I'm trying to understand why I can't get failover to work correctly between the two DNS servers I have set up in our domain. They are both Windows Server 2008 machines. The clients all have pointers to both in primary/secondary DNS entries. Each server points to itself for primary and the other for secondary.
When I disable the network connection on the primary, the secondary should take over DNS resolution for clients but it does not. Web browsers just time out. I had this working correctly for awhile when I had both servers running Server 2003, but since I upgraded to 2008, it hasn't worked. I think I have the configuration really close to the same, if not exactly the same, but now it doesn't work.
What am I missing here? I know that NSLOOKUP won't resolve correctly if the primary goes down, but web browsing should and I need this to work for failover purposes.