Re: Need help explaining in-addr.arpa to Limelight

[Joseph S D Yao <jsdy () center osis gov>]

On Mon, Oct 23, 2006 at 09:13:03PM -0400, Edward Lewis wrote:
> At 18:48 -0400 10/23/06, Joseph S D Yao wrote:
>
> > No, because in fact you can.  There is nothing magic about an
> > in-addr.arpa domain.
>
> I'd say there is some magic.  Possibly.

There are conventions.  There is RFC 2317.  There is no magic.  ;-)

You can have subdomains neustar.16.154.156.in-addr.arpa and
lewis.0.127.in-addr.arpa.  You can have a pointer at
456.24.154.156.in-addr.arpa, much good it will do you.

The "magic" in reverse DNS is keeping it aligned properly with forward
DNS according to all the conventions we've established, including RFC
2317 - which, OBTW, explicitly allows for non-standard subdomains used
in reverse DNS.  How about 158.16.neustar.com?  ;-)

> If an admin were granted the authority for a /25 worth of space, then 
> you can't just delegate that part of the in-addr.arpa domain.  That's 
> the RFC Joe Abley cited.
>
> A /24 can be delegated (assuming we are talking about 255 addresses, 
> from .0 to .255).  Perhaps, and this is weak speculation, the ISP in 
> question is not used to SWIPing /24 and has an institutional policy 
> of using RFC 2317 in all cases.

I've noticed of late less understanding of DNS in the people charged
with maintaining it out there.  Sad.

> As far as the DNS protocol goes, there's nothing different between 
> the forward and reverse.  But there are differences in the 
> conventions used for placing data.


Yup.  ;-)


-- 
Joe Yao
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