('培训大讲堂官方YY频道：3660mCCNA题库考试代号：640-802考试时间：英文110+30=140分钟通过分数：825题库版本：V104.4鸿鹄论坛招募CCNA、CCNP答疑讲师答疑地点：鸿鹄官方YY频道3660CCNA（640-802）题库V104.4CCNA（640-802）题库V104.4（情人节版）V104系列是官方的终结版本，以后不会再出V105V106V108等等========================================更新内容：V104.1修正V104中错误题目，确定经典争议题目答案；V104.2增加拖图题并可完美模拟考试，VCE题库增加中文注释；V104.3针对思科CCNA考试变题，更新考试新增题目93Q,更新V104.2实验题；V104.4增加全文中文注释，汇总V104.3九次更新，删除部分旧题目，为目前最新官方正版题库；2011.8.1增加每日新题，修订部分错误。增加5道新题，分别是519、520、521、522、523题修改176题、375题、443题、482题答案错误修改59题、88题、453题、107题、270题注释错误增加个别疑难拖图题注释，优化实验题=============================================QUESTION1Whenyouareloggedintoaswitch,whichpromptindicatesthatyouareinprivilegedmode?(当您登录到交换机，哪种提示表明你在特权模式？)A.%B.@C.>D.$E.#Answer:ESection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:特权模式就是#提示符QUESTION2Whichcommandshowssystemhardwareandsoftwareversioninformation?(哪些命令显示系统硬件和软件的版本信息？)A.showconfigurationB.showenvironmentC.showinventoryD.showplatformE.showversionAnswer:ESection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:查看系统的软件和硬件信息使用的命令是showversionQUESTION3CiscoCatalystswitchesCAT1andCAT2haveaconnectionbetweenthemusingportsFA0/13.An802.1Qtrunkisconfiguredbetweenthetwoswitches.OnCAT1,VLAN10ischosenasnative,butonCAT2thenativeVLANisnotspecified.Whatwillhappeninthisscenario?(思科Catalyst交换机CAT1和CAT2有它们之间的连接使用端口FA0/13。两个交换机之间用802.1Q中继配置，CAT1做为VLAN10的主机，但在CAT2上的本地VLAN未指定。在这种情况下会发生什么？)A.802.1Qgiantsframescouldsaturatethelink.B.VLAN10onCAT1andVLAN1onCAT2willsenduntaggedframes.C.AnativeVLANmismatcherrormessagewillappear.D.VLAN10onCAT1andVLAN1onCAT2willsendtaggedframes.Answer:CSection:Chapter10:VLANExplanation/Reference:如果两边native不匹配的话.switch将报native不匹配的日志信息QUESTION4Whichcommandwouldcorrectlyconfigureaserialportonarouterwiththelastusablehostaddressinthe（/29子网的路由器上配置的串行端口？）Answer:FSection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:QUESTION5validIPaddressofthishost?()Answer:CSection:Chapter3:IPAddressingandVLSMExplanation/Reference:考点：考查VLSMA：超出范围B：广播地址C：正确D：网络号E：超出范围QUESTION6Whichtwoaddressescanbeassigned{}Answer:BDSection:Chapter3:IPAddressingandVLSMExplanation/Reference:考点：考查VLSMA：网络号B/D：正确C：广播地址E：网络号QUESTION7Thenetworkadministratorhasaskedyoutocheckthestatusoftheworkstation\'sIPstackbypingingtheloopbackaddress.Whichaddresswouldyoupingtoperformthistask?{网络管理员已要求您通过ping环回地址检查工作站的IP堆栈的状态。您要执行此任务将ping哪个地址？}Answer:BSection:Chapter3:IPAddressingandVLSMExplanation/Reference:考点：使用ping来检测主机的IP栈。QUESTION8pingbetweenthehostsareunsuccessful.Whattwothingscanbedonetoallowcommunicationsbetweenthehosts?(Choosetwo.){}A.Replacethestraight-throughcablewithacrossovercable.B.Changethesubnetmaskofthehoststo/25.C.Changethesubnetmaskofthehoststo/26.Answer:ABSection:Chapter3:IPAddressingandVLSMExplanation/Reference:考点：同构设备使用交叉线，两端的IP需要在同一个子网。A：使用交叉线替换现有的直通线。正确。B：修改掩码为25位，正确。C：修改掩码为26为，错误。不能使他们在同一个子网。D/E：错误，都不能使他们在同一个子网。QUESTION9unabletopinganyremotedevices.Whatispreventingtherouterfrompingingremotedevices?()A.Thedefaultgatewayisnotanaddressonthissubnet.B.Thedefaultgatewayisthebroadcastaddressforthissubnet.C.TheIPaddressisthebroadcastaddressforthissubnet.D.TheIPaddressisaninvalidclassDmulticastaddress.Answer:BSection:Chapter3:IPAddressingandVLSMExplanation/Reference:考点：考查VLSM。A：默认网关不属于这个子网，错误B：默认网关是这个子网的广播地址，正确C：这个地址是子网的广播地址，错误D：这个地址是组播地址，错误。QUESTION10WhichcommandisusedtocopytheconfigurationfromRAMintoNVRAM?{哪个命令用于从RAM复制到NVRAM的配置}A.copyrunning-configstartup-configB.copystartup-config:running-config:C.copyrunningconfigstartupconfigD.copystartupconfigrunningconfigE.writeterminalAnswer:ASection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:QUESTION11WhichcommandisusedtoloadaconfigurationfromaTFTPserverandmergetheconfigurationintoRAM?(哪些命令用于从TFTP服务器加载配置或合并到RAM的配置？)A.copyrunning-config:TFTP:B.copyTFTP:running-configC.copyTFTP:startup-configD.copystartup-config:TFTP:Answer:BSection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:QUESTION12Asystemadministratortypesthecommandtochangethehostnameofarouter.WhereontheCiscoIFSisthatchangestored?A.NVRAMB.RAMC.FLASHD.ROME.PCMCIAAnswer:BSection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:running-config保存在RAM中startup-config保存在NVRAM中QUESTION13Whichcommandisusedtoconfigureadefaultroute?Answer:DSection:Chapter6:IPRoutingExplanation/Reference:QUESTION14IfIProutingisenabled,whichtwocommandssetthegatewayoflastresorttothedefaultgateway?（如果启用了IP路由，哪两个命令设置网关的最后到默认网关？）(Choosetwo.)Answer:CESection:Chapter6:IPRoutingExplanation/Reference:产生默认网关的两种方式ipdefault-networkiprouteQUESTION15WhichcommandwouldyouconfiguregloballyonaCiscorouterthatwouldallowyoutoviewdirectlyconnectedCiscodevices?(该命令将全局上配置使您可以直接查看的Cisco路由器连接Cisco设备吗？)A.enablecdpB.cdpenableC.cdprunD.runcdpAnswer:CSection:Chapter5:ManagingCiscoIOSExplanation/Reference:QUESTION16WhichcommandisusedtoseethepathtakenbypacketsacrossanIPnetwork?(哪些命令用于看到通过IP网络数据包所采取的路径？)A.showiprouteB.showrouteC.tracerouteD.traceiprouteAnswer:CSection:Chapter2:TCP/IPExplanation/Reference:哪条命令用于查看数据包转发所经过的路径A:查看路由表B：没有这条命令C：正确D：没这条命令QUESTION17Whichcommandisusedtodebugapingcommand?{哪些命令用于调试ping命令？}A.debugicmpB.debugipicmpC.debugtcpD.debugpacketAnswer:BSection:Chapter5:ManagingCiscoIOSExplanation/Reference:ping调用了icmp协议，而icmp数据包封装在ip包中。QUESTION18WhichcommanddisplaysCPUutilization?{哪个命令显示的CPU利用率呢？}A.showprotocolsB.showprocessC.showsystemD.showversionAnswer:BSection:Chapter5:ManagingCiscoIOSExplanation/Reference:查看CPU利用率。QUESTION19Whenconfiguringaserialinterfaceonarouter,whatisthedefaultencapsulation?{在配置一个串行接口的路由器，什么是默认的封装？}A.atm-dxiB.frame-relayC.hdlcD.lapbE.pppAnswer:CSection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:缺省封装是HDLCQUESTION20Whatmustbesetcorrectlywhenconfiguringaserialinterfacesothathigher-levelprotocolscalculatethebestroute?{什么时，必须设置正确配置串行接口，以便更高级别的协议计算最佳路线？}A.bandwidthB.delayC.loadD.reliabilityAnswer:ASection:Chapter6:IPRoutingExplanation/Reference:为了使高层路由协议计算最佳路由，串口的什么东西必须被设置正确？在接口下，只有带宽是可以配置的。QUESTION21AcompanyimplementsvideoconferencingoverIPontheirEthernetLAN.Theusersnoticethatthenetworkslowsdown,andthevideoeitherstuttersorfailscompletely.Whatisthemostlikelyreasonforthis?{公司对他们的以太网LANip实现视频会议。用户注意网络变慢，和视频断断续续或完全失败。最有可能的原因是什么？}A.minimumcellrate(MCR)B.qualityofservice(QoS)C.modulationD.packetswitchingexchange(PSE)E.reliabletransportprotocol(RTP)Answer:BSection:Chapter9:SwitchingExplanation/Reference:考点：当网络中使用视频会议后发现网络非常慢，什么原因引起的？QoS：用于定制策略对不同流量进行控制。QUESTION22WhichlayerintheOSIreferencemodelisresponsiblefordeterminingtheavailabilityofthereceivingprogramandcheckingtoseeifenoughresourcesexistforthatcommunication?{OSI参考模型在哪一层负责确定接收程序的可用性和检查足够的资源，是否存在该通信？}A.transportB.networkC.presentationD.sessionE.applicationAnswer:ESection:Chapter1:IntroductionExplanation/Reference:哪一层确定的接收程序的可用性？应用层提供QUESTION23Datatransferisslowbetweenthesourceanddestination.ThequalityofservicerequestedbythetransportlayerintheOSIreferencemodelisnotbeingmaintained.Tofixthisissue,atwhichlayershouldthetroubleshootingprocessbegin?{数据传输速度慢的源和目标之间。不保持在OSI参考模型的传输层所要求的服务质量。要解决此问题，在哪一层应故障排除过程开始？}A.presentationB.sessionC.transportD.networkE.physicalAnswer:DSection:Chapter1:IntroductionExplanation/Reference:解决网络问题，先确保网络层通信。QUESTION24WhichprotocolsarefoundinthenetworklayeroftheOSIreferencemodelandareresponsibleforpathdeterminationandtrafficswitching?{哪些协议在网络层OSI参考模型中找到，负责路径测定和交通切换？}A.LANB.routingC.WAND.networkAnswer:BSection:Chapter1:IntroductionExplanation/Reference:OSI网络层中什么提供了路径选择和流量转发？由路由协议提供。通过手工或者动态学习路由条目实现。QUESTION25Whichcommandrevealsthelastmethodusedtopowercyclearouter?A.showreloadB.showbootC.showrunning-configD.showversionAnswer:DSection:Chapter5:ManagingCiscoIOSExplanation/Reference:哪一个命令可以显示最近一次被用来重启路由器的方法？QUESTION26WhichthreeoptionsarevalidWANconnectivitymethods?(Choosethree.)A.PPPB.WAPC.HDLCD.MPLSE.L2TPv3F.ATMAnswer:ACFSection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:哪三种封装属于WAN链路的?A:点到点协议，正确B：无线加密技术，错误C:思科缺省封装格式，正确。D：多协议标签转换，错误E：隧道协议，错误F：正确。QUESTION27Refertotheexhibit.WhichWANprotocolisbeingused?A.ATMB.HDLCC.FrameRelayD.PPPAnswer:CSection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:由图中的红线可看到发送接受LMI信息。属于FR的数据包。QUESTION28WhatisthedifferencebetweenaCSU/DSUandamodem?【一个CSU/DSU和调制解调器之间的区别是什么？】A.ACSU/DSUconvertsanalogsignalsfromaroutertoaleasedline;amodemconvertsanalogsignalsfromaroutertoaleasedline.B.ACSU/DSUconvertsanalogsignalsfromaroutertoaphoneline;amodemconvertsdigitalsignalsfromaroutertoaleasedline.C.ACSU/DSUconvertsdigitalsignalsfromaroutertoaphoneline;amodemconvertsanalogsignalsfromaroutertoaphoneline.D.ACSU/DSUconvertsdigitalsignalsfromaroutertoaleasedline;amodemconvertsdigitalsignalsfromaroutertoaphoneline.Answer:DSection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:CSU/DSU一般是专线，MODEN是将模拟信号与数字信号转换QUESTION29Anetworkadministratormustconfigure200switchportstoaccepttrafficfromonlythecurrentlyattachedhostdevices.WhatwouldbethemostefficientwaytoconfigureMAC-levelsecurityonalltheseports?A.VisuallyverifytheMACaddressesandthentelnettotheswitchestoentertheswitchport-portsecuritymac-addresscommand.B.Haveenduserse-mailtheirMACaddresses.Telnettotheswitchtoentertheswitchport-portsecuritymac-addresscommand.C.Usetheswitchportport-securityMACaddressstickycommandonalltheswitchportsthathaveenddevicesconnectedtothem.[有端设备连接到他们的所有交换机端口上使用交换机端口端口安全MAC地址粘滞命令。]D.Useshowmac-address-tabletodeterminetheaddressesthatareassociatedwitheachportandthenenterthecommandsoneachswitchforMACaddressport-security.Answer:CSection:Chapter9:SwitchingExplanation/Reference:考点：有200台主机需要接入，采用什么方式来增强网络安全性？A：先验证mac安全性，然后在交换机上绑定。错误，工作量太大B：用户发送邮件认证再在交换机上配置，错误，不科学。C：使用port-security，正确。D：错误，工作量太大。QUESTION30WhentroubleshootingaFrameRelayconnection,whatisthefirststepwhenperformingaloopbacktest?【帧中继连接故障排除时，执行环回测试时的第一步是什么？】A.SettheencapsulationoftheinterfacetoHDLC.B.PlacetheCSU/DSUinlocal-loopmode.C.Enablelocal-loopmodeontheDCEFrameRelayrouter.D.VerifythattheencapsulationissettoFrameRelay.Answer:ASection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:在对FR进行排错的时候，当做回环测试的时候，第一步如何处理？A：讲接口配置成HDLC，正确，FR封装下无法正常ping自己端口QUESTION31WhatoccursonaFrameRelaynetworkwhentheCIRisexceeded?A.AllTCPtrafficismarkeddiscardeligible.B.AllUDPtrafficismarkeddiscardeligibleandaBECNissent.C.AllTCPtrafficismarkeddiscardeligibleandaBECNissent.D.AlltrafficexceedingtheCIRismarkeddiscardeligible.Answer:DSection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:在FR网络中，当CIR超过时会发生什么情况？D：所有超过的流量都丢弃。QUESTION32WhataretwocharacteristicsofFrameRelaypoint-to-pointsubinterfaces?(Choosetwo.)A.Theycreatesplit-horizonissues.B.Theyrequireauniquesubnetwithinaroutingdomain.C.Theyemulateleasedlines.D.Theyareidealforfull-meshtopologies.E.TheyrequiretheuseofNBMAoptionswhenusingOSPF.Answer:BCSection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:帧中继点到点子接口的特点？A：水平分割，错误。B：每个子接口需要一个独立的网段，正确。C：类似专线，正确。D:全网互联是理想拓扑，错误。通常是hub-spokeE：NBMA不支持OSPF，错误。QUESTION33A.debugipnatB.showaccess-listC.showipnattranslationD.showipnatstatisticsAnswer:BSection:Chapter8:NATExplanation/Reference:。允许的范围是通过ACL定义的。A：打开NAT转换的debug信息，错误B：查看acl信息，正确。C：查看NAT转换表，错误。D：查看静态NAT。错误QUESTION34Awirelessclientcannotconnecttoan802.11b/gBSSwithab/gwirelesscard.TheclientsectionoftheaccesspointdoesnotlistanyactiveWLANclients.Whatisapossiblereasonforthis?[一台带有b/g无线网上的无线客户机不能连接到一个8020.11b/g的基站。客户端部分没有发现可用的无线局域网。这种情况是什么原因？]A.Theincorrectchannelisconfiguredontheclient.B.Theclient\'sIPaddressisonthewrongsubnet.C.Theclienthasanincorrectpre-sharedkey.D.TheSSIDisconfiguredincorrectlyontheclient.Answer:DSection:Chapter11:WirelessExplanation/Reference:客户端无法连接到无限接入点，查看不到可用的无线信号。这通常是SSID信号没有配置正确。A：不正确的信道。错误B：客户端的IP地址配置错误C：客户端的共享key错误。D：SSID配置不正确。QUESTION35WhichtwofeaturesdidWPAv1addtoaddresstheinherentweaknessesfoundinWEP?(Choosetwo.)[哪两个功能WPAv1没有添加地址找到wep的固有弱点？（选择两个]A.astrongerencryptionalgorithmB.keymixingusingtemporalkeysC.sharedkeyauthenticationD.ashorterinitializationvectorE.perframesequencecountersAnswer:BESection:Chapter11:WirelessExplanation/Reference:考点：WPA1中增强哪两个在WEP中发现的弱点？WEP存在的隐患主要是依赖共享密钥A：更强的加密算法B：混合使用的密钥C：共享密钥认证D：较短的初始化向量E：一个帧一个序列计数器。QUESTION36WhichtwowirelessencryptionmethodsarebasedontheRC4encryptionalgorithm?(Choosetwo.)A.WEPB.CCKMC.AESD.TKIPE.CCMPAnswer:ADSection:Chapter11:WirelessExplanation/Reference:考点：哪两种无限加密技术依赖RC4A:有线等效保密协议B：英特尔开发一种协议C：高级加密标准D：暂时密钥集成协议E:基于AES的加密方式QUESTION37WhataretwocharacteristicsofRIPv2?(Choosetwo.)A.classfulroutingprotocolB.variable-lengthsubnetmasksC.broadcastaddressingD.manualroutesummarizationE.usesSPFalgorithmtocomputepathAnswer:BDSection:Chapter6:IPRoutingExplanation/Reference:A：有类路由协议，错误B：可变长度子网掩码，正确C：采用广播地址更新，错误D：手动路由汇总，正确E:使用spf算法计算路径，错误。QUESTION38WhichtwoEthernetfiber-opticmodessupportdistancesofgreaterthan550meters?A.1000BASE-CXB.100BASE-FXC.1000BASE-LXD.1000BASE-SXE.1000BASE-ZXAnswer:CESection:Chapter1:IntroductionExplanation/Reference:A：最长距离25米B：最长距离100米C：最长距离3000米D：最长距离550米E：最长距离70千米QUESTION39Whattwothingswillarouterdowhenrunningadistancevectorroutingprotocol?(Choosetwo.)A.Sendperiodicupdatesregardlessoftopologychanges.B.Sendentireroutingtabletoallroutersintheroutingdomain.C.Usetheshortest-pathalgorithmtothedeterminebestpath.D.Updatetheroutingtablebasedonupdatesfromtheirneighbors.E.Maintainthetopologyoftheentirenetworkinitsdatabase.Answer:ADSection:Chapter6:IPRoutingExplanation/Reference:考点：考查距离矢量路由协议特性A：周期性更新，正确B：发送整个路由表到整个路由域，错误，只发送给邻居C：使用SPF算法，错误D：依靠邻居发送更新来更新路由表，正确E：在数据库中维护整个网络的拓扑。错误QUESTION40Refertotheexhibit.Accordingtotheroutingtable,wherewilltheroutersendapacketdestinedforAnswer:CSection:Chapter6:IPRoutingExplanation/Reference:路由查找原则：最长掩码匹配原则。QUESTION41Whichcommandshowsifanaccesslistisassignedtoaninterface?A.showipinterface[interface]access-listsB.showipaccess-listsinterface[interface]C.showipinterface[interface]D.showipaccess-lists[interface]Answer:CSection:Chapter7:SecurityExplanation/Reference:QUESTION42Refertotheexhibit.WhichruledoestheDHCPserverusewhenthereisanIPaddressconflict?A.Theaddressisremovedfromthepooluntiltheconflictisresolved.B.Theaddressremainsinthepooluntiltheconflictisresolved.C.OnlytheIPdetectedbyGratuitousARPisremovedfromthepool.D.OnlytheIPdetectedbyPingisremovedfromthepool.E.TheIPwillbeshown,evenaftertheconflictisresolved.Answer:ASection:Chapter5:ManagingCiscoIOSExplanation/Reference:showipdhcpconflict命令可以查看哪些ip地址在使用上有冲突。有冲突的地址不再分配出去。A：地址被删除直到冲突解决，正确B:地址保留直到冲突解决，错误C/D：答案片面。E：当冲突解决后，地址会被显示。错误。QUESTION43Refertotheexhibit.YouareconnectedtotherouterasuserMike.WhichcommandallowsyoutoseeoutputfromtheOSPFdebugcommand?A.terminalmonitorB.showdebuggingC.showsessionsD.showipospfinterfaceAnswer:ASection:Chapter6:IPRoutingExplanation/Reference:A：让debug信息在终端上显示出来B：没这条命令C：查看会话信息。D:查看启用了ospf的接口的相关信息。QUESTION44Refertotheexhibit.Ifnumber2isselectedfromthesetupscript,whathappenswhentheuserrunssetupfromaprivilegedprompt?A.Setupisadditiveandanychangeswillbeaddedtotheconfigscript.B.Setupeffectivelystartstheconfigurationoverasiftherouterwasbootedforthefirsttime.C.Setupwillnotrunifanenablesecretpasswordexistsontherouter.D.Setupwillnotrun,becauseitisonlyviablewhennoconfigurationexistsontherouter.Answer:ASection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:[0]不保存进入IOS命令配置模式[1]不保存返回设置模式[2]保存退出A：设置和改动被保存到配置脚本B：为有效地重新开始配置，如果路由器是第一次启动的配置。C：如果配置了密码，设置不会运行D：设置不可用，因为它只能在没有配置存在时才有效。QUESTION45Refertotheexhibit.Which(config-router)commandwillallowthenetworkrepresentedontheinterfacetobeadvertisedbyRIP?A.redistributeethernet0B.networkethernet0Answer:DSection:Chapter6:IPRoutingExplanation/Reference:考点：怎么才能让接口通告RIP路由。通告network网段实现。QUESTION46Refertotheexhibit.Whatinformationcanbegatheredfromtheoutput?A.OnerouterisrunningRIPv1.C.Thenetworkcontainsaloop.Answer:DSection:Chapter6:IPRoutingExplanation/Reference:QUESTION47Refertotheexhibit.Whattypeofconnectionwouldbesupportedbythecablediagramshown?A.PCtorouterB.PCtoswitchC.servertorouterD.routertorouterAnswer:BSection:Chapter1:IntroductionExplanation/Reference:从图中可以看出这是一条直通线。同构设备使用交叉线，异构设备使用直通线。B：直通线AC/D同构设备使用交叉线QUESTION48Refertotheexhibit.Whattypeofconnectionwouldbesupportedbythecablediagramshown?A.PCtorouterB.PCtoswitchC.servertoswitchD.switchtorouterAnswer:ASection:Chapter1:IntroductionExplanation/Reference:QUESTION49WhichtwostatementsdescribetheCiscoimplementationofVLANs?(Choosetwo.)A.VLAN1isthedefaultEthernetVLAN.B.CDPadvertisementsareonlysentonVLAN1002.C.Bydefault,themanagementVLANisVLAN1005.D.Bydefault,theswitchIPaddressisinVLAN1005.E.VLAN1002through1005areautomaticallycreatedandcannotbedeleted.Answer:AESection:(none)Explanation/Reference:考点：考查vlan知识点。A：缺省都存在vlan1，端口都属于vlan1，正确B：CDP信息只发送到vlan1002，错误，vlan1002是fddi网络的vlan号。C：缺省情况交换机IP配置在vlan1005，错误，vlan1005trnet网络的vlan号。缺省在vlan1里面。D：vlan1002-1005自动生成并不能被删除，正确，他们都是被保留的特殊vlan。QUESTION50Refertotheexhibit.Whatcanbedeterminedabouttherouterfromtheconsoleoutput?A.NoconfigurationfilewasfoundinNVRAM.B.Noconfigurationfilewasfoundinflash.C.NoconfigurationfilewasfoundinthePCMCIAcard.D.Configurationfileisnormalandwillloadin15seconds.Answer:ASection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:启动时缺省读取保存在NVRAM里面的配置文件。提示进入对话模式，说明没有保存配置文件。QUESTION51Refertotheexhibit.Whatcanbedeterminedfromtheoutput?Answer:BSection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:age下面-代表是本地端口QUESTION52Refertotheexhibit.Whichcommandwouldallowthetranslationstobecreatedontherouter?Answer:ASection:Chapter8:NATExplanation/Reference:准确汇总掩码是21，答案中没有，退而求其次选19.QUESTION53shown.AtwhichOSIlayeristheproblem?A.datalinklayerB.applicationlayerC.accesslayerD.sessionlayerE.networklayerAnswer:ESection:Chapter2:TCP/IPExplanation/Reference:ping调用icmp，ping不通是网络层的原因。QUESTION54Refertotheexhibit.WhichvaluewillbeconfiguredforDefaultGatewayoftheLocalAreaConnection?Answer:BSection:Chapter3:IPAddressingandVLSMExplanation/Reference:QUESTION55Refertotheexhibit.TheuseratWorkstationBreportsthatServerAcannotbereached.WhatispreventingWorkstationBfromreachingServerA?A.TheIPaddressforServerAisabroadcastaddress.B.TheIPaddressforWorkstationBisasubnetaddress.C.ThegatewayforWorkstationBisnotonthesamesubnet.D.ThegatewayforServerAisnotonthesamesubnet.Answer:DSection:Chapter6:IPRoutingExplanation/Reference:QUESTION56Refertotheexhibit.Whatdoesthe()representintheoutput?A.Packetisdestinedforalocalinterfacetotherouter.B.Packetwastranslated,butnoresponsewasreceivedfromthedistantdevice.C.Packetwasnottranslated,becausenoadditionalportsareavailable.D.Packetwastranslatedandfastswitchedtothedestination.Answer:DSection:Chapter8:NATExplanation/Reference:QUESTION57Refertotheexhibit.WhatcommandsequencewillenablePATfromtheinsidetooutsidenetwork?B.(config-if)ipnatoutsideoverloadC.(config)ipnatinsidesourcelist1interfaceethernet1overloadD.(config-if)ipnatinsideoverloadAnswer:CSection:Chapter8:NATExplanation/Reference:overload是配置PAT的关键字QUESTION58Refertotheexhibit.WhatwillhappentoHTTPtrafficcomingfromtheInternetthatisdestinedforA.Trafficwillbedroppedperline30oftheACL.B.Trafficwillbeacceptedperline40oftheACL.C.Trafficwillbedropped,becauseoftheimplicitdenyallattheendoftheACL.D.Trafficwillbeaccepted,becausethesourceaddressisnotcoveredbytheACL.Answer:CSection:Chapter7:SecurityExplanation/Reference:ACL匹配规则：自上而下匹配，一旦匹配则终止，没有匹配到的丢弃。题目给的172是目的地址，表中ACL中172是源地址QUESTION59Refertotheexhibit.WhichstatementdescribestheeffectthattheRouter1configurationhasondevicesinA.DeviceswillnotbeabletouseTelnetorSSH.B.DeviceswillbeabletouseSSH,butnotTelnet.C.DeviceswillbeabletouseTelnet,butnotSSH.D.DeviceswillbeabletouseTelnetandSSH.Answer:BSection:Chapter7:SecurityExplanation/Reference:题目考查的是ACL用法，首先我们看图示F0/0是in方向，eq应该放在目的主机的后面，源主机是随机端口发出访问f0/1也设置为out方向，只能控制返回的数据，这里eq应该放在源主机也就是SVR-A的后面所以list100中10生效，20无效。list101中10生效，20无效。最后默认都拒绝，所以只允许ssh。QUESTION60WhatarethreeadvantagesofVLANs?(Choosethree.)A.VLANsestablishbroadcastdomainsinswitchednetworks.B.VLANsutilizepacketfilteringtoenhancenetworksecurity.C.VLANsprovideamethodofconservingIPaddressesinlargenetworks.D.VLANsprovidealow-latencyinternetworkingalternativetoroutednetworks.E.VLANsallowaccesstonetworkservicesbasedondepartment,notphysicallocation.F.VLANscangreatlysimplifyadding,moving,orchanginghostsonthenetwork.Answer:AEFSection:Chapter10:VLANExplanation/Reference:A：VLAN在交换网络中建立广播域，正确B：利用VLAN的数据包过滤，增强网络的安全性。错误，没有这个特性。C：提供了在大型网络中的保护IP地址的方法。错误。D：提供低延迟互联网络替代路由网络。错误E：vlan允许基于逻辑划分的网络访问，不是物理位置。正确。F：VLAN可以大大简化添加，移动或更改网络上的主机。正确。QUESTION61AnadministratorwouldliketoconfigureaswitchoveravirtualterminalconnectionfromlocationsoutsideofthelocalLAN.Whichofthefollowingarerequiredinorderfortheswitchtobeconfiguredfromaremotelocation?(Choosetwo.)A.TheswitchmustbeconfiguredwithanIPaddress,subnetmask,anddefaultgateway.B.TheswitchmustbeconnectedtoarouteroveraVLANtrunk.C.TheswitchmustbereachablethroughaportconnectedtoitsmanagementVLAN.D.TheswitchconsoleportmustbeconnectedtotheEthernetLAN.E.TheswitchmanagementVLANmustbecreatedandhaveamembershipofatleastoneswitchport.F.TheswitchmustbefullyconfiguredasanSNMPagent.Answer:ACSection:Chapter9:SwitchingExplanation/Reference:要想远程管理VLAN，1、交换机配置IP，2、路由可达。QUESTION62WhichofthefollowinghostaddressesaremembersofnetworksthatcanberoutedacrossthepublicInternet?(Choosethree.)Answer:CEFSection:Chapter3:IPAddressingandVLSMExplanation/Reference:考查公有IP地址的范围。除了上面的外都是公有IP。QUESTION63hosts?(Choosethree.)Answer:BCDSection:Chapter3:IPAddressingandVLSMExplanation/Reference:QUESTION64WhichofthefollowingarebenefitsofVLANs?(Choosethree.)A.Theyincreasethesizeofcollisiondomains.B.Theyallowlogicalgroupingofusersbyfunction.C.Theycanenhancenetworksecurity.D.Theyincreasethesizeofbroadcastdomainswhiledecreasingthenumberofcollisiondomains.E.Theyincreasethenumberofbroadcastdomainswhiledecreasingthesizeofthebroadcastdomains.F.Theysimplifyswitchadministration.Answer:BCESection:Chapter10:VLANExplanation/Reference:考查VLAN的特点A：增加冲突域的大小，错误B：允许逻辑划分网段，正确C：增强网络安全，正确。不同vlan不能直接通信。D：当减少冲突域时增加广播域的大小。错误E：减少广播域的大小时增加了广播域个数。正确。F:简化交换机管理。答非所问。QUESTION65WhichrouterIOScommandscanbeusedtotroubleshootLANconnectivityproblems?(Choosethree.)A.pingB.tracertC.ipconfigD.showiprouteE.winipcfgF.showinterfacesAnswer:ADFSection:Chapter6:IPRoutingExplanation/Reference:A：测试连通性D：查看是否有路由F：查看接口是否可用QUESTION66Refertotheexhibit.AfterHostApingsHostB,whichentrywillbeintheARPcacheofHostAtosupportthistransmission?A.B.C.D.E.F.Answer:DSection:Chapter2:TCP/IPExplanation/Reference:此题考查的是pc的arp表，不要和包的目的地址、源地址弄混了。在以太网寻址的时候，依靠的事MAC地址，每一个网段都需要寻找到自己的下一条（gateway）以自己的MAC作为sourcegateway的mac作为destination封装Frame，然后将Frame转发出去，但是数据包是不会进行变化的，也就是packet的头部信息不会发生改变。所以IP包头的source和des地址是不会变更的QUESTION67Whichtwotopologiesareusingthecorrecttypeoftwisted-paircables?(Choosetwo.)A.B.C.D.E.Answer:DESection:Chapter1:IntroductionExplanation/Reference:线缆问题，使用双绞线的设备。相同设备用crossover不同设备用cut-thought线缆。console使用的事rollor线缆QUESTION68Whichofthefollowingaretrueregardingbridgesandswitches?(Choosetwo.)A.Bridgesarefasterthanswitchesbecausetheyhavefewerports.B.Aswitchisamultiportbridge.C.BridgesandswitcheslearnMACaddressesbyexaminingthesourceMACaddressofeachframereceived.D.Abridgewillforwardabroadcastbutaswitchwillnot.E.Bridgesandswitchesincreasethesizeofacollisiondomain.Answer:BCSection:Chapter9:SwitchingExplanation/Reference:考查网桥和交换机的区别A：网桥比交换机更快速，因为他们有更少的端口。错误B：交换机是一个多端口网桥。