Very Strange Reverse DNS problems

Kevin Darcy kcd at
Wed Apr 19 22:49:43 UTC 2006

Gary Galloway wrote:

>I need some help resolving some very strange problems with Bind 9.3.1 running on FreeBSD 6.0
>I have a reverse zone that will answer as authoritative with some address in the zone but will answer non-authoritative with other addresses in the same zone file and then refer the query to the root servers.  The zone is setup as a master and is properly deligated to my server.  I am trying to migrate my DNS off of a couple of a windows server but have been unable to do so as Bind will not resolve the reverse addresses for my mail servers correctly.  Does anyone have any idea as to what would cause this server to think it is not authoritative on some IP address while still being authoritative on others in the same zone ????
The behavior as you describe it would be a violation of the RFCs, and 
not anything I've ever seen BIND do.

However, it is possible that you are mistaken about the zone from which 
the nameserver is answering. If the techniques of RFC 2317 are being 
employed, for instance, then there may be a CNAME in the main reverse 
zone, pointing to a name in *some*other* zone, and maybe the PTR record 
in that zone file has been deleted. If the authoritative nameserver for 
the main reverse zone doesn't also happen to be authoritative for the 
zone to which the CNAME points, it might properly give a 
non-authoritative response to the query.

It would help if you just told us what reverse zone you're talking 
about, assuming it's a public one, so that we could just look at it 
instead of having to engage in all of this speculation as to the cause 
of your problem. If it's not a public one, at least you could post the 
relevant part(s) of the zone file.

      - Kevin

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