Updating Routes In Place Using RtmUpdateAndUnlockRoute
Updating in place is generally more efficient than updating the routing table with an indirect method such as that used by the RtmAddRouteToDest function. This method is more efficient because the client is not required to obtain a handle, nor to pass the RTM_ROUTE_INFO structure to and from the routing table manager. This method also takes less time. However, directly updating the routing table can be risky, since the routing table manager is not functioning as an intermediary.
For sample code that shows how to use these functions, see Update a Route In Place Using RtmUpdateAndUnlockRoute.