What is the best way to setup DNS for Cross Forest Trusts.
Options to setup DNS for two way cross forest trusts are below:
1. If there is a root DNS server that can be made the root DNS server for both of the forest DNS namespaces, make it the root server by ensuring that the root zone contains delegations for each of the DNS namespaces. Also, update the root hints of all DNS servers with the new root DNS server.
Note: I have two AD, DNS servers in the souce forestA and one AD, DNS server in the target forestB
2. configure DNS conditional forwarders in each DNS namespace to route queries for names in the other namespace
3. configure DNS secondary zones in each DNS namespace to route queries for names in the other namespace.
I am doing cross forest migration from Exchange 2003 to Exchange 2010
When I migrate users to the new forest. They will still need to be able to access resources in the source forest, and access some servers on the old forest.