The value of vRtrPimNgCRPGrpPrefixInetGrpMask indicates the mask
which is combined with the value of vRtrPimNgCRPGrpPrefixInetGrpAddr
to get the range of multicast group addresses for which the router
advertizes to be the Candidate RP. The value of
vRtrPimNgAFGenCRPAddress is sent as the RP address.