31 Days Before Your CCNA Exam

Day 31Network Devices, Components, andDiagramsCCNA 640-802 Exam Topics■Describe the purpose and functions of various network devices.■■■■Select the components required to meet a network specification.Describe the components required for network and Internet communications.Interpret network diagrams.Differentiate between LAN/WAN operation and features.Key PointsAt its most fundamental level, a network can be divided into four elements:■■■■The rulesThe messagesThe mediaThe devicesFor today’s exam topics, we will focus on the devices used in today’s networks, the media used tointerconnect those devices, and the different types of network topologies.DevicesHubs and switches are used to connect end devices to a single LAN. The following describes whento use a hub and when to use a switch:■■Hubs are typically chosen as an intermediary device within a very small LAN where bandwidthusage is not an issue or cost limitations exist. In today’s networks, hubs are beingreplaced by switches.Switches are preferred over hubs as a local-area network (LAN) intermediary device becausea switch can segment collision domains and provide enhanced security.SwitchesWhen choosing a switch, the main factors to consider are the following:■Cost: Determined by the number and type of ports, network management capabilities, embeddedsecurity technologies, and optional advanced switching technologies.