Syncthing running but connection reset by peer


Since version 0.10.8, I’ve got problem with syncthing. It doesn’t work almost at all.

I’ve got syncthing running on two Synology NAS’es with processors:

  • Quad x64 architecture
  • Intel Atom architecture

And NAS with Atom after some time is resetting connection. I’ve got:

09:01:13 INFO: Connected to already connected device

On second one I’ve got:

09:02:13 INFO: TLS handshake: read tcp ipaddress:22000: connection reset by peer

WebGUI of Syncthings says that everything is ok. It gives status synchronizing 0% on Atom side and on Quad it gives first synchronizing 0%, but after some times it shows disconnected.

On Quad after disconnection SYncthing show wrong CPU Utilization… it gives about 300% CPU, but top is showing that 0% of CPU is used by Syncthing.

What to change in Syncthing to return to normal running? Should I remove all indexes folder or something like that?

Sounds weird. What version worked, before 0.10.8?

I couldn’t say which version it was, but it was one before 0.10.8

right now it seems to look better with v.0.10.9, but I’ll look into it in next few days

With version 0.10.9

I’ve got:

Server one:

Connection to ID closed: ping timeout
Established secure connection to ID at ip:port-remoteip:port
Device ID client is "syncthing v0.10.9"
Device ID name is "Name"
INFO: Connected to alreadyt connected device

And nothing more for 5 hours, nothing gets send. But on second server there are a lot of logs:

Puller .doc hash mismatch x 10
Puller .dwl hash mismatch
Puller ... pull: connection closed
Connection to ID closed: ping timeout
Established secure connection to ID at ip:port - remoteip:port
Device ID client is "syncthing v0.10.9"
Device ID name is "SecName"
TLS handshake read tcp ip:port: connection reset by peer
Puller (folder "Name"), file /volume/.../*.tmp : pull: no available source device

AND a log of pull: no available sources and second server is working like nothing happened, WebGUI on both server shows that everything is okay, on first server is showing that everything is synced, second server showing about 80% of synced items and nothing happens. And true is that syncing is not working at all after connection reset by peer.

One more thing, after about 30 minutes of have webGUI on second server it is showing that second server is disconnected.

Do you have rate limiter enabled?

no, everything got 0 in rate limiter.

Hello there,

are there any news concerning this issue? I have a similar problem trying to setup an initial simple folder sync with my Ubuntu and my two android mobile devices. Connected via wifi in my private LAN. All went well in terms of connection and device visibility until I shared the desired local folder with the two devices. Suddenly they are not able to connect to each other and syncing does not proceed.

The terminal log of the Ubuntu machine repeatedly states:

[VMKXK] 12:31:01 INFO: Established secure connection to [Device-ID] at [VMKXK] 12:31:01 INFO: Connection to [Device-ID] closed: read tcp connection reset by peer

What could be the reason for this behaviour? Any hints would be highly appreciated. Cheers, Nix

PS: syncthing protocol versions - Ubuntu v0.11.0, Linux (32 bit); Android 2x v0.10.30 (App 0.5.28)

Check on the other side why it’s disconnecting. It usually gives a reason. One potential reason is incompatibility between 0.10 and 0.11

Just to let you know, I filed an issue here.

@AudriusButkevicius Thanks for the immediate reply - unfortunately I have no clue how to do that. Any ideas?

I don’t think you should file issues for support, I think you should file issues for bugs. You should use the forum for support.

As I said, check the logs/console output on the other peer, as it might give you clues why it’s disconnecting. At the point you start syncthing, it prints the version, make sure that both versions are 0.10.x or 0.11.x

Edit: I closed your issue, the Android version (as it says in settings) is still at 0.10, hence incompatible with 0.11.

Sorry for filling the issue, @AudriusButkevicius .

To my understanding it was/is an actual bug. And I didn’t do it for support in the first place, but to raise awareness to this issue. So far I haven’t stumpled upon any piece of information that there are incompatibility issues between protocol versions. Do you have any suggestions in that case? Reinstall an earlier version on the linux box?

Maybe I am misreading something, but isn’t

… make sure that both versions are 0.10.x or 0.11.x


I closed your issue, the Android version (as it says in settings) is still at 0.10, hence incompatible with 0.11.

not somewhat contradictory? Don’t mean no offence, but I’m not getting it. I mentioned the devices are at v0.10.x and v0.11.0, respectively. You think these versions are incompatible or not?

As I stated above, the only “clue” i am getting is from my ubuntu machine - the connection is reset by the mobile peers. Not any information why it is doing it. It might help me to understand, how I might get similar information on the mobile devices. Do you happen to know that by chance?

Thx for the replies, Nix

The 0.10 series isn’t compatible with the 0.11 series

This is at the top of every place I could think of where someone might be able to download v0.11 or read about it, but maybe I missed somewhere? :smile:

There is a v0.11 update for Android, otherwise downgrading the other side to v0.10.31 for the moment seems a workable solution.

Ok, I am sorry guys. Installed syncthing via third-party ppa, and there was certainly no mention of it.

Thanks for pointing me to these options, @calmh !