nanog mailing list archives

Re: Performance Issues - PTR Records


From: Paul Ebersman <list-nanog2 () dragon net>
Date: Fri, 04 Nov 2011 09:28:14 -0700


paul4004> It is entirely possible they have it pointed to their
paul4004> non-existent or broken DNS.  Given current best practices, I
paul4004> see no reason not to assign a generic
paul4004> x.x.x.x-dynamic.customer.isp.com DNS across their netblock.

It's already been pointed out that lame delegations are more likely
problems for many. But the "we'll just pre-fill in-addr to avoid
problems" isn't going to work for ip6.arpa. If anyone has enough
hardware to serve the zone for a /48 (64k * 4bil * 4bil *
bytes-in-record), I'd love to see it. :)

We need to get web and app folks to stop counting on
ip6.arpa/in-addr.arpa as a validation of trustworthiness. PTR make some
sense for validating servers, MTAs, etc. and it's handy for traceroute
but it was never a great tool and it's getting less useful with time.


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