When discussing GPO version numbers, we mentioned Active Directory replication a couple of times. While checking up on the status and health of the replication process itself is generally a topic outside the scope of Group Policy, AD and GP are so intertwined that it's good to know how to check the status of the replication process.
There is some functionality built right into the GPMC for checking on the overall health of the AD replication process. After opening up GPMC, click on the name of your domain, and then look at the Status tab:
There is not a lot of information listed here by default. You can see the name of my DC1 domain controller listed, indicating that I am currently communicating with DC1 in order to pull information. The real results come when you click on that Detect Now button. This will query your Domain Controllers...