Tracking all RRsets for a given host

[Kevin Darcy]

Yes, PTR records are, technically speaking, just a way of mapping one
name to another, syntactically identical to CNAME records, but without
the aliasing functionality. Any time names in DNS need to be arbitrarily
associated or linked with one another, one should consider PTRs for the
job. Reverse DNS is merely the most *common* application of this
linking/association between DNS names. A couple of advantages that
PTR records have over, say, TXT records is that their RDATAs can benefit
from label compression and a certain amount of "free" syntactical
validation from named (if you mess up the contents of a TXT record, named
isn't going to catch that).


- Kevin

Michael Kjorling wrote:

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> Please allow me to add another point here to the excellent one Kevin
> made. Remember that to BIND, reverse and forward zones are identical.
> No distinction is made between the two.
>
> I'd suppose the only reason we don't mix A/CNAME/MX/etc and PTR RRs in
> what today is the "forward" zones is that we don't want to have to
> traverse the entire namespace to reverse-lookup an address. Which is a
> pretty darn good reason IMHO :)
>
> Michael Kjörling
>
> On Jun 15 2001 15:58 -0400, Kevin Darcy wrote:
>
> > There's no rule that says PTRs can only appear in reverse zones.
>
>