I have a Domain controller at 2 different sites with 2 different subnets. My goal is to have a primary DNS and a secondary DNS between sites. I've pointed each server to each other. The DNS address were also added to the Cisco router to be distributed to clients dynamically. The clients are receiving the address. But when I turn off the primary DNS server the secondary domain controller does not take over, what can possibly be the issue here ?
SnapOverflow
With an Active Directory domain running Windows Server DNS, it's best to think of it as a distributed system and not an active/passive, primary/secondary kind of application. Just run both domain controllers / DNS servers with Active Directory integrated primary zones. This is the standard approach, and far simpler.