Question about forwarder zones

[Cuttler, Brian R (HEALTH)]

We had an issue with forward zones not resolving this morning, resolved by restarting DNS but prompted me to ask a question I'd been wondering about.

We have multiple zones that we forward to DNS servers we do NOT manage.

The domain names take the form

Example.org
Bar.example.org
Foo.bar.example.org
Snafu.foo.bar.example.org

Despite the fact that these are all example.org and managed by our sister organization the servers they forward to are often different from one another.
That is bar.example.com might forward queries to a.a.a.a and a.b.b.a but foo.bar.example.com might forward to c.d.a.a and d.e.b.a.

What I'm trying to say is that the parent server for a forwarded zone is not necessarily, and is seldom the authoritative zone for a child zone.

So it got me wondering, when I want to resolve host.snafu.foo.bar.example.org, where does the chain of resolution start?

I'm hoping that it is the most _specific_ domain name, rather than the least or random, or first find in the physical zone file.

To me most specific makes the most sense, but I haven't run across that written anyplace in my searches and I'd like to know if I should reorder my zones or should employ some other mechanism to help assure I'm hitting the best-forwarders/most productive forwarder zone selection I can.

Thank you,
Brian


Brian Cuttler
Network and System Administrator, ITG - Information Technology Group
Wadsworth Center, NYS Department of Health
Biggs Lab, Empire State Plaza, Albany, NY 12201
(518) 486-1697 | Brian.Cuttler at health.ny.gov