Hi All,
Our SharePoint 2010 environment is using Microsoft NLB to cluster its front end web servers.
Yesterday, one of our active directory domain controllers was demoted and the server rebooted, this server also acts as one of our DNS servers. When it was rebooted, our SharePoint environment became unavailable; Users were getting prompted with an authentication box. Looking into it further there is a Host Unreachable error between the 2 load balancers. After about 20mins the domain controller was promoted again, server rebooted and everything became available again.
Can anyone shed any light on why this may have occurred. Is it simply that the load balancers lost the DNS and the ability to talk to each other. If so why did it not use the secondary DNS server configured in windows and remain alive? Or does the issue lie with the domain controller being demoted?
Any help appreciated.
Cammie