During normal Active Directory operations, changes made to the directory, policy, and SYSVOL on one domain controller are replicated to that domain controller’s replication partners. To determine whether replication is working properly, you can use the Domain Controller Diagnostics Tool (Dcdiag.exe) to perform a series of replication tests. To do this, follow these steps:
Start an elevated, administrator command prompt by clicking Start, right-clicking Command Prompt, and then clicking Run As Administrator.
At the command prompt, enter the following command: dcdiag /s: ServerName/test:replications, where ServerName specifies the name of the domain controller that you want to examine.
The output of the diagnostics ...