Hello!Ough, it is real BUG. I wonder, why nobody saw it until now.Alexey Kuznetsov.linux/net/ipv4/ip_ouptut.c else if (dev->hard_header) { if(dev->hard_header(skb, dev, ETH_P_IP, NULL, NULL, 0)>0) skb->arp=1; }+ else+ skb->arp = 1; /* * Find where to start putting bytes.