Ender204426777乾颐堂CCNAv3.0课程BuildingaSimpleNetworkUnderstandingEthernetandSwitchOperation理解以太网和交换机的操作乾颐堂CCNAv3.0Ender2044267772960Switch乾颐堂CCNAv3.0Ender204426777EthernetLANConnectionMediaThemechanicalpropertiesofEthernetdependonthetypeofphysicalmedium:•Coaxial(notusedanymore)-同轴电缆•Copper-铜介质•Fiber-optic-光纤•Ethernetwasoriginallybasedontheconceptofcomputerscommunicatingoverasharedcoaxialcable,sharingfilesandapplications.Ender.ICND1—1-63乾颐堂CCNAv3.0Ender204426777EthernetLANConnectionMedia(Cont.)•ModifyingEthernettoconformtoexistingtwisted-pairtelephonewiringenabledcostreduction.•UTP-basedEthernet,whichusescopper,becamewidelydeployedafterthe10BASE-Tstandard-铜芯的非屏蔽双绞线在10BASE-T之后广泛采用•Fiber-opticvariantsofEthernetofferhighperformance,electrical-光纤提供更好的性能和距离isolation,andlongdistance(tensofkilometerswithsomeversions).Ender.ICND1—1-64乾颐堂CCNAv3.0Ender204426777EthernetLANConnectionMedia(Cont.)UnshieldedTwisted-PairCable-非屏蔽双绞线CharacteristicValueSpeedandthroughputFrom10Mb/sto10Gb/sAveragecostpernodeLeastexpensiveMediaandconnectorsizeSmallMaximumcablelengthVariesEnder.ICND1—1-65乾颐堂CCNAv3.0Ender204426777EthernetLANConnectionMedia(Cont.)RJ-45ConnectorandJack连接器和插头Ender.ICND1—1-66乾颐堂CCNAv3.0Ender204426777双绞线线序绿白绿橙白蓝蓝白橙棕白棕12345678橙白橙绿白蓝蓝白绿棕白棕12345678国际上常用的制作双绞线的标准包括EIA/TIA568A和EIA/TIA568B两种。EIA/TIA568A的线序定义依次为绿白、绿、橙白、蓝、蓝白、橙、棕白、棕，其标号如下表所示。EIA/TIA568B的线序定义依次为橙白、橙、绿白、蓝、蓝白、绿、棕白、棕，其标号如下表所示。无论是采用端接方式A，还是端接方式B，在网络中都是通用的（1-2-3-6在工作）。乾颐堂CCNAv3.0Ender204426777EthernetLANConnectionMedia(Cont.)OpticalFiber(SingleMode单模光纤)Ender.ICND1—1-67电镀层乾颐堂CCNAv3.0Ender204426777EthernetLANConnectionMedia(Cont.)FiberTypesEnder.ICND1—1-68乾颐堂CCNAv3.0Ender204426777FiberConnectorTypesEnder.ICND1—1-69ExampleOther乾颐堂CCNAv3.0Ender204426777EthernetFr...
