The CLUSCTL_NODE_UNKNOWN node control code verifies that control codes are being processed on the node where execution of the control is directed.

The server SHOULD accept a CLUSCTL_NODE_UNKNOWN node control code request if its protocol server state is read-only and MUST accept the request for processing if it is in the read/write state, as specified in section 3.1.1.

Upon successful completion of the method, the server MUST return 0x00000000 (ERROR_SUCCESS). If control codes are not being processed, the server is required to return an implementation-specific error code.