Debugging zone delegation

[Simon Waters]

Joan Creus wrote:

> I am running BIND 8.2.2 (under Nortel NetID). One of my zones is
> delegated to two non-BIND name servers. However, I want all the
> queries to be resolved by just one of the servers, and have the other
> kick in only if the first one is down. This is accomplished by the
> "topology" statement, and it works just fine.

8.2.2 has a known security flaw.

The main reason to use topology is to ensure servers avoid over
committed links.

BIND 8 still prefers faster servers, over topology, so if the
server is so slow BIND 8 thinks it might be on a different
continent, or fails to respond, BIND 8 will preferentially use
faster servers in defiance of the hints given.

Given your less preferred servers are responding faster, BIND is
probably doing the right thing ;). Is the first server
overworked?

Do all your servers have a consistent view of the DNS?

On the BIND 9 code (Which doesn't do topology AFAIK) not
answering gets a huge great wad of penalty time added into the
servers average response time, which will take some living down,
which would be consistent with what you are seeing.

I don't think it is very tunable without a C compiler ;)

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