Indicates the number of leading one bits that form the mask to be logical-ANDed with the destination address before being compared to the value in the casaInetCidrRouteDest field. The values for the index objects casaInetCidrRouteDest and casaInetCidrRoutePfxLen must be consistent. When the value of casaInetCidrRouteDest (excluding the zone index, if one is present) is x, then the bitwise logical-AND of x with the value of the mask formed from the corresponding index object casaInetCidrRoutePfxLen MUST be equal to x. If not, then the index pair is not consistent and an inconsistentName error must be returned on SET or CREATE requests.