tinc: Network is unreachable

1 minute read Modified: 10 Aug, 2018

The problem

When the Fedora 20 server at my parents rebooted because of a general power failure, the tinc tunnel between my parents and myself didn’t work anymore.

Troubleshooting

I enabled the debug logging by sending an INT signal to the daemon.

tincd -n ubbink -k INT

This resulted in the following log items (journalctl -f -l –unit tincd@ubbink.service):

tinc.ubbink[9707]: Got INT signal
tinc.ubbink[9707]: Temporarily setting debug level to 5.  Kill me with SIGINT again to go back to level 0.
tinc.ubbink[9707]: Trying to connect to amys (xxx.xxx.xxx.xxx port 655)
tinc.ubbink[9707]: xxx.xxx.xxx.xxx port 655: Network is unreachable
tinc.ubbink[9707]: Could not set up a meta connection to amys
tinc.ubbink[9707]: Trying to re-establish outgoing connection in 35 seconds
tinc.ubbink[9707]: Purging unreachable nodes

I couldn’t find why this was happening because when I used netcat to connect to port 655 via udp everything worked.

nc -vu xxx.xxx.xxx.xxx 655

Also a telnet to port 655 worked, but why wasn’t tinc able to make the connection?

Solution

The solution was editing the tinc.conf and correcting the BindToInterface to have the right value. Because it seems fedora likes to create new network interfaces after a reboot :-( This also means the static routes I configured for the interface won’t work, but that is an issue for an other time.