Domain controller selection process

view story

http://serverfault.com – I have several networks which are isolated from one another apart from one of the networks hosting the primary domain controller. I am adding a new network, although when creating a domain controller on this network the domain name is not resolving to the PDC, rather it is selecting one of the other domain controllers in an isolated network and hence fails the dcpromo process. How can I tell the soon to be domain controller on the new network to only use the PDC as its source of communication on the domain? (HowTos)