Hi,
So i have a single domain in my company with three DNS servers. When the preferred and secondary DNS services are down or when they are rebooted, it doesn't seem that the third server services users requests. Although MS books claim that using multiple DNS servers is a fault-tolerance mechanism, well it's NOT. I issued ipconfig /flushdns and still same problem.
When i manually put the third server address as preferred, everything is fine.
What is the benefit of having multiple DNS servers then?