I am running tinc (1.0.19) on a cluster of around 40 servers (Xen virtual machines in two geographical locations). Overall it works very well, however yesterday it crashed on two machines in odd way. I was still able to ping VPN IPs of other hosts from the two affected machines but “vpn” interface was not visible when I run ifconfig. There was also no “tincd” process running (at least ps aux wasn’t showing it). They logged the following for approx. 20 minutes in the /var/log/syslog:

Mar 27 01:52:14 us16 tinc.vpn[9528]: Flushing meta data to <peer_host> (xxx.xxx.xxx.xxx port 655) failed: Connection reset by peer

and eventually:

Mar 27 01:53:03 us16 tinc.vpn[9528]: send_meta() called with NULL pointer!