一个轻量级的nat穿越服务器端，源码质量很高，很适合学习编程，特别是编写网络程序的人学习。-a lightweight nat through the server, the source of high quality, very suitable for learning programming, Special procedures for the preparation of network learning from the people.

一个用VC 编写的网络防火墙程序，能够处理常见的攻击，对于学习网络编程者有一定帮助

简单的防火墙,主要用于熟悉和学习基于vc网络编程的mfc类库的函数-firewall

vc++6.0实现防火墙，大家可以学习HOOK技术，网络编程。-vc++6.0 to achieve a firewall, you can learn HOOK, network programming.