Is there a way to protect a NAT router WAN interface against an ARP poisoning attack? Some "terrorist" poisons the ARP table entry responsible for the WAN gateway IP to MAC binding. The Internet access service provider has done little or nothing so far. So, I'm looking for possible solutions to protect my VPN routers. The perfect solution would be to add a permanent entry in the WAN ARP table. But, I do have just WRV200 and RV042 routers, at the moment. Is it possible to do something with them? Or, perhaps some other routers are able to deal with the problem.