Dns not updating active directory
The Invocation ID of a domain controller and its USN together serve as a unique identifier associated with every write-transaction performed on each domain controller and must be unique within the forest.
AD DS replication uses Invocation ID and USNs on each domain controller to determine what changes need to be replicated to other domain controllers.
In a virtual environment, administrators no longer have to repeatedly deploy a server image prepared by using sysprep.exe, promote the server to a domain controller and then complete additional configuration requirements for deploying each replica domain controller.
Note Administrators need to follow existing processes to deploy the first domain controller in a domain, such as using a to prepare a server virtual hard disk (VHD), promote the server to a domain controller and then complete any additional configuration requirements.
With Windows Server 2012 , AD DS employs safeguards on virtual domain controllers hosted on VM-Generation ID aware hypervisors and ensures that the accidental application of snapshots or other such hypervisor-enabled mechanisms that could rollback a virtual machine's state does not disrupt the AD DS environment (by preventing replication problems such as a USN bubble or lingering objects).
For example, the following illustration shows the sequence of events that occurs in Windows Server 2008 R2 and earlier operating systems when USN rollback is detected on VDC2, the destination domain controller that is running on a virtual machine.
These new virtualization features provide greater support for public and private clouds, hybrid environments where portions of AD DS exist on-premises and in the cloud, and AD DS infrastructures that reside completely on-premises.
In this document Virtual environments present unique challenges to distributed workloads that depend upon a logical clock-based replication scheme.
It also non-authoritatively synchronizes the SYSVOL folder in order to complete safe restoration.
This enables the safeguards to extend to the application of snapshots on VMs that were shutdown.