ccna 200 301 syllabus design and material development

ccna 200 301 syllabus design and material development.The second layer of a hierarchical network design can effectively reduce the network diameter. In Figure 9-1-1, assuming that PC1 and PC2 belong to different departments and inter-VLAN communication is possible on D1 devices at the aggregation layer, the path from PC1 to PC2 is Sl-Dl-S2,and the diameter of the network is 3.(2) Bandwidth AggregationIn Figure 9-1-1, multiple cables can be connected between S1 and D1, and link aggregation can be configured to provide faster uplinks and higher throughput.(3) RedundancyRedundancy is a part of creating a highly available network. Redundancy is divided into link redundancy and device redundancy. In "Figure 9.1", a link failure between any two switches does not affect the normal communication of the network, which is the use of link redundancy. Except for access layer S1 and S2, the failure of any one switch will not affect the communication of the network, which is using device redundancy. In a typical network, both link redundancy and device redundancy are often used to ensure high availability.The type of network an enterprise uses is often related to its business needs and financial resources. Many enterprises tend to use a flat type of network, with many switches connected together in a haphazard manner to save money or to keep the configuration simple, often with one computer poisoned, the whole company computer poisoned; part of the network down, the whole company network down.To put it mildly, the reader may not believe that I have encountered a business unit where the access layer is configured with Cisco 3560 switches, and all departments are configured in the same subnet through cascading of switches. All of the Layer 3 switches were factory configured by default and used as normal unmanaged Layer 2 switches, and in today's world where ARP viruses are prevalent, the network is down for at least a third of the day.277 A9.1.2 Switch Selection*.Switches, like routers, are divided into fixed-configuration and modular switches. In addition some switches support stacking, which can be further divided into stackable and non-stackable switches.