ip-filter不但具有SNAT、DNAT、端口映射、透明代理等已经成熟的功能，同时还实现了IPv4和IPv6协议以及IPSec安全协议的支持。此外还有诸如规则分组、blackhole、数据包捕获等特色-ip-filter not only had SNAT, DNAT, the port mapping, the transparent proxy and so on already the mature function, meanwhile has realized IPv4 and

一个IP数据包过滤工具库源码，含有一个IPMonitor程序，可以查看所有IP包头信息。对编写包过滤防火墙很有用- A IP data packet filters the tool room source code, includes a IPMonitor procedure, may examine all IP Baotou information. To compiles the package to filter the firewall to be very useful

通过ipfilter 来抓取数据包，并且过滤，符合规则的写在proc文件中-scratch data by ipfilter, get package filling the defined rool, and write the filted ip into proc file