摘要随着计算机网络的迅速发展，Internet给我们的生活上和工作上都带来了很多巨大的变化，可以说，互联网加快地推动了人类社会的发展与人类文明的进步，把我们带入了一个崭新的互联网时代。因此，我们在现实生活中已经越来越离不开它了，并且互联网也从正面或者间接的影响着我们的学习、工作以及生活等方方面面。虽然互联网在给我们的生活带来众多的便利和科技成果享受的同时，但是许多计算机网络信息安全的一系列的棘手问题也随之出现，而目前为了能够避免或者解决这些安全问题，常常用到的手段就是采取与之相关的防火墙技术了。86018

本论文设计的防火墙主要任务是能够简单的实现包过滤功能，在此之前，本文先介绍了防火墙的分类、体系结构以及相关发展历史，再简单的介绍了数据包的概念、TCP/IP协议以及Visual C++ 6。0，然后从防火墙的各个模块进行详细设计和说明，使防火墙可以对IP地址、TCP/UDP协议端口以及其他协议进行过滤，用户还可以设置过滤规则，所设计软件具有添加了日志统计功能。如果防火墙将某一个IP地址设置为黑名单的话，那么防火墙就会把从这个地址发来的一切数据包给屏蔽或阻止，使防火墙实现拦截功能。

毕业论文关键词：防火墙；包过滤技术；网络安全

Abstract With the rapid development of computer network, the Internet brings to our life and work on a lot of great changes, so to speak, to speed up to the Internet to promote the development of human society and the progress of human civilization, put us into a new era of Internet。 In real life, therefore, we have already more and more inseparable from it, and the Internet is from the front or indirectly affect our study, work and life and other aspects。 Though the Internet bring many convenience to our life and enjoy the scientific and technological achievements at the same time, but most of the computer network information security also come in a series of problems, and at present in order to be able to avoid or solve these security problems, often used method is to take the related firewall technology。

This paper designed the realization of the main task is to simple packet filter firewall functions, before this, this paper first introduces the classification, the architecture of firewall and related development history, and simply introduces the concept of the packet, TCP/IP protocol, and Visual c + + 6。0, then from the various modules of the firewall in detail design and illustration, the firewall can be the IP address and TCP/UDP port, and other protocol filtering, users can also set the filter rules, the designed software has added a log statistics function。 If the firewall set an IP address to the blacklist, the firewall will give all the packets sent out from this address to block or stop, make firewall interception function。

Key words: Firewall; Packet Filtering Technology; Network security

目  录

第一章 绪论 1

1。1 研究背景和意义 1

1。2 国内外研究现状 2

第二章 防火墙概述 5

2。1 防火墙的分类 5

2。1。1 分组过滤型防火墙 5

2。1。2 应用级网关型防火墙 6

2。1。3 代理服务型防火墙 6

2。1。4 复合型防火墙 7

2。2 防火墙的体系结构 7

2。2。1 屏蔽路由器 7

2。2。2 双穴主机网关