How do people do their own RDNS without a full class C ?

[Patrick Thomas]

So you are saying that:

if my nameserver is    www.example.com

and   192.168.0.5 == www.someotherexample.com

then my ISP can do this:

5	IN	CNAME	192-168-0-5.example.com.

and meanwhile, back on _my own_ nameserver, I have the real entry:

192-168-0-5	IN	PTR	www.someotherexample.com


?  Or did I misunderstand ?

thanks for this trick - it may be just what we need.

--patrick



On Tue, 8 Jan 2002, Kyle R. Green wrote:

>
> On Tuesday, January 8, 2002, at 10:36 PM, Patrick Thomas wrote:
>
> > Yes, but the problem is, I am running many many domains out of my 64
> > addresses, so it is not possible for them to simply add in generic PTRs
> > for each IP all pointing to the same .yourdomain.com ...
>
> Well, doesn't really matter:
>
> [Please note the ending dots that I forgot in the previous examples.]
>
> 0.168.192.in-addr.arpa:
>
> 5     IN     CNAME     192-168-0-5.yourdomain.com.
> 6     IN     CNAME     192-168-0-6.yourdomain.com.
> 7     IN     CNAME     192-168-0-7.yourdomain.com.
>
> yourdomain.com:
>
> 192-168-0-5     IN     PTR     www.yourdomain.com.
> 192-168-0-6     IN     PTR     www.someotherdomain.com.
> 192-168-0-7     IN     PTR     www.yetanotherdomain.com.
>
> The remote clients/servers will query the server authoritative for
> 0.168.192.in-addr.arpa to find out what the PTR for 5.168.192.in-
> addr.arpa is.  The CNAME will be encountered, resulting in another
> request to yourdomain.com's nameservers to find out what the PTR for
> 192-168-0-5.yourdomain.com is.  www.yourdomain.com. will be returned.
> It's a cheap hack that works, although I can't guarantee that it's 100%
> RFC compliant.
>
> It probably would never get the ISC Seal of Approval(TM).
>
> --
> Kyle R. Green
> kyle at kgreen.org
>
> Delores breezed along the surface of her life like a flat stone forever
> skipping along smooth water, rippling reality sporadically but oblivious
> to it consistently, until she finally lost momentum, sank, and due to an
> overdose of flouride as a child which caused her to suffer from chronic
> apathy, doomed herself to lie forever on the floor of her life as
> useless as an appendix and as lonely as a five-hundred pound barbell in
> a steroid-free fitness center.
>          -- Winning sentence, 1990 Bulwer-Lytton bad fiction contest.
>
>
>