This is a new Windows Server 2008 DNS option which isn't documented on Technet anywhere and to make matters worse it doesn't do what it appears to suggest.
In large enterprise installations using Windows Server 2003 I usually have branch offices with forwarders for "All other domains" configured to point at hub DNS Servers across the WAN, that host more domains and provide internet name resolution. I leave root hints on the branch DNS servers in case the WAN link goes down, at least they can get on the Internet locally via their local ISP connections and use the Root Hints for DNS name resolution.
Now in Server 2008 DNS under the Server\Forwarders Tab there is a checkbox option that says "Use root hints if no forwarders are available". This is unchecked by default. This seems to suggest to me that checking the box provides the functionality that I'm looking for, in other words, use the root hints if the forwarder doesn't respond.
But guess what, it doesn't work, but if you uncheck it does work.
What is going on here?! It's works in the opposite way to what it reads or am I going mad!
Apart from the weird lack of documentation and working in the opposite way to what it reads, why is the option there?
Surely if you don't want to use root hints you just remove them from the server? If you need them back you just use the copy from server button.
Anyone got any thoughts on this?