摘要:企业网的建设是推动经济发展、加快与世界经济接轨的迫切需求。在跨世纪改革中，世界各国都在加快现代化的脚步，其信息化程度的高低己成为当今世界衡量一个国家综合国力的重要标志。而运用先进的网络技术建设企业网，营造良好的企业管理与交流环境，丰富企业文化的内涵，将企业与中国经济的发展推向一个新的高峰，因此构建一个稳定、便捷、安全的网络环境势在必行。

　　　 本设计中企业网连接了包括市场部，销售部，采购部，操作部，IT部，投资关系部，融资部，会计部，人事部等企业内部部门及打印机、服务器和互联网的接入。通过使用常用的、稳定的、高效的局域网技术、广域网技术使企业网成为一个实用的、高可靠、高效率、高扩展性、高安全性的系统。

　　　 在企业汇聚层使用VLAN技术给用户提供灵活的网络接入服务，各VLAN相互隔离，提供安全性。同时为多个VLAN配置一个生成树，避免环路，提高稳定性。汇聚交换机之间通过使用链路捆绑技术，将多条物理链路捆绑在一起，实现高带宽，高可用性。在汇聚交换机之间部署热备份冗余协议，实现网关冗余，提高网络的稳定性。在核心交换机和核心路由器之间部署动态路由选择协议OSPF，实现路由的动态通告和学习。在网络边缘部署NAT，提供地址转换，减少公网IP地址的使用。移动用户访问公司内部，通过SSL VPN or EASY VPN ，提供安全的网络连接。

关键词  企业网；路由；Easy VPN；网络设计

Abstract:The construction of the enterprise network is to promote economic development and the urgent need to speed up with the world economy. In the cross-century reform, the countries of the world are accelerating the pace of modernization, its high and low degree of information has become an important symbol for today's world to measure a country's comprehensive national strength. Use of advanced network technology to build enterprise networks, can create a good corporate management and communication environment, rich the connotation of corporate culture, and promote the enterprise and economic development to a new peak. so to build a stable, convenient and secure network environment is imperative.

　　　In this design, the corporate network connection, including Marketing Department ,The sales department ,The purchasing department ,Operation department ,The IT department ,Investment relations ,The Financing Department ,The accounting department  and the personnel department. Enterprise network through the use of common, stable and efficient LAN, WAN technology become a practical, high reliability, high efficiency, high scalability, high security system.

　　　VLAN technology to provide flexible network access services to users in the enterprise access layer, and each VLAN is isolated from each other and provide security. A spanning tree for each VLAN configuration, is to avoid the loop and improve stability. The core switches through the use of trunking technology bundle multiple physical links together to achieve high bandwidth and high availability. Hot standby redundancy protocol deployed between the core switch is to realize the gateway redundancy and improve network stability. Between the core switches and core routers dynamic routing protocol the OSPF deployed is to realize routing dynamic announcements and learning. NAT deployed at the network edge provides address translation and reduce the use of public IP address. Mobile users access to the company through the SSL VPN or Easy VPN, to be provided with a secure network connection.

Keywords   Enterprise Network    Routing   Easy VPN   Network Design