question about overlapping reverse zones

[/dev/rob0]

On Tue, Aug 09, 2011 at 02:52:10PM +0200, Christian Pinedo Zamalloa
   wrote:
> I would like to know if it is possible to configure in Bind
> overlapping reverse zones. For example, load all reverse zones for
> IPv4 private addressing that come configured by default with the
> package Bind of my Linux distribution:
>
> zone "10.in-addr.arpa"      { type master; file "/etc/bind/db.empty"; };

BIND named does this by default now. Did you know that? Did your 
distribution BIND packager know that? :) See the "Built-in Empty 
Zones" section under "options Statement Definition and Usage" in
BIND 9 ARM chapter 6.

> And only add one new zone for a specific zone for which I need 
> reserve resolution:
> 
> zone "10.10.10.in-addr.arpa"      { type master; file
> "/etc/bind/db.rev.10.10.10"; };
> 
> - Could I configure two overlapping in-addr.arpa zones in Bind?

First off, understand that there is nothing "magical" about 
in-addr.arpa zones. DNS is DNS, and it all works the same way.

The right way to do it, if you need both zones, is to put proper 
delegation records in the parent domain.

The simple way to do it, if you only want records for 
10.10.10.in-addr.arpa and NXDOMAIN for the rest of 10.in-addr.arpa, 
would be to use 10.in-addr.arpa. Lo and behold, any reversed IP 
addresses which do not have corresponding PTR records will come up 
with NXDOMAIN results.

> - If I do a reverse zone resolution I suppose that the more 
> specific zone (for 10.10.10.10 zone 10.10.10.in-addr.arpa) would
> be the chosen by Bind to respond (instead of 10.in-addr.arpa). Is 
> that true?

I have no idea. You could try it and see? Or, just do it as I 
suggested, which is easier and better anyway.
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