一个VPN软件（freeswan）的源码可编译，有MakeFile文件

扫描包过滤防火墙的程序 -Scan packet filter fireware

基于ndis层的防火墙，相对TDI和SPI的防火墙，ndis防火墙更加底层，能过滤所有的网络底层包-Based on the NDIS layer firewalls, relative TDI and SPI firewall, ndis firewall more bottom to filter the bottom of all network packets

是一个利用ICMP协议进行通信的程序,为了能穿越防火墙,利用了ACK技术.-use ICMP is a protocol communications procedures, in order to cross the firewall, using the ACK technology.

利用操作系统提供的API函数写的防火墙-use of the operating system to write to the API function firewall

An Adventure How to implement a Firewall-Hook Driver

ipchains 防火墙分析-ipchains firewall analysis

监听与隐藏一书各章节的源代码。我将上传于此，对研究防火墙与网络通讯的朋友，或许有用。-eavesdropping with a hidden in the various sections of the source code. I will upload Here, the study of firewalls and network communications are friends, perhaps useful.

windows下的防火墙，支持对协议，源/目的端口的过滤。可以设置阻止列表。-under the windows firewall, support for the agreement, the source/destination port of the filter. The list can be set to stop.

微软的一个ndis驱动程序例子,写防火墙的朋友可以参考-A ndis driver example of Microsoft. and it can be referred to those who writes the firewall

自动关闭WINXP防火墙，把自己加入到例外-Auto shut down firewall, add to the except list