DNS Resolving with DNS behind tunnel suddenly stopped

[tomplast]

Hello!

I've been administrating an PfSense box now for more then a month without any problems, until today. My colleagues came to me
some hours ago and told me that they couldn't access machines behind the IPSec tunnel. After some network tests I found out that
I could still ping the machines in question, but no DNS resolving. The DNS server used for resolving those hosts is placed behind the IPSec Tunnel aswell.

If I did a manual lookup (bypassing the PfSense DNS forwarder and directly asked DNS server behind the tunnel) everything worked just fine.

I tried to restart dnsmasq, didn't solve anything.

THE SOLUTIONf was to restart the IPSec tunnel! After that everything worked as good as ever.

Now I would like to understand why  this problem arised and how to avoid it in the future. If you have any ideas and suggestions, please share :).

Here is the log output from racoon, http://pastebin.com/ZK9dbghW.

Thanks.