comcast ipv6 PTR

Cutler James R james.cutler at consultant.com
Wed Oct 9 18:08:32 UTC 2013


On Oct 9, 2013, at 12:35 PM, Blair Trosper <blair.trosper at 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 at consultant.com







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