http://www.hacking-tutorial.com/tips-and-trick/4-steps-to-prevent-man-in-the-middle-attack-arp-poisoning-in-lan/#sthash.et2oBZDP.dpbs

If we as a human absolutely we will know who is Alan and who is Brian by recognizing them from their face, but for our computer they depend on the ARP table network mapping (OSI layer 2 and layer 3).

人与人之间可以通过面部特征来相互识别，但是对电脑而言，它们之间的相互识别取决于arp表网络映射

<table border="1" cellpadding="1" cellspacing="1" style="width: 500px;">

Name           IP   Address                         MAC Address

Alan            192.168.1.2            00-00-00-00-00-00-00-01

Brian          192.168.1.3             00-00-00-00-00-00-00-02

Cracker      192.168.1.88             00-00-00-00-00-00-00-03

table>

So if Alan want to connect to Brian, the computer will translate Brian IP address(192.168.1.3) to its MAC address 00-00-00-00-00-00-00-02.

The correct way is should be like that, but because the attacker doing an ARP spoofing or ARP poisoning they will change the ARP mapping.

If the network already poisoned, when Alan want to send packet to Brian, Alan will translate Brian(192.168.1.3) with MAC 00-00-00-00-00-00-00-03 and vice versa.

- See more at: http://www.hacking-tutorial.com/tips-and-trick/4-steps-to-prevent-man-in-the-middle-attack-arp-poisoning-in-lan/#sthash.et2oBZDP.uTdOKxBq.dpuf   网络映射的相关知识

In this tutorial I will show you how the ARP spoofing can be happen and how to prevent it in your own computer so you will not be the victim.

1. To prevent ARP spoofing and man in the middle attack in your local area network you need to add a static ARP.

2. This trick become troublesome if your router changed frequently, so if you use this prevention method you need to delete the old one and add the new one if it changed

3. You can download and use my Static ARP routing changer to change your ARP static routing automatically

- See more at: http://www.hacking-tutorial.com/tips-and-trick/4-steps-to-prevent-man-in-the-middle-attack-arp-poisoning-in-lan/#sthash.et2oBZDP.5J4OybF2.dpuf

相关知识：

http://baike.baidu.com/view/547338.htm?fr=aladdin    OSI七层模型   【OSI layer 2 数据链路层(Datalink Layer)】   【OSI layer 3网络层(Network Layer)】

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另外一篇文章，解决arp攻击需要http://www.tp-link.us/article/?id=169

1.先给每一台电脑配置静态ip

2.禁用掉dhcp

开机自动配置

C:\Users\Administrator\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup 

netsh interface ip add neighbors "本地连接" "192.168.1.1" "00-1f-33-b5-a0-6e"

arp攻击的处理方法