nanog mailing list archives

Re: comcast ipv6 PTR


From: Blair Trosper <blair.trosper () gmail com>
Date: Mon, 14 Oct 2013 21:58:22 -0500

That gets to the core of the original question.  I figured there must be a
reason for the conscious omission.  However, I've noticed also that Comcast
hasn't bothered to give PTR to their routers, either.

I think that's a horse of a different color.  Leaving out PTR on the last
hop for the residential customer?  Sure.

Leaving out v6 PTR on your core/backbone/edge routers?  Surely that's not
acceptable...


On Mon, Oct 14, 2013 at 9:47 PM, John Levine <johnl () iecc com> wrote:

Is there any reason other than email where clients might demand RDNS?

There's a few other protocols that want rDNS on the servers.  IRC maybe.

Doing rDNS on random hosts in IPv6 would be very hard.  Servers are
configured with static addresses which you can put in the DNS and
rDNS, but normal user machines do SLAAC where the low 64 bits of the
address are quasi-random.  To get any sort of DNS you'd need for the
routers to watch when new hosts come on line and somehow tell the
relevant DNS servers what hosts need names.

This would be a lot of work, so nobody does it.

R's,
John




Current thread: