at home and after testing a little bit, I figured out that the problem lies in the fact that the IT appenrently blocked the domain syncthing.net and the domain does not resolve.
This probably causes problems because the relay and discovery servers are being accessed via *.syncthing.net domains, correct?
If I disconnect from the LAN and use the Wifi connection, everything works again. (The Wifi is less restricted since it is “eduroam”)
In your opinion: What would be the quickest way to get around this obstacle?
First need to determine the blocking technique – it could be simple DNS filtering or it could be something more advanced.
It’s more than likely your PC is getting its IP address and other network settings via the university DHCP server. If your PC is running Windows, try the following command:
The university I work for has a strict policy about this and using syncthing or any tools to transfer files from the university network to my home machine is strictly prohibited.
You may wish to verify what you’re trying to do isn’t a policy violation. They probably blocked syncthing on purpose.
If it isn’t, and you want to proceed I would suggest putting the hostname for your homelab machine into the device config on your university machine and bypass discovery. Also make sure relay is disabled and the port is forwarded on your home router to your homelab server.
But please double check. If they are doing some kind of deep packet inspection and detect you tried to circumvent the block…. At my university I would be fired.
Thank you very much for the prompt replies! I will test DNS lookup the next ASAP. (Yes, it’s Windows)
So there’s no other, alternative domain or a mirror of sorts?
Would running my own private relay and discovery services next to my Syncthing instance on my home lab solve the issue? My DynDNS domain is not blocked and I can use it to sync my Thunderbird calendar to my Nextcloud.
In case that’s relevant: I am running my services with Docker compose (using Portainer) and have a reverse proxy set up for the exposed services.
Why do you need to run discovery or a relay? One machine is having trouble reaching another machine that has a DDNS resolveable IP address. Forward the port on the router. Specify the hostname of the homelab machine on the university machine config, and done.
what am I missing? I think you’re making it too complicated.
