Good one indeed.
It is a known situation actually, and if you run a versions between 4.9.3
and 4.9.5-P1 included, there is a patch
in the contrib directory of the respective version (see www.vix.com).
This patch is called "noforward" patch and means what it means.
When applied, you can add something like :
noforward test.com c.b.a.in-add.arpa
When restarted, the DNS server A (in your example) will not forward any
request for something in or below the listed domains, even if the forwarder
Another alternative would be to make A secondary of ack.test.com, but if
your zones are big, it is less "bandwith friendly".
What I don't know yet is what hapens on 4.9.6 and 8.1. Neither the patch
not the directive seem to exist in one of these.
Maybe Cricket or Barry will help.
Best regards !
cc : (ccc : Thierry Agassis/AOT/LPSB/Unicible)
Date : 15.01.98 03:18:20
Objet : forwarders and zone delegation - a good one
This may take some explaining but here goes. I don't see a specific
reference to this issue in DNS and BIND.
I have a nameserver (A) that is primary for a zone, I'll call it test.com.
It also knows about a delegation to ack.test.com served by nameserver B. A
is a forwarder to nameserver C who DOES not know about the delegation. It
knows about test.com but not ack.test.com.
When I send a query to A for a host in ack.test.com (ie.
dave.ack.test.com), the lookup fails because A just goes to his forwarder C
who has no info on ack.test.com. In a forwarding situation, I thought is a
server could answer it would and then forward if it didn't know any info.
Here, A knows who to contact for info on ack.test.com yet he goes to his
forwarder. Is this correct behaviour? To rectify this would I have to let
C (the forwardee for lack of a better word), know about the delegation of
Any help would be much appreciated. Email response is better as I can't
regular updates to thsi group (ack!)