Allocating an Interface Index

If an interface provider successfully registers an interface by calling the NdisIfRegisterInterface function, NDIS allocates an interface index for that interface and returns the index value at the location that the pIfIndex parameter specifies. The interface index is a 16-bit value that is unique on the local computer. NDIS does not guarantee that it will allocate the same interface index when an interface provider registers the same NET_LUID value after the computer restarts. The interface index value zero (NET_IFINDEX_UNSPECIFIED) is reserved, and NDIS does not assign it to any interface.