This object controls the behaviour of the routing algorithm when a network route exists for routing a packet, but is temporarily unusable because the status of the associated interface prevents transmission. In such a case, the routing algorithm tries to select an alternate route to allow the packet to reach its destination. If set to disabled (1), default routes are discarded during the search for a suitable alternate route. If set to enabled (2), a default route may be selected for rerouting provided it is the most appropriate route available.