On Tue, Dec 06, 2016 at 04:02:21PM -0800, MRob wrote:
> > This could a messed-up DNS resolver anywhere in the path, including
> > a bad resolv.conf file under /var/spool/postfix/etc, or some
> > 'security' filter that breaks connectivity to some DNS server.
>
> Victor suggested in a mail prior to yours (Victor, please correct me if I
> misunderstand) that it could have been due to Microsoft providing ipv6
> responses for some domains, but some of those responses being EDNS0, which
> our local resolver may not know how to handle.
Quite the opposite, your resolver probably uses EDNS0, but Microsoft's
rather skimpy implementation of DNS in the load-balancers for that
zone don't grok EDNS0 (among other problems). So your resolver needs
to be able to back off to non-EDNS0 on FORMERR, but may not depending
on the software you're running.
> This seemed plausible, but
> now that I took out ipv6 and the error continues with A, I am less certain.
The query type is irrelevant.
--
Viktor.
