V_ip_id
counter_u64_add(V_ip_id, 1);
ip->ip_id = htons((*(uint64_t *)zpcpu_get(V_ip_id)) & 0xffff);
V_ip_id = counter_u64_alloc(M_WAITOK);
arc4rand(zpcpu_get_cpu(V_ip_id, i), sizeof(uint64_t), 0);
counter_u64_free(V_ip_id);