Re: comcast ipv6 PTR

[Cutler James R <james.cutler () consultant com>]

On Oct 9, 2013, at 12:35 PM, Blair Trosper <blair.trosper () gmail com> wrote:

> Does anyone know why (or can someone from Comcast explain why) there is no
> PTR on their residential/business IPv6 addresses?

Which IPv6 addresses:
  
1 delegated WAN address?

2 end systems on delegated LAN prefix or with static assignments?

In my experience with Comcast Business Internet:
 
1 the delegated WAN address does have an (almost useless) PTR record which is essentially the AAAA spelled backward.

2 PTR records for automatically configured end systems on a local LAN are a local responsibility. Static IP assignments 
may come with PTR entries, depending on business arrangements.

Since neither Comcast or any other DNS provider has any direct knowledge of your local network configuration, you 
cannot expect to see any PTR DNS records for local systems unless you make some business (and technical) arrangements 
with a DNS provider.

If you really need PTR record for your local SMTP servers, arrange for them with your DNS provider, even if that 
provider is you.

James R. Cutler
james.cutler () consultant com