正确C：通过检查数据包的sourcemac学习mac地址，正确D：网桥转发广播包，但交换机不转发。错误E：网桥和交换机增加冲突域的大小，错误。QUESTION69Whataresomeoftheadvantagesofusingaroutertosegmentthenetwork?(Choosetwo.)A.FilteringcanoccurbasedonLayer3information.B.Broadcastsareeliminated.C.Routersgenerallycostlessthanswitches.D.Broadcastsarenotforwardedacrosstherouter.E.Addingaroutertothenetworkdecreaseslatency.Answer:ADSection:Chapter1:IntroductionExplanation/Reference:A：可以基于层三的信息过滤数据。B：广播被淘汰。错误C：路由器的价格一般比交换机少。错误D：广播不会穿越路由器，正确。E:增加路由器后减少延迟。错误。QUESTION70Whichofthefollowingstatementsaretrueregardingbridgesandswitches?(Choose3.)A.Switchesareprimarilysoftwarebasedwhilebridgesarehardwarebased.B.BothbridgesandswitchesforwardLayer2broadcasts.C.Bridgesarefrequentlyfasterthanswitches.D.Switcheshaveahighernumberofportsthanmostbridges.E.Bridgesdefinebroadcastdomainswhileswitchesdefinecollisiondomains.F.BothbridgesandswitchesmakeforwardingdecisionsbasedonLayer2addresses.Answer:BDFSection:Chapter9:SwitchingExplanation/Reference:A：交换机基于软件，网桥基于硬件，错误。都是基于硬件B：都转发二层广播包，正确C：网桥比交换机快速。错误。D：交换机比网桥具有更多的端口，正确。E：网桥定义广播域，交换机定义冲突域，错误。F:基于二层地址转发数据。正确QUESTION71Whichcharacteristicsarerepresentativeofalink-stateroutingprotocol?(Choosethree.)A.providescommonviewofentiretopologyB.exchangesroutingtableswithneighborsC.calculatesshortestpathD.utilizesevent-triggeredupdatesE.utilizesfrequentperiodicupdatesAnswer:ACDSection:Chapter6:IPRoutingExplanation/Reference:链路状态路由协议有协议特点？A:提供查看拓扑的命令，正确。showipospfdatabaseB：邻居之间交换路由信息，错误。交换LSAC：计算最短路径，正确。D：利用触发更新，正确E：利用周期更新，错误。QUESTION72Whichofthefollowingstatementsdescribethenetworkshowninthegraphic?(Choosetwo.)A.Therearetwobroadcastdomainsinthenetwork.B.Therearefourbroadcastdomainsinthenetwork.C.Therearesixbroadcastdomainsinthenetwork.D.Therearefourcollisiondomainsinthenetwork.E.Therearefivecollisiondomainsinthenetwork.F.Therearesevencollisiondomainsinthenetwork.Answer:AFSection:Chapter1:IntroductionExplanation/Reference:路由器一个端口一个广播域交换机一个端口一个冲突域集线器一个冲突域。左边是集线器，右边是交换机。QUESTION73Usetheoutputfromtheroutershowninthegraphicabovetodeterminewhichofthefollowingarecorrect.(Choosetwo.)A.RouterJohnusesalink-stateroutingprotocol.B.RouterJohnwillreceiveroutingupdatesontheSerial0/0interface.C.RouterJohnwillreceiveroutingupdatesontheSerial0/1interface.D.RouterJohnwillsendroutingupdatesouttheSerial0/0interface.E.RouterJohnwillsendroutingupdatesouttheFastEthernet0/0interface.F.RouterJohnwillsendroutingupdatesouttheSerial0/1interface.Answer:BDSection:Chapter6:IPRoutingExplanation/Reference:由图中几处画红线的地方可知只有s0/0发送和接受路由信息。QUESTION74AnationalretailchainneedstodesignanIPaddressingschemetosupportanationwidenetwork.Thecompanyneedsaminimumof300sub-networksandamaximumof50hostaddressespersubnet.WorkingwithonlyoneClassBaddress,whichofthefollowingsubnetmaskswillsupportanappropriateaddressingscheme?(Choosetwo.)Answer:BESection:Chapter3:IPAddressingandVLSMExplanation/Reference:需要至少300个子网，每个子网至少50台主机。使用一个B类地址来划分。A：最多有256个子网，错误C：只有64个子网D：每个子网只有30个可用IPF：只有32个子网。QUESTION75(Choosetwo.)Answer:ACSection:Chapter3:IPAddressingandVLSMExplanation/Reference:QUESTION76AninboundaccesslisthasbeenconfiguredonaserialinterfacetodenypacketentryforTCPandUDPports21,23and25.WhattypesofpacketswillbepermittedbythisACL?(Choosethree.)A.FTPB.TelnetC.SMTPD.DNSE.HTTPF.POP3Answer:DEFSection:Chapter2:TCP/IPExplanation/Reference:acl拒绝了tcp/udp212325这三个端口的流量，哪些流量会被放行？A：FTP21端口B：TELNET23端口C：SMTP25端口D：DNS53端口E：HTTP80端口F:POP3110端口QUESTION77WhicharevalidmodesforaswitchportusedasaVLANtrunk?(Choosethree.)A.transparentB.autoC.onD.desirableE.blockingF.forwardingAnswer:BCDSection:Chapter10:VLANExplanation/Reference:有三种方式建立trunk链路auto、on、desirableQUESTION78OSPFroutingusestheconceptofareas.WhatarethecharacteristicsofOSPFareas?(Choosethree.)A.EachOSPFarearequiresaloopbackinterfacetobeconfigured.B.Areasmaybeassignedanynumberfrom0to65535.C.Area0iscalledthebackbonearea.D.HierarchicalOSPFnetworksdonotrequiremultipleareas.E.MultipleOSPFareasmustconnecttoarea0.F.SingleareaOSPFnetworksmustbeconfiguredinarea1.Answer:BCESection:Chapter6:IPRoutingExplanation/Reference:A：每个区域需要换回口，错误B：区域ID的范围是0--65535，正确C：区域0是骨干区域，正确D：分层的OSPF网络不需要多区域，错误。就是依赖多区域分层。E：多区域情况必须存在区域0，正确。F：单区域的区域号必须被配置为区域1，错误。QUESTION79Whatinformationdoesarouterrunningalink-stateprotocolusetobuildandmaintainitstopologicaldatabase?(Choosetwo.)A.hellopacketsB.SAPmessagessentbyotherroutersC.LSAsfromotherroutersD.beaconsreceivedonpoint-to-pointlinksE.routingtablesreceivedfromotherlink-stateroutersF.TTLpacketsfromdesignatedroutersAnswer:ACSection:Chapter6:IPRoutingExplanation/Reference:链路状态路由协议如何维护拓扑数据库？A：hello包用于维护邻居关系，正确。B：错误，没有这个概念。C：通过其他路由器的LSA，正确。D：从点到点链路接收，错误。答案片面E：从其他路由器接收路由表，错误。相互间不直接发送路由表。F：从DR接受TTL包，错误，答非所问。QUESTION80WhichstatementsdescribetheroutingprotocolOSPF?(Choosethree.)A.ItsupportsVLSM.B.Itisusedtoroutebetweenautonomoussystems.C.Itconfinesnetworkinstabilitytooneareaofthenetwork.D.Itincreasesroutingoverheadonthenetwork.E.Itallowsextensivecontrolofroutingupdates.F.ItissimplertoconfigurethanRIPv2.Answer:ACESection:Chapter6:IPRoutingExplanation/Reference:A：支持VLSM，正确B：在AS之间使用，错误。在AS内部使用C：限制了不稳定网络的范围，正确。通过划分区域实现。D：增加了网络的开销，错误。E：允许路由更新控制，正确。F：比RIPv2更容易配置，错误，答非所问。QUESTION81Theswitchesshowninthediagram,CoreandCore2,arebothCatalyst2950s.Theaddressingschemeforeachcompanysiteisasfollows:RouterEthernetport-1stusableaddressCore-2ndusableaddressCore2-3rdusableaddressForthisnetwork,whichofthefollowingcommandsmustbeconfiguredonCore2toallowittobemanagedremotelyfromanysubnetonthenetwork?(Choosethree.)A.Core2(config)#interfacef0/0B.Core2(config)#interfacevlan1C.Core2(config)#linecon0Core2(config-line)#passwordciscoD.Core2(config)#linevty04Core2(config-line)#passwordciscoAnswer:BDESection:Chapter10:VLANExplanation/Reference:实现远程管理，需要给交换机配置管理IP，需要路由可达B:配置管理IP。2层交换机只能在vlan中配置IPD：配置vty密码E:配置缺省网关QUESTION82AnadministratorisunsuccessfulinaddingVLAN50toaswitch.Whiletroubleshootingtheproblem,theadministratorviewstheoutputoftheshowvtpstatuscommand,whichisdisplayedinthegraphic.WhatcommandsmustbeissuedonthisswitchtoaddVLAN50tothedatabase?(Choosetwo.)A.Switch(config-if)#switchportaccessvlan50B.Switch(vlan)#vtpserverC.Switch(config)#config-revision20D.Switch(config)#vlan50nameTechE.Switch(vlan)#vlan50F.Switch(vlan)#switchporttrunkvlan50Answer:BESection:Chapter10:VLANExplanation/Reference:无法在交换机上添加vlan50的原因?从图中画红线地方可以看出交换机处于client模式，无法增加，删除，修改vlan。题目说在database中增加，所以选BEQUESTION83Answer:BCESection:Chapter3:IPAddressingandVLSMExplanation/Reference:QUESTION84Whichofthefollowingaretypesofflowcontrol?(Choosethree.)A.bufferingB.cut-throughC.windowingD.congestionavoidanceE.loadbalancingAnswer:ACDSection:Chapter2:TCP/IPExplanation/Reference:流控制有哪些？A：缓存B：直通C：窗口机制D：拥塞避免E：负载均衡。QUESTION85WhichdestinationaddresseswillbeusedbyHostAtosenddatatoHostC?(Choosetwo.)A.theIPaddressofSwitch1B.theMACaddressofSwitch1C.theIPaddressofHostCD.theMACaddressofHostCE.theIPaddressoftherouter\'sE0interfaceF.theMACaddressoftherouter\'sE0interfaceAnswer:CFSection:Chapter6:IPRoutingExplanation/Reference:数据包在转发的过程中，源目IP不变，源目MAC会变化。目的地不在同一个网段，数据先发送到网关。QUESTION86Whatcanbedeterminedfromthelineofshowiprouteoutputshownintheexhibit?(Choosetwo.)A.Thenextroutingupdatecanbeexpectedin35seconds.D.Thisrouteisusingthedefaultadministrativedistance.Answer:DESection:Chapter6:IPRoutingExplanation/Reference:s/1。A：错误。rip更新周期为30s，正常计时器不会超过30B：错误，这个ip是对端接口ipC：错误。s0/1的ip无法得知D：正确，rip缺省的管理距离是120E：正确。QUESTION87Refertotheexhibit.Alloftheroutersinthenetworkareconfiguredwiththeipsubnet-zerocommand.WhichnetworkaddressesshouldbeusedforLinkAandNetworkA?(Choosetwo.)Answer:BDSection:Chapter3:IPAddressingandVLSMExplanation/Reference:配置了ipsubnet-zero，可以使用全0网段。A：错误，120台主机，主机位至少为7位。B:正确，主机位32-25=7C：错误，主机位少于7位D：正确。因为使用了ipsubnet-zero。QUESTION88Answer:DESection:Chapter3:IPAddressingandVLSMExplanation/Reference:考点：考查VLSM知识点D/E都在这个范围内。QUESTION89ThenetworkadministratorhasdiscoveredthatthepowersupplyhasfailedonaswitchinthecompanyLANandthattheswitchhasstoppedfunctioning.IthasbeenreplacedwithaCiscoCatalyst2950seriesswitch.Whatmustbedonetoensurethatthisnewswitchbecomestherootbridgeonthenetwork?A.Lowerthebridgeprioritynumber.B.ChangetheMACaddressoftheswitch.C.IncreasetheVTPrevisionnumberforthedomain.D.Lowertherootpathcostontheswitchports.E.AssigntheswitchanIPaddresswiththelowestvalue.Answer:ASection:Chapter9:SwitchingExplanation/Reference:考点：STP的选举原则RID=优先级+mac地址小者优先QUESTION90Refertotheexhibit.Assumethatalloftherouterinterfacesareoperationalandconfiguredcorrectly.HowwillrouterR2beaffectedbytheconfigurationofR1thatisshownintheexhibit?A.RouterR2willnotformaneighborrelationshipwithR1.B.RouterR2willobtainafullroutingtable,includingadefaultroute,fromR1.C.R2willobtainOSPFupdatesfromR1,butwillnotobtainadefaultroutefromR1.D.R2willnothavearouteforthedirectlyconnectedserialnetwork,butallotherdirectlyconnectednetworkswillbepresent,aswellasthetwoEthernetnetworksconnectedtoR1.Answer:BSection:Chapter6:IPRoutingExplanation/Reference:考查OSPF产生默认路由的条件虽然默认路由出口错误但是邻居仍然回收到正确答案选：BQUESTION91WhichthreeIPaddressescanbeassignedtohostsifthesubnetmaskis/27andsubnetzeroisusable?(Choosethree.)Answer:ACDSection:Chapter3:IPAddressingandVLSMExplanation/Reference:掩码为27，所以一个子网可以有32个IP，可用的30个E：刚好是网络号，错误F：刚好是广播地址，错误QUESTION92A.forwardsthereceivedpacketouttheSerial0/0interfaceB.forwardsapacketcontaininganEIGRPadvertisementouttheSerial0/1interfaceC.forwardsapacketcontaininganICMPmessageouttheFastEthernet0/0interfaceD.forwardsapacketcontaininganARPrequestouttheFastEthernet0/1interfaceAnswer:CSection:Chapter6:IPRoutingExplanation/Reference:路由器中没有去往目的地的路由，返回一个ICMP报错报文去往源IP的路由下一跳是f0/0，所以选CQUESTION93Refertotheexhibit.FromRouterA,anetworkadministratorisabletopingtheserialinterfaceofRouterBbutunabletopinganyofthesubnetsattachedtoRouterB.Basedonthepartialoutputsintheexhibit,whatcouldbetheproblem?A.EIGRPdoesnotsupportVLSM.B.TheEIGRPnetworkstatementsareincorrectlyconfigured.C.TheIPaddressingontheserialinterfaceofRouterAisincorrect.D.Theroutingprotocolhassummarizedontheclassfulboundary.E.EIGRPhasbeenconfiguredwithaninvalidautonomoussystemnumber.Answer:DSection:Chapter6:IPRoutingExplanation/Reference:QUESTION94WhatarethreecharacteristicsoftheOSPFroutingprotocol?(Choosethree.)A.Itconvergesquickly.B.OSPFisaclassfulroutingprotocol.C.Itusescosttodeterminethebestroute.D.ItusestheDUALalgorithmtodeterminethebestroute.E.OSPFrouterssendthecompleteroutingtabletoalldirectlyattachedrouters.F.OSPFroutersdiscoverneighborsbeforeexchangingroutinginformation.Answer:ACFSection:Chapter6:IPRoutingExplanation/Reference:考查OSPF特性A：收敛快，正确B:有类路由，正确C：使用cost值确定最优路由，正确D：使用dual算法，错误，这个是EIGRP的算法E：发送全部路由信息，错误，增量更新。F：在交换信息之前先建立邻接关系，正确。QUESTION95Refertotheexhibit.SW1andSW2havedefaultconfigurations.Whatwillhappenifhost1sendsabroadcast?A.Hosts2,3,and4willreceivethebroadcast.B.Hosts1,2,3,and4willreceivethebroadcast.C.Host2andtheFa0/0interfaceofR1willreceivethebroadcast.D.Hosts1,2andtheFa0/0interfaceofR1willreceivethebroadcast.E.Hosts1,2,3,4andinterfaceFa0/0ofR1willreceivethebroadcast.F.Hosts2,3,4,andinterfacesFa0/0andFa0/1ofR1willreceivethebroadcast.Answer:CSection:Chapter6:IPRoutingExplanation/Reference:考查路由器的功能：隔离广播域，一个端口一个广播域。综上所述，选C。QUESTION96Arouterhaslearnedthreepossibleroutesthatcouldbeusedtoreachadestinationnetwork.OnerouteisThelastisfromRIPv2andhasametricof4.Whichrouteorrouteswilltherouterinstallintheroutingtable?A.theOSPFrouteB.theEIGRProuteC.theRIPv2routeD.allthreeroutesE.theOSPFandRIPv2routesAnswer:BSection:Chapter6:IPRoutingExplanation/Reference:考点：考查路由条目进入路由表的原则：最优路由才能进入。去往同一目的的多条路由，先比较AD值，AD值小者优先；AD值一直则比较metric值。AD值：EIGRP90OSPF110RIP120QUESTION97ForwhattwopurposesdoestheEthernetprotocolusephysicaladdresses?(Choosetwo.)A.touniquelyidentifydevicesatLayer2B.toallowcommunicationwithdevicesonadifferentnetworkC.todifferentiateaLayer2framefromaLayer3packetD.toestablishaprioritysystemtodeterminewhichdevicegetstotransmitfirstE.toallowcommunicationbetweendifferentdevicesonthesamenetworkF.toallowdetectionofaremotedevicewhenitsphysicaladdressisunknownAnswer:AESection:Chapter1:IntroductionExplanation/Reference:考点：考查mac地址的作用。A：在二层唯一确定一台设备，正确B：是设备在不同的网络中通信，错误，不同网络通信需要通过IP地址确定。C：区别二层和三层帧，错误。D：确定设备的优先级，错误。没有这个功能。E：是同一网络的不同设备可以通信，正确F：当不知道远程设备的物理地址时可以查询，错误。不能跨网段。QUESTION98AsaframeleavesaLayer3device,theLayer2encapsulationinformationischangedfromwhatitwaswhenitenteredthedevice.Forwhattworeasonscanthishappen?(Choosetwo.)A.Thedataismovingfrom10BASE-TXto100BASE-TX.B.TheWANencapsulationtypehaschanged.C.Thedataformathaschangedfromanalogtodigital.D.Thesourceanddestinationhostsareinthesamesubnet.E.ThesourceanddestinationMACaddresseshavechanged.Answer:BESection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:考点：数据包转发过程。当数据包离开三层设备时，二层封装哪些信息改变了。A：从10M网络到100M网络，错误。带宽改变不会改变数据包封装。B：广域网封装改变，正确。如从HDCL变成PPPC：数据格式从模拟型号变成数据信号，错误，物理层的信号方式变化不会影响二层数据格式。D：错误。E：原蜜MAC改变，正确。QUESTION99WhichtwostatementsaretrueregardingEIGRP?(Choosetwo.)A.PassiveroutesareintheprocessofbeingcalculatedbyDUAL.B.EIGRPsupportsVLSM,routesummarization,androutingupdateauthentication.C.EIGRPexchangesfullroutingtableinformationwithneighboringrouterswitheveryupdate.D.Ifthefeasiblesuccessorhasahigheradvertiseddistancethanthesuccessorroute,itbecomestheprimaryroute.E.Aqueryprocessisusedtodiscoverareplacementforafailedrouteifafeasiblesuccessorisnotidentifiedfromthecurrentroutinginformation.Answer:BESection:Chapter6:IPRoutingExplanation/Reference:A：被动路由在路由进程中由dual计算，错误。B：至此VLSM，路由汇总，认证，正确C：每次更新都发送全部的路由信息，错误，增量更新。D：如果可行后继路由器有一个比后继路由器高的通告距离，它会成为主路由条目，错误。E：如果不存在FS，使用查询进程去发现替代失效的路由信息，正确。QUESTION100Refertotheexhibit.Inthecommunicationbetweenhost1andhost2overthepoint-to-pointWAN,whichprotocolortechnologyisrepresentedbydashedlineA?A.IPB.T1C.PPPD.IEEE802.3Answer:ASection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:A：主机之间的通信依靠IP确定对方地址。B：T1，广域网线路的一种C：PPP，二层封装的一种。D：ieee802.3以太网封装。QUESTION101Refertotheexhibit.TheswitchinthegraphichasadefaultconfigurationandtheMACtableisfullypopulated.Inaddition,thisnetworkisoperatingproperly.ThegraphicrepresentsselectedheaderinformationinaframeleavinghostA.Whatcanbeconcludedfromthisinformation?B.TherouterwillforwardthepacketinthisframetotheInternet.C.Theswitchwillonlyforwardthisframetotheattachedrouterinterface.D.AlldevicesinthisLANexcepthostAwillpassthepackettoLayer3.Answer:DSection:Chapter9:SwitchingExplanation/Reference:QUESTION102Whatisanappropriateuseofadefaultroute?A.toprovideroutingtoalocalwebserverB.toprovideroutingfromanISPtoastubnetworkC.toprovideroutingthatwilloverridetheconfigureddynamicroutingprotocolD.toprovideroutingtoadestinationthatisnotspecifiedintheroutingtableandwhichisoutsidethelocalnetworkAnswer:DSection:Chapter6:IPRoutingExplanation/Reference:考点：考查缺省路由的特点A：提供路由到本地web服务器，错误B：提供从ISP到末节网络的路由，错误C：提供优先于动态路由协议的路由，错误。根据最长匹配原则，缺省路由最后才匹配。D：正确QUESTION103Refertotheexhibit.Ajuniornetworkengineerhaspreparedtheexhibitedconfigurationfile.Whattwostatementsaretrueoftheplannedconfigurationforinterfacefa0/1?(Choosetwo.)A.ThetwoFastEthernetinterfaceswillrequireNATconfiguredontwooutsideserialinterfaces.B.Addresstranslationonfa0/1isnotrequiredforDMZDevicestoaccesstheInternet.C.Thefa0/1IPaddressoverlapswiththespaceusedbys0/0.D.Thefa0/1IPaddressisinvalidfortheIPsubnetonwhichitresides.E.InternethostsmaynotinitiateconnectionstoDMZDevicesthroughtheconfigurationthatisshown.Answer:BESection:Chapter8:NATExplanation/Reference:DMZ使用公网地址，不需要做NAT，图中ACL第二条错将DMZ做了NAT，因此造成不能访问QUESTION104Refertotheexhibit.Tworoutershavejustbeenconfiguredbyanewtechnician.Allinterfacesareup.However,theroutersarenotsharingtheirroutingtables.Whatistheproblem?A.SplithorizonispreventingRouter2fromreceivingroutinginformationfromRouter1.B.Router1isconfiguredforRIPversion2,andRouter2isconfiguredforRIPversion1.C.Router1hasanACLthatisblockingRIPversion2.D.ThereisaphysicalconnectivityproblembetweenRouter1andRouter2.E.Router1isusingauthenticationandRouter2isnot.Answer:BSection:Chapter6:IPRoutingExplanation/Reference:考点：考查RIP版本知识点。两种版本不兼容。由提示信息可知R2发送V1，收到V2。A：水平分割保护R2从R1接收路由信息。错误。B：R2配置为V2，R2配置为V1,正确C：R1使用了acl拒绝了rip的V2D：R1和R2之间的物理链路有问题。错误。E：R1使用了认证，R2没有。错误QUESTION105Amedium-sizedcompanyhasaClassCIPaddress.IthastwoCiscoroutersandonenon-Ciscorouter.AllcompanyhasdecideditwouldbeagoodideatosplitthenetworkintothreesmallersubnetsandcreatetheoptionofconservingaddresseswithVLSM.Whatisthebestcourseofactionifthecompanywantstohave40hostsineachofthethreesubnets?asthenewsubnetworks.asthenewsubnetworks.Answer:DSection:Chapter6:IPRoutingExplanation/Reference:QUESTION106Refertotheexhibit.WhyhasthisswitchnotbeenelectedtherootbridgeforVLAN1?A.Ithasmorethanoneinterfacethatisconnectedtotherootnetworksegment.B.ItisrunningRSTPwhiletheelectedrootbridgeisrunning802.1dspanningtree.C.IthasahigherMACaddressthantheelectedrootbridge.D.IthasahigherbridgeIDthantheelectedrootbridge.Answer:DSection:Chapter9:SwitchingExplanation/Reference:考点：考查STP选举原则，RID小者优先。由提示可知根桥的RID为20481A：有超过1个接口连接到根网段，错误B：使用了RSTP，但是选举根桥时使用了802.1d，错误C：比根桥有更高的MAC地址，错误D：比根桥有更高的RID，正确。QUESTION107Refertotheexhibit.AttheendofanRSTPelectionprocess,whichaccesslayerswitchportwillassumethediscardingrole?A.Switch3,portfa0/1B.Switch3,portfa0/12C.Switch4,portfa0/11D.Switch4,portfa0/2E.Switch3,portGi0/1F.Switch3,portGi0/2Answer:CSection:Chapter9:SwitchingExplanation/Reference:SW1为跟桥，SW4会选择一个端口作为根端口，另一个堵塞。在两个端口cost相同的情况下，选择端口号小的为跟端口，端口号大的堵塞。QUESTION108Refertotheexhibit.HowmanypathscantheEIGRProutingprocessusetoforwardpacketsfromHQ_Routertoaneighborrouter?A.twoequal-costpathsB.twounequal-costpathsC.threeequal-costpathsD.threeunequal-costpathsE.fourequal-costpathsF.fourunequal-costpathsAnswer:FSection:Chapter6:IPRoutingExplanation/Reference:考点：考查EIGRP负载均衡。根据提示，variance=3maximum=4，所以支持不等价负载均衡，最多支持4条。A：2条等价路径，错误B：2条不等价路径，错误C：三条等价路径，错误D：三条不等价路径，错误E：四条等价路径，错误F：四条不等价路径，正确。QUESTION109Selecttheactionthatresultsfromexecutingthesecommands.Switch(config-if)#switchportport-securitySwitch(config-if)#switchportport-securitymac-addressstickyA.AdynamicallylearnedMACaddressissavedinthestartup-configurationfile.B.AdynamicallylearnedMACaddressissavedintherunning-configurationfile.C.AdynamicallylearnedMACaddressissavedintheVLANdatabase.D.StaticallyconfiguredMACaddressesaresavedinthestartup-configurationfileifframesfromthataddressarereceived.E.StaticallyconfiguredMACaddressesaresavedintherunning-configurationfileifframesfromthataddressarereceived.Answer:BSection:Chapter9:SwitchingExplanation/Reference:考点：考查交换机端口安全。sticky关键字使静态配置和动态学习的mac方式优势相结合A：把动态学习的mac保存到startup-config文件中，错误B：把动态学习的mac保存到running-config文件中，正确C：把动态学习的mac保存到vlan数据库中。错误。D：如果接收到数据帧中包含静态配置的MAC地址，它将被保存在startup-config文件，错误E:如果接收到数据帧中包含静态配置的MAC地址，它将被保存在running-config文件，错误静态配置的直接保存在running-config里了。QUESTION110Refertotheexhibit.Thefollowingcommandsareexecutedoninterfacefa0/1of2950Switch.2950Switch(config-if)#switchportport-security2950Switch(config-if)#switchportport-securitymac-addresssticky2950Switch(config-if)#switchportport-securitymaximum1TheEthernetframethatisshownarrivesoninterfacefa0/1.Whattwofunctionswilloccurwhenthisframeisreceivedby2950Switch?(Choosetwo.)B.OnlyhostAwillbeallowedtotransmitframesonfa0/1.C.Thisframewillbediscardedwhenitisreceivedby2950Switch.E.HostsBandCmayforwardframesoutfa0/1butframesarrivingfromotherswitcheswillnotbeforwardedoutfa0/1.forwardedoutfa0/1.Answer:BDSection:Chapter9:SwitchingExplanation/Reference:考点：考查交换机端口安全。maximum1说明只允许一个mac通过。B：仅允许主机A通过f0/1，正确C:当2950switch收到帧后丢弃，错误。应该是除f0/1外所有端口洪泛E：主机B和C的数据帧会从f0/1转发，但从其他交换接收到的不会，错误。QUESTION111Refertotheexhibit.Some2950seriesswitchesareconnectedtotheconferenceareaofthecorporateheadquartersnetwork.Theswitchesprovidetwotothreejacksperconferenceroomtohostlaptopconnectionsforemployeeswhovisittheheadquartersoffice.Whenlargegroupsofemployeescomefromotherlocations,thenetworkadministratoroftenfindsthathubshavebeenconnectedtowalljacksintheconferenceareaalthoughtheportsontheaccesslayerswitcheswerenotintendedtosupportmultipleworkstations.Whatactioncouldthenetworkadministratortaketopreventaccessbymultiplelaptopsthroughasingleswitchportandstillleavetheswitchfunctionalforitsintendeduse?A.ConfigurestaticentriesintheswitchMACaddresstabletoincludetherangeofaddressesusedbyvisitingemployees.B.ConfigureanACLtoallowonlyasingleMACaddresstoconnecttotheswitchatonetime.C.Usethemac-address-table1globalconfigurationcommandtolimiteachporttoonesourceMACaddress.D.ImplementPortSecurityonallinterfacesandusetheport-securitymaximum1commandtolimitportaccesstoasingleMACaddress.E.ImplementPortSecurityonallinterfacesandusetheport-securitymac-addressstickycommandtolimitaccesstoasingleMACaddress.F.ImplementPortSecurityatglobalconfigurationmodeandusetheport-securitymaximum1commandtoalloweachswitchonlyoneattachedhub.Answer:DSection:Chapter9:SwitchingExplanation/Reference:考点：考查交换机端口安全。题目想实现限制一个端口只接入一台设备。A：配置静态mac地址表。错误。无法达到限制效果。B：配置ACL允许同一个时刻仅一个mac地址连接到交换机。错误。C：在全局配置模式使用mac-address-table命令限制每个端口一个源mac地址。错误，无法实现。D：在所有端口使用portsecurity和maximum1限制一个端口允许一个mac地址，正确。E：部署portsecurity和port-securitymac-addresssticky命令，错误，无法实现。F：在所有端口使用portsecurity和maximum1限制一个端口允许一个hub，错误，一个hub下面可以接多台PC。QUESTION112RunningbothIPv4andIPv6onaroutersimultaneouslyisknownaswhat?A.4to6routingB.6to4routingC.binaryroutingD.dual-stackroutingE.NextGenroutingAnswer:DSection:Chapter13:IPv6Explanation/Reference:考点：考查IPv4和IPv6共存。同时使用IPv4和IPv6时称为双栈路由。QUESTION113WhatarethreeIPv6transitionmechanisms?(Choosethree.)A.6to4tunnelingB.VPNtunnelingC.GREtunnelingD.ISATAPtunnelingE.PPPtunnelingF.TeredotunnelingAnswer:ADFSection:Chapter13:IPv6Explanation/Reference:考点：考查IPv4-->IPv6的过度机制。主要有三种：6to4隧道：ISATAPtunneling：站内自动隧道寻址机制teredotunneling：Teredo目前尚为IEIF草案，将IPv6数据包包在UDP／IPv4数据包中传送。。QUESTION114IdentifythefourvalidIPv6addresses.(Choosefour.)A.::B.::192:168:0:1C.2000::D.2001:3452:4952:2837::E.2002:c0a8:101::42F.2003:dead:beef:4dad:23:46:bb:101Answer:ABEFSection:Chapter13:IPv6Explanation/Reference:：：不能放最后，A是特殊情况，记住QUESTION115Whichprotocolshouldbeusedtoestablishasecureterminalconnectiontoaremotenetworkdevice?Selectthebestresponse.A.ARPB.SSHC.TelnetD.WEPE.SNMPv1F.SNMPv2Answer:BSection:Chapter2:TCP/IPExplanation/Reference:考点：那种协议用于建立安全的远程访问。A：arp用于ip和mac的映射B：ssh，安全套接字。C：telnet，明文传输D：wep，无线加密技术E/F：snmp，简单网络管理协议QUESTION116Refertotheexhibit.AnetworkadministratorwantsSwitch3tobetherootbridge.WhatcouldbedonetoensureSwitch3willbetheroot?A.ConfiguretheIPaddressonSwitch3tobehigherthantheIPaddressesofSwitch1andSwitch2.B.ConfigurethepriorityvalueonSwitch3tobehigherthanthepriorityvaluesofSwitch1andSwitch2.C.ConfiguretheBIDonSwitch3tobelowerthantheBIDsofSwitch1andSwitch2.D.ConfiguretheMACaddressonSwitch3tobehigherthantheSwitch1andSwitch2MACaddresses.E.ConfigurealoopbackinterfaceonSwitch3withanIPaddresslowerthananyIPaddressonSwitch1andSwitch2.Answer:CSection:Chapter9:SwitchingExplanation/Reference:根桥的选举由BID决定，BID小者优先。BID=优先级+mac准成QUESTION117WhatisthemaximumdataratespecifiedforIEEE802.11bWLANs?A.10MbpsB.11MbpsC.54MbpsD.100MbpsAnswer:BSection:Chapter11:WirelessExplanation/Reference:802.11a：54Mbps802.11b：11Mbps802.11g：54、108Mbps802.11n：300MpbsQUESTION118Howdoesusingtheservicepasswordencryptioncommandonarouterprovideadditionalsecurity?A.byencryptingallpasswordspassingthroughtherouterB.byencryptingpasswordsintheplaintextconfigurationfileC.byrequiringentryofencryptedpasswordsforaccesstothedeviceD.byconfiguringanMD5encryptedkeytobeusedbyroutingprotocolstovalidateroutingexchangesE.byautomaticallysuggestingencryptedpasswordsforuseinconfiguringtherouterAnswer:BSection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:当使用这条命令后，所有在路由器上配置是密码都被加密。