Properly configuring recursive dns

Question

We have an internal intranet that we'd like to be hierarchical in nature, something like:

internal.example.com (ns at ns1.internal.example.com) clientA.internal.example.com (ns at ns1.clientA.internal.example.com) nodes.clientA.internal.example.com (ns at ns1.nodes.clientA.internal.example.com) Currently we have three dns servers (bind9 with webmin running in a simple docker container from https://github.com/sameersbn/docker-bind)

x.x.1.2 has the SOA for internal.example.com x.x.10.2 has the SOA for clientA.internal.example.com x.x.100.2 has the SOA for nodes.clientA.internal.example.com Querying each of these will properly return an ip that has been defined for that zone (ie host bob.internal.example.com x.x.1.2 returns the correct ip address for the machine 'bob').

The problem is that we've not able to get it to work so that:

ns1.internal.example.com queries ns1.clientA.internal.example.com for queries about xxx.clientA.internal.example.com and then ns1.clientA.internal.example.com queries ns1.nodes.clientA.internal.example.com for queries about xxx.nodes.clientA.internal.example.com. On x.x.1.2 we've tried setting

forwarders { x.x.10.2; }; and on x.x.10.2 setting recursion as

allow-recursion { x.x.1.2; }; but queries to x.x.1.2 still wont resolve xxx.clientA.internal.example.com.

We've also tried setting up a forward only dns server that only forwards to the x.x.1.2, x.x.10.2 and x.x.100.2 nameservers, but still no luck. All that is returned is "Host xxx.clientA.internal.example.com not found: 5(REFUSED)"

Thanks for any info or links to pages with more info.

Answer 1

Figured it out. It turns out all that was needed was for the other nameservers to know about the other nameservers, but as NS records (they were listed as A records, thinking that NS was reserved just for name servers for that particular SOA which is not the case).