update_route
extern void update_route(u_int32_t origin, u_int32_t mask,
update_route(rt[i].origin, rt[i].mask, rt[i].metric,
update_route(v->uv_subnet, v->uv_subnetmask, 0, 0, vifi);
update_route(p->pa_subnet, p->pa_subnetmask, 0, 0, vifi);
update_route(v->uv_subnet, v->uv_subnetmask, UNREACHABLE, 0, vifi);
update_route(p->pa_subnet, p->pa_subnetmask, UNREACHABLE, 0, vifi);