[dns-wg] DNS reverse configuration

Hi,

On 6 Oct 2021, at 11:35, Havard Eidnes wrote:

>>> My question is related to reverse DNS configuration.
>>> We are LIR for an organization (administration) owning a /16.
>>> 2 DNS servers of this organization have delegation for reverse
>>> requests.
>>>
>>> Due to IPv4 addresses exhaustion, we have dedicated the last /24 to
>>> another organization (administration).  The /24 is already used.
>>> Now the problem is that the (owner) organization doesn't want to 
>>> host
>>> our reverse records for the last /24.
>>>
>>> So, my question is it possible to declare 2 different DNS for
>>> delegation only for the /24 ?
>>
>> yes, it's possible. The solution is documented in RFC 2317 "Classless
>> IN-ADDR.ARPA delegation"
>> (https://datatracker.ietf.org/doc/html/rfc2317).
>>
>> It's a little bit tricky to understand but it works well.
>
> What?
>
> There's no need to involve the complexities of rfc2317 when you
> delegate the in-addr.arpa authority on octet boundaries.
> Delegating in-addr.arpa for a /24 from a zone serving a /16
> follows all the normal delegation rules of the DNS.
>

Sorry, I might have misunderstood the request.

Yes, if the full /24 is to be delegated, normal delegation on an octet 
boundary is possible.

If the /24 is used by two different organisations, each organisation 
running their own authoritative DNS servers, RFC 2317 is needed.

Greetings

Carsten