rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(dev);
if (!dst_metric(&rt->u.dst, RTAX_ADVMSS))
rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(net, dst_mtu(&rt->u.dst));
rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(dev);
if (!dst_metric(&rt->u.dst, RTAX_ADVMSS))
rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(net, dst_mtu(&rt->u.dst));