In a previous post we discussed the FSMO Roles and we know that one of the FSMO Roles is RID Master. What a RID Master does and whats its significant, let’s recap. RID Master – Each object must have a globally unique number (GUID). The RID master makes sure each domain controller issues unique numbers when you create objects such as users or computers. For example DC one is given RIDs 1-4999 and DC two is given RIDs 5000 – 9999.

In this post I will be showing you the command which you can run to check the available Relative Identifiers (RID) pool on one of your DCs.

You should have the Windows Server 2003 Support tools installed and the command to run is as follows:

dcdiag /v /test:ridmanager

/v is for verboselogging and the /test:ridmanager is to define the specific test and to avoid the other dcdiag test runs. Take a look at the attached screenshot above, It shows the current RID Allocation Pool and the Previous Allocation Pool. 500 RIDs are assigned from the RID Master and after 50% of the pool has been consumped, another request for pool refill is made to the RID Master.