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