Strange behaviour from Syncthing on one particular machine

Support
1

Until today, I was running Syncthing without any problems. I have four machines, and I recently reinstalled the operating system on one of them (call it machine A). I set up Syncthing to synchronize with my ‘central repository’ machine (machine B) as normal (entered IDs on both, told it which repositories to sync, etc). However, for some reason, I couldn’t connect at all - neither machine registered the other as being ‘connected’ at any point. Syncthing’s GUI at one end (but not both) spat repeated ‘unexpected EOF’ messages.

I then tried to sync machine A with a different computer (let’s say C). Now, this worked for a while, and then stopped again. When I tried running STTRACE=net syncthing, I got this message pair over and over again:

[DFHIJ] 2014/08/06 15:39:58.537647 main.go:659: DEBUG: dial WEUGXLYFGBXCE7T6FVFFH4RUIJHERLHQQZM333LPP5MUDAAW4ENQ 192.168.0.11:22000 [DFHIJ] 2014/08/06 15:42:05.808480 main.go:664: DEBUG: dial tcp 192.168.0.11:22000: connection timed out

Where WE etc is the ID of machine C. This doesn’t seem to have any effect on my other machines (B and C synchronize just fine, for example).

I’m not sure what’s causing this, and would appreciate some help.

2

A firewall of some kind would be the first suspect. What does the other end (192.168.0.11) say with STTRACE=net on?

3

I tried - the result is that the announce server never starts. If I try a restart, it takes an unusually long time to reboot, and I still have no announce server!

4

I seem to have the same problem, where I get dial/connection refused on node A (Ubuntu laptop), while node B (Raspberry Pi) doesn’t start the announce server according to the GUI (but it logs “INFO: Sending global discovery announcements”).

I also have ports 8000-9000 and 22000 forwarded on node B, so that shouldn’t be the problem.

5

If you guys mean that the announce server is shown as offline in the gui, that’s a sure sign that you have interference from a firewall. “Online” means that the node could send and receive data from the announce server. “Offline” means no reply, which in practice is due to either bad connectivity or a firewall. It’s not that the announce server itself is dead.

6

It’s not shown as ‘offline’ - it never appears in the first place!

However, I think I’ve solved it - it seems the wireless on my server machine is broken somehow, and interferes with the wired connection in some way, making Syncthing misbehave. Having disabled that, it now works fine.

7

Turns out in my case it was a misconfigured address for one node, resulting in strange, failing connections, and a too strictly configured firewall on a router that blocked even pings (and also connection to the announce server).

8