查询词典 Firewall

In this paper, the concept of network security and security structures of OSI and Internet is introduced, and various threats confronting the computer network are also discussed. Several kinds of network information security technologies, including firewall technology, virtual private network, intrusion detection system, data encryption technology, identity authentication and security protocol etc. are also examined. The security of internal network is the biggest problem in the construction of each network. The solution to this problem lies in setting up a firewall. The theory of a firewall and the approach to its actualization is studied. Intrusion detection system, an important part of the computer network security system, has gained extensive attention. IDS monitors the computer and network traffic for intrusion and suspicious activities. It not only detects the intrusion from the extranet hacker, but also the intranet users. The emergence of virtual private network paves the way for realizing secure connection of LAN quickly and at a relatively low cost. The concept, function, key techniques, including the tunnel technology, and the ways to realize VPN are expounded in this paper. Also introduced is the data encrypt network technology, which is called the soul of computer network security, such as digital digest, digital signature, digital certificate, digital encrypt arithmetic and so on. At the same time, the principle and the process of implementing network security by digital certificate and digital signature, the basic principle and characters of security protocols, and finally, three of the security protocols, concerning the security problems in network, IPsec, SLL and SET are analyzed in detail Computer network system should be a system of dynamic defence, both dynamic and static, passive as well as active, and even offensive, combined with management and technology.

本文系统地介绍了网络安全的概念、OSI及Internet的安全体系结构，并讨论了计算机网络面临的各种安全威胁；内部网络的安全问题是每个建网单位面临的最大问题，可以认为防火墙技术是解决网络安全的一个主要手段，本文研究了防火墙的原理及其实现手段；作为一种主动的防御措施，入侵检测系统作为网络系统安全的重要组成部分，得到了广泛的重视，TDS对计算机和网络资源上的恶意使用行为进行识别和响应，不仅检测来自外部的入侵行为，也监督内部用户的未授权活动；虚拟专用网技术的出现，为实现网络间的连接提供了快速安全但又相对便宜的手段，本文较深入的探讨了实现VPN的隧道技术，并对VPN的概念、功能、实现途径、基本构成、关键技术及发展前景等问题进行了全面论述；数据加密技术是网络安全核心技术之一，本文从数据加密算法、数字摘要、数字签名及数字证书等几方面简要介绍了数据加密技术，并分析用数字证书和数字签名实现网络安全的原理和过程；对安全协议的基本原理、主要特点进行了较为深入的研究，并就网络的安全性问题剖析了三种安全协议：IPsec协议、SLL协议和SET协议。

Finally, the paper introduces the affect of the firewall in the safeness of the network, and the god point and the weak point of the firewall. It emphasizes the policy of firewall's project.

最后介绍了防火墙的在网络安全中所起的作用，以及防火墙的优点和不足之处；重点讲了防火墙技术的设计策略。

For the safety of LAN and using firewall thriftily,the authors analyze the architecture of Netfilter in Linux2.4 kernel.Then the authors implement the firewall system based on embedded Linux OS,which has basic functions as Package Filtration,URL filtration,NAT and log.And,the firewall system integrates with DMZ which establishes a buffer zone between Internet and Intranet to make the Intranet safer,and connection tracking which maintains a table for connection track in order to get the more safer than package filtration.

为了构建安全可靠的网络，同时降低使用防火墙的成本，对Linux2.4内核防火墙结构Netfilter的实现机制进行了深入的研究和分析，并利用该机制设计实现了一个嵌入式Linux防火墙系统，该防火墙实现完善了包过滤、URL过滤、NAT和日志等防火墙基本功能，同时集成了非军事区，为Internet和Intranet之间建立了缓冲地带，以保证Intranet的安全。

This thesis mainly deals with the packet filter firewall by applicating Netfilter on the basis of Linux, consisting of seven parts: first, it generally describes the firewall; second, it introduces the exploiting platform Linux and the software debug environment; third, it simply analyzes some networking protocols; fourth, it analyzes the network attacks and their defensing measures; fifth, it describes the most important part of the thesis--the analysis of netfilter's frame and the exploiting and designing process of the firewall; sixth, it introduces the design of the device drivers of the Linux which is the theory base of exploting the user's interface ; the last part is the applicating guide of its exploiting process.

