nd6_output
nd6_output(ifp, ifp, m0, dst, NULL);
error = nd6_output(rt->rt_ifp, origifp, m, dst, rt);
error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
nd6_output(ifp, ifp, ln->ln_hold,
int nd6_output(struct ifnet *, struct ifnet *, struct mbuf *,
nd6_output(ifp, ifp, ln->ln_hold,