摘要：无论是实现防火墙, NAT 还是VPN, 首要的任务就是获得网络上传输的数据包，在此基础上才能进行下一步

的工作。通过分析Windows 的网络数据传输机制，可以定位出不同的处理关键点，从而在不同的层次上实现数据包的

捕获功能，以满足不同的需要。

关键词：关键点 服务提供者接口 网络设备接口规范 中间层驱动程序 钩子驱动程序-Abstract : Whether the purpose is to achieve a firewall, VPN or NAT. One of the first priorities is access to the network transmission of data packets, and on this basis can we proceed to the next stage of work. By analyzing the Windows network data transmission mechanism, the definition can be different from the key points thus different levels of data packet capture function, in order to meet different needs. Key words : key point services provider Network Interface Device Interface norms middle layer Driver Driver hook