Reverse DNS Delegation howto?

[Guido Roeskens]

Mark Andrews wrote:
>>I've run into a problem with delegating reverse DNS using BIND 8.2.4 that I
>>can't figure out and I'm hoping for some guidance.
>>
>>I have a couple of blocks delegated to me as w.x.y.0/23 which I handle with a
>>couple of zones 1) y.x.w.in-addr.arpa and 2) y+1.x.w.in-addr.arpa.
>>
>>Now I want to delegate the second zone to an outsourced dns service and I
>>can't quite see how to do it.
>>
>>If I create a zone file for y+1.x.w.in-addr.arpa with the following NS record
>>s:
>>
>>y+1.x.w.in-addr.arpa IN NS ns1.remotedomain.tld.
>>y+1.x.w.in-addr.arpa IN NS ns2.remotedomain.tld.
>>
>>It doesn't work and these records are not in named_dump.db although the soa
>>record is.  I figure this is because you aren't allowed to delegate a zone
>>twice and the y+1.x.w.in-addr.arpa zone has already been delegated once by my
>>upstream ISP.  Yes/No?
>>
>>Is there a correct way to accomplish this or will I have to get this done by
>>my upstream ISP?
> 
> 
> 	You get the parent to update the delegation.
This means, tell your provider to delegate them directly
to your customers name servers.
You may don't want to do this, then you could delegate
each IP in the /24 to your customer.
The customer needs then 256 zone files for each IP.

If you understand how the DNS systems works, you won't ask
your next question "why" ;-)

Guido