Thanks a lot, I 'll trying to solve the problem and report this problem to the net center.

We don't know who is the computer1,it's to difficult to find who lanched the arp_cheating because there are to many computers in my company in diffrent buildings.The only info I can check out is he/she 's IP(192.168.1.1,obviously it's a fake IP)and he/she 's MAC(00-03-0d-02-18-94, maybe it's also a ...

If computer1 start ARP cheating,my router was cheated,(respect computer1 as the gateway) so it send all the data to computer1.then my router can not connet to the internet and my notebook can not connet the internet to.

In my company,I want use my notebook and phone，so,I put a router in the ethernet, but someone in my company use arp attacker. the router can not defends it. How to solve this problem? （If my notebook connet to the ethernet directly,the software in the notebook can defends it.but the router can not)....