I would like to know if someone can recommend a better way to configure domain time synchronization for a group of Windows Server 2008 R2 servers than what I currently have configured. I have three domain controllers that are all Hyper-V guests. For all of these DCs, the host’s time synchronization feature of integration services is disabled. The DC’s are configured as authoritative time servers and the FSMO DC1 server uses the public nist-a and nist-b servers as its time source. DC2, DC3, and all other servers in this environment, both hosts and guests, are members of the one domain and look to DC1 for time. For all remaining guests (i.e. not the DCs) the time synchronization feature of integration services is enabled. The reason for this post is that I’m sporadically seeing the message that follows in the next paragraph and I would like to get all of my servers (both hosts and guests) to have their time be as accurate as possible:

*The time service detected a time difference of greater than 5000 milliseconds for 900 seconds. The time difference might be caused by synchronization with low-accuracy time sources or by suboptimal network conditions. The time service is no longer synchronized and cannot provide the time to other clients or update the system clock. When a valid time stamp is received from a time service provider, the time service will correct itself.*

If someone has a similar setup with virtualized DCs and has achieved highly accurate time synchronization across all servers in the domain, your input would be appreciated.

Thanks.