A:所有通过路由器的密码都被加密。错误B：正确C：当访问设备时提供加密的密码。错误D：通过配置一个加密的密钥为路由协议使用，错误E：在用户配置路由器时自动建议加密密码。错误QUESTION119Refertotheexhibit.WhenrunningOSPF,WhatwouldcauserouterAnottoformanadjacencywithrouterB?A.Theloopbackaddressesareondifferentsubnets.B.Thevalueofthedeadtimersontherouteraredifferent.C.Routesummarizationisenabledonbothrouters.D.TheprocessindentifieronrouterAisdifferentthantheprocessidentifieronrouterB.Answer:BSection:Chapter6:IPRoutingExplanation/Reference:考点：考查OSPF邻居建立的条件。区域ID，hello周期，网段，认证等。A：loopback地址不同网段，错误B：hello的死亡时间不一样，正确C：开启了路由汇总，错误。这个没关系D：两端的路由进程不一致。错误。QUESTION120Refertotheexhibit.Whatstatementistrueoftheconfigurationforthisnetwork?A.Theconfigurationthatisshownprovidesinadequateoutsideaddressspacefortranslationofthenumberofinsideaddressesthataresupported.B.BecauseoftheaddressingoninterfaceFastEthernet0/1,theSerial0/0interfaceaddresswillnotsupporttheNATconfigurationasshown.C.Thenumber1referredtointheipnatinsidesoucecommandrecerencesaccess-listnumber1.Answer:CSection:Chapter8:NATExplanation/Reference:A：该配置显示了内部全局地址不足以分配给所有内部局部地址，错误。使用了overload关键字，为PAT。B:不支持NAT转换，错误。C:ipnatinsidsource1中1为accesslist1QUESTION121Refertotheexhibit.Thenetworkisconverged.Afterlink-stateadvertisementsarereceivedfromRouter_A,Answer:ASection:Chapter6:IPRoutingExplanation/Reference:考点：考查OSPFcost值计算。cost=10的8次方除以带宽。在routerA上metric12，到routerE经过100M网络。A：正确B：错误，metric值不对。C：错误，下一跳接口不对。D：错误，metric值不对。QUESTION122Refertotheexhibit.ThecompanyusesEIGRPastheroutingprotocol.WhatpathwillpacketstakefromaA.ThepathofthepacketswillbeR3toR2toR1.B.ThepathofthepacketswillbeR3toR1toR2.C.ThepathofthepacketswillbebothR3toR2toR1andR3toR1.D.ThepathofthepacketswillbeR3toR1Answer:DSection:Chapter6:IPRoutingExplanation/Reference:考点：考查EIGRP的路径选择。从R3内网到R1的路径选择。链路的带宽一样，很明显是直接从R3到R1。QUESTION123Refertotheexhibit.SwitchportFastEthernet0/24onAlSwitch1willbeusedtocreateanIEEE802.1Qcomplainttrunktoanotherswitch.Basedontheoutputshown,Whatisthereasonthetrunkdoesnotform,eventhoughtthepropercablinghasbeenattached?A.VLANshavenotbeencreatedyet.B.AnIPaddressmustbeconfiguredfortheport.C.Theportiscurrentlyconfiguredforaccessmode.D.Thecorrectencapsulationtypehasnotbeenconfigured.E.Thenoshutdowncommandhasnotbeenenteredfortheport.Answer:CSection:Chapter10:VLANExplanation/Reference:由图中画红线的地方可知道接口配置为access模式。A：vlan没有创建，错误B：一个IP地址被配置在端口，错误。C：端口当前处于access模式,正确。D：没有配置正确的封装模式，错误。E：接口没有noshutdown，错误。QUESTION124Refertotheexhibit.Whatswitchprovesthespanning-treedesignatedportroleforthenetworksegmentthatservicestheprinters?A.Switch1B.Switch2C.Switch3D.Switch4Answer:CSection:Chapter9:SwitchingExplanation/Reference:题目求哪一个交换机为打印机提供指定端口？由图可知S1是根桥。指定端口是基于网段间选举的。S3--S4之间S3的BID比S4小，所以S3-S4之间的指定端口在S3上。QUESTION125received,whatdoesthisconfirm?A.ThePChasconnectivitywithalocalhost.B.ThePChasconnectivitywithaLayer3device.C.ThePChasadefaultgatewaycorrectlyconfiguredD.ThePChasconnectivityuptoLayer5oftheOSImodelE.ThePChastheTCP/IPprotocolstackcorrectlyinstalled.Answer:ESection:Chapter2:TCP/IPExplanation/Reference:QUESTION126ontheoutputfromRouterA,whataretwopossiblereasonsforthefailure?(Choosetwo.)A.ThecablethatisconnectedtoS0/0onRouterAisfaulty.B.InterfaceS0/0onRouterBisadministrativelydown.C.InterfaceS0/0onRouterAisconfiguredwithanincorrectsubnetmask.D.TheIPaddressthatisconfiguredonS0/0ofRouterB,isnotinthecorrectsubnet.E.InterfaceS0/0onRouterAisnotreceivingaclocksignalfromtheCSU/DSU.F.TheencapsulationthatisconfiguredonS0/0ofRotuerBdoesnotmatchtheencapsulationthatisconfiguredonS0/0ofRouterA.Answer:EFSection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:由图示可知RA和RB之间端口的协议处于down状态。一般是时钟或者封装等问题。A：线路故障，错误。因为物理层是up的B：管理性down，错误。C：子网配置不正确，错误。这个不影响端口状态。D：RB接口ip配置错误，错误。E：RA没有接受到时钟信息，正确。F：封装不匹配，正确。QUESTION127WhatisthedefaultroutingupdateperiodforRIPv2?A.15secondsB.30secondsC.180secondsD.240secondsAnswer:BSection:Chapter6:IPRoutingExplanation/Reference:QUESTION128Anetworkadministratorisdesigninganewcorporateinternetwork.Thecorporationisconcernedaboutdowntimeduetolinkfailureandalsoaboutlinkcosts.Whichtopologywillprovidesomeredundancytoincreasereliablityforallsitesbutwillcostlessthanafullyredundanttopology?A.B.C.D.Answer:BSection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:考点：在考虑冗余和费用的情况下，那种拓扑的最合适?A:R2R3之间的链路故障会影响网络B：正确C：相对B来说费用增加了D：R2失效影响较大。QUESTION129WhichtypeofattackischaracterizedbyfloodofpacketthatrequesingaTCPconnectiontoaserver?A.denialofserviceB.bruteforceC.reconnaissanceD.TrojanhorseAnswer:ASection:Chapter7:SecurityExplanation/Reference:考点：考查攻击方式与TCP的关系A：拒绝式服务攻击，正确。利用TCP三次握手的漏洞B：暴力攻击，错误。和TCP没联系C：侦察，错误，和TCP没联系D：特洛伊木马，错误，和TCP没联系QUESTION130Refertotheexhibit.ForwhattworeasonshastherouterloadeditsIOSimagefromthelocationthatisshown?(Choosetwo.)A.Router1hasspecificbootsystemcommandthatinstructittoloadIOSfromTFTPserver.B.Router1isactingasaTFTPserverforotherrouters.C.Router1cannotlocateavalidIOSimageinflashmemory.D.Router1defaultedtoROMMONmodeandloadedtheIOSimagefromaTFTPserver.E.CiscorouterswillfirstattempttoloadaimagefromTFTPformanagementpurposes.Answer:AESection:Chapter5:ManagingCiscoIOSExplanation/Reference:QUESTION131Whatisthepurposeusingthetraceroutecommand?A.tomapallthedevicesonanetwork.B.todisplaythecurrentTCP/IPconfigurationvalues.C.toseehowadeviceMACaddressismappedtoitsIPaddress.D.toseethepathapacketwilltakewhentravelingtoaspecifieddestination.E.todisplaytheMTUvaluesforeachrouterinaspecifiednetworkpathfromsourcetoadestination.Answer:DSection:Chapter2:TCP/IPExplanation/Reference:traceroute的主要功能就是跟踪数据包的下一跳QUESTION132Refertotheexhibit.Giventheoutputfromtheshowipeigrptopologycommand,whichrouteristhefeasiblesuccessor?A.B.C.D.Answer:BSection:Chapter6:IPRoutingExplanation/Reference:eigrp的可行条件为:路由的ADlearning->forwarding的状态,并且rstp的默认优先级应该为32768，所有的DP都将转发数据QUESTION168Refertotheexhibit.AnetworkadministratorattemptstopingHost2fromHost1andreceivestheresultthatareshown.Whatisapossibleproblem?A.ThelinkbetweenHost1andSwitch1isdown.B.TCP/IPisnotfunctioningonHost1.C.ThelinkbetweenRouter1andRouter2isdown.D.ThedefaultgatewayonHost1isincorrect.E.InterfaceFa0/0onRouter1isshudown.F.ThelinkbetweenSwitch1andRouter1isdown.Answer:CSection:Chapter6:IPRoutingExplanation/Reference:链路就已经失效.QUESTION169Refertotheexhibit.TheBigtimerouterisunabletoauthenticatetotheLittletimerouter.Whatisthecauseoftheproblem?A.Theusernamesareincorrectlyconfiguredonthetworouters.B.Thepasswordsdonotmatchonthetworouters.C.CHAPauthenticationcannotbeusedonaserialinterface.D.TherouterscannotbeconnectedfrominterfaceS0/0tointerfaceS0/0.E.WithCHAPauthentication,oneroutermustauthenticatetoanotherrouter.Therouterscannotbeconfiguredtoauthenticatetoeachother.Answer:BSection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:ppp在进行认证配置的时候.用户名要是对端的用户名.但是password要是两边共享的password!QUESTION170S0/0onR1isconfiguredasamultipointinterfacetocommunicatewithR2andR3inthehub-and-spokeFrameRelaytopologyshownintheexhibit.Originally,staticrouteswereconfiguredbetweentheserouterstosuccessfullyroutetrafficbetweentheattachednetworks.WhatwillneedtobedoneinordertouseRIPv2inplaceofthestaticroutes?A.Configurethenoipsubnet-zerocommandonR1,R2,andR3.B.DynamicroutingprotocolssuchasRIPv2cannotbeusedacrossFrameRelaynetworks.C.ConfiguretheS0/0interfaceonR1astwosubinterfacesandconfigurepoint-to-pointlinkstoR2andR3.thelastoctet.Answer:CSection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:中心节点在ping两边没有问题.因为rip中心节点可以收到来自两边的路由.但是因为水平分割的问题,中心节点不会讲路由更新再从这个接口发送出去.解决此问题最好的办法就是中心节点设置子接口对每一个分支机构,这样从一个子接口收到的路由更新可以从另外一个字节口发送出去.保证了网络的连通性QUESTION171Refertotheexhibit.ArouterinterfaceisbeingconfiguredforFrameRelay.However,astheexhibitshows,therouterwillnotacceptthecommandtoconfiguretheLMItype.Whatistheproblem?A.TheinterfacedoesnotsupportFrameRelayconnections.B.TheinterfacedoesnothaveanIPaddressassignedtoityet.C.Theinterfacerequiresthatthenoshutdowncommandbeconfiguredfirst.D.theinterfacerequiresthattheencapsulationframe-relaycommandbeconfiguredfirst.Answer:DSection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:串口的默认封装为hdlc,要先改变封装类型然后在改变封装的type,所以我闷在配置FR的时候先要进行FR的封装然后才改变FR的typeQUESTION172Refertotheexhibit.TwobuildingsontheSanJosecampusofasmallcompanymustbeconnectedtouseEthernetwithabandwidthofatleast100Mbps.Thecompanyisconcernedaboutpossibleproblemsfromvoltagepotentialdifferencebetweenthetwobuildings.Whichmediatypeshouldbeusedfortheconnection?A.UTPcableB.STPcableC.CoaxialcableD.FiberopticcableAnswer:DSection:Chapter1:IntroductionExplanation/Reference:QUESTION173UsershavebeencomplainingthattheirFrameRelayconnectiontothecorporatesiteisveryslow.Thenetworkadministratorsuspectsthatthelinkisoverloaded.BasedonthepartialoutputoftheRouter#showframerelaypvccommandshowninthegraphic,whichoutputvalueindicatestothelocalrouterthattrafficsenttothecorporatesiteisexperiencingcongestion?A.DLCI=100B.lasttimePVCstatuschanged00:25:40C.inBECNpackets192D.inFECNpackets147E.inDEpackets0Answer:CSection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:BECN为后向拥塞指示，FECN为前向拥塞指示QUESTION174Refertotheexhibit.Arouterbootstothepromptshownintheexhibit.Whatdoesthissignify,andhowshouldthenetworkadministratorrespond?A.ThispromptsignifiesthattheconfigurationfilewasnotfoundinNVRAM.Thenetworkadministratorshouldfollowthepromptstoenterabasicconfiguration.B.Thepromptsignifiesthattheconfigurationfilewasnotfoundinflashmemory.ThenetworkadministratorshoulduseTFTPtotransferaconfigurationfiletotherouter.C.ThepromptsignifiesthattheIOSimageinflashmemoryisinvalidorcorrupted.ThenetworkadministratorshoulduseTFTPtotransferanIOSimagetotherouter.D.Thepromptsignifiesthattheroutercouldnotauthenticatetheuser.ThenetworkadministratorshouldmodifytheIOSimageandreboottherouter.Answer:CSection:Chapter5:ManagingCiscoIOSExplanation/Reference:当路由器进入了rommon模式之下.我们首先要做的就是给其灌入IOS使用TFTPQUESTION175Refertotheexhibit.GivethisoutputforSwitchC,whatshouldthenetworkadministrator\'snextactionbe?A.CheckthetrunkencapsulationmodeforSwitchC\'sfa0/1port.B.ChecktheduplexmodeforSwitchC\'sfa0/1port.C.ChecktheduplexmodeforSwitchA\'sfa0/2port.D.CheckthetrunkencapsulationmodeforSwitchA\'sfa0/2port.Answer:CSection:Chapter9:SwitchingExplanation/Reference:出现错误报文,可能是因为双工不匹配或者链路不稳定等因素造成的QUESTION176Refertotheexhibit.Whichofthesestatementscorrectlydescribesthestateoftheswitchoncethebootprocesshasbeencompleted?A.AsFastEthernet0/12willbethelasttocomeup,itwillnotbeblockedbySTP.B.Remoteaccessmanagementofthisswitchwillnotbepossiblewithoutconfigurationchange.C.MoreVLANswillneedtobecreatedforthisswitch.D.TheswitchwillneedadifferentIOScodeinordertosupportVLANsandSTP.Answer:BSection:Chapter10:VLANExplanation/Reference:vlan1关闭的是intvlan1这个虚拟端口，关闭的并不是vlan1，这个vlan也是无法关闭的。QUESTION177Refertotheexhibit.Whichofthesestatementscorrectlydescribesthestateoftheswitchoncethebootprocesshasbeencompleted?A.OnlythedefaultVLANsareconfiguredonSwitchA.B.SwitchAdoesnothaveaVTPdomainnameconfigured.C.VTPpruningneedstobeenabledonSwitchA.D.SwitchCneedstohavetheVTPdomainnameconfigured.E.SwitchBisintransparentmode.Answer:BSection:Chapter10:VLANExplanation/Reference:vtp同步需要在一个domain之内的交换局同步.并且password需要一直。B和D都可以理解，但是题库要求要对状态的描述，从逻辑上来说B正确QUESTION178Refertotheexhibit.ThenetworkadministratorhasdiscorveredthattheVLANconfigurationofSwitchCisnotsynchronizedwiththerestoftheswitchednetwork.WhyisSwitchCnotreceivingVTPupdates?A.SwitchBisnotrelayingVTPadvertisementstoSwitchC.B.SwitchChasfewerexistingVLANsthandoesSwitchA.C.SwitchAsupportsagreaternumberofVLANsthandoesSwitchC.D.SwitchChasrevisionnumberhigherthanthatbeingadvertisedE.SwitchCshouldbeoperatinginVTPservermodetorecevieVTPupdates.F.SwitchBshouldbeoperatinginVTPserverorclientmodetorelayVTPupdates.Answer:DSection:Chapter10:VLANExplanation/Reference:vtp在通告或者同步vlan信息的时候是高的去通告其他所有的都同步高的,并不是同步server的QUESTION179addresseswilltherebepersubnet?A.8subnets,31hostsB.8subnets,32hostsC.16subnets,30hostsD.16subnets,32hostsE.AClassBaddresscan\'tbesubnettedintothefourthoctet.Answer:CSection:Chapter3:IPAddressingandVLSMExplanation/Reference:23-27为的掩码.那么将接用4位主机位所以可以划分成16个子网.27为掩码的可用地址为2的5次方-2=30个可用主机地址QUESTION180ATCP/IPTransferisdiagrammedintheexhibit.Awindowsizeofthreehasbeennegotiatedforthistransfer.WhichmessagewillbereturnedfromthereceivertothesenderaspartofthisTCP/IPtransfer?A.SendACK1-3B.SendACK3C.SendACK4D.SendACK4-6E.SendACK6F.SendACK7Answer:CSection:Chapter2:TCP/IPExplanation/Reference:考点：考查TCP的确认机制。在接收到第n个数据包后，发送给对方的数据序列号为n+1，一次性确认前面n个数据包。综上所述，发送ack=4的数据包。QUESTION181Refertotheexhibit.WhyisflashmemoryerasedpriortoupgradingtheIOSimagefromtheTFTPserver?A.TheroutercannotverifythattheCiscoIOSimagecurrentlyinflashisvalidB.FlashmemoryonCiscorouterscancontainonlyasingleIOSimage.C.Erasingcurrentflashcontentisrequestedduringthecopydialog.D.Inorderfortheroutertousethenewimageasthedefault,itmustbetheonlyIOSimageinflash.Answer:CSection:Chapter5:ManagingCiscoIOSExplanation/Reference:QUESTION182Refertotheexhibit.Whatisthemeaningofthetermdynamicasdisplayedintheoutputoftheshowframe-relaymapcommandshown?A.TheSerial0/0interfaceispassingtraffic.B.TheDLCI100wasdynamicallyallocatedbytherouter.D.TheDLCI100willbedynamicallychangedasrequiredtoadapttochangesintheFrameRelaycloud.ARP.Answer:ESection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:dynamic意思是映射是通过翻转ARP获取，而不是手动设置QUESTION183Whatcanbedonetosecurethevirtualterminalinterfacesonarouter?(Choosetwo.)A.Administrativelyshutdowntheinterface.B.Physicallysecuretheinterface.C.Createanaccesslistandapplyittothevirtualterminalinterfaceswiththeaccess-groupcommand.D.Configureavirtualterminalpasswordandloginprocess.E.Enteranaccesslistandapplyittothevirtualterminalinterfacesusingtheaccess-classcommand.Answer:DESection:Chapter7:SecurityExplanation/Reference:保障vty线路的安全,第一可以配置密码.第二可以使用ACL来控制访问的IP地址.但是ACL在vty线路下调用的命令是access-class,这个大家需要注意QUESTION184Refertotheexhibit.InthisVLSMaddressingscheme,whatsummaryaddresswouldbesentfromrouterA?Answer:ASection:Chapter6:IPRoutingExplanation/Reference:QUESTION185Refertotheexhibit.Theshowvtpstatuscommandisexecutedataswitchthatisgeneratingtheexhibitoutput.Whichstatementistrueforthisswitch?A.TheswitchforwardsitsVLANdatabasetootherswitchesintheICNDVTPdomain.B.TheconfigurationrevisionnumberincrementseachtimetheVLANdatabaseisupdated.C.TheswitchforwardsVTPupdatesthataresentbyotherswitchesintheICNDdomain.D.TheVLANdatabaseisupdatedwhenVTPinformationisreceivedfromotherswitches.Answer:CSection:Chapter10:VLANExplanation/Reference:透明模式下revisionnumber不增加，不接受更新但能转发更新QUESTION186Refertotheexhibit.Giventheoutputforthiscommand,iftherouterIDhasnotbeenmanuallyset,whatrouterIDwillOSPFuseforthisRouterD?Answer:CSection:Chapter6:IPRoutingExplanation/Reference:正确答案为:C选取最大LOOPBACK口地址QUESTION187Refertotheexhibit.Whatcouldbepossiblecausesforthe"Serial0/0isdown"interfacestatus?(Choosetwo.)A.ALayer1problemexists.B.Thebandwidthissettoolow.C.Aprotocolmismatchexists.D.Anincorrectcableisbeingused.E.ThereisanincorrectIPaddressontheSerial0/0interface.Answer:ADSection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:接口双down，证明物理层就有问题，所以这一题主要排查的问题首先是物理层QUESTION188Beforeinstallinganew,upgradedversionoftheIOS,whatshouldbecheckedontherouter,andwhichcommandshouldbeusedtogatherthisinformation?(Choosetwo.)A.theamountofavailableROMB.theamountofavailableflashandRAMmemoryC.theversionofthebootstrapsoftwarepresentontherouterD.showversionE.showprocessesF.showrunning-configAnswer:BDSection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:在升级IOS的时候，我们主要注意以下几点：1.flash空间是否充足2.查看设备的版本对是否支持IOSQUESTION189Refertotheexhibit.WhichtwostatementsaretrueaboutinterVLANroutinginthetopologythatisshownintheexhibit?(Choosetwo.)A.HostEandhostFusethesameIPgatewayaddress.B.Router1andSwitch2shouldbeconnectedviaacrossovercable.C.Router1willnotplayaroleincommunicationsbetweenhostAandhostD.D.TheFastEthernet0/0interfaceonRouter1mustbeconfiguredwithsubinterfaces.E.Router1needsmoreLANinterfacestoaccommodatetheVLANsthatareshownintheexhibit.F.TheFastEthernet0/0interfaceonRouter1andSwitch2trunkportsmustbeconfiguredusingthesameencapsulationtype.Answer:DFSection:Chapter10:VLANExplanation/Reference:在单臂路由的时候，首先路由器的接口要配置子接口针对每一个vlan一个逻辑接口，其次交换机的接口要配置trunk，并且封装要和路由器接口的封装一致QUESTION190Refertotheexhibit.WhichtwostatementsaretrueabouttheloopbackaddressthatisconfiguredonRouterB?(Choosetwo.)A.ItensuresthatdatawillbeforwardedbyRouterB.B.ItprovidesstabilityfortheOSPFprocessonRouterB.D.ItdecreasesthemetricforroutesthatareadvertisedfromRouterB.E.ItindicatesthatRouterBshouldbeelectedtheDRfortheLAN.Answer:BCSection:Chapter6:IPRoutingExplanation/Reference:loopback口作为在ospf当中，第一个ospf优先选择loopback作为RID，loopback作为RID可以保障ospf的稳定性，因为loopback接口只有当路由器不可用的时候才会downQUESTION191AnetworkadministratorisexplainingVTPconfigurationtoanewtechnician.WhatshouldthenetworkadministratortellthenewtechnicianaboutVTPconfiguration?(Choosethree.)A.AswitchintheVTPclientmodecannotupdateitslocalVLANdatabase.B.AtrunklinkmustbeconfiguredbetweentheswitchestoforwardVTPupdates.C.AswitchintheVTPservermodecanupdateaswitchintheVTPtransparentmode.D.AswitchintheVTPtransparentmodewillforwardupdatesthatitreceivestootherswitches.E.AswitchintheVTPservermodeonlyupdatesswitchesintheVTPclientmodethathaveahigherVTPrevisionnumber.F.AswitchintheVTPservermodewillupdateswitchesintheVTPclientmoderegardlessoftheconfiguredVTPdomainmembership.Answer:ABDSection:Chapter10:VLANExplanation/Reference:VTP的三个角色，以及VTP的特性，第一Client不能够增删改vlan信息，也就是不能update自己本地的vlandatabase，第二在配置vtp的两台交换机中间必须是trunk口用来传递vtp的通告以及vtp的根新第三在transparent模式的交换机讲转发它所收到的vtp更新以及vtp通告信息QUESTION192WhichtwolocationscanbeconfiguredasasourcefortheIOSimageinthebootsystemcommand?(Choosetwo.)A.RAMB.NVRAMC.flashmemoryD.HTTPserverE.TFTPserverF.TelnetserverAnswer:CESection:Chapter5:ManagingCiscoIOSExplanation/Reference:此题是一个概念性的题目，设备在读取IOS的时候有两种方式。一种是本地flash中的。一种是存储在TFTPserver中的flash叶就是网络读取QUESTION193WhataretworeasonsanetworkadministratorwoulduseCDP?(Choosetwo.)A.toverifythetypeofcableinterconnectingtwodevicesB.todeterminethestatusofnetworkservicesonaremotedeviceC.toobtainVLANinformationfromdirectlyconnectedswitchesD.toverifyLayer2connectivitybetweentwodeviceswhenLayer3failsE.toobtaintheIPaddressofaconnecteddeviceinordertotelnettothedeviceF.todeterminethestatusoftheroutingprotocolsbetweendirectlyconnectedroutersAnswer:DESection:Chapter5:ManagingCiscoIOSExplanation/Reference:CDP是一个二层协议，可以用来确认二层的连通性，以及查看远端3层的IP地址QUESTION194Refertotheexhibit.Bothswitchesareusingadefaultconfiguration.Whichtwodestinationaddresseswillhost4usetosenddatatohost1?(Choosetwo.)A.theIPaddressofhost1B.theIPaddressofhost4C.theMACaddressofhost1D.theMACaddressofhost4E.theMACaddressoftheFa0/0interfaceoftheR1routerF.theMACaddressoftheFa0/1interfaceoftheR1routerAnswer:AFSection:Chapter2:TCP/IPExplanation/Reference:E太网在进行寻址的时候，通过ARP请求道网关的MAC地址，将其封装到Frame的dest地址，Packet的sourceip和destip封装的事自己的IP作为source需要访问的终点的IP作为destIPQUESTION195Refertotheexhibit.Therouterhasbeenconfiguredwiththesecommands:hostnameGatewayinterfaceFastEthernet0/0noshutdowninterfaceFastEthernet0/1noshutdowninterfaceSerial0/0noshutdownWhatarethetworesultsofthisconfiguration?(Choosetwo.)B.HostsontheLANthatisconnectedtoFastEthernet0/1areusingpublicIPaddressing.C.TheaddressofthesubnetsegmentwiththeWWWserverwillsupportsevenmoreservers.D.TheaddressingschemeallowsusersontheInternettoaccesstheWWWserver.E.HostsontheLANthatisconnectedtoFastEthernet0/1willnotbeabletoaccesstheInternetwithoutaddresstranslation.Answer:DESection:Chapter8:NATExplanation/Reference:内网的私有网段要想访问外部，必须使用NAT地址转换。公网是不为私有网段路由的QUESTION196AcompanyisinstallingIPphones.Thephonesandofficecomputersconnecttothesamedevice.Toensuremaximumthroughputforthephonedata,thecompanyneedstomakesurethatthephonetrafficisonadifferentnetworkfromthatoftheofficecomputerdatatraffic.Whatisthebestnetworkdevicetowhichtodirectlyconnectthephonesandcomputers,andwhattechnologyshouldbeimplementedonthisdevice?(Choosetwo.)A.hubB.routerC.switchD.STPE.subinterfacesF.VLANAnswer:CFSection:Chapter10:VLANExplanation/Reference:本题考查的事voice的基本性质，在vocie的时候我们需要一个switch并且配置voicevlanQUESTION197WhataretwobenefitsofusingVTPinaswitchingenvironment?(Choosetwo.)A.Itallowsswitchestoreadframetags.B.ItallowsportstobeassignedtoVLANsautomatically.C.ItmaintainsVLANconsistencyacrossaswitchednetwork.D.ItallowsframesfrommultipleVLANstouseasingleinterface.E.ItallowsVLANinformationtobeautomaticallypropagatedthroughouttheswitchingenvironment.Answer:CESection:Chapter10:VLANExplanation/Reference:VTP可以让交换网络中位置vlan的一致性，也就是版本号的同步QUESTION198(Choosetwo.)D.ItconfigurestheroutertosendanytrafficforanunknowndestinationouttheinterfacewiththeaddressE.Itusesthedefaultadministrativedistance.F.Itisaroutethatwouldbeusedlastifotherroutestothesamedestinationexist.Answer:AESection:Chapter6:IPRoutingExplanation/Reference:QUESTION199WhataretwoadvantagesofLayer2Ethernetswitchesoverhubs?(Choosetwo.)A.decreasingthenumberofcollisiondomainsB.filteringframesbasedonMACaddressesC.allowingsimultaneousframetransmissionsD.increasingthesizeofbroadcastdomainsE.increasingthemaximumlengthofUTPcablingbetweendevicesAnswer:BCSection:Chapter1:IntroductionExplanation/Reference:SW和HUB的区别在于，SW可以对frame给予mac地址的过滤，而HUB只是傻瓜的转发，没有MAC地址学习的功能，SW是一个全双工的设备。而hub工作在半双工当中所以hub不支持同时传输Frame，它使用的是CSMA/CD机制QUESTION200Refertotheexhibit.AnetworkassociateneedstoconfiguretheswitchesandrouterinthegraphicsothatthehostsinVLAN3andVLAN4cancommunicatewiththeenterpriseserverinVLAN2.WhichtwoEthernetsegmentswouldneedtobeconfiguredastrunklinks?(Choosetwo.)A.AB.BC.CD.DE.EF.FAnswer:CFSection:Chapter10:VLANExplanation/Reference:本题考查的事vlan间路由的问题。要让不同的vlan进行通信。那么SW与SW之间的链路，SW与router之间的链路都需要配置成为trunk，用来传递不同vlan的数据QUESTION201WhichtwovaluesareusedbySpanningTreeProtocoltoelectarootbridge?(Choosetwo.)A.amountofRAMB.bridgepriorityC.IOSversionD.IPaddressE.MACaddressF.speedofthelinksAnswer:BESection:Chapter9:SwitchingExplanation/Reference:STP在选举RB的时候依靠的事桥ID，桥ID包含两个部分组成一个是桥优先级另一部分就是桥macQUESTION202Refertotheexhibit.Assumethattheroutingprotocolreferencedineachchoicebelowisconfiguredwithitsdefaultsettingsandthegivenroutingprotocolisrunningonalltherouters.Whichtwoconditionalroutingprotocolmentioned?(Choosetwo.)A.IfOSPFistheroutingprotocol,thepathwillbefromR1toR3toR4toR5.B.IfOSPFistheroutingprotocol,thepathwillbefromR1toR2toR5.C.IfOSPFistheroutingprotocol,thepathwillbefromR1toR5.D.IfRIPv2istheroutingprotocol,thepathwillbefromR1toR3toR4toR5.E.IfRIPv2istheroutingprotocol,thepathwillbefromR1toR5.Answer:AESection:Chapter6:IPRoutingExplanation/Reference:路由协议选路的问题。上图表明了链路带宽，如果是使用RIP协议的话。那么它选路和链路带宽没有关系。使用的是hop，所以选择hop最小的，而ospf在进行选路过程中看的事带宽，使用10的8次方处以带宽计算出来的度量最小的QUESTION203Refertotheexhibit.AnetworkadministratorisaddingtwonewhoststoSwitchA.Whichthreevaluescouldbeusedfortheconfigurationofthesehosts?(Choosethree.)Answer:ACFSection:Chapter10:VLANExplanation/Reference:单臂路由的问题。单臂路由子接口的IP就是主机的default-gatewayQUESTION204Anetworkadministratorchangestheconfigurationregisterto0x2142andrebootstherouter.Whataretworesultsofmakingthischange?