On Wed, Oct 09, 2013 at 11:35:16AM -0500, Blair Trosper wrote:
Does anyone know why (or can someone from Comcast explain why) there is no PTR on their residential/business IPv6 addresses?
Probably because of the considerations in http://tools.ietf.org/html/draft-howard-isp-ip6rdns-06. I seem to remember someone showing up in DNSOP one time to argue for a draft that the reverse mapping should just be optional under IPv6, but I can't lay my hands on the draft. The last time DNSOP tried to come up with recommendations about the reverse tree, the resulting document was http://tools.ietf.org/html/draft-ietf-dnsop-reverse-mapping-considerations-0.... It says, roughly, "Well, some peple use the reverse tree and some don't. You might want to think about that, or not." Despite asserting a version of "A or not-A", we were unable to achieve consensus, so I think the hope of consistency in the reverse tree is not supported by operational evidence. Best, A -- Andrew Sullivan Dyn, Inc. asullivan@dyn.com v: +1 603 663 0448