[ActiveDir] DNS server question

[Alborzfard, Alex]

My apologies if this is a bit off-topic, but I was wondering if I ask the masters (bowing my head of course!) a DNS scenario question:   I’m at a client site, where they’re running AD2K, w. 2 DCs both running DNS, one is actually running Exchange (Yikes!). One DNS has forwarders enabled and is pointing to client’s ISP and domain host DNS servers. There are continuous errors in event log about the 2 ISP servers not being recursive. The other doesn’t have forwarders enabled, but it’s the primary DNS server on Exchange box’s TCP/IP settings.   My questions are:   1-       Should I just check “Do not use recursion” box on DNS w. forwarding enabled or just remove the ISP DNS servers? 2-       Should I reverse the DNS servers order on Exchange box’s TCP/IP settings? 3-       Should I enable forwarding on the other DNS server and add external DNS servers? If so, which DNS servers: ISP’s or domain hosts’? 4-       Should I just leave things alone?   What are the ramifications of doing either?   Thanks   --Alex Alborzfard