Multiple masters expected behavior?

[Phil Mayers]

On 07/22/2010 10:59 PM, Peter Laws wrote:
> I have multiple interfaces on my master and multiple interfaces on most of
> my slaves.
>
> I've got one of the slaves set up so that its masters {}; statement has two
> of the master's interfaces in it.  The preferred is first, with the
> non-preferred second.  I was contemplating using this on all slaves to
> guard against a network path failure.
>
> Note that I also have both of the slave's interfaces in the also-notify
> statement on the master (it's an unpublished slave).
>
> I would have thought that BIND would always hit the first and never the
> second.  That doesn't seem to be the case however.  In fact, in a few cases
> I've seen it seems to use both, though not round-robinning that I can see
> from the logs.

I believe like all DNS servers, bind will pick the quickest-responding 
one (with the highest SOA serial, of course). It will certainly send SOA 
queries to both in case one master has a higher serial than the other.