CNAME TRICK

[Kevin Darcy]

If you control the real 1.227.199.in-addr.arpa, there's no need for you to use the
"CNAME TRICK" at all; just add the PTR to 1.227.199.in-addr.arpa as normal and you're
done.

So-called "classless delegation" (aka the "CNAME TRICK") is necessary when one
organization controls the C-class in-addr.arpa zone, but another organization wants
or needs to control the contents of just *some* of the PTR record(s) in that C-class
range. If you don't control 1.227.199.in-addr.arpa, specifically the one which is
delegated from in-addr.arpa on down, then whoever controls that zone -- "gate.net",
possibly your upstream provider? -- needs to add the CNAME. Then you just need to
create the PTR wherever that CNAME points.


- Kevin

Rick Gocher wrote:

> Hi All,
>
>         I seem to be having some problems figuring out this cname trick thing..  I
> have a website on a different class C than my DNS is primary for.  After
> reading up on cname trick info I believe I have to add a line similar to,
>
> 0.1.227.199.in-addr.arpa.   IN CNAME   199.227.1.0.sampledomain.com.
>
> but does it go in the forward zone file for sampledomain.com?
>
> Then,
>
> 199.227.1.0.sampledomain.com.  IN PTR   hostname.sampledomain.com
>
> Does this one go in the reverse zone file?
>
> When I add these lines in I get outsidezone errors and I still can't do
> reverse lookups on the domain.
>
> Any help is appreciated,
>
> Rick G