Mastering Active Directory

Directory Service Agent GUID and invocation ID

Domain controllers involved in the replication process are identified using two unique identifiers. First one is Directory Service Agent (DSA) GUID, and it is generated during the Dcpromo process; and it will never change in the life time of the domain controller. Then, the next is invocation ID. It will only change when an Active Directory restore happens. In a restore process, it will change; the otherwise, the existing domain controllers will identify it as an existing domain controller and will not replicate the data over.