本文介绍了运用Netfilter防火墙技术，在LINUX环境上实现包过滤防火墙的方法和过程，在内容上主要包括了七个部分：第一部分对防火墙的概述；第二部分则介绍此次开发的平台LINUX和软调环境；第三部分对几种网络协议做了简单的分析；第四部分分析了网络攻击及其防御措施；第五部分则是本次设计的核心部分Netfilter框架分析以及防火墙的开发设计思路；第六部分则介绍LINUX设备驱动程序的设计，它是开发用户接口部分的理论基础；最后则是所开发程序的使用说明部分。

This thesis mainly deals with the packet filter firewall by applicating Netfilter on the basis of Linux, consisting of seven parts: first, it generally describes the firewall; second, it introduces the exploiting platform Linux and the software debug environment; third, it simply analyzes some networking protocols; fourth, it analyzes the network attacks and their defensing measures; fifth, it describes the most important part of the thesis--the analysis of netfilters frame and the exploiting and designing process of the firewall; sixth, it introduces the design of the device drivers of the Linux which is the theory base of exploting the users interface ; the last part is the applicating guide of its exploiting process.

本文介绍了运用Netfilter防火墙技术，在LINUX环境上实现包过滤防火墙的方法和过程，在内容上主要包括了7个部分：第1部分对防火墙的概述；第2部分则介绍此次开发的平台LINUX和软调环境；第3部分对几种网络协议做了简单的分析；第4部分分析了网络攻击及其防御措施；第5部分则是本次设计的核心部分Netfilter框架分析以及防火墙的开发设计思路；第6部分则介绍LINUX设备驱动程序的设计，它是开发用户接口部分的理论基础；最后则是所开发程序的使用说明部分。

This thesis mainly deals with the packet filter firewall by applicating Netfilter on the basis of Linux, consisting of seven parts: first, it generally describes the firewall; second, it introduces the exploiting platform Linux and the software debug environment; third, it simply analyzes some networking protocols; fourth, it analyzes the network attacks and their defensing measures; fifth, it describes the most important part of the thesis--the analysis of netfilters frame and the exploiting and designing process of the firewall; sixth, it introduces the design of the device drivers of the Linux which is the theory base of exploting the users interface ; the last part is the applicating guide of its exploiting process.

本文介绍了运用Netfilter防火墙技术，在LINUX环境上实现包过滤防火墙的方法和过程，在内容上主要包括了七个部分：第一部分对防火墙的概述；第二部分则介绍此次开发的平台LINUX和软调环境；第三部分对几种网络协议做了简单的分析；第四部分分析了网络攻击及其防御措施；第五部分则是本次设计的核心部分Netfilter框架分析以及防火墙的开发设计思路；第六部分则介绍LINUX设备驱动程序的设计，它是开发用户接口部分的理论基础；最后则是所开发程序的使用说明部分。

Note that changing the rules in the set or add new rules to re-open the firewall to enable up-to-date entry into force of the firewall rules.

注意，在改变规则设置或添加了新规则后要重新开启防火墙，以使最新的防火墙规则生效。

Use a Firewall - I can not stress how important it is that you use a Firewall on your computer.

使用防火墙-我不能强调有多么重要的是你使用防火墙在您的计算机上。

On the basis of the light-weight system firewall of Linux kernel, this system disposes and transmits the gateway, and start the module of firewall, be used to filter the network data transmitted by the gateway, to stop the data come from illegal address and with forbidden character of packets.

本系统是基于Linux内核的轻型防火墙系统，通过配置转发网关，并启动防火墙模块，对网关转发的数据包进行过滤，对来自非法地址和含有非法字符串的数据包进行拦截。

Following on the official Tencent QQ2007 Ⅱ for example, now almost all of the computer to install antivirus software and firewall security software, firewall, the main role is to prevent illegal access and network attacks, security of our network security.

下面就以腾讯官方的QQ2007Ⅱ为例，现在的电脑中基本上都安装杀毒软件与防火墙等安全软件，防火墙作用主要是阻止非法访问与网络攻击，保障我们的网络安全。

Chimborazo and Cotopaxi, took me by the hand.

越过琴博腊索山和科托帕克西山。

This car is in a good condition.

这辆车的状况很好。