The MIB_ROUTESTATE structure contains information as to whether the route needs to be added to the forwarder or not. Typically, only the best routes are added to the forwarder.

 typedef struct _MIB_ROUTESTATE {
   BOOL bRoutesSetToStack;
 } MIB_ROUTESTATE,
  *PMIB_ROUTESTATE;

bRoutesSetToStack: This MUST be set to 0x00000001 to set routes to the forwarder.