North American Network Operators Group
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Re: AT&T refuses to provide PTR records?

  • From: Mark Foster
  • Date: Wed Oct 18 05:24:10 2006 

On Tue, 17 Oct 2006, Jack Bates wrote:


Mike Walter wrote:

We have a customer that has AT&T and they reassigned the IP space to our
name servers to allow us to do reverse DNS for them.
We had a similar situation. AT&T states that they will only handle rDNS using domains that they control. They will happily CNAME the IPs appropriately or reassign the IP space, depending on block size and request.

The issue we ran into was that we couldn't get them to *unassign* a CNAME for an IP block so that it would fail immediately, and so servers (web,ftp, etc) which requested rDNS for the connection information would time out connections waiting for the non-existent nameservers. We weren't really interested in handling rDNS for the IP given that it wasn't handling mail, web, or have any A records pointing to it. It is the easiest way to get it done, though.

Surely if you have _a_ matching forward and reverse DNS pair, that'd get you started?

My experience in this game was that you could create mail.xyz.com and point it to their IP as an A record, and point MX at this - no problems.
So long as the host had a valid and matching forward/reverse DNS entry there was no grief.

The issue was where there was no matching A/PTR set, this would increase the likelyhood of a spam host or something... right?

Or is it now a case of A/PTR must match the MX?

Mark.