CCNA内部培训ppt课件.ppt

内部培训CCNA教材,目录,第一章数据通信基本原理第二章管理CISCO设备第三章使用CDP和Telnet第四章路由器的构造和启动第五章交换机的基本配置第六章VLAN的配置第七章IP路由(static、rip、igrp、eigrp、ospf)第八章访问列表第九章NAT(网络地址转换)第十章点到点连接第十一章帧中继第十二章ISDN技术第十三章VPN技术第十四章无线技术,标准化组织,国际标准化组织（ISO）电子电器工程师协会（IEEE）美国国家标准局（ANSI）电子工业协会（EIA/TIA）国际电信联盟（ITU）INTERNET架构委员会（IAB）,标准化组织,在计算机网络的发展过程中有许多国际标准化组织做出了重大的贡献,他们统一了网络的标准,使各个网络产品厂家生产的产品的可以相互通信,目前为网络的发展做出贡献的标准化组织有:ISO:制定了大型的标准,包括与INTERNET相关的标准,ISO提出了OSI参考模型,OSI参考模型描述了网络的工作原理,为计算机网络构建了一个易于理解的,清晰的层次模型IEEE:提供了网络硬件上的标准使各种不同网络硬件厂商生产的硬件设备相互通信,IEEELAN标准是当今居于主导地位的LAN标准,它主要定了802.X协议族,期中802.3为以太网标准协议簇,802.4为令牌总线网(TOKENBUS)标准,802.5为令牌环网(TOKENRING)标准,802.11为无线局域网(WLAN)标准.ANSI:是公司政府和期它组织成员组成的自愿组织,主要定义了光纤分布式数据接口FDDI的标准EIA/TIA:定义了网络连接线线缆,如:RS232CAT5HSSIV.24同时还有线缆布放标准,如:568BITU:定义了作为广域边接的电信网络的标准;如:X.25FRINTERNET架构委员会(Iabinternetarchitecturboard)下设工程任务委员去(IETF)研究任务委员会(IRTF),号码分配委员会(IANA)负责各种INTERNET,的标准的定义,是目前最具影响力和国际标准化组织.,第章数据通信基本原理,一般通信的过程,Name,Address,传输层,数据链路层,物理层,网络层,上层数据,上层数据,TCP头,数据,IP头,0101110101001000010,数据,Frame头,表示层,应用层,会话层,段,包,比特,帧,PDU,封装数据,上层数据,IP+TCP+上层数据,Frame头,TCP+上层数据,IP头,上层数据,TCP头,0101110101001000010,传输层,数据链路层,物理层,网络层,表示层,应用层,会话层,解封装数据,OSI模式概述,应用层(高),会话层,表示层,应用层,OSI模式,数据流层,传输层,数据链路层,网络层,物理层,应用层(高),会话层,表示层,应用层,应用层作用,TelnetSMTPHTTPFTP,用户接口,例子,应用层,TelnetSMTPHTTPFTP,JPEG,用户接口,数据表示加密等特殊处理过程,例子,表示层,应用层,应用层作用,TelnetHTTP,JPEG,保证不同应用间的数据区分,用户接口,数据表示加密等特殊处理过程,OperatingSystem/ApplicationAccessScheduling,例子,会话层,表示层,应用层,应用层作用,保证不同应用间的数据区分,用户接口,数据表示加密等特殊处理过程,传输层,数据链路层,网络层,物理层,例子,会话层,表示层,应用层,应用层作用,数据流层的作用,EIA/TIA-232V.35,例子,物理层,设备间接收或发送比特流说明电压、线速和线缆等,802.3/802.2HDLC,EIA/TIA-232V.35,例子,数据流层的作用,数据链路层,物理层,将比特组合成字节进而组合成帧用MAC地址访问介质错误发现但不能纠正,设备间接收或发送比特流说明电压、线速和线缆等,802.3/802.2HDLC,EIA/TIA-232V.35,IPIPX,例子,数据流层的作用,网络层,数据链路层,物理层,将比特组合成字节进而组合成帧用MAC地址访问介质错误发现但不能纠正,设备间接收或发送比特流说明电压、线速和线缆等,提供路由器用来决定路径的逻辑寻址,TCPUDPSPX,802.3/802.2HDLC,EIA/TIA-232V.35,IPIPX,例子,数据流层的作用,传输层,数据链路层,物理层,可靠或不可靠的数据传输数据重传前的错误纠正,将比特组合成字节进而组合成帧用MAC地址访问介质错误发现但不能纠正,设备间接收或发送比特流说明电压、线速和线缆等,网络层,提供路由器用来决定路径的逻辑寻址,TCPUDPSPX,802.3/802.2HDLC,EIA/TIA-232V.35,IPIPX,表示层,应用层,会话层,例子,数据流层的作用,可靠或不可靠的数据传输数据重传前的错误纠正,将比特组合成字节进而组合成帧用MAC地址访问介质错误发现但不能纠正,设备间接收或发送比特流说明电压、线速和线缆等,传输层,数据链路层,物理层,网络层,提供路由器用来决定路径的逻辑寻址,PDU,PDU（protocoldataunit):每一层使用自己层的协议和别的系统的对应层相互通信，协议层的协议在对等层之间交换的信息叫协议数据单元。上层:messagetransportlayer:segmentNetworklayer:packetData-linklayer:FramePhysicallayer:bit,数据传输过程中的帧结构和包结构,,,Data,A,A,,Ethernet,B,B,,From,LAN,Frame,Relay,to,WAN,to,LAN,,,Data,,,Data,,,Data,,,Data,Framrelay,,,Data,Ethernet,,,Data,数据传输过程中，帧结构在改变，但是包结构不改变,第二章交换机和路由器简单配置,配置方式,EXEC模式,用户模式对交换机和路由器的有限操作命令提示符为主机名,主要有两个命令模式提供命令键入.,模式一:,EXEC模式(续),特权(或enabled)模式对交换机和路由器更深入的操作有配置和监视权力是进入其它配置模式的前提命令提示符为主机名#,模式二(也是最常用的模式):,Catalyst2950Switch启动界面,-SystemConfigurationDialog-Atanypointyoumayenteraquestionmark?forhelp.Usectrl-ctoabortconfigurationdialogatanyprompt.Defaultsettingsareinsquarebrackets.Continuewithconfigurationdialog?yes/no:yesEnterIPaddress:ip_addressEnterIPnetmask:ip_netmaskWouldyouliketoenteradefaultgatewayaddress?yes:yesIPaddressofthedefaultgateway:ip_addressEnterahostname:host_nameEnterenablesecret:secret_passwordWouldyouliketoconfigureaTelnetpassword?yesyesEnterTelnetpassword:telnet_passwordWouldyouliketoenableasaclustercommandswitch?noEnterclustername:cls_name,LoggingIntotheSwitchandEnteringtheEnablePassword,ConfigurationModes:Globalconfigurationmodewg_sw_a#configureterminalwg_sw_a(config)#Interfaceconfigurationmodewg_sw_a(config)#interfacee0/1wg_sw_a(config-if)#,ConfiguringtheSwitch,Setsthelocalidentityfortheswitch,ConfiguringSwitchIdentification,配置交换机的管理IP地址SW2950(config)#interfacevlan1SW2950(config-if)#ipaddressSW2950(config-if)#noshutdown配置交换机的网关Switch(config)#ipdefault-gatewayipaddress例如:SW2950(config)#ipdefault-gateway54,ConfiguringtheSwitchIPAddress,ShowingSwitchInitialStartupStatus,wg_sw_a#showversion,Displaystheconfigurationofthesystemhardware,softwareversion,namesandsourcesofconfigurationfiles,andbootimages,wg_sw_a#showrunning-configuration,Displaystheswitchscurrentactiveconfigurationfile,wg_sw_a#showinterfaces,Displaysstatisticsforallinterfacesconfiguredontheswitch,SwitchshowversionCommand,sw2950#showversionCiscoInternetworkOperatingSystemSoftwareIOS(tm)C2950Software(C2950-I6Q4L2-M),Version12.1(14)EA1a,RELEASESOFTWARE(fc1)Copyright(c)1986-2003byciscoSystems,Inc.CompiledTue02-Sep-0303:33byantoninoImagetext-base:0 x80010000,data-base:0 x805C0000ROM:BootstrapprogramisCALHOUNbootloadersw2950uptimeis1minuteSystemreturnedtoROMbypower-onSystemimagefileisflash:/c2950-i6q4l2-mz.121-14.EA1a.binciscoWS-C2950-24(RC32300)processorwith20710Kbytesofmemory.Lastresetfromsystem-resetRunningStandardImage24FastEthernet/IEEE802.3interface(s)32Kbytesofflash-simulatednon-volatileconfigurationmemory.BaseethernetMACAddress:00:0F:72:DB:4E:C0Motherboardserialnumber:FOC0813Y1H6Configurationregisteris0 xF,sw2950#showinterfacesfastEthernet0/1FastEthernet0/1isdown,lineprotocolisdown(notconnect)HardwareisFastEthernet,addressis000f.72db.4ec1(bia000f.72db.4ec1)MTU1500bytes,BW10000Kbit,DLY1000usec,reliability255/255,txload1/255,rxload1/255EncapsulationARPA,loopbacknotsetKeepaliveset(10sec)Auto-duplex,Auto-speedinputflow-controlisoff,outputflow-controlisoffARPtype:ARPA,ARPTimeout04:00:00Lastinputnever,output00:14:53,outputhangnever-More-,SwitchshowinterfacesCommand,路由器的简单配置任何时侯按Ctrl+C推出对话模式,Router#setup-SystemConfigurationDialog-Continuewithconfigurationdialog?yes/no:yesAtanypointyoumayenteraquestionmark?forhelp.Usectrl-ctoabortconfigurationdialogatanyprompt.Defaultsettingsareinsquarebrackets.Basicmanagementsetupconfiguresonlyenoughconnectivityformanagementofthesystem,extendedsetupwillaskyoutoconfigureeachinterfaceonthesystemWouldyouliketoenterbasicmanagementsetup?yes/no:no,出厂时的缺省配置,SetupInterfaceSummary,First,wouldyouliketoseethecurrentinterfacesummary?yes:InterfaceIP-AddressOK?MethodStatusProtocolBRI0unassignedYESunsetadministrativelydowndownBRI0:1unassignedYESunsetadministrativelydowndownBRI0:2unassignedYESunsetadministrativelydowndownEthernet0unassignedYESunsetadministrativelydowndownSerial0unassignedYESunsetadministrativelydowndown,InterfacesFoundDuringStartup,SetupInitialGlobalParameters,Configuringglobalparameters:EnterhostnameRouter:wg_ro_cTheenablesecretisapasswordusedtoprotectaccesstoprivilegedEXECandconfigurationmodes.Thispassword,afterentered,becomesencryptedintheconfiguration.Enterenablesecret:ciscoTheenablepasswordisusedwhenyoudonotspecifyanenablesecretpassword,withsomeoldersoftwareversions,andsomebootimages.Enterenablepassword:sanfranThevirtualterminalpasswordisusedtoprotectaccesstotherouteroveranetworkinterface.Entervirtualterminalpassword:sanjoseConfigureSNMPNetworkManagement?no:,SetupInitialProtocolConfigurations,ConfigureLAT?yes:noConfigureAppleTalk?no:ConfigureDECnet?no:ConfigureIP?yes:ConfigureIGRProuting?yes:noConfigureRIProuting?no:ConfigureCLNS?no:ConfigureIPX?no:ConfigureVines?no:ConfigureXNS?no:ConfigureApollo?no:,SetupInterfaceParameters,BRIinterfaceneedsisdnswitch-typetobeconfiguredValidswitchtypesare:0none.OnlyifyoudontwanttoconfigureBRI.1basic-1tr6.1TR6switchtypeforGermany2basic-5ess.ATmaskis/24DoyouwanttoconfigureSerial0interface?no:,SetupScriptReviewandUse,Thefollowingconfigurationcommandscriptwascreated:hostnameRouterenablesecret5$1$/CCk$4r7zDwDNeqkxFO.kJxC3G0enablepasswordsanfranlinevty04passwordsanjosenosnmp-server!noappletalkroutingnodecnetroutingiproutingnoclnsroutingnoipxroutingnovinesroutingnoxnsroutingnoapolloroutingisdnswitch-typebasic-5ess,interfaceBRI0shutdownnoipaddress!interfaceEthernet0noshutdownipaddress1nomopenabled!interfaceSerial0shutdownnoipaddressend0GototheIOScommandpromptwithoutsavingthisconfig.1Returnbacktothesetupwithoutsavingthisconfig.2Savethisconfigurationtonvramandexit.Enteryourselection2:,LoggingIntotheRouter,Youcanabbreviateacommandtothefewestcharactersthatmakeauniquecharacterstring.,RouterUser-ModeCommandList,wg_ro_c?Execcommands:access-enableCreateatemporaryAccess-ListentryatmsigExecuteAtmSignallingCommandscdChangecurrentdeviceclearResetfunctionsconnectOpenaterminalconnectiondirListfilesongivendevicedisableTurnoffprivilegedcommandsdisconnectDisconnectanexistingnetworkconnectionenableTurnonprivilegedcommandsexitExitfromtheEXEChelpDescriptionoftheinteractivehelpsystemlatOpenalatconnectionlockLocktheterminalloginLoginasaparticularuserlogoutExitfromtheEXEC-More-,wg_ro_c#?Execcommands:access-enableCreateatemporaryAccess-Listentryaccess-profileApplyuser-profiletointerfaceaccess-templateCreateatemporaryAccess-ListentrybfeFormanualemergencymodessettingcdChangecurrentdirectoryclearResetfunctionsclockManagethesystemclockconfigureEnterconfigurationmodeconnectOpenaterminalconnectioncopyCopyfromonefiletoanotherdebugDebuggingfunctions(seealsoundebug)deleteDeleteafiledirListfilesonafilesystemdisableTurnoffprivilegedcommandsdisconnectDisconnectanexistingnetworkconnectionenableTurnonprivilegedcommandseraseEraseafilesystemexitExitfromtheEXEChelpDescriptionoftheinteractivehelpsystem-More-,Youcancompleteacommandstringbyenteringtheuniquecharacterstring,thenpressingtheTabkey.,RouterPrivileged-ModeCommandList,帮助机制,上下文关联帮助,错误信息提示,指出所输入交换机命令的错误所在，以便于修改或纠正.,可以重新调出以前运行过的命令，用来再次运行、查看或修改.,之前命令保存区,提供命令清单和与特定命令相关联的参数.,路由上下文帮助,Router#clok,TranslatingCLOK,%Unknowncommandorcomputername,orunabletofindcomputeraddress,Router#,clearclock,Router#,%Incompletecommand.,Router#,setSetthetimeanddate,Router#,%Incompletecommand.,Router#,hh:mm:ssCurrentTime,Router#,clockset19:56:00,%Incompletecommand.,Router#,clockset19:56:00?,Dayofthemonth,MONTHMonthoftheyear,Router#,clockset19:56:00048,%Invalidinputdetectedatthemarker,Router#,clockset19:56:0004August,%Incompletecommand.,Router#,clockset19:56:0004August?,Year,CommandPromptingSyntaxCheckingCommandPrompting,showversionCommand,wg_ro_a#showversionCiscoInternetworkOperatingSystemSoftwareIOS(tm)2500Software(C2500-JS-L),Version12.0(3),RELEASESOFTWARE(fc1)Copyright(c)1986-1999byciscoSystems,Inc.CompiledMon08-Feb-9918:18byphanguyeImagetext-base:0 x03050C84,data-base:0 x00001000ROM:SystemBootstrap,Version11.0(10c),SOFTWAREBOOTFLASH:3000BootstrapSoftware(IGS-BOOT-R),Version11.0(10c),RELEASESOFTWARE(fc1)wg_ro_auptimeis20minutesSystemrestartedbyreloadSystemimagefileisflash:c2500-js-l_120-3.bin(outputomitted)-More-Configurationregisteris0 x2102,(一行中长字串会自动滚卷).,光标移动到命令行的开始位置.,光标移动到命令行的结束位置.,回移一个单词,下移一个字符.,回移一个字符.,下移一个单词,使用增强的编辑命令,删除当前字符,Router$valueforcustomers,employees,andpartners.,Ctrl-PorUparrow,调出最近(前一)使用过的命令,Ctrl-NorDownarrow,调出更近使用过的命令,Routershowhistory,显示命令保存区内容,Routerterminalhistorysizelines,设置命令缓冲区大小,查看之前用过的命令,ViewingtheConfiguration,showrunning-configandshowstartup-configCommands,wg_ro_c#showstartup-configUsing1359outof32762bytes!version12.0!-More-,wg_ro_c#showrunning-configBuildingconfiguration.Currentconfiguration:!version12.0!-More-,InNVRAM,InRAM,Displaysthecurrentandsavedconfiguration,OverviewofRouterModes,基本实验操作,WisdomenableWisdom#configureterminalWisdom(config)#noipdomain-lookupWisdom(config)#lineconsole0Wisdom(config-line)#loggingsynchronousWisdom(config-line)#noexec-timeoutWisdom(config-line)#passwordciscoWisdom(config-line)#loginWisdom(config-line)#exitWisdom(config)#linevty04Wisdom(config-line)#loggingsynchronousWisdom(config-line)#noexec-timeoutWisdom(config-line)#passwordciscoWisdom(config-line)#loginWisdom(config-line)#endWisdom#configureterminalWisdom(config)#enablesecretciscoWisdom(config)#endWisdom#servicepassword-encryption/手工加密,不再显示明文密码,保存配置,wg_ro_c#wg_ro_c#copyrunning-configstartup-configDestinationfilenamestartup-config?Buildingconfigurationwg_ro_c#,CopiesthecurrentconfigurationtoNVRAM,保存命令Copyrunning-configstartup-config=write,Setsthelocalidentityormessagefortheaccessedrouterorinterface,配置路由器主机名等参数,配置路由器的密码,两条常用的命令,Router(config)#lineconsole0Router(config-line)#exec-timeout00,Router(config)#lineconsole0Router(config-line)#loggingsynchronous,阻止会话退出,使光标还原到原来的位置，重新显示被覆盖的命里,Uniqueaddressingallowscommunicationbetweenendstations.Pathchoiceisbasedondestinationaddress.Locationisrepresentedbyanaddress,IP地址规划,主机通信对IP地址的要求,1、网络中IP地址必须唯一2、在一个交换网络中主机必须有相同的网络号才能通信3、在不同的交换网络中（用路由器分开的网络），主机不能有相同的网络号,IP寻址,IP地址分类,不带子网的IP寻址,带子网的IP寻址(这里的子网掩码为24位),子网地址,子网掩码,二进制子网掩码子网掩码只能有这9个数字,Subnetsnotinusethedefault,没有子网的子网掩码缺省子网掩码,Networknumberextendedbyeightbits,有子网的子网掩码,有子网的子网掩码(续),Networknumberextendedbytenbits,划分子网的几个捷径:,1.你所选择的子网掩码将会产生多少个子网?:2的x次方-2(x代表掩码位,即2进制为1的部分)2.每个子网能有多少主机?:2的y次方-2(y代表主机位,即2进制为0的部分)3.有效子网是?:有效子网号=256-10进制的子网掩码4.每个子网的广播地址是?:广播地址=下个子网号-15.每个子网的有效主机分别是?:忽略子网内全为0和全为1的地址剩下的就是有效主机地址.最后有效1个主机地址=下个子网号-2(即广播地址-1),子网划分,Othersubnets,,2,4,申请到一段C类地址，将这段地址分配给网络中的主机，要求有5个子网，每个子网最少有20台主机，地址分配的步骤：1、确定网络的主机位n，利用32-n算出网络位，然后算出子网掩码2、根据子网掩码，确定每段IP地址的范围,配置路由器IP地址,wg_ro_c#configureterminalwg_ro_c(config)#interfaceethernet0wg_ro_c(config-if)#ipaddresswg_ro_c(config-if)#noshutdownwg_ro_c(config-if)#exit,showinterfaces,Router#showinterfacesEthernet0isup,lineprotocolisupHardwareisLance,addressis00e0.1e5d.ae2f(bia00e0.1e5d.ae2f)Internetaddressis1/24MTU1500bytes,BW10000Kbit,DLY1000usec,rely255/255,load1/255EncapsulationARPA,loopbacknotset,keepaliveset(10sec)ARPtype:ARPA,ARPTimeout04:00:00Lastinput00:00:07,output00:00:08,outputhangneverLastclearingofshowinterfacecountersneverQueueingstrategy:fifoOutputqueue0/40,0drops;inputqueue0/75,0drops5minuteinputrate0bits/sec,0packets/sec5minuteoutputrate0bits/sec,0packets/sec81833packetsinput,27556491bytes,0nobufferReceived42308broadcasts,0runts,0giants,0throttles1inputerrors,0CRC,0frame,0overrun,1ignored,0abort0inputpacketswithdribbleconditiondetected55794packetsoutput,3929696bytes,0underruns0outputerrors,0collisions,1interfaceresets0babbles,0latecollision,4deferred0lostcarrier,0nocarrier0outputbufferfailures,0outputbuffersswappedout,接口的几种状态诊断的步骤,检查串口,Router#showinterfaceserial0Serial0isup,lineprotocolisupHardwareisHD64570Internetaddressis/24MTU1500bytes,BW64Kbit,DLY20000usec,rely255/255,load1/255EncapsulationHDLC,loopbacknotset,keepaliveset(10sec)Lastinput00:00:09,output00:00:04,outputhangneverLastclearingofshowinterfacecountersneverInputqueue:0/75/0(size/max/drops);Totaloutputdrops:0Queueingstrategy:weightedfairOutputqueue:0/1000/64/0(size/maxtotal/threshold/drops)Conversations0/1/256(active/maxactive/maxtotal)ReservedConversations0/0(allocated/maxallocated)5minuteinputrate0bits/sec,0packets/sec5minuteoutputrate0bits/sec,0packets/sec(outputomitted),BW64Kbit,检查串行线是否连接好,Router#showcontrollerserial0HDunit0,idb=0 