(Choosetwo.)A.TheIOSimagewillbeignored.B.Therouterwillprompttoenterinitialconfigurationmode.C.TherouterwillboottoROM.D.AnyconfigurationentriesinNVRAMwillbeignored.E.Theconfigurationinflashmemorywillbebooted.Answer:BDSection:Chapter5:ManagingCiscoIOSExplanation/Reference:0x2142寄存器值，是在启动的时候不调用nvram中的start-config，会按照初始状态进行启动QUESTION205routeandsenttoR1.WhichtwopacketdestinationaddresseswillR1forwardtoR2?(Choosetwo.)Answer:BESection:Chapter6:IPRoutingExplanation/Reference:QUESTION206WhichthreestatementsaretypicalcharacteristicsofVLANarrangements?(Choosethree.)A.AnewswitchhasnoVLANsconfigured.B.ConnectivitybetweenVLANsrequiresaLayer3device.C.VLANstypicallydecreasethenumberofcollisiondomains.D.EachVLANusesaseparateaddressspace.E.AswitchmaintainsaseparatebridgingtableforeachVLAN.F.VLANscannotspanmultipleswitches.Answer:BDESection:Chapter10:VLANExplanation/Reference:vlan的特征：vlan之间默认是不能够通信的，需哟啊通信则需要第三层设备进行路由一个vlan就是一个逻辑子网sw为每一个vlan维护一个单独的桥接表，这个其实比较难以理解，但是我们知道一个vlan就是一个逻辑子网，那么不同的vlan对于交换机而言当然是不同的表项了。QUESTION207QoSpoliciesareappliedontheswitchesofaLAN.Whichtypeofcommandwillshowtheeffectsofthepolicyinrealtime?A.showcommandB.debugcommandC.configurationcommandD.rommoncommandAnswer:BSection:Chapter9:SwitchingExplanation/Reference:问什么命令能够实时的查看policies的结果。实时查看我们只能开启debug来看是否有匹配到Qos的policiesQUESTION208WhichcommandwillshowtheMACaddressesofstationsconnectedtoswitchports?A.showmac-addressB.showarpC.showtableD.showswitchportAnswer:BSection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:查看station连接switch的端口。我们只需要查看arp的解析就OK了。也就是showarp，因为stations有流量需要访问。就会向switch发送arp的请求，showmacaddress-table也是可以看得到的。但是A的命令是错误的QUESTION209WhatisthenameoftheVTPmodeofoperationthatenablesaswitchtoforwardonlyVTPadvertisementswhilestillpermittingtheeditingoflocalVLANinformation?A.serverB.clientC.tunnelD.transparentAnswer:DSection:Chapter10:VLANExplanation/Reference:哪一种vtp的mode转发vtp通告并且维护自己本地的vlan信息，这种情况就是透明模式的特点QUESTION210WhichportstateisintroducedbyRapid-PVST?A.learningB.listeningC.discardingD.forwardingAnswer:CSection:Chapter9:SwitchingExplanation/Reference:Rpvst新增了一种端口角色----discardingQUESTION211Whatspeedsmustbedisabledinamixed802.11b/gWLANtoallowonly802.11gclientstoconnect?A.6,9,12,18B.1,2,5.5,6C.5.5,6,9,11D.1,2,5.5,11Answer:DSection:Chapter11:WirelessExplanation/Reference:1,2,5.5,11是802.11b的传输速率QUESTION212Refertotheexhibit.WhichVLSMmaskwillallowfortheappropriatenumberofhostaddressesforNetworkA?A./25B./26C./27D./28Answer:ASection:Chapter3:IPAddressingandVLSMExplanation/Reference:66个主机的话。那么我们2的X次方-2要大于等于66，很容易算出掩码为/25QUESTION213Refertotheexhibit.WhichsubnetmaskwillplaceallhostsonNetworkBinthesamesubnetwiththeleastamountofwastedaddresses?Answer:BSection:Chapter3:IPAddressingandVLSMExplanation/Reference:310个主机,那么2的X次方-2>=310QUESTION214Refertotheexhibit.WhichmaskiscorrecttousefortheWANlinkbetweentheroutersthatwillprovideconnectivitywhilewastingtheleastamountofaddresses?A./23B./24C./25D./30Answer:DSection:Chapter3:IPAddressingandVLSMExplanation/Reference:中间的point-to-point链路最节省地址的掩码就是/30QUESTION215Refertotheexhibit.Whatisthemostappropriatesummarizationfortheseroutes?Answer:BSection:Chapter6:IPRoutingExplanation/Reference:做汇总.显然我们要在第三个位组做汇总,通过二进制换算我们可以知道0-3最多只需要2bit就能表示0-3所有的数字.所以24-2得到掩码/22QUESTION216WhichtwotasksdoestheDynamicHostConfigurationProtocolperform?(Choosetwo.)A.SettheIPgatewaytobeusedbythenetwork.B.PerformhostdiscoveryusedDHCPDISCOVERmessage.C.ConfigureIPaddressparametersfromDHCPservertoahost.D.Provideaneasymanagementoflayer3devices.E.MonitorIPperformanceusingtheDHCPserver.F.AssignandrenewIPaddressfromthedefaultpool.Answer:CFSection:Chapter2:TCP/IPExplanation/Reference:考查的是DHCP提供的服务.DHCP主要的服务时向主机提供ip地址,并且如果你要添加或者更新ip地址.需要在dhcppool中添加就OK了QUESTION217Whichtwobenefitsareprovidedbyusingahierarchicaladdressingnetworkaddressingscheme?(Choosetwo.)A.reducesroutingtableentriesB.auto-negotiationofmediaratesC.efficientutilizationofMACaddressesD.dedicatedcommunicationsbetweendevicesE.easeofmanagementandtroubleshootingAnswer:AESection:Chapter1:IntroductionExplanation/Reference:提供分层的网络地址规划,第一个我们容易实时路由汇总从而减少路由条目,第二给我们在管理方面还错误排查方面提供了便利QUESTION218WhichtwobenefitsareprovidedbycreatingVLANs?(Choosetwo.)A.addedsecurityB.dedicatedbandwidthC.providessegmentationD.allowsswitchestoroutetrafficbetweensubinterfacesE.containscollisionsAnswer:ACSection:Chapter10:VLANExplanation/Reference:vlan的主要特点第一个提供网络安全因为默认vlan间是不能够通信的,第二个提供了网络分段.因为一个vlan就是一个逻辑子网QUESTION219WhichtwolinkprotocolsareusedtocarrymultipleVLANsoverasinglelink?(Choosetwo.)A.VTPB.802.1qC.IGPD.ISLE.802.3uAnswer:BDSection:Chapter10:VLANExplanation/Reference:trunk的封装就两个,一个位ieee公有的802.1q一个位cisco私有的isl封装类型QUESTION220Whichtwoprotocolsareusedbybridgesand/orswitchestopreventloopsinalayer2network?(Choosetwo.)A.802.1dB.VTPC.802.1qD.STPE.SAPAnswer:ADSection:Chapter9:SwitchingExplanation/Reference:阻止二层的环路就是生成树协议.这里802.1d以及stp都是阻止二层环路的有效手段QUESTION221Answer:ASection:Chapter3:IPAddressingandVLSMExplanation/Reference:QUESTION222Theipsubnetzerocommandisnotconfiguredonarouter.WhatwouldbetheIPaddressofEthernet0/0Answer:CSection:Chapter3:IPAddressingandVLSMExplanation/Reference:QUESTION223Answer:BSection:Chapter3:IPAddressingandVLSMExplanation/Reference:QUESTION224A.510B.1022C.1024D.2048Answer:BSection:Chapter3:IPAddressingandVLSMExplanation/Reference:QUESTION225WheredoesroutingoccurwithintheDoDTCP/IPreferencemodel?A.applicationB.internetC.networkD.transportAnswer:BSection:Chapter2:TCP/IPExplanation/Reference:路由在tcp/ip协议栈的internet层注意是DOD模型不是OSI模型QUESTION226WhichVTPmodeiscapableofcreatingonlylocalVLANsanddoesnotsynchronizewithotherswitchesintheVTPdomain?A.clientB.dynamicC.serverD.staticE.transparentAnswer:ESection:Chapter10:VLANExplanation/Reference:vtptransparent的功能为,不同步vlan信息,转发vtp通告可以在本地增删改vlan信息,维护本地的数据库QUESTION227WhichswitchwouldSTPchoosetobecometherootbridgeintheselectionprocess?A.32768:11-22-33-44-55-66B.32768:22-33-44-55-66-77C.32769:11-22-33-44-55-65D.32769:22-33-44-55-66-78Answer:ASection:Chapter9:SwitchingExplanation/Reference:stp选举跟桥首先比较优先级大小.然后比较mac地址大小QUESTION228Aswitchisconfiguredwithallportsassignedtovlan2withfullduplexFastEthernettosegmentexistingdepartmentaltraffic.WhatistheeffectofaddingswitchportstoanewVLANontheswitch?A.Morecollisiondomainswillbecreated.B.IPaddressutilizationwillbemoreefficient.C.Morebandwidthwillberequiredthanwasneededpreviously.D.Anadditionalbroadcastdomainwillbecreated.Answer:DSection:Chapter10:VLANExplanation/Reference:vlan的特性是对广播域的分割.增加广播域的数量,减少广播域的大小因为一个vlan就是一个广播域QUESTION229WhichtwostatementsabouttheuseofVLANstosegmentanetworkaretrue?(Choosetwo.)A.VLANsincreasethesizeofcollisiondomains.B.VLANsallowlogicalgroupingofusersbyfunction.C.VLANssimplifyswitchadministration.D.VLANsenhancenetworksecurity.Answer:BDSection:Chapter10:VLANExplanation/Reference:vlan是一个逻辑分组,Avlan=一个逻辑子网=一个广播域并且vlan间默认是不通信的,从而间接保证了网络的安全QUESTION230Oncorporatenetwork,hostsonthesameVLANcancommunicatewitheachother,buttheyareunabletocommunicatewithhostsondifferentVLANs.WhatisneededtoallowcommunicationbetweentheVLANs?A.arouterwithsubinterfacesconfiguredonthephysicalinterfacethatisconnectedtotheswitchB.arouterwithanIPaddressonthephysicalinterfaceconnectedtotheswitchC.aswitchwithanaccesslinkthatisconfiguredbetweentheswitchesD.aswitchwithatrunklinkthatisconfiguredbetweentheswitchesAnswer:ASection:Chapter10:VLANExplanation/Reference:考查单臂路由的基本配置,在配置单臂路由的时候.我们要针对每一个需要路由的vlan建立一个子接口.并且配上IP地址.此ip即为host的网关QUESTION231WhenaDHCPserverisconfigured,whichtwoIPaddressesshouldneverbeassignabletohosts?(Choosetwo.)A.networkorsubnetworkIPaddressB.broadcastaddressonthenetworkC.IPaddressleasedtotheLAND.IPaddressusedbytheinterfacesE.manuallyassignedaddresstotheclientsF.designatedIPaddresstotheDHCPserverAnswer:ABSection:Chapter3:IPAddressingandVLSMExplanation/Reference:不能够被主机使用的ip也就是两个.一个网络号或者子网号,还一个就是广播地址QUESTION232WhichstatementdescribestheprocessofdynamicallyassigningIPaddressesbytheDHCPserver?A.Addressesareallocatedafteranegotiationbetweentheserverandthehosttodeterminethelengthoftheagreement.B.Addressesarepermanentlyassignedsothatthehostsusesthesameaddressatalltimes.C.Addressesareassignedforafixedperiodoftime,attheendoftheperiod,anewrequestforanaddressmustbemade.D.Addressesareleasedtohosts,whichperiodicallycontacttheDHCPservertorenewthelease.Answer:DSection:Chapter2:TCP/IPExplanation/Reference:DHCP的主要作用就是向主机提供地址租约,并且租约如果快到期了.主机需要向DHCPserver重新续租QUESTION233WhichnetworkprotocoldoesDNSuse?A.FTPB.TFTPC.TCPD.UDPE.SCPAnswer:DSection:Chapter2:TCP/IPExplanation/Reference:此题答案并不严格,严格讲DNS有两个端口号一个为TCP一个为UDP并且端口号都为53DNS解析用UDP效率高但不能保证完整性DNS服务器之间同步使用TCP保证数据正确QUESTION234Whentwohostsaretryingtocommunicateacrossanetwork,howdoesthehostoriginatingthecommunicationdeterminethehardwareaddressofthehostthatitwantsto"talk"to?A.RARPrequestB.ShowNetworkAddressrequestC.ProxyARPrequestD.ARPrequestE.ShowHardwareAddressrequestAnswer:DSection:Chapter2:TCP/IPExplanation/Reference:host在建立通信,需要通过arp请求来请求道目标IP的mac地址.QUESTION235Host1istryingtocommunicatewithHost2.Thee0interfaceonRouterCisdown.Whichofthefollowingaretrue?(Choosetwo.)A.RouterCwilluseICMPtoinformHost1thatHost2cannotbereached.B.RouterCwilluseICMPtoinformRouterBthatHost2cannotbereached.C.RouterCwilluseICMPtoinformHost1,RouterA,andRouterBthatHost2cannotbereached.D.RouterCwillsendaDestinationUnreachablemessagetype.E.RouterCwillsendaRouterSelectionmessagetype.F.RouterCwillsendaSourceQuenchmessagetype.Answer:ADSection:Chapter6:IPRoutingExplanation/Reference:因为RC的e0口down，所以主机1的数据包到达RC后，RC向主机返回一个icmp的目的地不可达信息。QUESTION236ToconfiguretheVLANtrunkingprotocoltocommunicateVLANinformationbetweentwoswitches,whattworequirementsmustbemet?(Choosetwo.)A.EachendofthetrunklinemustbesettoIEEE802.1Eencapsulation.B.TheVTPmanagementdomainnameofbothswitchesmustbesetthesame.C.Allportsonboththeswitchesmustbesetasaccessports.D.OneofthetwoswitchesmustbeconfiguredasaVTPserver.E.Arollovercableisrequiredtoconnectthetwoswitchestogether.F.AroutermustbeusedtoforwardVTPtrafficbetweenVLANs.Answer:BDSection:Chapter10:VLANExplanation/Reference:两个交换机之间使用VTP的前提？A：必须使用802.1e封装，错误。B：VTP域名必须一致，正确。C：所有端口必须设置为access口，错误。D：其中一个必须设置为sever模式。正确E：使用反转先连接，错误。F：必须使用一个路由中转数据，错误。QUESTION237WhichofthefollowingdescribetheprocessidentifierthatisusedtorunOSPFonarouter?(Choosetwo.)A.Itislocallysignificant.B.Itisgloballysignificant.C.ItisneededtoidentifyauniqueinstanceofanOSPFdatabase.D.ItisanoptionalparameterrequiredonlyifmultipleOSPFprocessesarerunningontherouter.E.AllroutersinthesameOSPFareamusthavethesameprocessIDiftheyaretoexchangeroutinginformation.Answer:ACSection:Chapter6:IPRoutingExplanation/Reference:配置OSPF的时候，ospf后面的进程号的意义：rouerospf#A：本地有意义，正确B：全局有意义，错误C：用于确定一个ospf数据库实例，正确。本地路由器上一个进程号一个数据库。D：这是一个可选参数，错误E：区域中的所有路由必须使用相同的进程号，错误。QUESTION238Whatfunctionsdoroutersperforminanetwork?(Choosetwo.)A.packetswitchingB.accesslayersecurityC.pathselectionD.VLANmembershipassignmentE.bridgingbetweenLANsegmentsF.microsegmentationofbroadcastdomainsAnswer:ACSection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:路由器的作用A：转发数据，正确B：接入层安全，错误。通常由交换机实现。C：路径选择，正确D：VLAN成员分配，错误。E：桥接不同网段，错误。不够准确F：缩小广播域的分割，错误。QUESTION239WhichseriesofcommandswillconfigurerouterR1forLAN-to-LANcommunicationwithrouterR2?TheA.R1(config)#interfaceethernet0R1(config-if)#noshutdownB.R1(config)#interfaceethernet0R1(config-if)#noshutdownC.R1(config)#interfaceserial0R1(config-if)#clockrate56000D.R1(config)#interfaceserial0R1(config-if)#noshutdownE.R1(config)#routerripF.R1(config)#routerripR1(config-router)#version2Answer:ADFSection:Chapter6:IPRoutingExplanation/Reference:QUESTION240AnetworkadministratorwantstoensurethatonlytheservercanconnecttoportFa0/1onaCatalystswitch.TheserverispluggedintotheswitchFa0/1portandthenetworkadministratorisabouttobringtheserveronline.WhatcantheadministratordotoensurethatonlytheMACaddressoftheserverisallowedbyswitchportFa0/1?(Choosetwo.)A.ConfigureportFa0/1toacceptconnectionsonlyfromthestaticIPaddressoftheserver.B.EmployaproprietaryconnectortypeonFa0/1thatisincompatiblewithotherhostconnectors.C.ConfiguretheMACaddressoftheserverasastaticentryassociatedwithportFa0/1.D.BindtheIPaddressoftheservertoitsMACaddressontheswitchtopreventotherhostsfromspoofingtheserverIPaddress.E.ConfigureportsecurityonFa0/1torejecttrafficwithasourceMACaddressotherthanthatoftheserver.F.ConfigureanaccesslistontheswitchtodenyservertrafficfromenteringanyportotherthanFa0/1.Answer:CESection:Chapter9:SwitchingExplanation/Reference:服务器接到f0/1口，有什么方法使仅服务器才能接入？B：静态配置ARPE：portsecurityQUESTION241TheinternetworkinfrastructureofcompanyXYZconsistsofasingleOSPFareaasshowninthegraphic.Thereisconcernthatalackofrouterresourcesisimpedinginternetworkperformance.Aspartofexaminingtherouterresources,theOSPFDRsneedtobeknown.AlltherouterOSPFprioritiesareatthedefaultandtherouterIDsareshownwitheachrouter.WhichroutersarelikelytohavebeenelectedasDR?(Choosetwo.)A.Corp-1B.Corp-2C.Corp-3D.Corp-4E.Branch-1F.Branch-2Answer:DFSection:Chapter6:IPRoutingExplanation/Reference:DR的选举1、一个多路访问网段中选举2、优先级大的当选；优先级相同，RID大的当选。如图中两个椭圆的多路网络中选举。QUESTION242AtwhichlayersoftheOSImodeldoWANsoperate?(Choosetwo.)A.applicationlayerB.sessionlayerC.transportlayerD.networklayerE.datalinklayerF.physicallayerAnswer:EFSection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:QUESTION243Whichroutingprotocolscanbeusedwithintheenterprisenetworkshowninthediagram?(Choosethree.)A.RIPv1B.RIPv2C.IGRPD.OSPFE.BGPF.EIGRPAnswer:BDFSection:Chapter6:IPRoutingExplanation/Reference:由图中可知，使用IGP路由协议，需支持无类路由。QUESTION244Refertothegraphic.R1isunabletoestablishanOSPFneighborrelationshipwithR3.Whatarepossiblereasonsforthisproblem?(Choosetwo.)A.AlloftheroutersneedtobeconfiguredforbackboneArea1.B.R1andR2aretheDRandBDR,soOSPFwillnotestablishneighboradjacencywithR3.C.AstaticroutehasbeenconfiguredfromR1toR3andpreventstheneighboradjacencyfrombeingestablished.D.ThehelloanddeadintervaltimersarenotsettothesamevaluesonR1andR3.E.EIGRPisalsoconfiguredontheserouterswithaloweradministrativedistance.F.R1andR3areconfiguredindifferentareas.Answer:DFSection:Chapter6:IPRoutingExplanation/Reference:影响OSPF邻居形成的几个因素：区域ID，hello时间，网段，认证等A：所有的路由器需配置在区域1,错误B：R1/R2是DR/BDR，所以OSPF不会和R3建立邻居关系.C：配置了静态路由保护了邻居的建立，错误。D：hello包周期不一致，正确E：配置了EIGRP。错误F：R1和R3配置了不同的区域。正确。QUESTION245WhichstatementsaretrueaboutEIGRPsuccessorroutes?(Choosetwo.)A.AsuccessorrouteisusedbyEIGRPtoforwardtraffictoadestination.B.Successorroutesaresavedinthetopologytabletobeusediftheprimaryroutefails.C.Successorroutesareflaggedas"active"intheroutingtable.D.Asuccessorroutemaybebackedupbyafeasiblesuccessorroute.E.Successorroutesarestoredintheneighbortablefollowingthediscoveryprocess.Answer:ADSection:Chapter6:IPRoutingExplanation/Reference:successorrouter是最优路径的下一跳。A:被用作转发流量，正确。B：保存在拓扑库中，当主路由失败时被使用，错误。C：在路由表中显示为active，错误。在数据库中的显示。D：FS做为一个备份路由。正确E：后继路由器存储在邻居表中，错误。在拓扑库中。QUESTION246Refertothediagram.Allhostshaveconnectivitywithoneanother.Whichstatementsdescribetheaddressingschemethatisinuseinthenetwork?(Choosethree.)E.TheLANinterfaceoftherouterisconfiguredwithoneIPaddress.F.TheLANinterfaceoftherouterisconfiguredwithmultipleIPaddresses.Answer:BCFSection:Chapter10:VLANExplanation/Reference:1、子网掩码要使两个IP处于不同网段。2、在路由器上配置子接口，用单臂路由实现通信。QUESTION247Refertothediagram.Whichthreestatementsdescribetherouterportconfigurationandtheswitchportconfigurationasshowninthetopology?(Choosethree.)A.TheRouter1WANportisconfiguredasatrunkingport.B.TheRouter1portconnectedtoSwitch1isconfiguredusingsubinterfaces.C.TheRouter1portconnectedtoSwitch1isconfiguredas10Mbps.D.TheSwitch1portconnectedtoRouter1isconfiguredasatrunkingport.E.TheSwitch1portconnectedtoHostBisconfiguredasanaccessport.F.TheSwitch1portconnectedtoHub1isconfiguredasfullduplex.Answer:BDESection:Chapter10:VLANExplanation/Reference:1、使用单臂路由。2、交换机互联路由器的接口需配置成trunk模式.3、交换机连主机的接口配置成access模式。QUESTION248WhichroutingprotocolswillsupportthefollowingIPaddressingscheme?(Choosethree.)A.RIPversion1B.RIPversion2C.IGRPD.EIGRPE.OSPFAnswer:BDESection:Chapter6:IPRoutingExplanation/Reference:必须使用支持无类路由的路由协议。RIPv1,IGRP属于有类路由协议。QUESTION249Refertothepartialcommandoutputshown.Whichtwostatementsarecorrectregardingtherouterhardware?(Choosetwo.)A.TotalRAMsizeis32KB.B.TotalRAMsizeis16384KB(16MB).C.TotalRAMsizeis65536KB(64MB).D.Flashsizeis32KB.E.Flashsizeis16384KB(16MB).F.Flashsizeis65536KB(64MB).Answer:CESection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:QUESTION250TheEthernetnetworksconnectedtorouterR1inthegraphichavebeensummarizedforrouterR2assummary?(Choosetwo.)Answer:ADSection:Chapter6:IPRoutingExplanation/Reference:QUESTION251Theshowinterfacesserial0/0commandresultedintheoutputshowninthegraphic.Whatarepossiblecausesforthisinterfacestatus?(Choosethree.)A.Theinterfaceisshutdown.B.Nokeepalivemessagesarereceived.C.Theclockrateisnotset.D.Noloopbackaddressisset.E.Nocableisattachedtotheinterface.F.Thereisamismatchintheencapsulationtype.Answer:BCFSection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:串口通过keepalive包保活端口。协议层down通常是时钟，封装，线缆使用不对造成。QUESTION252WhichofthefollowingdescribeprivateIPaddresses?(Choosetwo.)A.addresseschosenbyacompanytocommunicatewiththeInternetB.addressesthatcannotberoutedthroughthepublicInternetC.addressesthatcanberoutedthroughthepublicInternetD.aschemetoconservepublicaddressesE.addresseslicensedtoenterprisesorISPsbyanInternetregistryorganizationAnswer:BDSection:Chapter3:IPAddressingandVLSMExplanation/Reference:私有地址的特性A：可以和互联网通信，错误B：不能和互联网通信，正确。C：能被互联网路由,错误D：用于节省IP地址，正确。通过nat实现。E：需要经过授权使用，错误。QUESTION253Refertotheexhibit.Thenetworkshowninthediagramisexperiencingconnectivityproblems.Whichofthefollowingwillcorrecttheproblems?(Choosetwo.)Answer:BDSection:Chapter10:VLANExplanation/Reference:考查VLSM。网关和主机IP需在同一个子网。路由器子接口IP为这个vlan中主机的网关QUESTION254AnetworkassociateistryingtounderstandtheoperationoftheFLDCorporationbystudyingthenetworkintheexhibit.TheassociateknowsthattheserverinVLAN4providesthenecessaryresourcestosupporttheuserhostsintheotherVLANs.Theassociateneedstodeterminewhichinterfacesareaccessports.Whichinterfacesareaccessports?(Choosethree.)A.Switch1-Fa0/2B.Switch1-Fa0/9C.Switch2-Fa0/3D.Switch2-Fa0/4E.Switch2-Fa0/8F.Router-Fa1/0Answer:ACDSection:Chapter10:VLANExplanation/Reference:接主机的都需要设置为access口QUESTION255Refertotheexhibit.WhichdestinationaddresseswillHostAusetosenddatatoHostB?(Choosetwo.)A.theIPaddressofSwitch1B.theIPaddressofRouter1Fa0/0C.theIPaddressofHostBD.theMACaddressofSwitch1E.theMACaddressofRouter1Fa0/0F.theMACaddressofHostBAnswer:CESection:Chapter6:IPRoutingExplanation/Reference:QUESTION256Thenetworksecuritypolicyrequiresthatonlyonehostbepermittedtoattachdynamicallytoeachswitchinterface.Ifthatpolicyisviolated,theinterfaceshouldshutdown.Whichtwocommandsmustthenetworkadministratorconfigureonthe2950Catalystswitchtomeetthispolicy?(Choosetwo.)A.Switch1(config-if)#switchportport-securitymaximum1B.Switch1(config)#mac-address-tablesecureC.Switch1(config)#access-list10permitiphostD.Switch1(config-if)#switchportport-securityviolationshutdownE.Switch1(config-if)#ipaccess-group10Answer:ADSection:Chapter9:SwitchingExplanation/Reference:QUESTION257commandswillaccomplishthis?(Choosetwo.)Answer:CDSection:Chapter6:IPRoutingExplanation/Reference:考点：静态路由的配置方式下一跳可以写出口和邻居IPQUESTION258WhatshouldbedonepriortobackingupanIOSimagetoaTFTPserver?(Choosethree.)A.Makesurethattheservercanbereachedacrossthenetwork.B.CheckthatauthenticationforTFTPaccesstotheserverisset.C.AssurethatthenetworkserverhasadequatespacefortheIOSimage.D.Verifyfilenamingandpathrequirements.E.Makesurethattheservercanstorebinaryfiles.F.AdjusttheTCPwindowsizetospeedupthetransfer.Answer:ACDSection:Chapter5:ManagingCiscoIOSExplanation/Reference:考点：考查升级IOS时的注意事项1、确保网络连通性，2、确保设备有存放IOS的空间，3、确认文件的路径和名字综上所述，ACD。QUESTION259Whatarethepossibletrunkingmodesforaswitchport?(Choosethree.)A.transparentB.autoC.onD.desirableE.clientF.forwardingAnswer:BCDSection:Chapter9:SwitchingExplanation/Reference:考点：考查交换机在trunk模式下的模式auto：不会主动发DTP信息on：强制成为trunk，也主动发DTP信息desirable：DTP主动模式，发DTP和对方协商QUESTION260beassignedtohostsinthethirdsubnetiftheipsubnet-zerocommandisconfiguredontherouter?(Choosethree.)Answer:ACDSection:Chapter3:IPAddressingandVLSMExplanation/Reference:子网。划分为8个子网，网络位向主机位借了三位。八个子网分别为：QUESTION261Refertothegraphic.Host1cannotreceivepacketsfromHost2.AssumingthatRIPv1istheroutingprotocolinuse,whatiswrongwiththeIPconfigurationinformationshown?(Choosetwo.)A.Thefa0/1interfaceofrouterR2hasbeenassignedabroadcastaddress.B.Thefa0/1networkonrouterR2overlapswiththeLANattachedtoR1.C.Host2hasbeenassignedtheincorrectsubnetmask.E.Host2onrouterR2isonadifferentsubnetthanitsgateway.Answer:BCSection:Chapter6:IPRoutingExplanation/Reference:C：正确D：明显和给出信息不同E：处于同一个网段，错误。QUESTION262WhatarethreevalidreasonstoassignportstoVLANsonaswitch?(Choosethree.)A.tomakeVTPeasiertoimplementB.toisolatebroadcasttrafficC.toincreasethesizeofthecollisiondomainD.toallowmoredevicestoconnecttothenetworkE.tologicallygrouphostsaccordingtofunctionF.toincreasenetworksecurityAnswer:BEFSection:Chapter10:VLANExplanation/Reference:考点：考查vlan的特性，选出三个把端口分配到vlan的原因。A:使VTP更容易部署，错误，答非所问B：限制广播流量，正确C：较少冲突域的范围，错误，没有这个作用D：允许更多的设备接入，错误，答非所问E：逻辑划分网段，正确，一个vlan一个网段。F：增加网络安全，正确。不同vlan不能直接通信。QUESTION263Refertothetopologyshownintheexhibit.WhichportswillbeSTPdesignatedportsifallthelinksareoperatingatthesamebandwidth?(Choosethree.)A.SwitchA-Fa0/0B.SwitchA-Fa0/1C.SwitchB-Fa0/0D.SwitchB-Fa0/1E.SwitchC-Fa0/0F.SwitchC-Fa0/1Answer:BCDSection:Chapter9:SwitchingExplanation/Reference:B的mac最小为根桥，B的俩端口为指定端口.A的F0/0和C的F0/0为根端口。A的mac较小，A的F0/1为指定端口，C的F0/1堵塞QUESTION264WhichstatementsdescribetwoofthebenefitsofVLANTrunkingProtocol?(Choosetwo.)A.VTPallowsroutingbetweenVLANs.B.VTPallowsasingleswitchporttocarryinformationtomorethanoneVLAN.C.VTPallowsphysicallyredundantlinkswhilepreventingswitchingloops.D.VTPsimplifiesswitchadministrationbyallowingswitchestoautomaticallyshareVLANconfigurationinformation.E.VTPhelpstolimitconfigurationerrorsbykeepingVLANnamingconsistentacrosstheVTPdomain.F.VTPenhancessecuritybypreventingunauthorizedhostsfromconnectingtotheVTPdomain.Answer:DESection:Chapter10:VLANExplanation/Reference:考点：考查VTP的特性A:允许vlan间路由，错误，答非所问B：允许单一链路承载多个vlan信息，错误，答非所问C：允许物理冗余，错误，这个是STP的功能。D：自动分享vlan配置信息，正确。E：减少vtp域中vlan名字错误配置，正确，仅需配置一个，其他的自带学习，减少配置量从而减少错误概率。F：增强安全性，未通过认证的主机不能加入。错误。没有这个功能。QUESTION265WhataretworesultsofenteringtheSwitch(config)#vtpmodeclientcommandonaCatalystswitch?(Choosetwo.)A.TheswitchwillignoreVTPsummaryadvertisements.B.TheswitchwillforwardVTPsummaryadvertisements.C.TheswitchwillprocessVTPsummaryadvertisements.D.TheswitchwilloriginateVTPsummaryadvertisements.E.Theswitchwillcreate,modifyanddeleteVLANsfortheentireVTPdomain.Answer:BCSection:Chapter10:VLANExplanation/Reference:考点：考查vtp的client模式特性，不能增加，删除，修改vlan，只能从sever的报文中接收。A：忽略VTP信息，错误B：转发vtp信息，正确C：处理vtp信息，正确D：自己产生vtp通告，错误E：创建，修改，删除vlan，错误QUESTION266thathasbeennewlyconnectedtothenetwork.Whichprotocolswereusedduringthetest?(Choosetwo.)A.ARPB.CDPC.DHCPD.DNSE.ICMPAnswer:AESection:Chapter2:TCP/IPExplanation/Reference:考点：ping的数据包处理过程，涉及两个协议。ARP,用于获取目的mac地址；icmp，ping调用的协议。QUESTION267Refertotheexhibit.HostAistosenddatatoHostB.HowwillRouter1handlethedataframereceivedfromHostA?