文档介绍：摘 要
计算机网络发展和技术提升给网络安全带来了很大冲击,Internet安全成了新信息安全热点。网络安全，是计算机信息系统安全一个关键方面。如同打开了潘多拉魔盒，计算机系统互联，在大大扩展信息资源共享空间同时，也将其本身暴露在更多恶意攻击之下。怎样确保网络信息存放、处理安全和信息传输安全问题，就是我们所谓计算机网络安全。信息安全是指预防信息财产被有意或偶然非法授权泄露、更改、破坏或使信息被非法系统辩识、控制；确保信息保密性、完整性、可用性、可控性。信息安全包含操作系统安全、数据库安全、网络安全、病毒防护、访问控制、加密和判别七个方面。设计一个安全网络系统，必需做到既能有效地预防对网络系统多种多样攻击，确保系统安全，同时又要有较高成本效益，操作简易性，和对用户透明性和界面友好性。
针对计算机网络系统存在安全性和可靠性问题，本文从网络安全提出及定义、网络系统安全风险分析，网络攻击通常手段，企业局域网安全设计标准及其配置方案提出部分见解，而且进行了总结，就目前网络上普遍安全威胁，提出了网络安全设计关键理念和安全管理规范并针对常见网络故障进行分析及处理,以使企业中用户在计算机网络方面增强安全防范意识，实现了企业局域网网络安全。
关键词：网络安全； 路由器； 防火墙； 交换机； VLAN
Abstract
The development of computer networks and technologies to enhance network security is a big blow, Internet security has become a new hotspot of information security. Network security is the security of computer information systems in an important aspect. Like opening of the Pandora's Box, the computer systems of the Internet, greatly expanded information resources sharing space at the same time, will be its own exposure to the more malicious attacks under. How to ensure that the network of information storage, processing and transmission of information security security, is the so-called computer network security. Information security is to prevent information from the property have been deliberately or accidentally leaked authorized illegal, altered, damage or illegal information system identification, control; ensure confidentiality, integrity, availability, controllable. Information security, including the safety of the operating system, database security, network security, virus protection, access control, encryption and identification of seven areas. Design of a network security system, which must be done to effectively prevent the network all of the attacks, guarantee the safety of the system, and also have a higher cost-effectiveness, operational simplicity, and transparent to the user interface and friendly.
Computer network system of security and reliability problems, the pap