The domain controller is listed beneath the site that it is a member ofAfter running DCDIAG, I recommend that you run some quick replication tests. DCDIAG does perform a replication test of its own, but as I mentioned before, the level of testing that DCDIAG performs is minimal. DCDIAG's job is to test basic functionality, not to perform an exhaustive series of tests against every domain controller in your forest.
You might be wondering why I am recommending performing a replication test when we have already used DCDIAG to confirm that the domain controller is working properly. The reason for this is because many performance problems are actually replication based. I therefore think that it makes sense to take a quick look to make sure that replication is completely functional before digging into other potential causes of performance problems.
There are several different tools that you can use to diagnose replication related problems, but probably the easiest one to use is the Active Directory Replication Monitor. To launch the Active Directory Replication Monitor, simply enter the REPLMON command at the Run prompt. Doing so will cause Windows to open an empty Active Directory Replication Monitor console.
To use the Active Directory Replication Monitor, you must begin by selecting a server to monitor. To do so, select the Add Monitored Server command from the console's Edit menu. This will cause the Active Directory Replication Monitor to launch the Add Monitored Server Wizard.
The wizard's first screen gives you a choice of either adding a domain controller specifically by name or of searching the Active Directory for domain controllers to add. I'm assuming that you know the names of your domain controllers, so select the Add the Server Explicitly By Name option and click Next.
At this point, you will be asked to enter the name of the server that you want to monitor. This screen also has a check box that you can select if you should need to provide the Active Directory Replication Monitor with an alternate set of credentials.
After you enter the name of the server that you want to monitor, you will see a screen that looks something like the one that you see above. If you look at the figure, you will notice that although you are looking at a single domain controller, it is displayed in a hierarchical manner with regard to the site that it is located in. You will also notice that there are three separate containers listed beneath the domain controller. These three containers correspond to the three default partitions that make up the Active Directory; the domain partition, the configuration partition, and the schema partition.