DNS Reverse Zone Delegation

Hi,

we run a demo network 192.168.25.0/24 with 2 Windows-based DNS-Servers.

ns1.lab.myorg.com manages the zones
lab.myorg.com
25.168.192.in-addr.arpa

ns2.demo.myorg.com manages the zones
demo.myorg.com
25.168.192.in-addr.arpa

Both of them automatically create reverse entries for forward entries,
and both of them think they are responsible for the whole
192.168.25.0/24 network. This does not create collisions, since
host01.lab.myorg.com ... host29.lab.myorg.com uses 192.168.25.1 ...
192.168.25.29, while host30.demo.myorg.com ... host40.demo.myorg.com
uses 192.168.25.30 ... 192.168.25.40.

I know this setup is suboptimal, but for the moment I cannot change it
and I'm just looking for a workaround:

I set up a new Linux-based DNS ns3.demo.myorg.com with 3 Zones:
demo.myorg.com and lab.myorg.com are forwarder zones and
25.168.192.in-addr.arpa delegates to ns1 or ns2 as appropriate.

I first considered rfc2317 delegation, but the address ranges for lab
and demo are not at binary boundaries like 192.168.25.0/25 and
192.168.25.128/25. Then I came across
http://homepages.tesco.net/J.deBoyne...elegation.html

I thought I simply had to set up the zone file for
25.168.192.in-addr.arpa like this:

$GENERATE 1-29 $ NS ns1.lab.myorg.com.
$GENERATE 30-40 $ NS ns2.demo.myorg.com.

However when I do an nslookup - ns3.demo.myorg.com, the lookup works for
some IP addresses, while I get an NXDOMAIN for others. nslookup -
ns2.demo.myorg.com works for the same address, which fails on ns3.

Any ideas why?

Christian


Christian Barmala

Christian Barmala wrote:
> we run a demo network 192.168.25.0/24 with 2 Windows-based DNS servers.

I found a workaround: I do a
host -l 25.168.192.in-addr.arpa ns1.lab.myorg.com
host -l 25.168.192.in-addr.arpa ns2.demo.myorg.com
and concatenate the two outputs into a zone file for ns3.demo.myorg.com.
Some additional tweaking is required, but that's the basic idea. This
way I can even map yet more chaotic setups, which you often find in
demo/test/lab/temp environments.

Christian