Remote Device Disconnected, can't get it to reconnect

Firstly, thanks for continuing to maintain and develop this software, it proves its worth daily.

I have an instance of Syncthing running on my local machine (receive only) that syncs to a remote server (send only) that has become disconnected and I can’t get them to connect again to resume syncing.

In attempting to fix, I have tried:

  • upgrading both the latest version of Syncthing 1.27.12
  • deleting & re-adding the folder to be synced
  • deleting & re-adding the remote device

None of which have worked so I’m out of ideas and would appreciate some pointers or guidance.

My local machine is running macOS Catalina 10.15.7 and the it’s syncing to a remote Linux server. Thanks in advance for any help.

Looking into the logs on the remote server side, this keeps repeating:

2024-09-30 07:33:27 Listen (BEP/tcp): TLS handshake: tls: client offered only unsupported versions: [303 302 301]

Sync was working fine up to 26-Sep and the only change I can think of, is re-starting my local machine for the first time in a long time.

Could there be some kind of “security appliance” in the network of either side? Sounds like the TLS endpoint Syncthing is talking to is actually not the other Syncthing instance, but something else intercepting the TLS-secured connection.

Same thing has happened to me since yesterday. Can’t find a solution either. I also have a receive only server to a send only one. Received is a NAS with docker, and send is a seedbox.

Nothing new that I’m aware off, certainly on my side. I will raise a support ticket for the server though to see if they are aware of the issue for other clients running Syncthing.

I use Syncthing on a hosted seedbox and my NAS – today I ran into this exact same issue.

Reinstalling Syncthing on the seedbox and reconfiguring the shared devices/folders on both installations solved the problem.

2 Likes

Thanks, that appears to be working for me – running through the initial sync now and both instances are communicating with each other.

1 Like