ARP欺骗攻击程序。Hacker发送伪装的ARP Reply告诉A，计算机B的MAC地址是Hacker计算机的MAC地址。

Hacker发送伪装的ARP Reply告诉B，计算机A的MAC地址是Hacker计算机的MAC地址。

这样A与B之间的通讯都将先经过Hacker，然后由Hacker进行转发。于是Hacker可以捕获到所有A与B之间的数据传输（如用户名和密码）。

-ARP spoofing attack program. Hacker sends fake ARP Reply told A, Computer B' s MAC address is the MAC address of a computer Hacker. Hacker sends fake ARP Reply told B, computer A' s MAC address is the MAC address of a computer Hacker. This communication between A and B will go through Hacker, and then carried forward by the Hacker. Hacker can then capture all the data between A and B transmission (such as user name and password).