m wrote: ^ ? > I am receiving flip-flops from (?) each machine in my LAN (SNATed), > I have turned on proxy_arp (public IPs in LAN also present) Why proxy_arp? > Situation is like : each computer send me ARP packet one time with > correct MAC and second time with ... MAC of serwer interface :( No, each host sends you the ARP reply and in addition the server sends you an ARP reply as well, because this is how proxy_arp works.