The DRS_MSG_DCINFOREQ_V1 structure defines the request message sent to the IDL_DRSDomainControllerInfo method.

 typedef struct {
   [string] WCHAR* Domain;
   DWORD InfoLevel;

Domain: The domain for which the client requests information. The domain can be an FQDN (1) or a NetBIOS domain name.

InfoLevel: The response version requested by the client: 1, 2, 3, or 0xFFFFFFFF. The responses at InfoLevel 1, 2, and 3 all contain information about DCs in the given domain. The information at InfoLevel 1 is a subset of the information at InfoLevel 2, which is a subset of the information at InfoLevel 3. InfoLevel 3 includes information about the RODCs in the given domain. InfoLevel 0xFFFFFFFF server returns information about the active LDAP connections.