# Two Fedora 27 machines not connecting to each other
**URL:** https://forum.syncthing.net/t/two-fedora-27-machines-not-connecting-to-each-other/11288
**Category:** Support
**Created:** [February 15, 2018, 2:41pm UTC](https://forum.syncthing.net/t/two-fedora-27-machines-not-connecting-to-each-other/11288 "2018-02-15T14:41:49Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@1138-4EB](https://forum.syncthing.net/u/1138-4EB)
#### Post date: [February 15, 2018, 2:41pm UTC](https://forum.syncthing.net/t/two-fedora-27-machines-not-connecting-to-each-other/11288/1 "2018-02-15T14:41:50Z")
I installed syncthing through `dnf` in two Fedora 27 machines. The version is 0.14.43.
I tried the default setup, which implies a quite complex network topology in my company. I can ping from one machine to the other, either with the DNS name or the IP. I can connect through SSH in both directions. Also, both machines show `Listener 3/3` and `Discovery 2/2` in the GUI. However, they cannot connect; both of them are shown as ‘Disconnected’.
NOTE: this same setup has been working ok for a couple of years. Last successful connection was on october. Global discovery never worked, but setting DNS/ip addresses did.
Alternatively, I tried using an OvisLink EVO-W10BAR, where UPnP is enabled. Still not connecting. `Listener 3/3` and `Discovery 2/2` is shown, and both logs are the same:
```
[25BF3] 14:58:12 INFO: Detected 0 NAT devices
[25BF3] 14:58:22 INFO: Relay listener (dynamic+https://relays.syncthing.net/endpoint) shutting down
[25BF3] 14:58:22 INFO: c.S.listenerSupervisor: Failed service 'dynamic+https://relays.syncthing.net/endpoint' (1.000000 failures of 2.000000), restarting: true, error: "{dynamic+https://relays.syncthing.net/endpoint dynamic+https://relays.syncthing.net/endpoint} returned unexpectedly", stacktrace: [unknown stack trace]
[25BF3] 14:58:22 INFO: Relay listener (dynamic+https://relays.syncthing.net/endpoint) starting
[25BF3] 14:58:42 INFO: Relay listener (dynamic+https://relays.syncthing.net/endpoint) shutting down
[25BF3] 14:58:42 INFO: c.S.listenerSupervisor: Failed service 'dynamic+https://relays.syncthing.net/endpoint' (1.629943 failures of 2.000000), restarting: true, error: "{dynamic+https://relays.syncthing.net/endpoint dynamic+https://relays.syncthing.net/endpoint} returned unexpectedly", stacktrace: [unknown stack trace]
[25BF3] 14:58:42 INFO: Relay listener (dynamic+https://relays.syncthing.net/endpoint) starting
[25BF3] 14:59:02 INFO: Relay listener (dynamic+https://relays.syncthing.net/endpoint) shutting down
[25BF3] 14:59:02 INFO: Entering the backoff state.
```
Last, I tried connecting both computers directly (without any intermediate device), manually setting the IP for each of them. It won’t work either.
Any clue about how to troubleshoot this?
* * *
There are other remote Win10 and Win7 machines which used to be connected to these, and they are also not working now. However, I want to focus on getting the direct/local connection first, because I am afraid that this could be related to some configuration in Fedora.
---
### Author:  [@AudriusButkevicius](https://forum.syncthing.net/u/AudriusButkevicius)
#### Post date: [February 15, 2018, 3:19pm UTC](https://forum.syncthing.net/t/two-fedora-27-machines-not-connecting-to-each-other/11288/2 "2018-02-15T15:19:17Z")
Feels like a firewall issue or a proxy that is not setup.
---
### Author:  [@wwwutz](https://forum.syncthing.net/u/wwwutz)
#### Post date: [February 17, 2018, 6:19pm UTC](https://forum.syncthing.net/t/two-fedora-27-machines-not-connecting-to-each-other/11288/3 "2018-02-17T18:19:29Z")
I can reproduce the error message with `c.S.listenerSupervisor` with this `[unknown stack trace]` which I consider a bug. I’ll dig into this deeper.
I set up 2 virtualboxes on a windows host, installed fedora27, `dnf install syncthing` and let both talk to each other. quick tests went fine, no way to reproduce your problem.
So I followed Audrius helpful hint and dropped one of the machines dead on my gateway/rooter. `iptools -A FORWARD -s 192.168.1.70 -j DROP` no internet for you little fedora-vm. Seconds later: `[unknown stack trace]`.
I even build and ran the latest&greatest by:
```
# sudo dnf install go
# p=go/src/github.com/syncthing
# mkdir $p
# cd $p
# git clone https://github.com/syncthing/syncthing
# go run build.go
[...]
# bin/syncthing
```
and after shutting down internet access I got the same problem. Also in my setup it doesn’t _see_ the other vms anymore.
But this could also be normal… I’ll dig into this later.
logfile: [https://gist.github.com/wwwutz/b7233f99b3f089d9964163177baa1dda](https://gist.github.com/wwwutz/b7233f99b3f089d9964163177baa1dda)
---
### Author:  [@AudriusButkevicius](https://forum.syncthing.net/u/AudriusButkevicius)
#### Post date: [February 17, 2018, 6:48pm UTC](https://forum.syncthing.net/t/two-fedora-27-machines-not-connecting-to-each-other/11288/4 "2018-02-17T18:48:36Z")
Not sure why it would panic, feels like a bug, but until @calmh fixes suture to panic on panics, we won’t know what the panic is.
---
### Author:  [@AudriusButkevicius](https://forum.syncthing.net/u/AudriusButkevicius)
#### Post date: [February 17, 2018, 6:51pm UTC](https://forum.syncthing.net/t/two-fedora-27-machines-not-connecting-to-each-other/11288/5 "2018-02-17T18:51:27Z")
Yet this shouldn’t affect anything apart from the log messages, if a direct connection is possible.
---
### Author:  [@calmh](https://forum.syncthing.net/u/calmh)
#### Post date: [February 17, 2018, 6:57pm UTC](https://forum.syncthing.net/t/two-fedora-27-machines-not-connecting-to-each-other/11288/6 "2018-02-17T18:57:04Z")
That’s not a panic, that’s just the relay thing failing to talk to the relay pool. For some reason. That it doesn’t care to log.
---
### Author:  [@AudriusButkevicius](https://forum.syncthing.net/u/AudriusButkevicius)
#### Post date: [February 17, 2018, 7:24pm UTC](https://forum.syncthing.net/t/two-fedora-27-machines-not-connecting-to-each-other/11288/7 "2018-02-17T19:24:12Z")
Right, given internet cable was yanked, it makes sense that it fails like that
---
### Author:  [@system](https://forum.syncthing.net/u/system)
#### Post date: [March 19, 2018, 7:34pm UTC](https://forum.syncthing.net/t/two-fedora-27-machines-not-connecting-to-each-other/11288/8 "2018-03-19T19:34:54Z")
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