大学校园网-毕业设计--论文

摘要

随着现代网络技术的飞速发展，计算机网络已经涉及到人们生活的各个方面。校园网越来越普及，当前的学习、工作和通信方式已经完全实现了网络化。本文首先介绍了有关网络的一些基本概念知识，让读者对网络有个大概了解。然后对校园网的现状及未来发展进行分析，进而讨论了在设计与规划校园网时所要考虑的主要因素。最后给出校园网方案的具体实施，这一部分包括逻辑拓扑、物理拓扑的规划，虚拟局域网(Virtual Local Area Network,VLAN)划分，IP地址规划以及校园网所具有的功能。

大学校园网是基于分层网络架构而设计的，实现了域名解析系统(Domain Name System，DNS)、动态主机配置协议(Dynamic Host Configuration Protocol，DHCP)、网络地址转换(Network Address Translation,NAT)等基本服务并启用认证授权记账(Authentication Authorization Accounting，AAA)服务。校园网内部企业的远程用户可以通过虚拟专用网络(Virtual Private Network，VPN)穿越Internet与校园进行通信，移动用户可以通过PPPoE拨号接入访问Internet资源。校园网内部各VLAN 之间通过动态路由协议连通。划分VLAN可以进行流量管理，并在一定程度上可以提供网络安全性，但为了维护VLAN信息的一致，各楼栋内接入交换设备采用VLAN中继协议(VLAN Trunking Protocol，VTP)。校园网内还采用链路聚合技术增加网络冗余，以提高网络的稳定性和负载均衡；鉴于安全，维护人员需通过安全外壳协议(Secure Shell,SSH)对校园网设备进行远程管理维护。

关键词：虚拟局域网；逻辑拓扑；物理拓扑；分层网络；域名解析系统；动态主机配置协议；网络地址转换；认证授权记账；虚拟专用网络；动态路由协议；链路聚合；安全外壳协议

ABSTRACT

With the rapid development of modern network technology,computer network has been involved in all aspects of people's lives.The community local area network(LAN) is becoming increasingly popular,and nowadays our studies,works,and communication mode has been fully achieved network partake.At the beginning,this article introduces some basic concepts about network knowledge,so that readers will have a general idea of t he network.Then we have been further discussed the main factors when designing and planning the LAN by analyzing the status and the future development of current local area network.Finally,we give a concrete implementation of community programs,which includes the planning of logical topology,physical topology and IP address,virtual local area network(VLAN) division and the fuction of the community LAN.

The community network of college ,which is based on the layered network architecture,achieves the Domain Name System(DNS),Dynamic Host Configuration Protocol(DHCP),Network Address Translation(NAT) and other basic services as well as enabling Authentication Authorization Accounting(AAA).The remote users in the community business can communicate with the enterprise across the Internet by a virtual private network(VPN),and the mobile users can have access to the Internet resources by PPPoE dial-up.The connectivity of the internal inter-VLAN in the community come true by making use of dynamic routing protocol.The VLAN is not only beneficial to traffic management,but also to some extent provides the network security.In order to maintain the consistency of the VLAN information,all the swithing equipments in the building use the VLAN trunking protocol mode.Besides,there is also taking full advantage of link aggregation to increase network redundancy and improve network stability and load balancing.In view of safety,maintaince staff should be by virtue of secure shell protocol(SSH) for remote management and maintenance of equipment.

Keywords:VLAN; logical topology; physical topology; layered network architecture; DNS; DHCP; NAT; AAA; VPN; dynamic routing protocol; link aggregation; SSH