6.1.2.3.1 DC and Application NC Replica
A DC is instructed to host an application NC replica if:
The attribute msDS-NC-Replica-Locations on the crossRef representing the NC contains the DSName of the nTDSDSA object representing the DC.
A DC is hosting an application NC replica when the following are true:
The attribute msDS-hasMasterNCs on the nTDSDSA object representing the DC contains the DSName of the NC root representing the NC.
The attribute msDS-HasInstantiatedNCs on the nTDSDSA object representing the DC contains an Object(DN-Binary) value such that the DN field is the DSName of the NC root representing the NC, and the Data field contains the value of the instanceType attribute on the NC root object on the DC.