# Strange behaviour from Syncthing on one particular machine
**URL:** https://forum.syncthing.net/t/strange-behaviour-from-syncthing-on-one-particular-machine/644
**Category:** Support
**Created:** [August 6, 2014, 3:44am UTC](https://forum.syncthing.net/t/strange-behaviour-from-syncthing-on-one-particular-machine/644 "2014-08-06T03:44:12Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@koz](https://forum.syncthing.net/u/koz)
#### Post date: [August 6, 2014, 3:44am UTC](https://forum.syncthing.net/t/strange-behaviour-from-syncthing-on-one-particular-machine/644/1 "2014-08-06T03:44:12Z")
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.
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### Author:  [@calmh](https://forum.syncthing.net/u/calmh)
#### Post date: [August 6, 2014, 6:35am UTC](https://forum.syncthing.net/t/strange-behaviour-from-syncthing-on-one-particular-machine/644/2 "2014-08-06T06:35:56Z")
A firewall of some kind would be the first suspect. What does the other end (192.168.0.11) say with STTRACE=net on?
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### Author:  [@koz](https://forum.syncthing.net/u/koz)
#### Post date: [August 9, 2014, 4:45am UTC](https://forum.syncthing.net/t/strange-behaviour-from-syncthing-on-one-particular-machine/644/3 "2014-08-09T04:45:15Z")
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!
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### Author:  [@Nutomic](https://forum.syncthing.net/u/Nutomic)
#### Post date: [August 9, 2014, 3:01pm UTC](https://forum.syncthing.net/t/strange-behaviour-from-syncthing-on-one-particular-machine/644/4 "2014-08-09T15:01:32Z")
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.
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### Author:  [@calmh](https://forum.syncthing.net/u/calmh)
#### Post date: [August 9, 2014, 7:49pm UTC](https://forum.syncthing.net/t/strange-behaviour-from-syncthing-on-one-particular-machine/644/5 "2014-08-09T19:49:48Z")
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.
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### Author:  [@koz](https://forum.syncthing.net/u/koz)
#### Post date: [August 9, 2014, 11:04pm UTC](https://forum.syncthing.net/t/strange-behaviour-from-syncthing-on-one-particular-machine/644/6 "2014-08-09T23:04:33Z")
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.
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### Author:  [@Nutomic](https://forum.syncthing.net/u/Nutomic)
#### Post date: [August 10, 2014, 3:17pm UTC](https://forum.syncthing.net/t/strange-behaviour-from-syncthing-on-one-particular-machine/644/7 "2014-08-10T15:17:16Z")
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).
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### Author:  [@system](https://forum.syncthing.net/u/system)
#### Post date: [May 12, 2017, 12:56pm UTC](https://forum.syncthing.net/t/strange-behaviour-from-syncthing-on-one-particular-machine/644/8 "2017-05-12T12:56:38Z")