x121C04,driverstructureat0 x127078buffersize1524HDunit0,V.35DTEcable.,Showsthecabletypeofserialcables,V.35DTECable,第三章使用CDP和Telnet管理网络,CDP协议,是一个提供关于直接相连的交换机、路由器和其它Cisco设备的综合信息的专有PROTOCOLCDP能够发现直接相邻的设备而不管这些设备所运行的是什么协议栈物理介质必须能够支持SubnetworkAccessProtocol(SNAP),上层地址,Cisco专有的链路层协议,介质必须能够支持SNAP,TCP/IP,NovellIPX,CDP能发现并显示关于直接相连的Cisco设备的信息,ATM,Others,LANs,帧中继,AppleTalk,Others,CDP运行在使用10.3或更新版CiscoIOS的路由器以及Cisco交换机和集线器上能获取的信息包括:设备名对应各协议的地址端口名角色特征平台,CDP,CDP,CDP,用CDP发现直接相邻的设备,使用CDP,SwitchB,RouterA,RouterB,SwitchA,,,,,,,S0,S1,RouterA#shcdp?entryInformationforspecificneighborentryinterfaceCDPinterfacestatusandconfigurationneighborsCDPneighborentriestrafficCDPstatisticsRouterA(config)#nocdprunRouterA(config)#interfaceserial0RouterA(config-if)#nocdpenable,使用showcdpneighbor命令,RouterA#shcdpneighborsCapabilityCodes:R-Router,T-TransBridge,B-SourceRouteBridgeS-Switch,H-Host,I-IGMP,r-RepeaterDeviceIDLocalIntrfceHoldtmeCapabilityPlatformPortIDRouterBSer0148R2522Ser1SwitchAEth0167TS19002,,,,,,,S0,S1,SwitchB,RouterA,RouterB,SwitchA,使用showcdpentry命令,RouterA#shcdpentry*-DeviceID:RouterBEntryaddress(es):IPaddress:Platform:cisco2522,Capabilities:RouterInterface:Serial0,PortID(outgoingport):Serial1Holdtime:168secVersion:CiscoInternetworkOperatingSystemSoftwareIOS(tm)2500Software(C2500-JS-L),Version12.0(3),RELEASESOFTWARE(fci)Copyright(c)1986-1999byciscoSystems,Inc.CompiledMon08-Feb-9918:18byphanguye,其它CDP命令,RouterA#shcdptrafficCDPcounters:Packetsoutput:56,Input:38Hdrsyntax:0,Chksumerror:0,Encapsfailed:3Nomemory:0,Invalidpacket:0,Fragmented:0RouterA#shcdpinterfaceBRI0isadministrativelydown,lineprotocolisdownEncapsulationHDLCSendingCDPpacketsevery60secondsHoldtimeis180seconds,,,,,,,S0,S1,SwitchB,RouterA,RouterB,SwitchA,用Telnet连接到远端设备,远端设备,,,,,,,S0,S1,RouterA#telnetTrying.Open-Catalyst1900ManagementConsoleCopyright(c)CiscoSystems,Inc.1993-1998Allrightsreserved.EnterpriseEditionSoftwareEthernetAddress:00-90-86-73-33-40PCANumber:73-2239-06PCASerialNumber:FAA02359H8KModelNumber:WS-C1924-ENSystemSerialNumber:FAA0237X0FQ.SwitchB,SwitchB,RouterA,RouterB,SwitchA,查看Telnet连接,,,,,,,S0,S1,RouterA#shsessionConnHostAddressByteIdleConnName0*00RouterA#shuserLineUserHost(s)IdleLocation*0con03211vty0idle,SwitchB,RouterA,RouterB,SwitchA,挂起一个Telnet会话,,,,,,,S0,S1,RouterB#xRouterA#shsessionConnHostAddressByteIdleConnName0RouterA#resume1RouterB#,SwitchB,RouterA,RouterB,SwitchA,RouterA#disconnectClosingconnectiontoconfirmRouterA#clearline11confirmOK,断开一个Telnet会话,清除由远端设备建立的会话,断开由自己建立的当前会话,,,,,10