DNS Delegated Zone Query

Question

I have a query regarding delegated DNS zones. We have a primary dns zone setup (test.local) that replicates between our AD setup that spans multiple geographical locations (London, New York & Munich). We also have a delegated sub domain (mydelegatedsubdomain.test.local) that's delegated to a number of alternate non Windows name servers (which also span all sites).

I know this is possible with conditional forwarders, but I can't see a way of doing this with delegated domains or stub zones. We want DNS requests for the subdomain to go to the delegated name servers for that respective site. For example, if a resource sent a DNS query for the sub domain mydelegatedsubdomain.test.local to a domain controller in London, we want it to then prioritise forwarding that query to a name server in that same site. As far as I can see, it performs a round robin between the available name servers in the delegated sub domain. This means we're sending DNS queries from London to New York or Munich.

Is there a way of controlling this? We can't create a conditional forwarder as it's a sub domain of test.local. In addition to this, we can't use stub zones as that would round robin between all possible name servers for the delegated zone. I also can't find a way of setting individual name servers per DC (like you can with conditional forwarders).