How can one get DNS to prioritize specific subnets over others?

Question

I have a network with three subnets accessing a DNS server running on Windows Server 2008:

• 10.1.1.0
• 10.1.2.0
• 10.2.0.0

The DNS server is on both the 10.1.1.0 network and the 10.1.2.0 network.

Most of the clients are on the 10.1.1.0 and the 10.1.2.0 subnets such any client can access any other client on either subnet. Those clients are just fine.

The clients on 10.2.0.0 are the issue. Clients on 10.2.0.0 only have access to the 10.1.1.0 subnet and not the 10.1.2.0 subnet.

As I understand it, if a client on the 10.2.0.0 subnet requests a client that has all three addresses, the DNS will prioritize the 10.2.0.0 address over the others.

However, when a 10.2.0.0 client requests a client that has only a 10.1.1.0 and 10.1.2.0 address, it does a RoundRobin guessing algorithm.

The issue that is happening is that a request from a 10.2.0.0 client to a client on both the 10.1.1.0 and 10.1.2.0 subnets is resolving to a 10.1.2.0 address instead of a 10.1.1.0 address.

Is there a way to tell the DNS: "If a request comes from 10.2.0.0, prioritize the 10.1.1.0 addresses."?

Answer 1

I dont believe so.
By default Microsoft DNS will respond with the 'nearest' server to the machine the request came from, though you can force it to use standard round-robin through a registry change.

For the issue you are having though, can you not just remove the DNS entry for the 10.1.2.0 address ? If not, then you would need to configure a separate DNS server on the 10.2.0.0 subnet with the specific entries you desire.