(Choosethree.)A.Router1willstripoffthesourceMACaddressandreplaceitwiththeMACaddressontheforwardingFastEthernetinterface.B.Router1willstripoffthesourceIPaddressandreplaceitwiththeIPaddressontheforwardingFastEthernetinterface.C.Router1willstripoffthedestinationMACaddressandreplaceitwiththeMACaddressofHostB.D.Router1willstripoffthedestinationIPaddressandreplaceitwiththeIPaddressofHostB.E.Router1willforwardthedataframeoutinterfaceFastEthernet0/1.F.Router1willforwardthedataframeoutinterfaceFastEthernet0/2.Answer:ACFSection:Chapter6:IPRoutingExplanation/Reference:考点：考查以太网环境中数据包从源到目的过程源/目的ip和mac地址的变化。源目IP不变，源目mac变A：R1使用转发接口的mac替换源MAC，正确B：替换源IP，错误，源IP不变C：替换目的IP为下一跳入接口的mac，正确D:替换目的IP，错误E：从f0/1转发数据，错误，根据arp表应该是f0/2QUESTION268Refertotheexhibit.WhatwillRouter1dowhenitreceivesthedataframeshown?(Choosethree.)E.Router1willforwardthedatapacketoutinterfaceFastEthernet0/1.F.Router1willforwardthedatapacketoutinterfaceFastEthernet0/2.Answer:ACFSection:Chapter6:IPRoutingExplanation/Reference:考点：数据通信过程源目IP/mac地址的变化。A：源MAC替换为f0/2口的mac，正确B：替换源IP，错误C：替换目的mac为下一跳入口的MAC，正确D：替换目的IP，错误E：从f0/1转发数据，错误F：正确QUESTION269Refertotheexhibit.HostApingsHostB.WhatsourceMACaddressandsourceIPaddressarecontainedintheframeastheframeleavesR2destinedforhostB?Answer:BDSection:Chapter6:IPRoutingExplanation/Reference:考查知识点和题目51一样QUESTION270Refertotheexhibit.AnetworkassociatehasconfiguredOSPFwiththecommand:Aftercompletingtheconfiguration,theassociatediscoversthatnotalltheinterfacesareparticipatinginOSPF.WhichthreeoftheinterfacesshownintheexhibitwillparticipateinOSPFaccordingtothisconfigurationstatement?(Choosethree.)A.FastEthernet0/0B.FastEthernet0/1C.Serial0/0D.Serial0/1.102E.Serial0/1.103F.Serial0/1.104Answer:BCDSection:Chapter6:IPRoutingExplanation/Reference:综上所述，BCDQUESTION271ACatalyst2950needstobereconfigured.Whatstepswillensurethattheoldconfigurationiserased?(Choosethree.)A.Eraseflash.B.Restarttheswitch.C.DeletetheVLANdatabase.D.Erasetherunningconfiguration.E.Erasethestartupconfiguration.F.Modifytheconfigurationregister.Answer:BCESection:Chapter9:SwitchingExplanation/Reference:考点：考查恢复交换机出厂配置。有两点，1、配置信息，保存在startup-config中；2、vlan数据库，存放在vlan.dat中。A：删除flash，错误，这样把IOS都删除了B：重启交换机，正确，删除后重启C：删除vlan数据库，正确QUESTION272Refertotheexhibit.TheFMJmanufacturingcompanyisconcernedaboutunauthorizedaccesstothePayrollServer.TheAccounting1,CEO,Mgr1,andMgr2workstationsshouldbetheonlycomputerswithaccesstothePayrollServer.Whattwotechnologiesshouldbeimplementedtohelppreventunauthorizedaccesstotheserver?(Choosetwo.)A.accesslistsB.encryptedrouterpasswordsC.STPD.VLANsE.VTPF.wirelessLANsAnswer:ADSection:Chapter10:VLANExplanation/Reference:考点：考查ACL和VLAN的作用。通过vlan隔离网段，通过acl实现控制一部分IP访问QUESTION273Refertotheexhibit.Whatcommandsmustbeconfiguredonthe2950switchandtheroutertoallowcommunicationbetweenhost1andhost2?(Choosetwo.)A.Router(config)#interfacefastethernet0/0Router(config-if)#noshutdownB.Router(config)#interfacefastethernet0/0Router(config-if)#noshutdownRouter(config)#interfacefastethernet0/0.1Router(config-subif)#encapsulationdot1q10Router(config-subif)#interfacefastethernet0/0.2Router(config-subif)#encapsulationdot1q20C.Router(config)#routereigrp100D.Switch1(config)#vlandatabaseSwitch1(config-vlan)#vtpdomainXYZSwitch1(config-vlan)#vtpserverE.Switch1(config)#interfacefastethernet0/1Switch1(config-if)#switchportmodetrunkF.Switch1(config)#interfacevlan1Answer:BESection:Chapter10:VLANExplanation/Reference:考点：考查单臂路由的配置。路由器上使用子接口，一个子接口对应一个vlan，封装vlanid。交换机与路由器的互联口使用trunkQUESTION274WhichthreeLayer2encapsulationtypeswouldbeusedonaWANratherthanaLAN?(Choosethree.)A.HDLCB.EthernetC.TokenRingD.PPPE.FDDIF.FrameRelayAnswer:ADFSection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:考点：考查广域网链路的二层封装协议主要有HDLC,PPP,FRQUESTION275Refertotheexhibit.Thetwoconnectedportsontheswitcharenotturningorangeorgreen.Whatwouldbethemosteffectivestepstotroubleshootthisphysicallayerproblem?(Choosethree.)A.EnsurethattheEthernetencapsulationsmatchontheinterconnectedrouterandswitchports.B.EnsurethatcablesAandBarestraight-throughcables.C.EnsurecableAispluggedintoatrunkport.D.Ensuretheswitchhaspower.E.Rebootallofthedevices.F.Reseatallcables.Answer:BDFSection:Chapter9:SwitchingExplanation/Reference:考点：考查交换机端口颜色的定义。绿色正常，橘黄色有故障。A：确认以太网封装是否匹配，错误。封装错误不会在端口LED显示B：确认线缆A/B是否为直通线，正确。异构设备使用直通线C：确认线缆A是否插到trunk口，错误。D：确认是否通电，正确。E：重启设备，错误。F：重置所有电缆，正确。QUESTION276Refertotheexhibit.WhichthreestatementsaretrueabouthowrouterJAXwillchooseapathtotheA.Bydefault,ifRIPv2istheroutingprotocol,onlythepathJAX-ORLwillbeinstalledintotheroutingtable.B.TheequalcostpathsJAX-CHI-ORLandJAX-NY-ORLwillbeinstalledintheroutingtableifRIPv2istheroutingprotocol.C.WhenEIGRPistheroutingprotocol,onlythepathJAX-ORLwillbeinstalledintheroutingtablebydefault.D.WhenEIGRPistheroutingprotocol,theequalcostpathsJAX-CHI-ORL,andJAX-NY-ORLwillbeinstalledintheroutingtablebydefault.E.WithEIGRPandOSPFbothrunningonthenetworkwiththeirdefaultconfigurations,theEIGRPpathswillbeinstalledintheroutingtable.F.TheOSPFpathswillbeinstalledintheroutingtable,ifEIGRPandOSPFarebothrunningonthenetworkwiththeirdefaultconfigurations.Answer:ADESection:Chapter6:IPRoutingExplanation/Reference:本题还是路由选路的问题，首先我们要知道T1线路的速率为1.544MT3线路的速率为45M。RIP仅看hop不关心链路状态。eigrp和ospf等协议的度量都是跟路带宽来计算的。所以要考察带宽的大小。QUESTION277Refertotheexhibit.WhichthreestatementscorrectlydescribeNetworkDeviceA?(Choosethree.)IPsubnet.eachother.eachother.Answer:BDESection:Chapter6:IPRoutingExplanation/Reference:其实这题，主要考察的事掩码的问题。如果想中间的设备不需要三层设备作路由那么两边必须在同一个子QUESTION278SwitchportsoperatinginwhichtworoleswillforwardtrafficaccordingtotheIEEE802.1wstandard?(Choosetwo.)A.alternateB.backupC.designatedD.disabledE.rootAnswer:CESection:Chapter9:SwitchingExplanation/Reference:不管是802.1w还是802.1d等stp协议。用来转发数据的接口都只有dp和rpQUESTION279Refertotheexhibit.GiventheoutputshownfromthisCiscoCatalyst2950,whatisthemostlikelyreasonthatinterfaceFastEthernet0/10isnottherootportforVLAN2?A.ThisswitchhasmorethanoneinterfaceconnectedtotherootnetworksegmentinVLAN2.B.ThisswitchisrunningRSTPwhiletheelecteddesignatedswitchisrunning802.1dSpanningTree.C.Thisswitchinterfacehasahigherpathcosttotherootbridgethananotherinthetopology.D.ThisswitchhasalowerbridgeIDforVLAN2thantheelecteddesignatedswitch.Answer:CSection:Chapter9:SwitchingExplanation/Reference:在选举rp的时候。首先考虑的是到达跟桥cost最小的为rp，我个人认为在本交换机上对于vlan2也应该有一个rp从这图我们看到有两个root可以判断他有可能使用的事pvst，那么pvst对于每一个vlan每一个交换机应该有一个rp，只是我这个接口没有本sw上另外一个接口到达rb的cost小而已但这题的选项只有C更适合QUESTION280Refertotheexhibit.ThenetworkadministratormustestablisharoutebywhichLondonworkstationscanforwardtraffictotheManchesterworkstations.Whatisthesimplestwaytoaccomplishthis?A.ConfigureadynamicroutingprotocolonLondontoadvertiseallroutestoManchester.B.ConfigureadynamicroutingprotocolonLondontoadvertisesummarizedroutestoManchester.C.ConfigureadynamicroutingprotocolonManchestertoadvertiseadefaultroutetotheLondonrouter.F.ConfigureManchestertoadvertiseastaticdefaultroutetoLondon.Answer:ESection:Chapter6:IPRoutingExplanation/Reference:london要访问manchester的主机，那么我们只要知道那个一个静态路由讲数据包发出去就可以，通过子网汇QUESTION281Refertotheexhibit.Thiscommandisexecutedon2960Switch:fa0/1Whichtwoofthesestatementscorrectlyidentifyresultsofexecutingthecommand?(Choosetwo.)A.Portsecurityisimplementedonthefa0/1interface.Answer:BESection:Chapter9:SwitchingExplanation/Reference:我们在一个接口静态制定了mac地址的话。那么这个接口指接搜这个mac地址的frame，并且mac地址会保存在macaddtable表明是static制定的QUESTION282WhichofthefollowingdescribestherolesofdevicesinaWAN?(Choosethree.)A.ACSU/DSUterminatesadigitallocalloop.B.Amodemterminatesadigitallocalloop.C.ACSU/DSUterminatesananaloglocalloop.D.Amodemterminatesananaloglocalloop.E.ArouteriscommonlyconsideredaDTEdevice.F.ArouteriscommonlyconsideredaDCEdevice.Answer:ADESection:Chapter14:WideAreaNetwork(WAN)Explanation/Reference:csu/dsu是用来阻止数字环路的，而猫是用来阻止模拟环路的。路由器是DTE设备。所以必须需要DCE设备来给其提供时钟同步。QUESTION283WhataretwocharacteristicsofTelnet?(Choosetwo.)A.Itsendsdataincleartextformat.B.ItisnolongersupportedonCisconetworkdevices.C.ItismoresecurethanSSH.D.Itrequiresanenterpriselicenseinordertobeimplemented.E.ItrequiresthatthedestinationdevicebeconfiguredtosupportTelnetconnections.Answer:AESection:Chapter2:TCP/IPExplanation/Reference:telnet在数据传递的时候是明文的。不够安全。并且如果要对设备使用telnet我们要在vty线路下配置密码，并且要允许telnet连接到设备QUESTION284Whataretwosecurityappliancesthatcanbeinstalledinanetwork?(Choosetwo.)A.ATMB.IDSC.IOSD.IOXE.IPSF.SDMAnswer:BESection:Chapter7:SecurityExplanation/Reference:B.入侵检测系统E.入侵防御系统QUESTION285Asingle802.11gaccesspointhasbeenconfiguredandinstalledinthecenterofasquareoffice.Afewwirelessusersareexperiencingslowperformanceanddropswhilemostusersareoperatingatpeakefficiency.Whatarethreelikelycausesofthisproblem?(Choosethree.)A.mismatchedTKIPencryptionB.nullSSIDC.cordlessphonesD.mismatchedSSIDE.metalfilecabinetsF.antennatypeordirectionAnswer:CEFSection:Chapter11:WirelessExplanation/Reference:能够对802.11g有干扰的，应该都是工作在2.4G左右的设备。比如说微波炉，无绳电话，金属对于无线是有吸附作用的。可能会引起信号的衰竭QUESTION286Ahostisattemptingtosenddatatoanotherhostonadifferentnetwork.Whatisthefirstactionthatthesendinghostwilltake?A.Dropthedata.B.Sendthedataframestothedefaultgateway.C.CreateanARPrequesttogetaMACaddressforthereceivinghost.D.SendaTCPSYNandwaitfortheSYNACKwiththeIPaddressofthereceivinghost.Answer:CSection:Chapter2:TCP/IPExplanation/Reference:主机要发送数据的话。首先要请求到网关或者下一跳的mac地址进行二层的封装QUESTION287Refertotheexhibit.WhattwofactscanbedeterminedfromtheWLANdiagram?(Choosetwo.)A.Theareaofoverlapofthetwocellsrepresentsabasicserviceset(BSS).B.Thenetworkdiagramrepresentsanextendedserviceset(ESS).C.Accesspointsineachcellmustbeconfiguredtousechannel1.D.Theareaofoverlapmustbelessthan10%oftheareatoensureconnectivity.E.ThetwoAPsshouldbeconfiguredtooperateondifferentchannels.Answer:BESection:Chapter11:WirelessExplanation/Reference:QUESTION288Whichtwodevicescaninterferewiththeoperationofawirelessnetworkbecausetheyoperateonsimilarfrequencies?(Choosetwo.)A.copierB.microwaveovenC.toasterD.cordlessphoneE.IPphoneF.AMradioAnswer:BDSection:Chapter11:WirelessExplanation/Reference:能够对wireless802.11g有干扰的，应该都是工作在2.4G左右的设备。比如说微波炉，无绳电话，金属对于无线是有吸附作用的。可能会引起信号的衰竭QUESTION289WhichtwostatementsdescribecharacteristicsofIPv6unicastaddressing?(Choosetwo.)A.Globaladdressesstartwith2000::/3.B.Link-localaddressesstartwithFE00:/12.C.Link-localaddressesstartwithFF00::/10.D.Thereisonlyoneloopbackaddressanditis::1.E.Ifaglobaladdressisassignedtoaninterface,thenthatistheonlyallowableaddressfortheinterface.Answer:ADSection:Chapter13:IPv6Explanation/Reference:ipv6的常规问题，globaladdress的其实段位2000::/3这个是定义好了的,D选项说的是换回地址,也就是ipv4的QUESTION290Refertotheexhibit.Whichstatementistrue?A.TheFa0/11roleconfirmsthatSwitchAistherootbridgeforVLAN20.B.VLAN20isrunningthePerVLANSpanningTreeProtocol.D.SwitchAisnottherootbridge,becausenotalloftheinterfacerolesaredesignated.Answer:DSection:Chapter9:SwitchingExplanation/Reference:stp对于RB所有的接口都是dpQUESTION291WhichtwoofthesestatementsaretrueofIPv6addressrepresentation?(Choosetwo.)A.TherearefourtypesofIPv6addresses:unicast,multicast,anycast,andbroadcast.B.AsingleinterfacemaybeassignedmultipleIPv6addressesofanytype.C.EveryIPv6interfacecontainsatleastoneloopbackaddress.D.Thefirst64bitsrepresentthedynamicallycreatedinterfaceID.E.LeadingzerosinanIPv616bithexadecimalfieldaremandatory.Answer:BCSection:Chapter13:IPv6Explanation/Reference:每个Ipv6接口至少包括一个环回口地址：由mac地址转换不用手动设置QUESTION292Whatarethreebasicparameterstoconfigureonawirelessaccesspoint?(Choosethree.)A.SSIDB.RTS/CTSC.AES-CCMPD.TKIP/MICE.RFchannelF.authenticationmethodAnswer:AEFSection:Chapter11:WirelessExplanation/Reference:wireless三要素ssidRFchannel以及认证需求QUESTION293Asystemadministratorinstalledanewswitchusingascripttoconfigureit.IPconnectivitywastestedusingpingstoSwitchB.LaterattemptstoaccessNewSwitchusingTelnetfromSwitchAfailed.Whichstatementistrue?A.Executingpasswordrecoveryisrequired.B.Thevirtualterminallinesaremisconfigured.C.UseTelnettoconnecttoRouterAandthentoNewSwitchtocorrecttheerror.D.PowercycleofNewSwitchwillreturnittoadefaultconfiguration.Answer:BSection:Chapter9:SwitchingExplanation/Reference:B.虚拟终端（VTY）配置不正确QUESTION294WhichtwoofthesestatementsregardingRSTParecorrect?(Choosetwo.)A.RSTPcannotoperatewithPVST+.B.RSTPdefinesnewportroles.C.RSTPdefinesnonewportstates.D.RSTPisaproprietaryimplementationofIEEE802.1DSTP.E.RSTPiscompatiblewiththeoriginalIEEE802.1DSTP.Answer:BESection:Chapter9:SwitchingExplanation/Reference:RSTP定义了新的端口类型，包括隔离端口，备份端口等，rstp如果与stp同时存在的话。那么将兼容成stpQUESTION295Whichthreeofthesestatementsregarding802.1Qtrunkingarecorrect?(Choosethree.)A.802.1QnativeVLANframesareuntaggedbydefault.B.802.1Qtrunkingportscanalsobesecureports.C.802.1Qtrunkscanuse10Mb/sEthernetinterfaces.D.802.1Qtrunksrequirefull-duplex,point-to-pointconnectivity.E.802.1QtrunksshouldhavenativeVLANsthatarethesameatbothends.Answer:ACESection:Chapter10:VLANExplanation/Reference:802.1qnativevlan是不做标记的，并且在trunk两边的native需要一致QUESTION296Refertotheexhibit.Eachofthesefourswitcheshasbeenconfiguredwithahostname,aswellasbeingconfiguredtorunRSTP.Nootherconfigurationchangeshavebeenmade.WhichthreeoftheseshowthecorrectRSTPportrolesfortheindicatedswitchesandinterfaces?(Choosethree.)A.SwitchA,Fa0/2,designatedB.SwitchA,Fa0/1,rootC.SwitchB,Gi0/2,rootD.SwitchB,Gi0/1,designatedE.SwitchC,Fa0/2,rootF.SwitchD,Gi0/2,rootAnswer:ABFSection:Chapter9:SwitchingExplanation/Reference:stp的问题，我们可以通过mac地址确定跟桥为switchC，那么C上的端口都为dp，A的f0/1，d的g0/2为rp，那么B哪一个是RP呢。从D过来的bpdu的cost都为23，从a过来的为19+19=38，所以B的rp为gi0/1，那么阻塞端口应该在A和B之间的网段，A的f0/2这个网段收到的BPDUcost最小为19，而B的g0/2收到的BPDUcost最小应该为23，所以B的g0/2应为BLK.1G链路的cost为4,100M链路cost为19.100M链路cost为19.1G链路cost为4.QUESTION297Refertotheexhibit.AjuniornetworkadministratorwasgiventhetaskofconfiguringportsecurityonSwitchAtoallowonlyPC_Atoaccesstheswitchednetworkthroughportfa0/1.Ifanyotherdeviceisdetected,theportistodropframesfromthisdevice.TheadministratorconfiguredtheinterfaceandtesteditwithsuccessfulpingsfromPC_AtoRouterA,andthenobservestheoutputfromthesetwoshowcommands.WhichtwoofthesechangesarenecessaryforSwitchAtomeettherequirements?(Choosetwo.)A.Portsecurityneedstobegloballyenabled.B.Portsecurityneedstobeenabledontheinterface.C.Portsecurityneedstobeconfiguredtoshutdowntheinterfaceintheeventofaviolation.D.PortsecurityneedstobeconfiguredtoallowonlyonelearnedMACaddress.E.Portsecurityinterfacecountersneedtobeclearedbeforeusingtheshowcommand.F.TheportsecurityconfigurationneedstobesavedtoNVRAMbeforeitcanbecomeactive.Answer:BDSection:Chapter9:SwitchingExplanation/Reference:题目要求，只允许PCA在f0/1口，那么我们首先要设置port-security，并且mac最大为1，而且还要是用sticky来记录pc-a的mac，这样就可以达到f0/1只能为pc-a使用QUESTION298WhichofthefollowingcorrectlydescribestepsintheOSIdataencapsulationprocess?(Choosetwo.)A.Thetransportlayerdividesadatastreamintosegmentsandmayaddreliabilityandflowcontrolinformation.B.ThedatalinklayeraddsphysicalsourceanddestinationaddressesandanFCStothesegment.C.Packetsarecreatedwhenthenetworklayerencapsulatesaframewithsourceanddestinationhostaddressesandprotocol-relatedcontrolinformation.D.PacketsarecreatedwhenthenetworklayeraddsLayer3addressesandcontrolinformationtoasegment.E.Thepresentationlayertranslatesbitsintovoltagesfortransmissionacrossthephysicallink.Answer:ADSection:Chapter1:IntroductionExplanation/Reference:传输层将数据分段，并且加入flowcontrol等信息。在网络层就将数据进行打包，并加上ip包头，链路层。将包进行成Frame，封装二层头部QUESTION299Forwhichtypeofconnectionshouldastraight-throughcablebeused?A.switchtoswitchB.switchtohubC.switchtorouterD.hubtohubE.routertoPCAnswer:CSection:Chapter1:IntroductionExplanation/Reference:直通线连接在不同的设备之上，所以这里我们选择不同的设备之间的连接QUESTION300Whichsetofcommandsisrecommendedtopreventtheuseofahubintheaccesslayer?A.switch(config-if)#switchportmodetrunkswitch(config-if)#switchportport-securitymaximum1B.switch(config-if)#switchportmodetrunkswitch(config-if)#switchportport-securitymac-address1C.switch(config-if)#switchportmodeaccessswitch(config-if)#switchportport-securitymaximum1D.switch(config-if)#switchportmodeaccessswitch(config-if)#switchportport-securitymac-address1Answer:CSection:Chapter9:SwitchingExplanation/Reference:说怎么解决接入层接hub的问题，防止介入hub可以使用port-security限制端口的mac地址数量就解决了QUESTION301HowmanybitsarecontainedineachfieldofanIPv6address?A.24B.4C.8D.16Answer:DSection:Chapter13:IPv6Explanation/Reference:QUESTION302Bydefault,eachportinaCiscoCatalystswitchisassignedtoVLAN1.Whichtworecommendationsarekeytoavoidunauthorizedmanagementaccess?(Choosetwo.)A.CreateanadditionalACLtoblocktheaccesstoVLAN1.B.MovethemanagementVLANtosomethingotherthandefault.C.MoveallportstoanotherVLANanddeactivatethedefaultVLAN.D.Limittheaccessintheswitchusingportsecurityconfiguration.E.UsestaticVLANintrunksandaccessportstorestrictconnections.F.ShutdownallunusedportsintheCatalystswitch.Answer:BFSection:Chapter10:VLANExplanation/Reference:题目要求管理未经授权的访问，这里我们可以将管理vlan设置成其他的，并且把所有不使用的接口都关闭这是最简单也是比较有效的方法QUESTION303WhichCiscoCatalystfeatureautomaticallydisablestheportinanoperationalPortFastuponreceiptofaBPDU?A.BackboneFastB.UplinkFastC.RootGuardD.BPDUGuardE.BPDUFilterAnswer:DSection:Chapter9:SwitchingExplanation/Reference:bpduguard如果开启了。那么在access接口接受到了bpdu的话，switch认为可能是一种攻击。会将接口进入err-disableQUESTION304WhichtypeofcableisusedtoconnecttheCOMportofahosttotheCOMportofarouterorswitch?A.crossoverB.straight-throughC.rolledD.shieldedtwisted-pairAnswer:CSection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:com-com使用的是rolled线缆。QUESTION305Whatisknownas"one-to-nearest"addressinginIPv6?A.globalunicastB.anycastC.multicastD.unspecifiedaddressAnswer:BSection:Chapter13:IPv6Explanation/Reference:QUESTION306WhichoptionisavalidIPv6address?A.2001:0000:130F::099a::12aB.2002:7654:A1AD:61:81AF:CCC1C.FEC0:ABCD:WXYZ:0067::2A4D.2004:1:25A4:886F::1Answer:DSection:Chapter13:IPv6Explanation/Reference:A.只能一个冒号B.应该8个字段C.16进制没有WXYZQUESTION307WhichlayeroftheOSIreferencemodelusesthehardwareaddressofadevicetoensuremessagedeliverytotheproperhostonaLAN?A.physicalB.datalinkC.networkD.transportAnswer:BSection:Chapter1:IntroductionExplanation/Reference:物理地址是在datalink上用来寻址的，比如说以太网的mac地址QUESTION308WhichlayeroftheOSIreferencemodelusesflowcontrol,sequencing,andacknowledgementstoensurethatreliablenetworkingoccurs?A.datalinkB.networkC.transportD.presentationE.physicalAnswer:CSection:Chapter1:IntroductionExplanation/Reference:QUESTION309WhatistheprinciplereasontouseaprivateIPaddressonaninternalnetwork?A.Subnetstrategyforprivatecompanies.B.Manageandscalethegrowthoftheinternalnetwork.C.ConservepublicIPaddressessothatwedonotrunoutofthem.D.Allowaccessreservedtothedevices.Answer:CSection:Chapter3:IPAddressingandVLSMExplanation/Reference:内部网络使用了私有地址，如果不使用nat的话我们是没办法访问外部网络的。因为公共网络不会给私有地址路由QUESTION310WhichIPaddresscanbeassignedtoanInternetinterface?Answer:BSection:Chapter3:IPAddressingandVLSMExplanation/Reference:QUESTION311WhatwillhappenifaprivateIPaddressisassignedtoapublicinterfaceconnectedtoanISP?A.AddressesinaprivaterangewillbenotroutedontheInternetbackbone.B.OnlytheISProuterwillhavethecapabilitytoaccessthepublicnetwork.C.TheNATprocesswillbeusedtotranslatethisaddressinavalidIPaddress.D.Severalautomatedmethodswillbenecessaryontheprivatenetwork.E.AconflictofIPaddresseshappens,becauseotherpublicrouterscanusethesamerange.Answer:ASection:Chapter3:IPAddressingandVLSMExplanation/Reference:内部网络使用了私有地址，如果不使用nat的话我们是没办法访问外部网络的。因为公共网络不会给私有地址路由QUESTION312WhenisitnecessarytouseapublicIPaddressonaroutinginterface?A.Connectarouteronalocalnetwork.B.Connectaroutertoanotherrouter.C.Allowdistributionofroutesbetweennetworks.D.TranslateaprivateIPaddress.E.ConnectanetworktotheInternet.Answer:ESection:Chapter3:IPAddressingandVLSMExplanation/Reference:如果在网络中使用了公有地址。那么肯定是想将网络链入internetQUESTION313Whatisthefirst24bitsinaMACaddresscalled?A.NICB.BIAC.OUID.VAIAnswer:CSection:Chapter1:IntroductionExplanation/Reference:mac地址的前24为称为组织唯一标识（OUI）也就是固定分配的QUESTION314InanEthernetnetwork,underwhattwoscenarioscandevicestransmit?(Choosetwo.)A.whentheyreceiveaspecialtokenB.whenthereisacarrierC.whentheydetectnootherdevicesaresendingD.whenthemediumisidleE.whentheservergrantsaccessAnswer:CDSection:Chapter1:IntroductionExplanation/Reference:考查的CSMA/CD问题，在ethernet中如果检测到没有其他的设备在发送信息，网络是空闲状态，那么自己才发送信息QUESTION315WhichtermdescribestheprocessofencapsulatingIPv6packetsinsideIPv4packets?A.tunnelingB.hashingC.routingD.NATAnswer:ASection:Chapter13:IPv6Explanation/Reference:将ipv6的包封装成ipv4的包。那么这里显然使用的是6-to-4tunnel达到ipv6和ipv4的兼容问题QUESTION316WhichstatementaboutRIPngistrue?A.RIPngallowsforrouteswithupto30hops.B.RIPngisenabledoneachinterfaceseparately.C.RIPngusesbroadcaststoexchangeroutes.D.TherecanbeonlyoneRIPngprocessperrouter.Answer:BSection:Chapter13:IPv6Explanation/Reference:在配置ripng的时候。我们需要到街口下一个一个敲命令ipv6ripXQUESTION317WhichstatementaboutIPv6istrue?A.Addressesarenothierarchicalandareassignedatrandom.B.OnlyoneIPv6addresscanexistonagiveninterface.C.Thereare2.7billionaddressesavailable.D.Broadcastshavebeeneliminatedandreplacedwithmulticasts.Answer:DSection:Chapter13:IPv6Explanation/Reference:ipv6在地址规划的时候并没有ipv4的broadcast，但是新增了一个anycastQUESTION318Whichlinefromtheoutputoftheshowipinterfacecommandindicatesalayer1problem?A.Serial0/1isup,lineprotocolisdownB.Serial0/1isdown,lineprotocolisdownC.Serial0/1isup,lineprotocolisupD.Serial0/1isadministrativelydown,lineprotocolisdownAnswer:BSection:Chapter4:IntroductiontoCiscoIOSExplanation/Reference:layer1如果出现了问题。那么接口肯定是一个双down，这里B是自然down而D是管理型关闭。这里大家要注意QUESTION319Anetworkadminwantstoknoweveryhopthepacketstakewhenheaccessescisco.com.Whichcommandisthemostappropriatetouse?A.pathcisco.comB.debugcisco.comC.tracecisco.comD.traceroutecisco.comAnswer:DSection:Chapter2:TCP/IPExplanation/Reference:问怎么知道cisco.com的packet经过的路径。那么我们需要时用traceroute来查看到达cisco.com所经过的下一跳QUESTION320Whenahosttransmitsdataacrossanetworktoanotherhost,whichprocessdoesthedatagothrough?A.standardizationB.conversionC.encapsulationD.synchronizationAnswer:CSection:Chapter1:IntroductionExplanation/Reference:数据在通过一个网络到另一个网络的时候.我们需要进行数据包的封装.比如说封装ip头部.二层头部等信息.从而保障网络寻址QUESTION321Anadministratorattemptsatraceroutebutreceivesa"DestinationUnreadable"message.Whichprotocolisresponsibleforthatmessage?A.RARPB.RUDPC.ICMPD.SNMPAnswer:CSection:Chapter2:TCP/IPExplanation/Reference:问这个message是什么提供的.我们一看这个肯定是icmp的回包QUESTION322WhichtwocommandscorrectlyverifywhetherportsecurityhasbeenconfiguredonportFastEthernet0/12onaswitch?(choosetwo)A.SW1#showswithportport-securityinterfaceFastEthernet0/12B.SW1#showswithportport-secureinterfaceFastEthernet0/12C.SW1#showport-secureinterfaceFastEthernet0/12D.SW1#showrunning-configAnswer:CDSection:NewExplanation/Reference:QUESTION323WhichcomponentofVPNtechnologyensuresthatdatacanbereadonlybyitsintendedrecipient?A.dataintegrityB.encryptionC.keyexchangeD.authenticationAnswer:DSection:NewExplanation/Reference:哪个VPN组件可以确保数据只能让预定的人读取QUESTION324Refertotheexhibit.Whatistheeffectoftheconfigurationthatisshown?A.IttellstherouterorswitchtotryestablishanSSHconnectionfirstandifthatfailtousetelnet.B.ItconfiguresacisconetworkdevicetousetheSSHprotocolonincomingcommunicationsviathevirtualterminalports.C.ItallowssevenfailedloginattemptsbeforetheVTYlinesaretemporarilyshutdown.E.ItconfiguresSSHgloballyforalllogins.Answer:BSection:NewExplanation/Reference:此条命令允许5条SSH虚链路QUESTION325Whichofthefollowingaretrueregardingthedebugoutputshowninthegraphic?