So what we have setup is AD, Exchange, and DNS ... all has been working great for the past two years (Why it stopped now who knows?) but i've tried setting it up two different ways. The first is having the DNS servers on the DNS server only point to itself (188.8.131.52) and have the DNS configured with forwarders... this one seemed to work great for a very long time, but then randomly we would lose internet (Because the dns wouldn't resolve like google.com).
So we kept the forwarders and just added one of our ISP DNS servers into the secondary on the DNS Server so that it had itself (184.108.40.206) and our ISP DNS (xxx.xxx.xxx.xxx). This worked great also, if our local dns forwarders for some reason didn't return anything, it would just hit the ISP DNS directly.
Our problem now comes in where if our DNS server doesn't respond, It naturally goes to the next one in the list which is our ISP DNS ... which gives an incorrect address for our internal machines (obviously). I can't find anything in the event logs... i'm totally lost.
Is it a problem with our DNS? Too many requests?