2.4.3 nTDSDSA Object
On a DC, the nTDSDSA object represents the replication agent, which is responsible for processing the DRS Protocol.
The nTDSDSA object has the RDN of "CN=NTDS Settings" and is a child of the Server object of the DC.
The GUID of this nTDSDSA object is invariant for the lifetime of the DC. The implementation MAY use this GUID value as an alternative identifier for the DC.<10>