(choosetwo)A.Thisrouterwasconfiguredwiththecommands:RtrA(config)#routerripRtrA(config-router)#version2B.Thisrouterwasconfiguredwiththecommands:RtrA(config)#routerripE.Thisrouterwasconfiguredwiththecommands:RtrA(config)#routerripF.split-horizonwasdisabledonthisrouter.Answer:BCSection:NewExplanation/Reference:QUESTION326Thenetworkadministratorisaskedtoconfigure113point-to-pointlinks.WhichIPaddressingschemebestdefinestheaddressrangeandsubnetmaskthatmeettherequirementandwastethefewestsubnetandhostaddresses?Answer:DSection:NewExplanation/Reference:113个point-to-point链路而不是IP。每个链路需要2个有效的IP地址，即2个主机位。113个需要7位，一共需要9位，所以掩码为23QUESTION327VLAN3isnotyetconfiguredonyourswitch.Whathappensifyousettheswitchportaccessvlan3commmandinterfaceconfigurationmode?A.ThecommandisacceptedandtherespectiveVLANisaddedtovlandat.B.Thecommandisrejected.C.ThecommandisacceptedandyoumustconfiguretheVLANmanually.D.Theportturnsamber.Answer:ASection:NewExplanation/Reference:在PT和真机环境下回自动创建vlan。切莫用路由器的IOS做此实验。QUESTION328Whichparametercanbetunedtoaffecttheselectionofastaticrouteasabackup.whenadynamicprotocolisalsobeingused?A.linkbandwidthB.hopcountC.linkcostD.administrativedistanceE.linkdelayAnswer:DSection:NewExplanation/Reference:选择路由先看管理距离，小的优先QUESTION329Refertotheexhibit.IntheFrameRelaynetwork,whichipaddresswouldbeassignedtotheinterfaceswithpoint-to-poinPVCs?Answer:BSection:NewExplanation/Reference:虚链路为点对点，R2为子接口，每条虚链路各自一个网段QUESTION330Whywillaswitchneverlearnabroadcastaddress?A.Broadcastframesareneversenttoswiches.B.Broadcastaddressesuseanincorrectformatfortheswitchingtable.C.Abroadcastaddresswillneverbethesourceaddressofaframe.D.Broadcastsonlyusenetworklayeraddressing.E.Abroadcastframeisneverforwardedbyaswitch.Answer:CSection:NewExplanation/Reference:QUESTION331WichcommandcanyouusetomanuallyassignastaticIPV6addresstoarouterinterface?A.ipv6addressPREFIX_1::1/64B.ipv6autoconfig2001:db8:2222:7272::72/64C.ipv6autoconfigD.ipv6address2001:db8:2222:7272::72/64Answer:DSection:NewExplanation/Reference:IPv6在路由器上设置地址的命令QUESTION332TheEIGRPconfigurationintheGlencoerouterusesasinglenetworkstatement.FromtheoutputshowninthegraphwouldadvertisethesenetworksinEIGRP?Answer:BSection:NewExplanation/Reference:此处要求用一条命令宣告QUESTION333WhichIPsecsecurityprotocolshouldbeusedwhenconfidentialityisrequired?A.AHB.MD5C.PSKD.ESPAnswer:DSection:NewExplanation/Reference:封装安全载荷协议EncapsulatingSecurityPayload（ESP）QUESTION334Whatisthefunctionofthecommandswitchporttrunknativevlan999onaswitch?A.ItdesignatesVLAN999foruntaggedtraffic.B.ItblocksVLAN999trafficfrompassingonthetrunk.C.ItcreatesaVLAN999interface.D.ItdesignatesVLAN999asthedefaultforallunkowntaggedtraffic.Answer:ASection:NewExplanation/Reference:设置vlan999为本征vlan，交换机默认本征vlan为vlan1.此题正确答案为A.QUESTION335WhichcommandcanbeusedfromaPCtoverfytheconnectivitybetweenhostthatconnectthroughpath?A.tracertaddressB.pingaddressC.arpaddressD.tracerouteaddressAnswer:ASection:NewExplanation/Reference:traceroute是路由器的命令QUESTION336InwhichsolutionisarouterACLused?A.protectingaserverfromeunauthorizedaccesB.controllingpathselection,basedontheroutemetricC.reducingrouterCPUutilizationD.filterringpacketsthatarepassingthrougharouterAnswer:DSection:NewExplanation/Reference:ACL应用在路由器，提供包过滤的功能QUESTION337Whichstatementistrue,asrelatestoclassfulorclasslessrouting?A.RIPV1andOSPFareclasslessroutingprotocols.B.Classfulroutingprotocolssendthesubnetmaskinroutingupdates.C.Automaticsummarizationatclassfulboundariescancauseproblemsondisc……D.EIGRPandOSPFareclassfulroutingprotocolsandsummarizeroutesbydef……Answer:CSection:NewExplanation/Reference:自动汇总会将IP地址汇总为主类地址，必须手动关闭QUESTION338ArouterhastwoFastEthernetinterfacesandneedstoconnecttofourvlansinthelocalnetwork.Howcanyouaccomplishthistask,usingthefewestphysicalinterfacesandwithoutdecreasingnetworkperformance?A.AddtwomoreFastEthernetinterfaces.B.Addasecondroutertohandlethevlantraffic.C.UseahubtoconnectthefourvlanswithaFastEthernetinterfaceonrouter.D.Implementarouter-on-a-stickconfiguration.Answer:DSection:NewExplanation/Reference:设置一个单臂路由QUESTION339Refertotheexhibit.Howmanybroadcastdomainsareconfiguredonswitch2?A.5B.20C.4D.1Answer:CSection:NewExplanation/Reference:一个vlan就是一个广播域QUESTION340Whatistheeffectofusingtheservicepassword-encryptioncommand?A.nlypasswordsconfiguredafterthecommandhasbeenenteredwillbeencrypted.B.Onlytheenablepasswordwillbeencrypted.C.OnlytheenablesecretpasswordwillbeencryptedD.Itwillencryptthesecretpasswordandremovetheenablesecretpasswordfromtheconfiguration.E.Itwillencryptallcurrentandfuturepasswords.Answer:ESection:NewExplanation/Reference:E.加密已经有的和未来的密码QUESTION341Refertotheexhibit.AtechnicianhasinstalledSwithchBandneedstoconfigureitforremoteaccessfromthemanagementworkstationconnectedSwitchAWhichsetofcommandsisrequiredtoaccomplishthistask?A.SwitchB(config)#interfaceFastEthernet0/1SwitchB(config)#noshutdownSwitchB(config)#interfacevlan1SwitchB(config)#noshutdownC.SwitchB(config)#interfacevlan1SwitchB(config)#noshutdownSwitchB(config)#interfacevlan1SwitchB(config)#noshutdownAnswer:BSection:NewExplanation/Reference:想要远程管理交换机需要在交换机上的配置，B正确QUESTION342Refertotheexhibit.ThespeedofallseriallinksisE1andthespeedoftheallEthernetlinksis100Mb/s.AstaticroutewillbeestablishedontheManchesterroutertothedirecttraffictowardtheinternetoverthemostdirectpathavailable.WhatconfigurationontheManchesterrouterwillestablisharoutertowardtheinternetfortrafficthatoriginatesfromworkstationontheManchesterLAN?Answer:FSection:NewExplanation/Reference:设置静态路由QUESTION343WhatFrameRelaymechanismisusedtobuildthemapillustratedintheaccompanyinggraphic?A.inversemultiplexingB.LMImapingC.InverseARPD.ARPE.ProxyARPAnswer:CSection:NewExplanation/Reference:帧中继使用InverseARP将IP地址解析为DLCI号QUESTION344Refertotheexhibit.Anetworkengineeristroubleshootinganinternetconnectivityproblemonthecomputer.Whatiscausingtheproblem?A.wrongDNSserverB.wrongdefaultgatewayC.incorrectIPaddressD.incorrectsubnetmaskAnswer:CSection:NewExplanation/Reference:QUESTION345Howmanybroadcastdomainsareshowninthegraphicassumingonlythedefaultvlanisconfiguredontheswitches?A.oneB.sixC.twelveD.twoAnswer:ASection:NewExplanation/Reference:QUESTION346HowdoseaDHCPserverdynamicallyassignIPaddresstohost?A.Addressesareallocatedafteranegotiationbetweentheserverandthehosttodeterminethelengthoftheagreement.B.Addressesareassignedforafixedperiodoftime.Attheendofperiod,anewquestforanaddressmustbemade,andanotheraddressisthenassigned.C.Addressesareleasedtohost.AhostwillusuallykeepthesameaddressbyperiodicallycontactingtheDHCPsevertorenewthelease.D.Addressesarepermanentlyassignedsothatthehostusesthesameaddressatalltimes.Answer:CSection:NewExplanation/Reference:QUESTION347WhichtypeofEIGRProuteentrydescribesafeasiblesuccessor?A.aprimaryroute,storedintheroutingtableB.abackuproute,storedintheroutingtableC.abackuproute,storedinthetopologytableD.aprimaryroute,storedinthetopologytableAnswer:CSection:NewExplanation/Reference:可行后继作为替补存在拓扑表中QUESTION348WhatisthepurposeoftheinverseARP?A.tomapaknownDLCItoanIPaddressB.tomapaknownIPaddresstoaMACaddressC.tomapknownSPIDtoaMACaddressD.tomapaknownDLCItoaMACaddressE.tomapaknownIPaddresstoaSPID.F.tomapaknownMACaddresstoanIPaddressAnswer:ASection:NewExplanation/Reference:反向ARP的作用，前面已经讲过QUESTION349Whatisthedefaultmaximumnumberofequal-costpathsthatcanbeplacedintotheroutingofaciscoOSPFrouter?A.16B.2C.unlimitedD.4Answer:DSection:NewExplanation/Reference:OSPF默认等价均衡链路为4条QUESTION350WhichIPV6routingprotocolusesmulticastgroupFF02::9tosendupdates?A.RIPngB.OSPFv3C.staticD.IS-ISforIPv6Answer:ASection:NewExplanation/Reference:RIPng通过组播地址FF02：：9更新QUESTION351WhataretwobenefitsofusingNAT?(choosetwo)A.NATprotectsnetworksecuritybecauseprivatenetworksarenotadvertised.B.NATacceleratestheroutingprocessbecausenomodificationsaremadeonthepackets.C.DynamicNATfacilitatesconnectionsfromtheoutsideofthenetwork.D.NATfacilitatesend-to-endcommunicationwhenIPsecisenable.E.NATeliminatestheneedtore-addressallhostthatrequireextemalaccess.F.NATconservesaddressesthroughhostMAC-levelmultiplexing.Answer:AESection:NewExplanation/Reference:E.NAT消除了当需要外部链接时每个主机都需要一个不同IP地址QUESTION352WhichthreestatementsaboutRSTParetrue?(choosethree)A.RSTPsignificantlyreducestopologyreconvergingtimeafteralinkfailure.B.RSTPexpendstheSTPportrolesbyaddingthealternateandbackuproles.C.RSTPportatatesareblocking,discarding,learing,orforwarding.D.RSTPalsousestheSTPproprsal-agreementsequence.E.RSTPusethesametimer-baseedprocessasSTPonpoint-to-pointlinks.F.RSTPprovidesafastertransitiontotheforwardingstateonpoint-to-pointlinksthanSTPdoes.Answer:ABFSection:NewExplanation/Reference:A能够减少汇聚时间B比STP增加了端口角色alternat和backupF在点到点链路提供比STP更快的传输和转发QUESTION353Refertotheexhibit.Theserial0/0interfaceoftheTamparouterconnectstheOriandorouter.Whichtwostatementsaretrueabouttheconnectionbetweenthesetworouters?(choosetwo)A.TheonlydevicewithwhichtheTamparouterwillnegotiateadatalinkistheOrlandorouter.C.Thelinkusesathree-wayhandshakeforauthentication.D.Thelinkusesatwo-wayhandshakeforauthentication.E.DataexchangesbetweentheOriandoandTamparoutersareencrypted.Answer:BCSection:NewExplanation/Reference:QUESTION354AswitchisconfiguredasavtpseverwithadomainnameofCCNA.Whichciscoiosprivilegedmodecommand,followedbyareloadoftheswith,willresettheVTPmanagementdomainnameoftheswitchtoaNULLvalue?A.#vtpdomainunsetB.#deletevlan.datC.#novtpdomainD.#vtpdomainnullAnswer:BSection:NewExplanation/Reference:删除VTP数据需要删掉vlan数据库并重启QUESTION355hostsallowedonthissubnet?A.4094B.1024C.8190D.2046E.4096Answer:ASection:NewExplanation/Reference:2的12次方减2QUESTION356WhichtwostatementsaboutstaticNATtranslationsaretrue?(choosetwo)A.TheyarealwayspresentintheNATtable.B.Theyallowconnectiontobeinitiatedfromtheoutside.C.Theycanbeconfiguredwithaccesslists,toallowtwoormoreconnectionstobeinitiatedfromtheoutside.D.Theyrequirenoinsideoroutsideinterfacemarkingsbecauseaddressesarestaticallydefined.Answer:ABSection:NewExplanation/Reference:静态NATA出现在NAT表中B允许来自外部的链接QUESTION357WhichoftheserepresentsanIPv6link-localaddress?A.FE08::280e:611:a:f14f:3d69B.FE81::280f:512b:e14f:3d69C.FE80::380e:611a:e14f:3d69D.FEFE:0345:5f1b::e14d:3d69Answer:CSection:NewExplanation/Reference:IPv6本地地址FE80开头后面为本地mac地址QUESTION358WhatarethreefeaturesoftheIPV6protocol?(choosethree)A.complicatedheaderB.plug-and-playC.nobroadcastsD.checksumsE.optionalIPsecF.autoconfigurationAnswer:BCFSection:NewExplanation/Reference:B即插即用C没广播地址F自动设置QUESTION359Assumingdefaultsetting,howcanyouerasetheVTPdatabaseofVLANsonaCISCOIOSswitchrunninginVTPservermode?A.EnableVTPpruningB.Fromprivilegedmode,erasethestartupconfigurationfile,thenreload.C.Fromprivilegedmode,erasethevlandatefile,thenreload.D.Cycletheswitchpower.Answer:CSection:NewExplanation/Reference:删除VTP数据需要删掉vlan数据库并重启QUESTION360Refertotheexhibit.whichaddressandmaskcombinationasummaryoftherouteslearnedbyEIGRP?Answer:ESection:NewExplanation/Reference:路由汇总一定要汇总为最小的网段QUESTION361RefertotheexhibitAframeonvlan1onswitchs1issenttoswitchs2whentheframeisreceivedonvlan2,whatcausesthisbehavior?A.trunkmodemismatchesB.vlansthatdonotcorrespondtoauniqueIPsubnetC.nativevlanmismatchesD.allowingonlyvlan2onthedestination.Answer:CSection:NewExplanation/Reference:两交换机本征vlan不一样，不能正常通信QUESTION362Refertotheexhibit.ThenetworkadministratornormallyestablishesatelnetsessionwiththeswitchfromhostA.However,hostAisunavailable.Theadministrator′sattempttotheswitchfromhostBfails,butpingstotheothertwohostsaresuccessful.whatistheissue?A.HostBandtheswitchneedtobeinthesamesubnet.B.Theswitchneedsandappropriatedefaultgatewayassigned.C.Theswitchinterfaceconnectedtotherouterisdown.D.HostBneedtobeassignedanIPaddressinvlan1.Answer:BSection:NewExplanation/Reference:远程管理交换机需要在交换机上设置defaultgateway和vlanIPQUESTION363Whatvalueisprimarilyusedtodeterminewhichportbecomestherootportoneachnonrootswitchinaspanning-treetopology?A.lowestportMACaddressB.portprioritynumberandMACaddress.C.VTPrevisionnumberD.highestportprioritynumber.E.pathcostAnswer:ESection:NewExplanation/Reference:此处为选举跟端口。选举跟桥先看优先级QUESTION364Refertotheexhibit.Router1wasjustsuccessfullyrebooted.identifythecurrentOSPFrouterIDforRouter1.Answer:ASection:NewExplanation/Reference:routerid如果没有手动设置，先选环回口最大ip地址，没有环回口选物理端口最大IP地址QUESTION365WhydolargeOSPFnetworksuseahierarchicaldesign?(choosethree)A.toconfinenetworkinstabilitytosingleareasofthenetwork.B.toreducethecomplexityofrouterconfigurationC.tospeedupconvergenceD.tolowercostsbyreplacingrouterswithdistributionlayerswitchesE.todecreaselatencybyincreasingbandwidthF.toreduceroutingoverheadAnswer:ACFSection:NewExplanation/Reference:QUESTION366AnetworkadministratorreceivesanerrormessagewhiletringtoconfiguretheEthernetinterfaceofaA.TheaddressisabroadcastaddressB.TheEhernetinterfaceisfaultyC.VLSM-capableroutingprotocolsmustbeenablefirstontherouter.D.Thisaddressisanetworkaddress.Answer:DSection:NewExplanation/Reference:此地址为网络地址QUESTION367Whichtwoareadvantagesofstaticroutingwhencomparedtodynamicrouting?(choosetwo)A.Securityincreasesbecauseonlythenetworkadministratormaychangetheroutingtables.B.Configurationcomplexitydecreasesasnetworksizeincreases.C.Routingupdatesareautomaticallysenttoneighbors.D.Routesummarizationiscompuedautomaticallybytherouter.E.RoutingtrafficloadisreducedwhenusedinstubnetworklinksF.Anefficientalgorithmisusedtobuildroutingtables,usingautomaticupdates.G.Routingtablesadaptautomaticallytotopologychanges.Answer:AESection:NewExplanation/Reference:静态路由相比动态路由的好处QUESTION368Acompanyhasasmallnetwork,consistingofasingleswitchandasinglerouter.Theswitchhasbeenconfiguredwithtwovlans,androute-on-a-stickisbeingconfiguredontherouterforinter-vlanrouting.Atrunkisconfiguredtoconnecttheswitchtotherouter.Whatistheminimumnumberofroutersubinterfacesthatarerequiredforallthevlanstocommunicate?A.oneB.threeC.twoD.zeroAnswer:CSection:NewExplanation/Reference:单臂路由一个vlan需要一个子接口QUESTION369Whichcommandcanbearoutertoverifythelayer3pathtoahost?A.tracerouteaddressB.tracertaddressC.sshaddressD.telnetaddressAnswer:ASection:NewExplanation/Reference:tracert是windows的命令QUESTION370Whichdosetheframe-relayinterface-dlcicommandconfigure?A.remoteDLCIonthemaininterfaceB.localDLCIonthemaininterfaceC.localDLCIonthesubinterfaceD.remoteDLCIonthesubinterfaceAnswer:CSection:NewExplanation/Reference:只有子接口使用此命令QUESTION371WhatistheOSPFdefaultfrequency,inseconds,atwhichaciscoroutersendshellopacketsonamultiaccessnetwork?A.10B.40C.30D.20Answer:ASection:NewExplanation/Reference:OSPF发送hello包默认10sQUESTION372Refertotheexhibt.HostAhastestedconnectivitytoaremotenetwork.WhatisthedefaultgatewayforhostA?Answer:ASection:NewExplanation/Reference:与外网通信先送网关QUESTION373WhichcommandsisnecessarytopermitSSHorTelnetaccesstoaciscoswitchthatisotherwiseconfiguredforthesevtylineprotocols?A.transporttypeallB.transportoutputallC.transportpreferredallD.transportinputallAnswer:DSection:NewExplanation/Reference:D.defineallprotocolstousewhentoconnectingtoterminalserverQUESTION374WhichcommandshowsyouractiveTelnetconnections?A.showsessionB.showcdpneighborsC.showusersD.showqueueAnswer:ASection:NewExplanation/Reference:哪一个命令显示活动的telnet对话QUESTION375WhichtwostatesaretheportstateswhenRSTPhasconverged?(choosetwo)A.blockingB.learningC.discardingD.forwardingE.listeningAnswer:CDSection:NewExplanation/Reference:在RSTP中只有三种端口状态，Discarding、Leaning和Forwarding。QUESTION376TherearenobootsystemcommandsinarouterconfigurationinNVRAM.Whatisthefallbacksequencethatrouterwillusetofindaniosduringreload?A.Flash,TFTPserver,ROMB.Flash,NVRAM,ROMC.ROM,NVRAM,TFTPserverD.NVRAM,TFTPserver,ROME.TFTPserver,Flash,NVRAMAnswer:ASection:NewExplanation/Reference:默认路由器加载IOS顺序QUESTION377Refertothegraphic.AhostisconnectedtoswitchportFa0/3withacrossovercable.Thehostandswitchhave…asshown.However,theportindicatoronswitchportFa0/3isnoton,andthehostcannotcommunicatewith…tovlan2onthesameswitch.Basedontheinformationgiven.whatistheproblem?A.Theswitchhasbeenassignedanincorrectsubnetmask.B.SwitchportFA0/3isnotconfiguredasatrunkportC.SwitchportFA0/3hasbeenblockedbySTPD.TheswitchandthehostsmustbeinthesamesubnetE.ThecableisthewrongtypeAnswer:ESection:NewExplanation/Reference:电脑与交换机错用了交叉线QUESTION378Refertotheexhibit.Whichuser-modepasswordhasjustbeenset?A.TelnetB.AuxiliaryC.SSHD.ConsoleAnswer:ASection:NewExplanation/Reference:QUESTION379DNSserversprovidewhatservice?A.theyrunaspellcheckonhostnamestoensureaccurateroutingB.theymapindividualhoststotheirspecificIPaddressC.theyconvertdomainnamesintoIPaddressD.GivenanIPaddress,theydeterminethenameofthehostthatis…Answer:CSection:NewExplanation/Reference:域名解析QUESTION380WhichcommandenablesRSTPonaswitch?A.spanning-treemoderapid-pvstB.spanning-treeuplinkfastC.spanning-treebackbonefastD.spanning-treemodemstAnswer:ASection:NewExplanation/Reference:启用RSTP的命令QUESTION381WhichtwoarefeaturesofIPv6?(choosetwo)A.multicastB.broadcastC.allcastD.podcastE.anycastAnswer:AESection:NewExplanation/Reference:A组播E任意播ipv6没有广播QUESTION382Whichstatementaboutaccessliststhatareappliedtoaninterfaceistrue?A.youcanapplymultipleaccesslistswiththesameprotocolorindifferent…B.youcanconfigoneaccesslist,perdirection,perlayer3protocolC.youcanplaceasmanyaccesslistsasyouwantonanyinterfaceD.youcanapplyonlyoneaccesslistonanyinterfaceAnswer:BSection:NewExplanation/Reference:一个端口可以配置Inout两个ACL，正确答案为BQUESTION383WhichitemrepresentsthestandardIPACL?B.access-list110permitipanyanyAnswer:ASection:NewExplanation/Reference:标准ACL范围1-99QUESTION384WhatisonebenefitofPVST+?A.PVST+reducestheCPUcyclesforalltheswitchesinthenetworkB.PVST+automaticallyselectstherootbridgelocation,toprovideoptimiz…C.PVST+allowtherootswitchlocationtobeoptimizedpervlan.D.PVST+supportsLayer3loadbalancingwithoutloops.Answer:CSection:NewExplanation/Reference:QUESTION385ofthefollowingstatementistrueconceringthiscommand?A.Thebroadcastoptionallowspackets,suchasRIPupdates,tobeforwardedaccessthePVC.B.Thecommandshoudbeexecutedfromthegobleconfigurationmode.C.102isheremoteDLCIthatwillrecivetheinformation.E.ThiscommandisrequiredforallFrameRelyconfigurationsAnswer:ASection:NewExplanation/Reference:QUESTION386Refertotheexhibit,howmanyinterfacesonR1shouldbeconfiguredasipnatinsidetograntexternalaccesstotheentire….?A.1B.3C.4D.5Answer:CSection:NewExplanation/Reference:R1下面的端口分为了两个子端口，在两个子端口上设置ipnatinsideQUESTION387Whichcanbedonetosecurethevirtualterminalinterfacesonarouter?(choosetwo)A.Administrativelyshutdowntheinterfaces.B.Physicallysecuretheinterfaces.C.Configureavirtualterminalpasswordandloginprocess.D.Enteranaccesslistandapplyittotheterminalinterfacesusingtheaccess-classcommand.E.Createanaccesslistandapplyittotheterminalinterfacesusingtheaccess-groupcommand.Answer:CDSection:NewExplanation/Reference:QUESTION388Refertotheexhibit,anetworkadministratorcannotestablishatelnetsessionwiththeindicatedrouter.Whatisthecauseofthisfailure?A.Alevel5passwordisnotsetB.ThevtypasswordismissingC.TheconsolepasswordismissingD.AnACLisblockingTelnetaccessAnswer:BSection:NewExplanation/Reference:QUESTION389WhichprotocolisanopenstandardprotocolframeworkthatiscommonlyusedinVPNs,toprovidsecureend-to-endcommunication?A.L2TPB.IPsecC.PPTPD.RSAAnswer:BSection:NewExplanation/Reference:QUESTION390YourbossislearningaCCNAtrainingcourse,refertotheexhibit.TheaccesslisthasbeenconfiguredontheS0/0interfaceofrouterRTBintheoutbounddirection.Whichtwopackets,ifroutedtotheinterface,willbedenied?(Choosetwo)access-list101permitipanyanyAnswer:DESection:NewExplanation/Reference:QUESTION391Refertothegraphic.IthasbeendecidedthatPC1shouldbedeniedaccesstoServer.WhichofthefollowingcommandsarerequiredtopreventonlyPC1fromaccessingServer1whileallowingallothertraffictoflownormally?(Choosetwo)A.Router(config)#interfacefa0/0Router(config-if)#ipaccess-group101outB.Router(config)#interfacefa0/0Router(config-if)#ipaccess-group101inRouter(config)#access-list101permitipanyanyRouter(config)#access-list101permitipanyanyAnswer:BCSection:NewExplanation/Reference:QUESTION392Anaccesslistwaswrittenwiththefourstatementsshowninthegraphic.Whichsingleaccessliststatementwillcombineallfourofthesestatementsintoasinglestatementthatwillhaveexactlythesameeffect?Answer:CSection:NewExplanation/Reference:QUESTION393AnetworkadministratorwantstoaddalinetoanaccesslistthatwillblockonlyTelnetaccessbythehoststhistask?access-list101permitipanyanyaccess-list101permitipanyanyaccess-list1permitipanyanyaccess-list1permitipanyanyAnswer:ASection:NewExplanation/Reference:QUESTION394Asanetworkadministrator,youhavebeeninstructedtopreventalltrafficoriginatingontheLANfromenteringtheR2router.WhichthefollowingcommandwouldimplementtheaccesslistontheinterfaceoftheR2router?A.access-list101inB.access-list101outC.ipaccess-group101inD.ipaccess-group101outAnswer:CSection:NewExplanation/Reference:QUESTION395LAN:Howwilltheaboveaccesslistsaffecttraffic?B.Notraffic,exceptforFTPtrafficwillbeallowedtoexitE0D.AlltrafficexitingE0willbedeniedAnswer:DSection:NewExplanation/Reference:QUESTION396TheaccesscontrollistshowninthegraphichasbeenappliedtotheEthernetinterfaceofrouterR1usingtheipaccess-group101incommand.WhichofthefollowingTelnetsessionswillbeblockedbythisACL?(Choosetwo)Answer:BDSection:NewExplanation/Reference:QUESTION397ThefollowingconfigurationlinewasaddedtorouterR1Whatistheeffectofthisaccesslistconfiguration?A.ermitallpacketsmatchingthefirstthreeoctetsofthesourceaddresstoalldestinationsB.permitallpacketmatchingthelastoctetofthedestinationaddressandacceptallsourceaddressesC.permitallpacketmatchingthehostbitsinthesourceaddresstoalldestinationsD.permitallpacketfromthethirdsubnetofthenetworkaddresstoalldestinationsAnswer:ASection:NewExplanation/Reference:QUESTION398AdefaultFrameRelayWANisclassifiedaswhattypeofphysicalnetwork?A.point-to-pointB.broadcastmulti-accessC.nonbroadcastmulti-accessD.nonbroadcastmultipointE.broadcastpoint-to-multipointAnswer:CSection:NewExplanation/Reference:QUESTION399WhichofthefollowingarekeycharacteristicsofPPP?(Choosethree.)A.canbeusedoveranalogcircuitsB.mapsLayer2toLayer3addressC.encapsulatesseveralroutedprotocolsD.supportsIPonlyE.provideserrorcorrectionAnswer:ACESection:NewExplanation/Reference:QUESTION400Refertotheexhibit.Whatisthemeaningofthetermdynamicasdisplayedintheoutputoftheshowframe-relaymapcommandshown?A.TheSerial0/0interfaceispassingtraffic.B.TheDLCI100wasdynamicallyallocatedbytherouterD.TheDLCI100willbedynamicallychangedasrequiredtoadapttochangesintheFrameRelaycloudARPAnswer:ESection:NewExplanation/Reference:QUESTION401WhichofthefollowingdescribestherolesofdevicesinaWAN?