Documentation for RFC2136 Plugin?

[markuspachali]

Hi all,
I'm experiencing some strange behaviour with the RFC2136 Plugin. Sometimes it's using the systems IPv4 address and sometimes the IPv6 address for updating the DNS records. Both should work with my DNS server but the problem is, that (regarding to the logfiles of my nameserver) when using the systems IPv6 address to connect to the DNS server the configured rndc key is never used. When using the systems IPv4 address the configured rndc key is mostly used but not always.
I cannot explain that behavior and trying to understand why. I've tried to find some documentation and/or log files on the system for the RFC2136 plugin but I couldnt find something.
Can anyone tell me where I can find the log files or some documentation?

Thanks for your support,
Markus