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.
