consolidating Reverse Zones

[Tony Finch]

Edwardo Garcia <wdgarc88 at gmail.com> wrote:
>
> I guess bind can not consolidate like this and we have to put up with a
> million /24 zone files ?  I was thinking because we can do classless dele
> with smaller than /24, it would work on bigger  :)

It is possible! The basic idea (very briefly) is:

With classless reverse DNS for prefixes longer than /24, you need a CNAME
in the /24 zone pointing at each address in the classless zone.

For shorter prefixes, you need a DNAME in the /16 zone pointing at each
/24 in the classless zone.

There are some documents explaining how we use this trick in production
at https://www.dns.cam.ac.uk/domains/reverse/ with links to the less
Cambridge-specific explanations in the last two paragraphs of that page,
viz:

https://www.dns.cam.ac.uk/domains/reverse/technical.html

https://tools.ietf.org/html/draft-fanf-dnsop-rfc2317bis

Tony.
-- 
f.anthony.n.finch  <dot at dotat.at>  https://dotat.at/
Lundy, Fastnet: Northwest 4 or 5, occasionally 6 in Lundy. Rough or
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