(Choosethree.)A.ACSU/DSUterminatesadigitallocalloopB.AmodemterminatesadigitallocalloopC.ACSU/DSUterminatesananaloglocalloopD.AmodemterminatesananaloglocalloopE.ArouteriscommonlyconsideredaDTEdeviceF.ArouteriscommonlyconsideredaDCEdeviceAnswer:ADESection:NewExplanation/Reference:QUESTION402HowshouldarouterthatisbeingusedinaFrameRelaynetworkbeconfiguredtoavoidsplithorizonissuesfrompreventingroutingupdates?A.Configureaseparatesub-interfaceforeachPVCwithauniqueDLCIandsubnetassignedtothesubinterfaceB.ConfigureeachFrameRelaycircuitasapoint-to-pointlinetosupportmulticastandbroadcasttrafficC.Configuremanysub-interfacesonthesamesubnetD.Configureasinglesub-interfacetoestablishmultiplePVCconnectionstomultipleremoterouterinterfacesAnswer:ASection:NewExplanation/Reference:QUESTION403TheFrameRelaynetworkinthediagramisnotfunctioningproperly.Whatisthecauseoftheproblem?A.TheGallantrouterhasthewrongLMItypeconfiguredB.InverseARPisprovidingthewrongPVCinformationtotheGallantrouterC.TheS3interfaceoftheSteelerouterhasbeenconfiguredwiththeframe-relayencapsulationietfcommandD.Theframe-relaymapstatementintheAttallarouterforthePVCtoSteeleisnotcorrectE.TheIPaddressontheserialinterfaceoftheAttallarouterisconfiguredincorrectlyAnswer:DSection:NewExplanation/Reference:QUESTION404AsaCCNAcandidate,youmusthaveafirmunderstandingoftheIPv6addressstructure.RefertoIPv6address,couldyoutellmehowmanybitsareincludedineachfiled?A.24B.4C.3D.16Answer:DSection:NewExplanation/Reference:QUESTION405Refertotheexhibit.Howmanybroadcastdomainsexistintheexhibitedtopology?A.oneB.twoC.threeD.fourE.fiveF.sixAnswer:CSection:NewExplanation/Reference:QUESTION406Refertotheexhibit.ThenetworkadministratorhascreatedanewVLANonSwitch1andaddedhostCandhostD.TheadministratorhasproperlyconfiguredswitchinterfacesFastEthernet0/13throughFastEthernet0/24tobemembersofthenewVLAN.However,afterthenetworkadministratorcompletedtheconfiguration,hostAcouldcommunicatewithhostB,buthostAcouldnotcommunicatewithhostCorhostD.Whichcommandsarerequiredtoresolvethisproblem?A.Router(config)#interfacefastethernet0/1.3Router(config-if)#encapsulationdot1q3B.Router(config)#routerripC.Switch1#vlandatabaseSwitch1(vlan)#vtpv2-modeSwitch1(vlan)#vtpdomainciscoSwitch1(vlan)#vtpserverD.Switch1(config)#interfacefastethernet0/1Switch1(config-if)#switchportmodetrunkSwitch1(config-if)#switchporttrunkencapsulationislAnswer:ASection:NewExplanation/Reference:QUESTION407Onanetworkofonedepartment,therearefourPCsconnectedtoaswitch,asshowninthefollowingfigure:AftertheSwitch1restarts.HostA(thehostontheleft)sendsthefirstframetoHostC(thehostontheright).Whatthefirstthingshouldtheswitchdo?D.NoneoftheaboveAnswer:CSection:NewExplanation/Reference:QUESTION408Refertotheexhibit.ThenetworkadministratorisinacampusbuildingdistantfromBuildingB.WANRouterishostinganewlyinstalledWANlinkoninterfaceS0/0.ThenewlinkisnotfunctioningandtheadministratorneedstodetermineifthecorrectcablehasbeenattachedtotheS0/0interface.HowcantheadministratoraccuratelyverifythecorrectcabletypeonS0/0inthemostefficientmanner?A.TelnettoWANRouterandexecutethecommandshowinterfacesS0/0B.TelnettoWANRouterandexecutethecommandshowprocessesS0/0C.TelnettoWANRouterandexecutethecommandshowrunning-configurationD.TelnettoWANRouterandexecutethecommandshowcontrollerS0/0E.PhysicallyexaminethecablebetweenWANRouterS0/0andtheDCE.F.EstablishaconsolesessiononWANRouterandexecutethecommandshowinterfacesS0/0Answer:DSection:NewExplanation/Reference:QUESTION409WhiletroubleshootingaconnectivityissuefromaPCyouobtainthefollowinginformation:YouthenconductthefollowingtestsfromthelocalPC:Whatistheunderlyingcauseofthisproblem?A.Aremotephysicallayerproblemexists.B.ThehostNICisnotfunctioning.C.TCP/IPhasnotbeencorrectlyinstalledonthehost.D.Alocalphysicallayerproblemexists.Answer:DSection:NewExplanation/Reference:QUESTION410AnetworkadministratoristroubleshootingtheOSPFconfigurationofroutersR1andR2.TherouterscannotestablishanadjacencyrelationshipontheircommonEthernetlink.Thegraphicshowstheoutputoftheshowipospfinterfacee0commandforroutersR1andR2.Basedontheinformationinthegraphic,whatisthecauseofthisproblem?A.TheOSPFareaisnotconfiguredproperly.B.ThepriorityonR1shouldbesethigher.C.ThecostonR1shouldbesethigher.D.Thehelloanddeadtimersarenotconfiguredproperly.E.Abackupdesignatedrouterneedstobeaddedtothenetwork.F.TheOSPFprocessIDnumbersmustmatch.Answer:DSection:NewExplanation/Reference:QUESTION411ThisgraphicshowstheresultsofanattempttoopenaTelnetconnectiontorouterACCESS1fromrouterRemote27.Whichofthefollowingcommandsequenceswillcorrectthisproblem?A.ACCESS1(config)#lineconsole0ACCESS1(config-line)#passwordciscoB.Remote27(config)#lineconsole0Remote27(config-line)#loginRemote27(config-line)#passwordciscoC.ACCESS1(config)#linevty04ACCESS1(config-line)#loginACCESS1(config-line)#passwordciscoD.Remote27(config)#linevty04Remote27(config-line)#loginRemote27(config-line)#passwordciscoE.ACCESS1(config)#enablepasswordciscoF.Remote27(config)#enablepasswordciscoAnswer:CSection:NewExplanation/Reference:QUESTION412WhenupgradingtheIOSimage,thenetworkadministratorreceivestheexhibitederrormessage.Whatcouldbethecauseofthiserror?A.ThenewIOSimageistoolargefortherouterflashmemory.B.TheTFTPserverisunreachablefromtherouter.C.ThenewIOSimageisnotcorrectforthisrouterplatform.D.TheIOSimageontheTFTPserveriscorrupt.E.ThereisnotenoughdiskspaceontheTFTPserverfortheIOSimage.Answer:BSection:NewExplanation/Reference:QUESTION413Whichstatementistrue?A.AnIPv6addressis64blongandisrepresentedashexadecimalcharacters.B.AnIPv6addressis32blongandisrepresentedasdecimaldigits.C.AnIPv6addressis128blongandisrepresentedasdecimaldigits.D.AnIPv6addressis128blongandisrepresentedashexadecimalcharacters.Answer:DSection:NewExplanation/Reference:IPV6地址长度为128比特,十六进制QUESTION414Whichcommandsetsandautomaticallyencryptstheprivilegedenablemodepassword?A.enbalepasswordc1scoB.secretenablec1scoC.passwordenablec1scoD.enablesecretc1scoAnswer:DSection:NewExplanation/Reference:A和D是设置密码命令，D是加密密码设置QUESTION415InwhichcircumstancearemultiplecopiesofthesameunicastframelikelytobetransmittedinaswitchedLAN?A.afterbrokenlinksarere-establishedB.inanimproperlyimplementedredundanttopologyC.whenupper-layerprotocolsrequirehighreliabilityD.duringhightrafficperiodsE.whenadualringtopologyisinuseAnswer:BSection:NewExplanation/Reference:题目问在哪一个环境下交换机在lan出现多个相同的单播帧A.链路断后重启B.拓扑中有不合适的冗余，正确C上层协议需要高可靠度D在高流量的阶段E在双环拓扑该题为最新修订，之前答案选E，错误QUESTION416Refertotheexhibit.WhichisthemostefficientsummarizationthatR1canusetoadvertiseitsnetworkstoR2?Answer:ASection:NewExplanation/Reference:做一个最精确的路由汇总，将图中IP地址做汇总QUESTION417Refertotheexhibit.Basedontheexhibitedroutingtable,howwillpacketsfromahostwithintheA.TherouterwillforwardpacketsfromR3toR2toR1B.TherouterwillforwardpacketsfromR3toR1C.TherouterwillforwardpacketsfromR3toR1toR2D.TherouterwillforwardpacketsfromR3toR2toR1ANDfromR3toR1Answer:DSection:NewExplanation/Reference:从路由表中可以看到，到目的地址有两条等价均衡的路径QUESTION418Whichlayer2protocolencapsulationtypesupportssynchronousandasynchronouscircuisandhasbuilt-insecuritymechanisms?A.FrameRelayB.HDLCC.x.25D.PPPAnswer:DSection:NewExplanation/Reference:哪一个二层协议封装支持同步和异步电路并内嵌安全机制？答案：PPPQUESTION419WhichcommandcanbeusedtoverifytheDLCIdestinationaddressinaFrameRelaystaticconfiguration?A.showframe-relayend-to-endB.showframe-relaymapC.showframe-relaylmiD.showframe-relaypvcAnswer:BSection:NewExplanation/Reference:QUESTION420Refertotheexhibit.Thenetworkadministratorrequireseasyconfigurationoptionsandminimalroutingprotocoltraffic.Whichtwooptionsprovideadequateroutingtableinformationfortrafficthatpassesbetweenthetworoutersandsatisfytherequestsofthenetworkadministrator?(choosetwo)A.adynamicroutingprocotolonInternetRoutertoadvertisesummarizedrouterstoCentralRouter.B.adynamicroutingprocotolonCentralRoutertoadvertisesummarizedrouterstoInternetRouter.D.adynamicroutingprocotolonInternetRoutertoadvertiseallroutestoCentralRouer.E.adynamicroutingprocotolonCentralRouertoadvertiseallroutestoInternetRouterF.astatic,defaultrouteonCentralRouterthatdirectstraffictoInternetRouter.Answer:CFSection:NewExplanation/Reference:题目要求用简单设置和最小路由流量的路由，所以采用静态路由或默认路由QUESTION421addres?Answer:ASection:NewExplanation/Reference:求网段的网络地址，即此网段的第一个IP地址QUESTION422Refertotheexibit.Threecisco2950switchesaresettotheirdefaultprioritysettings.Duringthespanningtreeprocess,whichswitchwillbeelectedastherootbridge?A.Switch3B.Switch4C.Switch2D.Switch1Answer:DSection:NewExplanation/Reference:默认优先级，看mac地址，最小的选为跟桥QUESTION423Whichthreeelementsmustbeusedwhenyouconfigurearouterinterfaceforvlantrunking?(choosethree)A.oneIPnetworkorsubnetworkforeachsubinterfaceB.subinterfacenumberingthatmatchesvlantagesC.subinterfaceencapsulationidentifiersthatmatchvlantagsD.amanagementdomainforeachsubinterfaceE.onephysicalinterfaceforeachsubinterfaceF.onesubinterfacepervlanAnswer:ACFSection:NewExplanation/Reference:考察单臂路由的设置A一个网络或子网对应一个子接口，正确B子接口号必须和vlan号一样，不正确C子接口封装标识符必须和vlan号一样，正确D每一个子接口需要一个管理域，不正确E每一个子接口需要一个物理端口，不正确F一个子接口对应一个vlan，正确QUESTION424Areceivinghostcomputesthechecksumonaframeanddeterminesthattheframeisdamaged.Theframeisthendiscarded.AtwhichOSIlayerdidthishappen?A.sessionB.networkC.physicalD.datalinkE.transportAnswer:DSection:NewExplanation/Reference:帧的处理是在二层QUESTION425considerthemostreliableinformationaboutthepathtothatnetwork?Answer:ESection:NewExplanation/Reference:直连端口的路由管理距离最小为0QUESTION426WhichtwostatementsdescribetheadvantagestotheuseofRIPovertheuseofOSPF?(choosetwo)A.RIPrequireslesstimetoconvergeB.RIPuseslessbandwidthC.RIPislesscomplextoconfigureD.RIPdemandsfewerrouterresourcesE.RIPhasamoreaccuratemetricAnswer:CDSection:NewExplanation/Reference:RIP相比OSPF的好处？ARIP汇聚时间更短。错BRIP占用更少的带宽。错。距离矢量协议采用定时更新，占带宽较大CRIP设置更简单，正确DRIP占用更少的路由器资源，正确ERIP有一个更精确的metric，错，使用跳数作为metric，不精确QUESTION427Whichstatementaboutvlanoperationonciscocatalystswitchesistrue?A.whenapacketisreceivedfroman802.1Qtrunk,thevlanidcanbedeterminedfromthesourceMACaddresstable.B.unkownunicastframesareretransmittedonlytotheportsthatbelongtothesamevlanC.portsbetweenswitchesshouldbeconfiguredinaccessmodesothatvlanscanspanacrosstheportsD.broadcastandmulticastframesareretransmittedtoportsthatareconfiguredondifferentvlan.Answer:BSection:NewExplanation/Reference:A通过源mac地址确定vlan，不正确B未知单播帧只在本vlan传播，正确C交换机之间应该设置为trunkDvlan能分割广播域，广播不能跨vlan传输QUESTION428WhichcommandsarerequiredtoproperlyconfigurearoutertoproperlyconfigurearoutertorunOSPFA.Router(config)#routerospf1B.Router(config)#routerospf0C.Router(config)#routerospfarea0Answer:ADSection:NewExplanation/Reference:OSPF的配置进程号范围1-65535，宣告网段需要反掩码+区域QUESTION429TheenablesecretcommandisusedtosecureaccesstowhichCLImode?A.userEXECmodeB.globalconfigurationmodeC.privilegedEXECmodeD.auxiliarysetupmodeAnswer:CSection:NewExplanation/Reference:注意此题不是问在什么模式下设置，而是问为进入那种模式保障安全QUESTION430Refertotheexhibit.ExplainhowtheroutesinthetablearebeingaffectedbythestatuschangeoninterfaceEthernet0.A.TherouterispoisoningtheroutesandmulticastingthenewpathcostsviainterfaceEthernet1.B.TherouterisreceivingupdatesaboutunreachablenetworksfromrouterthatareconnectedtointerfaceEthernet1.C.TherouterispoisoningtheroutesandbroadcastingthenewpathcostsviainterfaceEthernet1.D.TherouterisrequestingupdatesforthesenetworksfromroutersthatareconnectedtointerfaceEtherne1.Answer:ASection:NewExplanation/Reference:E0端口down，部分路由收不到更新，将此部分路由的metric设为16，通过E1端口发布QUESTION431InwhichintegrationmethodisanIPV6packetencapsulatedwithinanIPV4protocol?A.proxy.B.dual-stackC.tunnelingD.dot1qAnswer:CSection:NewExplanation/Reference:将IPV6包封装在IPV4协议内，隧道技术QUESTION432Whichtwocommandscanbeusedtoverifyatrunklinkconfigurationtstatusonagivenciscoswitch?(choosetwo)A.showinterfacesinterfaceB.showinterfacesinterfacetrunkC.showinterfacesinterfaceswitchportD.showipinterfacebriefE.showinterfacesvlanAnswer:BCSection:NewExplanation/Reference:查看trunk命令，showinterfacetrunk和showinterfaceswitchport，只能选BCQUESTION433Assumingthedefaultswitchconfiguration,whichapproachshouldyouusetoconfiguretheextendedvlanrange(1006through4094)onaciscocatalyst3750seriesswitch?A.ConfiguretheswitchtobeinVTPclientmode.B.ConfiguretheswitchtobeinVTPdomaintmode.C.ConfiguretheswitchtobeinVTPtransparentmode.D.ConfiguretheswitchtobeinVTPv2.Answer:CSection:NewExplanation/Reference:vlan号1006-4094属于扩展vlan，只能在透明模式配置QUESTION434askedtodevelopanIPaddressingplantoallowthemaximumnumberofsubnetswithasmanyas30hostseach.WhichIPaddressrangemeetstheserequirements?Answer:BSection:NewExplanation/Reference:30台主机还需要一个网关，所以需要31个有效IP地址QUESTION435Whichthreestatementsaccuratelydescribelayer2Ethernetswitches?(choosethree)A.Microsegmentationdecreasesthenumberofcollisionsonthenetwork.B.ifaswitchreceivesaframeforanunkowndestination,itusesARPtoresolvetheaddress.C.SpanningTreeProtocolallowsswitchestoautomaticallysharevlaninformation.D.Inaproperlyfunctioningnetworkwithredundantswitchedpaths,eachswitchedaegmentwillcontainonerootbridgewithallitsportsintheforwardingstate.Allotherswitchesinthatbroadcastdomainwillhaveonlyonerootport.E.Establishingvlansincreasesthenumberofbroadcastdomains.F.Switchesthatareconfiguredwithvlansmakeforwardingdecisionsbasedonbothlayer2andlayer3addressinformation.Answer:ADFSection:NewExplanation/Reference:A为分割减少冲突的数量，这里是冲突并不是冲突域，正确B收到未知目的帧会产生泛洪C这是vtp的特性，不是stp的D在一个能够正常运行的网络冗余交换路径，每一个交换网段将包括一个跟桥。所有端口都在转发状态，其他本广播域的交换机有一个根端口。正确E.不看题目要求这句话没问题，但是题目要求对二层的描述，广播域就不和题意了Fvlan使转发基于二层和三层，正确QUESTION436Refertotheexhibit.TheLaksideCompanyhastheinternetworkintheexhibit.TheadministratorwouldliketoreducethesizeofroutingtableontheCentralrouter.WhichpartialroutingtableentryintheCentralrouterepresentsaroutesummarythatrepresentsthevlansinPhoenixbutnoadditionalsubnets?Answer:ASection:NewExplanation/Reference:对PHOENIX做路由汇总QUESTION437Refertotheexhibit.WhichtwodevicescanbeusedtocompletetheconnectionbetweentheWANrouteratthecustomersiteandtheserviceprovider?A.modemB.FrameRelayswitchC.CSU/DSUD.WANswitchE.ISDNTAF.ATMswitchAnswer:ACSection:NewExplanation/Reference:问号处应该是DCE设备.A和C是DCE设备，一个是模拟的一个是数字的QUESTION438WhichPPPsubprotocolnegotiatesauthenticationoptions?A.NCPB.LCPC.ISDND.DLCIE.SLIPAnswer:BSection:NewExplanation/Reference:PPP的哪一个子协议能够协商验证：LCPQUESTION439WhichtwodatalinklayersaresupportedbyciscoiossoftwareforIPv6?(choosetwo)A.PPPB.FDDIC.FrameRelayPVCD.NBMAE.FrameRelaySVCAnswer:ACSection:NewExplanation/Reference:支持IPV6的二层协议有哪些QUESTION440Whichtermdescribesaspanning-treenetworkthathasallswitchportsineithertheblockingorforwardingstate?A.redundantB.spannedC.provisionedD.convergedAnswer:DSection:NewExplanation/Reference:收敛以后交换机端口只有堵塞和转发状态QUESTION441Whichtwoofthesearecharacteristicsofthe802.1Qprotocol?(choosetwo)A.itisalayer2messagingprotocolwhichmaintainsvlanconfigurationsacrossnetwork.B.itincludesan8-bitfieldwhichspecifiesthepriorityofaframe.C.itisusedexclusivelyfortaggingvlanframesanddosenotaddressnetworkreconvergencefollowingswitchednetworktopologychanges.D.itmodifiesthe802.3frameheader,andthusrequiresthattheFCSberecomputed.E.itisatrunkingprotocolcapableofcarringuntaggedframes.Answer:DESection:NewExplanation/Reference:A描述的是vtp的特性B应该是3bitCexclusively是唯一的意思。802.1Q不是唯一的D修改帧的头部，需要重新进行FCS校验，正确E是一个trunk协议并支持不打标记的帧，正确QUESTION442Refertotheexhibit.Whichtwostatementsaretrueoftheinterfacesonswitch1?(choosetwo)A.AhubisconnecteddirectlytoFastEthernet0/5B.FastEthernet0/1isconfiguredasatrunklink.C.FastEthernet0/5hasstaticallyassignedmacaddressD.InterfaceFastEthernet0/2hasbeendisable.E.MultipledevicesareconnecteddirectlytoFastEthernet0/1.F.FastEthernet0/1isconnectedtoahostwithmultiplenetworkinterfacecards.Answer:ABSection:NewExplanation/Reference:图中可以看出F0/1,F0/2为trunk。F0/5端口有多个mac地址，而且不是trunk，只能是接了一个hubQUESTION443Whichtwostatementsapplytodynamicaccesslists?(choosetwo)A.theyoffersimplermanagementinlargeinternetworks.B.youcancontrolloggingmessages.C.theyallowpacketstobefilteredbasedonupper-layersessioninformation.D.youcansetatime-basedsecuritypolicy.E.theyprovidealevelofsecurityagainstspoofing.F.theyareusedtoauthenticateindividualusers.Answer:AFSection:NewExplanation/Reference:这里是动态ACL，而不是自反ACL。动态ACL的有点：1、使用口令机制对每个用户进行身份认证2、简化了大型网际网络的管理3、在许多情况下，可以减少ACL需要的路由器处理量4、可以降低网络黑客入侵网络的机会5、可以在不影响所配置的其他安全限制的情况下，创建通过防火墙进行的用户动态访问QUESTION444Anetworkengineerwantstoallowatemporaryentryforaremoteuserwithaspecificusenameandpasswordsothattheusercanaccesstheentirenetworkovertheinternet.whichACLcanbeused?A.reflexiveB.extendedC.standardD.dynamicAnswer:DSection:NewExplanation/Reference:网络工程师想要允许一个临时站与一个特定的usename远程用户和密码,这样用户可以访问整个网络.whichACL可以使用?动态ACLQUESTION445WhichparameterorparametersareusedtocalculateOSPFcostinciscorouters?A.Bandwidth,Delay,andMTUB.BandwidthC.BandwidthandMTUD.Bandwidth,MTU,Reliability,Delay,andLoadAnswer:BSection:NewExplanation/Reference:OSPF使用带宽计算costQUESTION446whichcommandisusedtoenableCHAPauthenticationwhitPAPasthefallbackmethodonaserialinterface?A.(config-if)#authenticationpppchapfallbackpppB.(config-if)#authenticationpppchappapC.(config-if)#pppauthenticationchappapD.(config-if)#pppauthenticationchapfallbackpppAnswer:CSection:NewExplanation/Reference:要求使用chap认证，pap认证作为备用QUESTION447assumingthedefaultswitchconfigurationwhichvlanrangecanbeaddedmodifiedandremovedonaciscoswitch?A.2through1001B.1through1001C.1through1002D.2through1005Answer:ASection:NewExplanation/Reference:交换机上默认那些是可以修改和移动的vlan。2-1001QUESTION448whichaddressrangeefficientlysummarizestheroutingtableoftheaddressesforroutermain?Answer:CSection:NewExplanation/Reference:将这11个IP地址做汇总QUESTION449WhatisthemostlikelyreasonforthedispartlybetweentheactualnetworknumbersatthebranchesandtheroutesintheroutingtableonGateway-Router?A.Branch-Router2isconfiguredtosendbothRIPv1andRIPv2updates.B.Gateway-RouterisconfiguredtoonlyreceiveRIPv2updates.C.Gateway-routerisconfiguredtoreceiveonlyRIPv1updates.D.Branch-Router1isconfiguredtoonlysendRIPv1updatesAnswer:DSection:NewExplanation/Reference:RIPV1是有类路由，路由表中可以看出R1的路由是主类的QUESTION450Anetworkadministratorneedstoconfigureportsecurityonaswitch.whichtwostatementsaretrue?(choosetwo)A.ThenetworkadministratorcanapplyportsecuritytodynamicaccessportsB.Thenetworkadministratorcanconfigurestaticsecureorstickysecuremacaddressesinthevoicevlan.C.Thestickylearningfeatureallowstheadditionofdynamicallylearnedaddressestotherunningconfiguration.D.ThenetworkadministratorcanapplyportsecuritytoEtherChannels.E.Whendynamicmacaddresslearningisenabledonaninterface,theswitchcanlearnnewaddresses,uptothemaximumdefined.Answer:CESection:NewExplanation/Reference:A.动态端口不能应用的端口安全B.intheviocevlan不正确C.保存在runningconfiguratin正确D.EtherChannels不能应用端口安全E自动学习mac地址可以学到所设置的最大数量，正确QUESTION451validIPaddressescanthetechnicianuseforthehosts?(choosethree)Answer:CDESection:NewExplanation/Reference:块大小是32，所以最后一位是32的倍数或32倍数-1都不可以QUESTION452WhichcommandhelpsanetworkadministratortomanagememorybydisplayingflashmemoryandNVRAMutilization?A.showsecureB.showfilesystemsC.showflashD.showversionAnswer:BSection:NewExplanation/Reference:查看flash和NVRAM的里利用率QUESTION453WhichIEEEstandardprotocolisinitiatedasaresultofsuccessfulDTPcompletioninaswitchoverFastEthernet?A.802.3adB.802.1wC.802.1QD.802.1dAnswer:CSection:NewExplanation/Reference:动态中继协议DTP，是VLAN组中思科的私有协议，主要用于协商两台设备间链路上的中继过程及中继封装802.1Q类型。QUESTION454Whichcommandenhancesthe802.1Dconvergencetimeonportsthatareconnectedtohosts?A.spanning-treebackbonefastB.spanning-treeuplinkfastC.spanning-treeportfastD.spanning-treecost512Answer:CSection:NewExplanation/Reference:连接到主机的端口使用spanning-treeportfastQUESTION455Whichtwostatementsarecharacteristicsofadistancevectorroutingprotocol?(choosetwo)A.RIPisanexampleofdistancevectorroutingprotocols.B.Updatesareperiodicandincludetheentireroutingtable.C.RoutingupdatesaresentonlyaftertopologychangesD.Theprotocolcanbeusefulinhub-and-spokeandhierarchicalnetworks.E.ConvergenceisusuallyfasterthanwithlinkstateprotocolsF.EachrouterhasitsownviewofthetopologyAnswer:ABSection:NewExplanation/Reference:ARIP是距离矢量路由协议B周期性更新整个路由表C这条是链路状态协议的特性D协议可以用在中心型分层网络，不正确E会聚比链路状态要慢F只是和邻居更新，不会维护整个拓扑QUESTION456WhichofthefollowingprotocolsusesbothTCPandUDPports?A.SMTPB.TelnetC.FTPD.DNSAnswer:DSection:NewExplanation/Reference:主机使用域名解析用的是UDP。域名解析服务器之间同步信息使用的是TCP.QUESTION457Whichtwoprivilegedmodeciscoioscommandscanbeusedtodetermineaciscorouterchassisserialnumber?(choosetwo)A.showinventoryB.showflash:filesysC.dirflash:includechassisD.showdiagE.showcontrollersAnswer:ADSection:NewExplanation/Reference:考察查看机器序列号的命令QUESTION458Refertotheexhibit.Anewsubnetwith60hostshasbeenaddedtothenetwork.Whichsubnetaddressshouldthisnetworkusetoprovideenoughusableaddresseswhilewastingthefewestaddresses?Answer:BSection:NewExplanation/Reference:要考虑到图中已经用掉的网段QUESTION459Refertotheexhibit.WhyaretwoOSPFdesignatedroutersidentifiedonCore-Router?A.Core-Routerisconnectedmorethanonemulti-accessnetworkC.TworouterIDshavethesameOSPFpriorityandarethereforetiedforDRelectionD.TheDRecectionisstillunderwayandtherearetwocontendersfortherole.Answer:ASection:NewExplanation/Reference:为什么一个路由器上会出现俩DR?DR/BDR是指端口并不是指路由器，所以一个路由器接入多个ospf网络，会出现此种情况QUESTION460IthasbecomenecessarytoconfigureanexistingserialinterfacetoacceptasecondFrameRelayvirtualcircuit.Whichofthefollowingprocessesarerequiredtoaccomplishthistask?(choosethree)A.configurestaticframerelaymapentriesforeachsubinterfacenetwork.B.removetheipaddressfromthephysicalinterfaceC.createthevirtualinterfaceswiththeinterfacecommandD.configureeachsubinterfacewithitsownIPaddressE.disablesplithorizontopreventroutingloopsbetweenthesubinterfacenetworksF.encapsulatethephysicalinterfacewithmultipointPPPAnswer:BCDSection:NewExplanation/Reference:现存有一条帧中继需要加第二条帧中继，需要创建子接口，使用点对多点A点对多点需要frame-relaymapE取消水平分割不是为了防止路由环路F用多点PPP封装物理端口,错QUESTION461Refertothegraphic.Computer1isconsolesintoswitchA.TelnetconnectionsandpingsrunfromthecommandpromptonswitchAfail.Whichofthefollowingcouldcausethisproblem?A.switchAdosenothaveacdpentryforswitchBorrouterJAXB.switchAdosenothaveanIPaddressC.port1onswitchAshouldbeanaccessportratherthanatrunkportD.switchAisnotdirectlyconnectedtorouterJAXE.switchAdoesnothaveadefaultgatewayassignedAnswer:ESection:NewExplanation/Reference:图中vlan1没有配置IP地址，这可能管理vlan不是vlan1，别的vlan没有显示出来。题目说ping和telnet都失败，至少说明交换机已经配置了IP地址。原因就是没有配置默认网关了QUESTION462Refertotheexhibit.Whatistheresultofsettingthenologincommand?A.TheisavirtuallylimitlesssupplyofIPaddressesB.TelnetaccessrequiresanewpasswordatfirstloginC.TelnetaccessrequiresapasswordD.TelnetaccessisdeniedAnswer:ASection:NewExplanation/Reference:A不限制IP地址接入QUESTION463WhichIPv6addressisvalid?A.2031:0:130F::9C0:876A:130BB.2001:0DB8:0000:130F:0000:0000:08GC:140BC.2001:0DB8:0:130H::87C:140BD.2031::130F::9C0:876A:130BAnswer:ASection:NewExplanation/Reference:B十六进制没有GC也没有HD只能有一个：：QUESTION464Refertotheexhibit.Whichthreevariables(router,protocolport,androuterACLdirection)applytoanextendedACLthatwillpreventstudent01fromsecurelybrowsingtheinternet?A.OUTB.Router3C.HTTTPD.INE.Router1Answer:BCDSection:NewExplanation/Reference:我们选择在R3上的in方向。如果在R3的out的方向会增加路由器不必要的负担QUESTION465WhataretwocharacteristicsofaswitchthatisconfiguredasaVTPclient?(choosetwo)A.ifaswitchthatisconfiguredtooperateinclientmodecannotaccessaVTPserver,thentheswitchrevertstotransparentmode.B.Thelocalvlanconfigurationisupdatedonlywhenanupdatethathasahigherconfigurationrevisionnumberisreceived.C.Vtpadvertisementsarenotforwardedtoneighboringswitchesthatareconfiguredinvtptransparentmode.D.Whenswitchesinvtpclientmodearerebooted,theysendavtpadvertisementrequesttothevtpservers.E.VtpclientisthedefaultvtpmodeF.Onswitchesthatareconfiguredtooperateinclientmode,vlanscanbecreated,deleted,orrenamedlocallyAnswer:BDSection:NewExplanation/Reference:考察VTP客户端的特点A如果交换机在客户端模式不能介入VTP服务器，将会转到透明模式。错，不会转到透明模式B只有当收到更高的修正版本号更新，本地vlan设置才会更新。正确C透明模式下VTP广播不会转发给邻居路由器。