Autor: Michael Haardt Data: A: exim-users Assumpte: Re: [exim] Bug in DNS resolver or in DNS setup?
> I checked the DNS setup, and it looks OK to me (no lame delegation, > zones are consistent etc). It is a little uncommon that the reverse
> zone contains a CNAME for a PTR record, but Exim has no trouble to find
> out the hostname, so that appears to work.
>
> I have no idea why looking up the host fails, though. Any ideas?
I investigated this further and the problem appears to exist with other
hosts, too, like some kind of temporary error is being ignored.
I extracted all host lookup failures first:
awk '/no IP address found for/{ print $9 }' mainlog
Looking them up, there are quite a few which actually resolve. Most of
them are caused by zones not being in sync, but a few resolve, all
servers agree on that and the zone serials are old. Like:
