Reverse Zones - Subnets?

[Matt]

Ok,
I *am* the ISP.  We just recently migrated from Windows DNS to Bind.
We were given a class /29 to reverse, and I'm trying to figure out the
syntax in the named.conf file and in the zone record.  So I already
have an upstream pointing the records at us for reversal.. I just need
to make sure I've got the actual reveral correct, but only for a /29
not the whole /24.

On 7/7/06, Nicolas Riendeau <knightr at istop.com> wrote:
> Hi!
>
> Matt wrote:
> > Hi,
> > How do I do a reversal for only part of a subnet?  ie 192.168.1.1/29 ?
> >  How do I just do a reversal for that part, instead of the whole
> > 192.168.1.1/24 block?
> >
> I do hope this address range is only used as an example and that you don't really
> want to do that for that address range... (-;
>
> You should used RFC 2317, "Classless IN-ADDR.ARPA delegation" which is available at
> http://www.ietf.org/rfc/rfc2317.txt for anything smaller than a /24.
>
> Essentially what you do is that in the zone which includes the /24 you want to have
> delegated to another server you make CNAMEs instead of PTRs and these CNAMEs point to
> PTR in another zone.
>
> There is a convention for creating these zones names in the RFC but some people use
> others, please check with your ISP if your ISP has control over that zone... If the
> zone name is built using the RFC 2317 convention or one similar, you must also add NS
> records so that it knows where the zone which contains the PTRs actually is (you
> delegate that zone to that server)...
>
> In the new zone, hosted on the DNS which is actually going to resolve the reverse DNS
> for that range of addresses you create the actual PTR records..
>
> Good luck (if your unlucky as I was when I had to get this done by my employer's ISP
> and hosting company, you're going to need it***) and have a nice day!
>
> Nick
>
> *** I actually had to tell them how to do it and find the info on how you do it with
> a microsoft dns (hosting company use that...).
>
>