The value of vRtrInetCidrRouteBkupMetric indicates the routing
metric for a backup route. The semantics of this metric are determined
by the routing-protocol specified in the route's ipCidrRouteProto
value. The value of vRtrInetCidrRouteBkupMetric is only
valid when vRtrInetCidrRouteBkupFlags has a value of 'hasLfa'.