文件名称：思科园区网解决方案Gigabit Campus Network DesignPrinciples and Architecture
文件大小：670KB
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更新时间：2012-07-10 09:00:07
思科园区网解决方案.pdf
The availability of multigigabit campus switches from Cisco presents customers the opportunity to build extremely high-performance networks with high reliability. Gigabit Ethernet and Gigabit EtherChannel® provide the high-capacity trunks needed to connect these gigabit switches. If the right network design approach is followed, performance and reliability are easy to achieve. Unfortunately, some alternative network design approaches can result in a network with lower performance, reliability, and manageability. With so many features available, and with so many permutations and combinations possible, it is easy to go astray. This paper is the result of Cisco’s experience with many different customers and it represents a common sense approach to network design that will result in simple, reliable, manageable networks. The conceptual approach followed in this paper has been used successfully in routed and switched networks around the world for many years. This hierarchical approach is called the “multilayer design.” The multilayer design is modular and capacity scales as building blocks are added. A multilayer campus intranet is highly deterministic, which makes it easy to troubleshoot as it scales. Intelligent Layer 3 services reduce the scope of many typical problems caused by misconfigured or malfunctioning equipment. Intelligent Layer 3 routing protocols such as Open Shortest Path First (OSPF) and Enhanced Interior Gateway Routing Protocol (EIGRP) handle load balancing and fast convergence. The multilayer model makes migration easier because it preserves the existing addressing plan of campus networks based on routers and hubs. Redundancy and fast convergence to the wiring closet are provided by Hot Standby Router Protocol (HSRP). Bandwidth scales from Fast Ethernet to Fast EtherChannel and from Gigabit Ethernet to Gigabit EtherChannel. The model supports all common campus protocols. The multilayer model will be described, along with two main scalability options appropriate for building-sized networks up to large campus networks. Five different backbone designs with different performance and scalability are also presented. In this paper the term backbone is used to represent the switches and links in the core of the network through which all traffic passes on its way from client to server.