On 9 October 2013 09:58, Andrew Sullivan <asulli...@dyn.com> wrote: > 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-06. > 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.
Yet, apparently, Google has very recently completely stopped accepting email with no PTR records. On my Linode over the summer, it seems like this was the first mention of IPv6 in my errorlog: Aug 17 03:16:07 (none) dma[7de9.b8dd8ca8]: remote delivery to gmail-smtp-in.l.google.com [2607:f8b0:400e:c01::1b] failed after final DATA: 550-5.7.1 [2600:3c01:XXXX:: 16] The sender does not meet basic ipv6 sending#015#012550-5.7.1 guidelines of authentication and rdns resolution of sending ip.#015#012550-5.7.1 Please review#015#012550 5.7.1 https://support.google.com/mail/answer/81126for more information. zo6si1884856pac.170 - gsmtp Prior to 2013-08-17, most messages were delivered nightly without much problems (although these cron jobs did often end up in the Spam folder, and had to be rescued manually); after 2013-08-17, there was only one nightly message that got through, on 2013-08-26, and completely nothing since then: Sep 6 03:15:50 (none) dma[7f00.b9012ca8]: remote delivery to gmail-smtp-in.l.google.com [2a00:1450:4008:c01::1a] failed after final DATA: 550-5.7.1 [2600:3c01:XXXX:: 16] Our system has detected that this message#015#012550-5.7.1 does not meet IPv6 sending guidelines regarding PTR records and#015#012550-5.7.1 authentication. Please review#015#012550 5.7.1 https://support.google.com/mail/answer/81126 for more information. qk9si240507bkb.323 - gsmtp Oct 9 03:15:48 (none) dma[966a.b8dc0ca8]: remote delivery to gmail-smtp-in.l.google.com [2607:f8b0:400e:c01::1b] failed after final DATA: 550-5.7.1 [2600:3c01:XXXX:: 16] Our system has detected that this message#015#012550-5.7.1 does not meet IPv6 sending guidelines regarding PTR records and#015#012550-5.7.1 authentication. Please review#015#012550-5.7.1 https://support.google.com/mail/?p=ipv6_authentication_error for more#015#012550 5.7.1 information. vs7si29857999pbc.145 - gsmtp C.
