tailieunhanh - Network+Certification_Microsoft Press note (17)

Chapter 17, Network Troubleshooting Procedures.|1|Chapter Network a NetworkChapter 17, Lesson Network Computer .|2||3||4|Network technicians often have to troubleshoot problems on you work on an unfamiliar network installation, you should the network’s basic hardware configuration1You often must approach a problem without having any the network infrastructure and the equipment used to build itaIn a perfect world, you would have access to schematic diagrams cabling and an inventory of the network hardware, but this , you must examine the equipment yourself to find out what to have many different portsMost of the ports on computers manufactured today are labeled, might come across units that have no markings1When ports are unlabeled, you must be able to discern their functionsThe ports on a typical computer are located either on the on expansion cards that plug into the system bus1If the same type of port can have more than one function, you tell what a port does by where it is located2The locations of the motherboard ports vary, depending on the design computer3An older computer might have the motherboard ports grouped in area away from the motherboard itselfaOn an older computer, the motherboard ports are separate are bolted to the back of the computer case and connected to with cablesbThe expansion slots are grouped in a different area, where the by the expansion cards installed in the system are located4A newer computer might have all of the motherboard ports lined up in a newer computer, the ports are part of the motherboard(1) The ports run horizontally along the bottom of the computer(2) All ports are located on the motherboard, including the , which is typically provided by an expansion cardD.|5||6|E.|7|2Serial nearly always use serial portsaA few proprietary networking systems use standard (UTP) cable that plugs into an adapter connected to port2Computers manufactured today typically have two serial ports on , both of which use male DB-9 connectors3Older computers may also use DB-25 connectors for serial portsaThe typical configuration used to be one DB-9 connector and connector4Because nine pins more than satisfy the requirements for , a computer can use either a DB-9 or a connections can run at speeds from 110 to 115,200 bits (bps)6D-type connectors are not used exclusively for serial portsaParallel ports also use DB-25 connectors (although they are of male)bIn rare cases, Small Computer System Interface (SCSI) adapters connectorscDB-9 connectors were at one time used as video ports to monitors, although they were female instead of maledDo not confuse the various functions of DB-9 and DB-25 connectors;.they are not interchangeableParallel ports were designed for use by printersaIn recent years, parallel ports have been enhanced to provide bidirectional communications between the computer and device2Parallel ports always use a female DB-25 connector3The average computer today has one parallel port4A select group of SCSI devices can also be plugged into a computer’ portaThese devices use the same basic principles of communication SCSI devices, but they use a different interface to parallel port interface is slower than that of a dedicated adaptercF

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