› Forums › Network Management › Networking › Reverse DNS for CIDR other than /24, /16, or /8 networks › Re: RFC 2317?
It seems you’re interested in RFC 2137: Classless in-addr.arpa registration. This involves a whole lot of aliasing (CNAME) records for IPv4 routes smaller than /24.
There’s a fair bit of prep work you’d need to do to support this, though. I’ve been out of the loop on this sort of thing since 2006.
For anything /24 or larger though, you’re kinda stuck with one zone for each /24. You could create two or more /24s with a bunch of CNAME records and have them point to records in a classless zone sized for a /23 I suppose, but at that point you’re better off making two or more normal /24 zones just to stay sane.