介绍了关于互联网网络安全的关键技术,并在此基础上重点研究了基于Linux 的防火墙技术。分析了如何利用Ipchains 和Netfilter 建立基于Linux 操作系统的的防火墙。最后对基于Linux 的防火墙的未来发展作了展望。 关键词:防火墙 Ipchains Netfilter Linux Abstract:The key techniques of network secureity are introduced here. The techniques of of firewall based on Linux are also disscused in this paper.How to build a firewall based on Linux using the frame of Ipchains and Netfilter analysed.Finally,the prospects for the development of future firewall are given. Key words:firewall;Ipchains ;Netfilter ;Linux