I am having issues with DNS resolving external names when using forwarders. I tried two different sets of ISP forwarders. With these added, Internet lookups are very slow. When I removed the forwarders, Internet speed is okay.
I have one 2003 R2 AD server running DNS and DHCP. DHCP was pushing our AD IP as primary and 4.2.2.2 (Verizon) as secondary but clients would frequently use the secondary which would cause internal lookups to fail...among other things. I removed the secondary 4.2.2.2 so it no longer gets pushed to the clients.
Now, when I add forwarders, Internet lookups are really slow. I will also add that when I add any forwarders from my mmc console to the server, I get "validation not support" but the addresses are being resolved.
How can I get forwarders to work correctly?