A bit of a weird problem here and hope someone can help describe and/or fix with me. We were on a /24 network A.A.A.A and recently switched to B.B.B.B. The nameservers were all updated with the registrar, they show in the root nameserver and everything - so far so good, right? I can dig the root servers and get the new IPs, whois is good and all the "is it plugged in?" groundwork looks great.
I'm running DNS on the new network at B.B.B.254 and the old network at A.A.A.254 as the changes still propagate around the world. The A.A.A.254 DNS server is actually feeding the world the IPs for B.B.B.B to catch stragglers who haven't seen the upstream changes yet, normal business. Each server also runs reverse DNS for it's own IP range.
SO! In the logging of queries on the old A.A.A.254 server I am seeing an odd request for the PTR zone from B.B.B.254 for it's own reverse IP B network! And, it's always for two IPs -- my firewall (.4) and VPN server (.6) - no others than these two.
04-Aug-2009 09:56:09.755 client B.B.B.254#37384: query: 4.B.B.B.in-addr.arpa IN PTR +
04-Aug-2009 10:00:05.380 client B.B.B.254#37385: query: 6.B.B.B.in-addr.arpa IN PTR +
Why is there a query like this, asking for the IP zone that B.B.B.254 is already hosting, going to my A.A.A.254 server?! I shouldn't be seeing any queries from B.B.B.254 to A.A.A.254 at all, yet I'm still getting these odd PTR jobs that I can't quite figure out. A 'dig -x' from B doesn't cause it to go to A, so it's nothing that simple. I've scoured every config file on B (it's a linux/bind9 box) for any reference to the A network, can't find anything.
Anyone have a clue what's going on here and how I can fix it? Why is the new server B asking A for this PTR, when it knows it hosts that range itself?
I've followed various trails such as:
dig +norecurse 4.B.B.B.in-addr.arpa PTR @x.arin.net
dig +norecurse 4.B.B.B.in-addr.arpa PTR @a.[authority server name]
...and that all looks right. Any ideas welcome where further to look to track down what's causing this request loop, I'm at a bit of a loss what to look at next.