错，可以转发D客户模式下重启，发送一个vtp请求。正确E默认模式应该是服务器模式F客户端模式不能修改创建vlanQUESTION466Whattwostatisticsappearinshowframe-relaymapoutput?(choosetwo)A.ThenumberofFECNpacketsthatarereceivedbytherouterB.ThenumberofBECNpacketsthatarereceivedbytherouter.C.TheipaddressofthelocalrouterD.ThevalueofthelocalDLCIE.ThestatusofthePVCthatisconfiguredontherouterAnswer:DESection:NewExplanation/Reference:QUESTION467Whichcommandcanyouusetodeterminetheciscoiosfeaturesetonaciscorouter?A.showversionB.dirflash:includeiosC.showenvironmentD.showdiagE.showinventoryAnswer:ASection:NewExplanation/Reference:查看路由器IOS特性QUESTION468Whatarethreebenefitsofimplementingvlans?(choosethree)A.AmoreefficientuseofbandwidthcanbeachievedallowingmanyphysicalgroupstousethesamenetworkinfrastructureB.Broadcaststormscanbemitigatedbydecreasingthenumberofbroadcastdomains,thusincreasingtheirsize.C.Ahigherlevelofnetworksecuritycanbereachedbyseparatingsensitivedatatrafficfromothernetworktraffic.D.Port-basedvlansincreaseswitch-portuseefficient,thanksto802.1QtrunksE.Amoreefficientuseofbandwidthcanbeachievedallowingmanylogicalnetworkstousethesamenetworkinfrastructure.F.Broadcaststormscanbemitigatedbyincreasingthenumberofbroadcastdomains,thusreducingtheirsize.G.VLANsmakeiteasierforITstafftoconfigurenewlogicalgroups,becausethevlansallbelongtothesamebroadcastdomain.Answer:CEFSection:NewExplanation/Reference:A错，不是通过物理上组合，而是逻辑上的B错，应该是增加广播域的数量C一个更高的层次网络安全可以实现,以分离的敏感数据从其他网络。正确Dthanksto802.1Qtrunks不正确E正确，logical是逻辑的意思F正确G错误，是VTP的作用不是vlan的QUESTION469IntheimplementationofVLSMtechniquesonanetworkusingasingleClassCIPaddress,whichsubnetmaskisthemostefficientforpoint-to-pointseriallinks?Answer:CSection:NewExplanation/Reference:点到点链路需要两个有效IP地址QUESTION470Aswitchhasbeenconfiguredwithtwovlansandisconnectedtoarouterwithatrunkforinter-vlanrouting.OSPFhasbeenconfiguredontherouter,astheroutingprotocolforthenetwork.Whichstatementaboutthisnetworkistrue?A.Forthetwovlanstocommunicate,anetworkstatementforthetrunkinterfaceneedstobeaddedtotheOSPFconfiguration.B.Forthetwovlanstocommunicate,anetworkstatementforeachsubinterfaceneedstobeaddedtotheOSPFconfiguration.C.Directinter-vlancommunicationdoesnotrequireOSPF.D.OSPFcannotbeusedifrouter-on-a-stickisconfiguredontherouter.Answer:CSection:NewExplanation/Reference:两个vlan之间通信使用的是直连路由，不需要OSPFQUESTION471WhichcommandenablesIPv6forwardingonaciscorouter?A.ipv6hostB.ipv6unicast-routingC.ipv6localD.ipv6neighborAnswer:BSection:NewExplanation/Reference:在路由器上激活IPV6的命令QUESTION472commandoutputandgraphic,whatisthemostlikelycauseoftheproblem?A.incorrectbandwidthconfigurationB.incorrectLMIconfigurationC.incorrectmapstatementD.incorrectIPaddressAnswer:CSection:NewExplanation/Reference:QUESTION473AciscorouterisbootingandhasjustcompletedthePOSTprocess.ItisnowreadytofindandloadanIOSimage.whatfunctiondoestherouterperformnext?A.ItcheckstheconfigurationregisterB.ItattemptstobootfromaTFTPserverC.ItloadsthefirstimagefileinflashmemoryD.ItinspectstheconfigurationfileinNVRAMforbootinstructionsAnswer:ASection:NewExplanation/Reference:下一步检查configurationregister然后决定加载配置QUESTION474Refertotheexhibit.WhichstatementdescribesDLCI17?A.DLCI17describestheISDNcircuitbetweenR2andR3.B.DLCI17describesaPVConR2.ItcannotbeusedonR3orR1.C.DLCI17istheLayer2addressusedbyR2todescribeaPVCtoR3.D.DLCI17describesthedial-upcircuitfromR2andR3totheserviceprovider.Answer:CSection:NewExplanation/Reference:DLCI号是一个二层地址，和mac类似QUESTION475Answer:DESection:NewExplanation/Reference:QUESTION476Whichspreadspectrumtechnologydoesthe802.11bstandarddefineforoperation?A.IRB.DSSSC.FHSSD.DSSSandFHSSE.IR,FHSS,andDSSSAnswer:BSection:NewExplanation/Reference:802.11b采用DSSS扩频技术QUESTION477Refertotheexhibit.HostAcannotpingHostB.Assumingroutingisproperlyconfigured,whatcouldbethecauseofthisproblem?A.HostAisnotonthesamesubnetasitsdefaultgatewayB.TheaddressofSwitchAisasubnetaddressC.TheFa0/0interfaceonRouterAisonasubnetthatcannotbeusedD.TheserialinterfacesoftheroutersarenotonthesamesubnetE.TheFa0/0interfaceonRouterBisusingabroadcastaddressAnswer:DSection:NewExplanation/Reference:QUESTION478WhichprotocolprovidesamethodofsharingVLANconfigurationinformationbetweentwoCiscoswitch?A.VTPB.802.1QC.RSTPD.STPAnswer:ASection:NewExplanation/Reference:交换机共享vlan信息，VTP协议QUESTION479WhichthreeapproachescanbeusedwhilemigratingfromanIPV4addressingschemetoanIPV6scheme.(choosethree)A.staticallymapIPV4addresstoIPV6addressesB.configurationIPv4tunnelsbetweenIPV6islandsC.useDHCPv6tomapIPV4addressestoIPV6addressesD.useproxyingandtranslationtotranslateIPV6packetsintoIPV4packetsE.configureIPV6directlyF.enabledual-stackroutingAnswer:ABFSection:NewExplanation/Reference:答案是ABF。IPV6向IPV4过渡书上有三种方法：隧道，双栈，NAT-PT.A是静态NAT-PYB是隧道F是双栈QUESTION480DNSserversprovidewhatservice?A.TheyrunaspellcheckonhostnamestoensureaccurateroutingB.TheyconvertdomainnamesintoIPaddressC.GivenanIPaddress,theydeterminethenameofthehostthatissoughtD.TheymapindividualhoststotheirspecificIPaddressesAnswer:BSection:NewExplanation/Reference:域名解析服务器将网址域名解析为IP地址QUESTION481WhatisthealternativenotationfortheIPV6addressB514:82C3:0000:0000:0029:EC7A:0000:EC72?A.B514:82C3:0029::EC7A:0000:EC72B.B514:82C3:0029:EC7A:EC72C.B514:82C3::0029:EC7A:0:EC72D.B514:82C3::0029:EC7A:EC72Answer:CSection:NewExplanation/Reference:考试时候C可能会出现14:82C3::0029:EC7A:0:EC72这种情况，系统错误，不用管它，选CQUESTION482whichcommandallowsyoutoverifytheencapsulationtype(CISCOORIETF)foraframerelaylink?A.showframe-relaymapB.showframe-relaylmiC.showinterserialD.showframe-relaypvcAnswer:CSection:NewExplanation/Reference:帧中继封装有两种cisco和ietf。默认是cisco。showinterserial真机实验结果：封装cisco----encapsulationframe-relay封装ietf-------encapsulationframe-relayietfQUESTION483thenetworkadministratorhasbeenaskedtogivereasonsformovingfromipv4toipv6.whataretwovalidreasonsforadoptingipv6overipv4?(choosetwo)A.telnetaccessdoesnotrequireapasswordB.natC.nobroadcastD.chanageofdestinationaddressintheipv6headerE.chanageofsourceaddressintheipv6headerF.autoconfigurationAnswer:CFSection:NewExplanation/Reference:要求给出IPV4向IPv6转换的理由，也就是v6的优点。C没有广播,F自动设置QUESTION484WhichIPsecsecurityprotocolshouldbeusedwhenconfidentialityisrequired?A.PSKB.AHC.MD5D.ESPAnswer:DSection:NewExplanation/Reference:ESP提供机密性、数据源认证、无连接的完整性、抗重播服务（一种部分序列完整性的形式）和有限信息流机密性。QUESTION485AtwhichlayeroftheOSImodelisRSTPusedtopreventloops?A.datalinkB.networkC.physicalD.transportAnswer:ASection:NewExplanation/Reference:QUESTION486WhichdevicemightbeinstalledatabranchofficetoenableandmanageanIPsecsite-to-siteVPN?A.CiscoIOSIPsec/SSLVPNclientB.CiscoVPNClinetC.ISDNterminaladapterD.CiscoAdaptiveSecurityApplianceAnswer:DSection:NewExplanation/Reference:QUESTION487Whichstatementistrue,asrelatestoclassfulorclasslessrouting?A.AutomaticsummarizationatclassfulboundriescancauseproblemsondiscontinuoussubnetsB.EIGRPandOSPFareclassfulroutingprotocolsandsummarizeroutesbydefaultC.RIPv1andOSPFareclasslessroutingprotocolsD.ClassfulroutingprotocolssendthesubnetmaskinroutingupdatesAnswer:ASection:NewExplanation/Reference:A自动汇总将路由汇总成主类地址，在不连续网段会出错。正确B错都是无类路由协议OSPF没有自动汇总C错RIPV1是有类路由协议D错有类路由协议路由更新不需要子网掩码QUESTION488Refertotheexhibit,HostApingsinterfaceS0/0onrouter3,whatistheTTLvalueforthatping?A.253B.252C.255D.254Answer:ASection:NewExplanation/Reference:默认是255，每经过一个路由器减1QUESTION489WhichaddressistheIPV6all-RIP-routersmuticastgroupaddressthatisusedbyRIPngasthedestaionaddress?A.FF02::AB.FF05::101C.FF02::9D.FF02::6Answer:CSection:NewExplanation/Reference:IPV6RIPng的组播地址FF02::9QUESTION490WhatisthedefaultadministrativedistanceofOSPF?A.120B.100C.90D.110Answer:DSection:NewExplanation/Reference:OSPF默认管理距离110QUESTION491WhichencapsulationtypeisaFrameRelayencapsulationtypethatissupportedbyCiscorouters?A.IETFB.HDLCC.Q9333-AAnnexAD.ANSIAnnexDAnswer:ASection:NewExplanation/Reference:A.Cisco支援Frame-Relay封装格式:Cisco&IETFB.HDLC->Cisco预设pointtopoint封装C&D->是Frame-Relaylmi-typeQUESTION492WhichtwostatementsaboutusingtheCHAPauthenticationmechanisminaPPPlinkaretrue?(choosetwo)A.CHAPusesatwo-wayhandshakeB.CHAPauthenticationperiodicallyoccursafterlinkestablishmentC.CHAPhasnoprotectionfromplaybackattacksD.CHAPauthenticationisperformedonlyuponlinkestablishmentE.CHAPusesathree-wayhandshakeF.CHAPauthenticationpasswordsaresentinplaintextAnswer:BESection:NewExplanation/Reference:PAP是两次握手机制；CHAP通过3次握手，CHAP定期发出挑战，以确保远程节点有有效的密码，CHAP采用MD5加密算法，而PAP采用明文A.CHAP认证采用的是两次握手机制B.CHAP的认证是链路建立之后周期性发生的C.CHAP认证没有重放攻击的保护D.执行CHAP认证只是在链路建立的时候E.CHAP认证采用的三次握手机制F.CHAP认证的密码是采用明文的方式传输的QUESTION493Refertotheexhibit.Whatisthereasonthattheinterfacestatusis“administrativelydown,lineprotocoldown”?A.ThereisamismatchinencapsulationtypesB.ThewrongtypeofcableisconnectedtotheinterfaceC.TheinterfacehasbeenconfiguredwiththeshutdowncommandD.TheinterfaceisnotreceivinganykeepalivesE.TheinterfaceneedstobeconfiguredasaDTEdeviceF.ThereisnoencapsulationtypeconfiguredAnswer:CSection:NewExplanation/Reference:注释：很明显是物理层的问题，以前题库中出现过此题，以前是双选，现在变成单选了。仔细看一下B选项被舍弃了，因为这是串口，串口线只有一种两个端口，DTE和DCE，两头接错属于时钟配置错误是protocoldown。QUESTION494Whichcommandencryptsallplaintextpasswords?A.Router(config)#password-encryptionB.Router(config)#servicepassword-encryptionC.Router#servicepassword-encryptionD.Router#password-encryptionAnswer:BSection:NewExplanation/Reference:QUESTION495WhichCiscoIOSdiagnosticscommandcandisrupttheoperationofarouterunderhigh-loadconditions?A.showrunning-configB.showprocessescpuC.debugallD.logginghostipaddressAnswer:CSection:NewExplanation/Reference:题目说的了路由器是在高负载的情况下运行的，而debug命令是要占用大量的CPU的占用率很高的，debug不要乱用，数据流量很大的时候，debug信息会把内存全部消耗，造成设备死机。QUESTION496WhichthreestatementsaboutEIGRParetrue?(choosethree)A.EIGRPconvergesfastRIPbecauseofDUALandbackuproutesthatarestoredinthetopologytable.B.EIGRPusesahelloprotocoltoestablishneighborrelationshipsC.EIGRPusessplithorizonandreversepoisoningtoavoidroutingloops.D.EIGRPusesperiodicupdatestoexchangeroutinginformationE.EIGRPallowsroutersofdifferentmanufacturerstointeroperateF.EIGRPsupportsVLSMandauthenticationforroutingupdates.G.EIGRPuseabroadcastaddresstosendroutinginformation.Answer:ABFSection:NewExplanation/Reference:QUESTION497Refertotheexhibit.Whydosethetelnetconnectinfailwhenahostattemptstoconnectaremoterouter?A.NopasswordwassetforttylinesB.NopasswordwassetforauxlinesC.NopasswordwassetforvtylinesD.NopasswordwassetforctylinesAnswer:CSection:NewExplanation/Reference:QUESTION498Refertotheexhibit,TheVLANconfigurationofS1isnotbeinginthisVTPenabledenvironment.TheVTPanduplinkportconfigurationsforeachswitcharedisplayed.Whichtwocommandsets,ifissued,resolvethisfailureandallowVTPtooperateasexpected?(choosetwo)A.S2(config)#vtpmodetransparentB.S1(config)#vtpmodeclientC.S2(config)#interfacef0/24S2(config-if)#switchportmodeaccessS2(config-if)#endD.S2(config)#vtpmodeclientE.S1(config)#interfacef0/24S1(config-if)#switchportmodetrunkS1(config-if)#endAnswer:BESection:NewExplanation/Reference:如图所示，SW1的VLAN配置在此VTP下没有被启用，VTP和它的上行端口配置如图所示，请问使用哪两个命令可以排除此故障，达到VTP预期的效果？SW1和SW2都处于同一个VTP模式下，但SW1处于透明模式，仅转发通告，地整个域内的信息不能同步；SW1是接入模式，SW2是动态自动模式，二者结合是接入模式，所以应该将SW1配置为中继模式，VTP域中的各个VLAN才能进行通信。A.S2(config)#vtpmodetransparent//将s2vtp的模式设为透明模式B.S1(config)#vtpmodeclient//将s1vtp的模式设为客服端模式C.S2(config)#interfacef0/24//进入s2的0/24好端口S2(config-if)#switchportmodeaccess//将其设为可访问模式S2(config-if)#end//退出端口配置模式D.S2(config)#vtpmodeclient//将s2VTP的模式设为客服端模式E.S1(config)#interfacef0/24//进入S1的0/24号端口S1(config-if)#switchportmodetrunk//将其设为干到模式S1(config-if)#end//退出端口配置模式QUESTION499WhichnamedescribesanIPV6host-enabletunnelingtechniquethatusesIPV4UDP,doesnotrequirededicatedgatewaytunnels,andcanpassthroughexistingIPV4NATgateways?A.dualstackB.dynamicC.TeredoD.Manual6to4Answer:CSection:NewExplanation/Reference:Teredo是一项IPv6/IPv4转换技术，能够实现在处于单个或者多个IPv4NAT后的主机之间的IPv6自动隧道。来自Teredo主机的IPv6数据流能够通过NAT，因为它是以IPv4UDP数据格式发送的。如果NAT支持UDP端口解析，那么它就支持Teredo。QUESTION500Whichpairingreflectsacorrectprotocol-and-metricrelationship?A.OSPFandmumberofhopsandreliabilityB.EIGRPandlinkcostC.IS-ISanddelayandreliabilityD.RIPv2andnumberofhopsAnswer:DSection:NewExplanation/Reference:A.OSPFandnumberofhopsandreliability（OSPF与跳数和可靠性）实际ospf是通过接口宽带计算出花费值来度量的B.EIGRPandlinkcost（EIGRP与链路花费值）实际eigrp是以带宽、延时、负载、可靠性及MTU来度量的C.IS-ISanddelayandreliability（IS-IS与延迟和可靠性）实际is-is是以默认、延迟、开销、差错来度量的，主要用默认度量，相当于ospf的cost值度量D.RIPv2andnumberofhops（ripv2与跳数）rivp2是以跳数来度量的，所以选DRIP使用跳数作为其度量值；EIGRP使用带宽、延迟、可靠性、负载作为其度量值；OSPF的度量称为开销，开销=10^8/带宽（bit/s）;IS-IS使用开销作为其度量值，和OSPF类似。QUESTION501HowareVTPadvertisementsdeliveredtoswitchesacrossthenetwork?A.anycastframesB.multicastframesC.broadcastframesD.unicastframesAnswer:BSection:NewExplanation/Reference:vtp是通过什么方式进行跨网段通告的?anycastframes（任意广播帧），multicastframes（组播帧），broadcastframes（广播帧），unicastframes（单播帧）。通告将数据帧发送到一个多点广播地址（组播地址），以使所有相邻设备都能收到这些帧。QUESTION502A.definesthesourceIPaddressthatisusedinallbroadcastpacketsonDLCI202C.definesthedestinationIPaddressthatisusedinallbroadcastpacketsonDLCI202Answer:BSection:NewExplanation/Reference:broadcast支持广播没错吧！命令也有说明映射关系！！翻译选项A说------定义源ip地址--显然不对。。。。。而C应该是说-------定义了目标IP地址，它是在所有的广播数据包上使用的DLCI202。。。。也说不通的QUESTION503Refertotheexibit.Anattempttodenywebaccesstoasubnetblocksalltrafficfromthesubnet.WhichinterfacecommandimmedicatelyremovestheeffectofACL102?A.noipaccess-group102inB.noipaccess-group102outC.noipaccess-list102inD.noipaccess-class102outE.noipaccess-class102inAnswer:BSection:NewExplanation/Reference:在端口应用ACL是ipaccess-group命令。Ipaccess-class是在VTY应用的命令。QUESTION504WhicharethreereasonsthatanorganizationwithmultiplebranchofficesandroamingusersmightimplementaCiscoVPNsolutioninsteadofpoint-to-pointWANlinks?(choosethree)A.reducedcostB.betterthroughputC.increasedsecurityD.scalabilityE.reducedlatencyF.broadbandincompatibilityAnswer:ACDSection:NewExplanation/Reference:答案：ACD.VPN英文全称是“VirtualPrivateNetwork”，翻译过来就是“虚拟专用网络”。vpn被定义为通过一个公用网络（通常是因特网）建立一个临时的、安全的连接，是一条穿过混乱的公用网络的安全、稳定隧道。特点：1.安全保障2.服务质量保证（QoS）3.可扩充性和灵活性4.可管理性A节约成本C增强安全性D易扩展B提高吞吐量---感觉应该是P2P的优点E减少潜在因素F带宽不是很有关系QUESTION505WhichtwoCiscoIOScommands,usedintroubleshooting,canenabledebugoutputtoaremotelocation?(choosetwo)A.nologgingconsoleB.terminalmonitorC.logginghostip-addressD.snmp-serverenabletrapssyslogE.showloggingredirectflash:output.txtAnswer:BESection:NewExplanation/Reference:A是用来停止向控制台发送信息B是用来打开终端显示信息中心发送的调试/日志/告警信息功能C是将日志记录到服务器D是用来发送snmptraps信息（snmp-serverenabletraps），syslog是单独配置的E是用来查看日志重新定下文件QUESTION506WhichtwodataintergrityalgorithmsarecommonlyusedinVPNsolutions?(choosetwo)A.HMAC-MD5B.RSAC.HMAC-SHA-1D.DH1E.DH2Answer:ACSection:NewExplanation/Reference:正确答案，选A和C，解释如下。integrity指完整性。MessageDigestAlgorithmMD5（中文名为消息摘要算法第五版）为计算机安全领域广泛使用的一种散列函数，用以提供消息的完整性保护。效验文件完整性或者有没有被修改。安全哈希算法（SecureHashAlgorithm）SHA。SHA1产生一个160位的消息摘要。当接收消息的时候，这个消息摘要可以用来验证数据的完整性。B.RSA签名提供对等体认证，通过加密提供保密性D.EDH1DH2都是用于安全链接共享密钥QUESTION507Anetworkadministratorneedstoconfigureaseriallinkbetweenthemainofficeandaremotelocation.Therouterattheremoteofficeisanon-ciscorouter.Howshouldthenetworkadministratorconfiguretheserialinterfaceofthemainofficeroutertomaketheconnection?A.Main(config)#interfaceserial0/0Main(config-if)#noshutB.Main(config)#interfaceserial0/0Main(config-if)#encapsulationietfMain(config-if)#noshutC.Main(config)#interfaceserial0/0Main(config-if)#encapsulationframe-relayMain(config-if)#authenicationchapMain(config-if)#noshutD.Main(config)#interfaceserial0/0Main(config-if)#encapsulationpppMain(config-if)#noshutAnswer:DSection:NewExplanation/Reference:remoteoffice使用非思科路由器，则mainoffice是思科路由器。HDLC是Cisco路由器在同步串行线路上的默认封装方式。每个厂商的HDLC都是专用的。PPP用于异步串行（拨号）或同步串行（isdn）介质。PPP的基本目标是在数据链路层点到点链路上传输第3层包。它不是一个专用协议，这就意味着如果你的路由器并不都是Cisco的，可以在串行接口上配置PPP封装。串行接口两端的路由器都配置PPP才能工作。帧中继有两种封装类型----Cisco和IETF.除非手动输入IETF，否则默认封装是Cisco。如果用帧中继连接一条Cisco设备和一条非Cisco设备，要选择IETF封装类型。命令格式如下Router(config)#ints0/0/0Router(config-if)#encapsulation?frame-relayFrameRelaynetworkshdlcSerialHDLCsynchronouspppPoint-to-PointprotocolRouter(config-if)#encapsulationframe-relay?ietfUseRFC1490/RFC2427encapsulation由此判断选项B和C，命令格式不正确。如果当一台思科路由器和一台非思科路由器通过串行连接在一起时，必须配置PPP或另外一种封装方法，像帧中继，因为默认的HDLC不能工作。QUESTION508Refertotheexhibit.StatementsA,B,C,andDofACL10havebeenenteredintheshownorderandapp;iedtointerfaceE0inbound,topreventallhosts(exceptthosewhoseaddressesarethefirstandlastIPofnetwork.HowcantheACLstatementsbere-arrangedsothatthesystemworksasintended?A.CDBAB.DBACC.ACDBD.BADCAnswer:ASection:NewExplanation/Reference:每个访问列表的最后一行隐含“deny”语句。因此要在访问列表末尾使用“permitany”命令。每个列表应当至少有一个允许语句，否则将会拒绝所有流量。所以，BCD错。QUESTION509Onwhichoptionsarestandardaccesslistbased?A.sourceaddressandsubnetmaskB.destinationaddressandwildcardmaskC.sourceaddressandwildcardmaskD.destinationaddressandsubnetmaskAnswer:CSection:NewExplanation/Reference:Sourceaddess标准的访问列表只使用IP数据包的源IP地址作为测试条件。wildcardmask实际上，为了指定任意范围的主机，只能在访问列表中使用通配符。QUESTION510Whichciscoioscommandcanhelptodeterminethetimingofvariousdebugevents,relativetoeachother,whenyouaredebuggingacomplicatedrouterissue?A.servicetimestampsdebugdatetimemsecB.showclockdetailC.clockcalendar-validD.servicetimestampslogdatetimemsecAnswer:ASection:NewExplanation/Reference:servicetimestampsdebugdatetimemsec是调试debug的时间servicetimestampslogdatetimemsec是调试日志时间showclockdetail修改时间的信息clockcalendar-valid使时间同步Adebug默认Debug不显示时间本命令是显示时间帧的方便使用DLOG加上日志时间SHOWLOGQUESTION511WhichthreearecharacteristicsofanIPV6anycastaddress?(choosethree)A.any-to-manycommunicationmodelB.deliveryofpacketstothegroupinterfacethatisclosesttothesendingdeviceC.one-to-manycommunicationmodelD.thesameaddressformultipledevicesinthegroupE.one-to-nearestcommunicationmodelF.auniqueIPV6addressforeachdeviceinthegroupAnswer:BDESection:NewExplanation/Reference:A多对多通信模型B数据包传送到该组接口，转发到最近的节点C一对多通信模型D同组中多个接口共用一个地址E发送到任播地址的分组被转发到最近的端口（节点）F组中每个节点有一个唯一的IV6地址（每台设备可以有一个以上的端口，所以用节点来表示）题目考查IPV6的任播3个特点：1.数据包传送到该组接口，转发到最近的节点2.同组中多个接口共用一个地址3.发送到任播地址的分组被转发到最近的端口（节点）考试可以这么记：anycast=》closet、nearest、samedressformultipledevices近、近、一个地址多个设备QUESTION512WhatisthepurposeoftheciscoVlanTrunkingprotocol?A.toprovideamechanismtodynamicallyassignvlanmembershiptoswitchportsB.toallowtraffictobecarriedfrommultiplevlansoverasinglelinkbetweenswitchesC.toallownativevlaninformationtobecarriedoveratrunklinkD.toprovideamechanismtomanuallyassignvlanmembershiptoswitchportsE.toallowformanagingtheadditions,deletions,andchangesofvlansbetweenswitchsAnswer:ESection:NewExplanation/Reference:在交换机端口上开启trunk封装的目的是什么？A创建动态VLANB中继端口用途C访问端口用途D创建静态VLANEVTP协议的基本目标就是跨网络管理已配置的VLAN并对VLAN进行添加、删除、和改名。VTP目的在VTP域内同步VLAN信息，这样就不必在每个交换上配置相同的VLAN信息．vtp的作用：VTP从一个中心控制点开始，维护整个企业网上VLAN的添加、添加和重命名工作，确何配置的一致性。QUESTION513Threeswitchesareconnectedtooneantherviatrunkports.Assumingthedefaultswitchconfiguration,whichswitchiselectedastherootbridgeforthespanning-treeinstanceofvlan1?A.theswitchwiththelowestMACaddressB.theswitchwiththehigestMACaddressC.theswitchwitchthehigestIPaddressD.theswitchwiththelowestIPaddressAnswer:ASection:NewExplanation/Reference:在运行STP协议的网络中选择根桥需要利用桥ID.桥ID由桥优先级（所有思科交换机上默认优先级为32768）和MAC地址组合来决定的。在网络中，桥ID最小的网桥成为根桥。桥ID=桥优先级+桥mac越小越优先QUESTION514WhenyouaretroubleshootinganACLissueonarouter,whichcommandcanhelpyoutoverifywhichinterfacesareaffectedbytheACL?A.showipaccess-listB.showaccess-listC.listipinterfaceD.showinterfaceE.showipinterfaceAnswer:ESection:NewExplanation/Reference:A,showipaccess-list显示访问控制列表B,Showaccess-lists显示当前所有ACL的内容C,没有该命令D,showinterfaces[int]查看的是某个interface的物理层和数据链路层的信息。它给出了硬件地址，逻辑地址和封装方式的信息E,showipinterface[int]提供路由器interface的第三层配置信息。包括接口状态，IP地址，子网掩码，基本的IP信息和访问列表QUESTION515Switch-1dowiththisdata?A.switch-1willdropthedatabecauseitdosenothaveanentryforthatMACaddressB.switch-1willfloodthedataoutallofitsportfromwhichthedataoriginatedC.switch-1willforwardthedatatoitsdefaultgatewayD.switch-1willsendanARPrequestoutallitsportsexcepttheportfromwhichthedataoriginatedAnswer:BSection:NewExplanation/Reference:答案：B没有mac地址会泛红A.Switch-1willdropthedatabecauseitdoesnothaveanentryforthatMACaddress.(Switch-1会丢弃该数据，因为它没有该MAC地址条目)B.Switch-1willfloodthedataoutallofitsportsexcepttheportfromwhichthedataoriginated.(Switch-1会泛洪该数据到所有的接口，除了该数据的源接口)C.Switch-1willsendanARPrequestoutallitsportsexcepttheportfromwhichthedataoriginated.(Switch-1会发送ARP请求到所有的接口，除了该数据的源接口)D.Switch-1willforwardthedatatoitsdefaultgateway.(Switch-1会往默认网关发送该数据)QUESTION516WhichcommandisusedtodisplaythecollectionofOSPFlinkstates?A.showipospflsadatabaseB.showipospflink-stateC.showipospfneighborsD.showipospfdatabaseAnswer:DSection:NewExplanation/Reference:题目要求显示OSPF链路状态的详细信息showipospfdatabase显示详细的LSA信息QUESTION517Refertotheexhibit.WhattworesultswouldoccurifthehubweretobereplacedwithaswitchthatisconfiguredwithoneEthernetVLAN?(choosetwo)A.Thenumberofcollisiondomainswoulddecrease.B.Thenumberofcollisiondomainswouldincrease.C.Thenumberofbroadcastdomainswouldremainthesame.D.Thenumberofcollisiondomainswouldremainthesame.E.Thenumberofbroadcastdomainswouldincrease.Answer:BCSection:NewExplanation/Reference:hub不可以隔离冲突域，所有端口同一个冲突域中，交换机可以隔离冲突域，每个端口在不同冲突域中，故换成交换机冲突域个数会增加，大小会减小，而hub交换机都不可隔离广播域所有端口都在同一个广播域中，故广播域数量不变A冲突域数量减少B冲突域数量增加C广播域数量不变D冲突域数量不变E广播域数量增加QUESTION518Twoswitchesareconnectedthroughatrunklink.whichtwocommandsshowthatthereisanativeVLANmismatchonthatlink?(choosetwo)A.showinterfacesinterfaceB.showvlanbriC.showinterfacesinterfaceswitchportD.showinterfaceinterfacetrunkE.showinterfacesvlanAnswer:CDSection:NewExplanation/Reference:SW1#showinterfacesf0/24switchportName:Fa0/24Switchport:EnabledAdministrativeMode:trunkOperationalMode:trunkAdministrativeTrunkingEncapsulation:dot1qOperationalTrunkingEncapsulation:dot1qNegotiationofTrunking:OnAccessModeVLAN:1(default)TrunkingNativeModeVLAN:1(default)SW1#showinterfacestrunkPortModeEncapsulationStatusNativevlanFa0/24on802.1qtrunking1QUESTION519Onwhichoptionsarestandardaccesslistsbased?A.destinationaddressandwildcardmaskB.sourceaddressandwildcardmaskC.destinationaddressandsubnetmaskD.sourceaddressandsubnetmaskAnswer:BSection:NewExplanation/Reference:标准控制列表使用源地址和通配符QUESTION520WhichthreestatementsaboutVTPfeaturesaretrue?（choosethree）A.Whenproperlyconfigured,VTPminimizesVLANmisconfigurationsandconfigurationinconsistenciesB.EachbroadcastdomainonaswitchcanhaveitsownuniqueVTPdomainC.VTPworksatLayer3oftheOSImodelandrequiresthatamanagementVLANIPaddressbeconfigured.D.Whenproperlyconfigured,VTPmaintainsVLANconfigurationconsistencyandacceleratestrunklinknegotiation.E.VTPpruningisusedtoincreaseavailablebandwidthintrunklinksF.Client,server,andtransparentarevalidVTPmodesG.ToconfigureaswitchtobepartoftwoVTPdomains,eachdomainmusthaveitsownpasswordsAnswer:AESection:NewExplanation/Reference:B:vtp是vlan之间共享vlan信息的，所以每一个广播域这里不对C：VTP不需要管理IPG：同一个域必须使用同一个密码.密码可以不一样FFQUESTION521AtwhichlayeroftheOSImodeldosePPPperform?A.Layer3B.Layer4C.Layer2D.Layer5Answer:CSection:NewExplanation/Reference:QUESTION522WhichcommanddisplaystheCHAPauthenticationprocessasitoccursbetweentworouters?A.debugauthenticationB.debugchappppC.debugchapauthenticationD.debugpppauthenticationAnswer:DSection:NewExplanation/Reference:显示网络中凉台路由器之间的CHAP认证过程，使用命令debugpppauthenticationQUESTION523Youhavebeenaskedtocomeupwithasubnetmaskthatwillallowallthreewebserverstobeonthesamenetworkwhileprovidingthemaxnumberofsubnets.Whichnetworkaddressandsubnetmaskmeetthisrequirement?Answer:ASection:NewExplanation/Reference:',)
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