We currently have Windows 2003 AD with 2 domain controllers DC-1 and DC-2. Both have DNS, DHCP roles installed on them. I am trying to migrate this domain to Windows 2008. I have devised a multi step plan to perform this upgrade. I have created a Windows 2008 R2 Standard DCTEMP. I have joined it the domain, I have installed DNS on it. AD Integrated zones got copied over. I have created secondary dns zones and transfered them from DC-1 (ie DC-1 is primary for those zones). All servers, clients have DC-1 and DC-2 in their IP settings for DNS resolution. Once I turn off DNS services on DC-1, DNS resolution of public names stops working. I have forwarders set up on new DC (ie DCTEMP). I cant seem to find where it is using DC-1 for outside DNS resolution.