Re: Multiple PTR records

[Shane Kerr <shane@ripe.net>]

On 2001-06-07 20:24:38 +0000, Kevin Darcy wrote:
> 
> I wonder if this would be good BCP material (?). RFC 2181 (not a BCP
> of course but Standards Track) almost seems to *encourage* multiple
> PTRs by "clarifying" that it is supported in the protocol. Now that
> the cat is out of the bag, perhaps there should be a BCP stating that,
> while multiple PTRs are technically possible, they are generally
> undesirable and when taken to extremes can in fact cause problems.
> 
> I would not volunteer to write such a document, of course, given my
> even-more-radical view that reverse DNS should probably go away or its
> use be severely limited (and I don't think keeping reverse DNS around
> solely as a sort of "ISP intelligence test" is really a strong
> argument, even when couched in terms of spam-prevention).

This is an intriguing idea.  To be honest, at first glance it doesn't
seem *too* radical to me.  I mean, what's the real "use case" for
referse DNS?  Certainly any "match forward/reverse" for "security" has
long been discredited.  The ability to put a machine name in my utmp
entry seems like a very small gain for such a large system.

OTOH, my understanding of the IPv6 world is, "yes IPv6 numbers are
totally ridiculous, so use DNS for everything".  In such a world,
reverse DNS seems to take on a huge importance.  Not that I've heard any
proposals how ISP's are going to manage running reverse DNS for the /48
they're going to have to give out to each dial-up customer.  (I'm sure
that somebody has a clever solution for this, I just haven't heard it.)

-- 
Shane