Sync Mac --> QNAP via VPN --> no sync

Support
1

Hello,

I have a problem to get a synchronisation work using a VPN. My configuration:

  • MacBook Pro, establishing VPN with VPN-Tracker
  • QNAP

On both machines Syncthing is running and synchronisation works in a ‘normal’ network environment fine. What happens after VPN is up:

  • The Macbook is detecting the QNAP (pic 1)
  • I confirm the connection request and the new device appears in the device list
  • After a while a message appears: Bad cerificate … cetificate is valid for QNAP, not syncing (pic 2)

Any ideas?

Thanks for your support, Christoph

2

Does it sync fine without the VPN?

It seems that you are either pointing the mac at the wrong port of QNAP, or it has a bad certificate, or port forwarding/UPnP is setup somehow incorrectly, or worse… someone is performing MITM attack.

3

Hello Audrius,

thanks for your quick reply. Yes, sync works well without VPN. I’m pretty new in syncthing, where can I check a log file?

4

Do you have addresses configured manually?

5

Yes. I filled in the IP for the QNAP manually, e.g. 192.168.178.2:8090, 192.168.1.8:8090

In the log file I found this after establishing the VPN:

Apr 1 11:29:31 Christoph-MacBook.local discoveryd[62]: Basic DNSResolver UDNS Send(): UDP Sendto() failed to DNSNameServer 192.168.117.65 Port 53 errno 51, fd 78, ErrLogCount 41 ResolverIntf:5 │ Apr 1 11:29:31 Christoph-MacBook.local discoveryd[62]: Basic DNSResolver UDNS Send(): UDP Sendto() failed to DNSNameServer 192.168.117.65 Port 53 errno 51, fd 78, ErrLogCount 42 ResolverIntf:5 │ Apr 1 11:29:32 Christoph-MacBook.local discoveryd[62]: Basic DNSResolver UDNS Send(): UDP Sendto() failed to DNSNameServer 192.168.117.65 Port 53 errno 51, fd 78, ErrLogCount 43 ResolverIntf:5 │ Apr 1 11:29:32 Christoph-MacBook.local discoveryd[62]: Basic DNSResolver UDNS Send(): UDP Sendto() failed to DNSNameServer 192.168.117.65 Port 53 errno 51, fd 78, ErrLogCount 44 ResolverIntf:5 │ Apr 1 11:29:32 Christoph-MacBook.local discoveryd[62]: Basic DNSResolver UDNS Send(): UDP Sendto() failed to DNSNameServer 192.168.117.65 Port 53 errno 51, fd 78, ErrLogCount 45 ResolverIntf:5 │ Apr 1 11:29:32 Christoph-MacBook.local discoveryd[62]: Basic DNSResolver UDNS Send(): UDP Sendto() failed to DNSNameServer 192.168.117.65 Port 53 errno 51, fd 78, ErrLogCount 46 ResolverIntf:5 │ Apr 1 11:29:32 Christoph-MacBook com.apple.xpc.launchd[1] (net.openvpn.client[10452]): Service exited with abnormal code: 1 │ Apr 1 11:29:32 Christoph-MacBook com.apple.xpc.launchd[1] (net.openvpn.client): Service only ran for 1 seconds. Pushing respawn out by 9 seconds.

6

I think 8090 is your web UI port, not the protocol port. Protocol port is 22000 by default.

7

:grimacing: … my stupid mistake! of course it’s port 22000 … and it’s working now.

thanks for your support!

8