思科认证CCNA英文考试试卷

思科认证CCNA英文考试试卷考试时长：120分钟满分：100分试卷名称：思科认证CCNA英文考试试卷考核对象：CCNA认证备考学员及行业从业者题型分值分布：-判断题（共10题，每题2分，总分20分）-单选题（共10题，每题2分，总分20分）-多选题（共10题，每题2分，总分20分）-案例分析（共3题，每题6分，总分18分）-论述题（共2题，每题11分，总分22分）总分：100分---一、判断题（每题2分，共20分）1.ThedefaultsubnetmaskforaClassBnetworkis.2.ArouterusestheMACaddresstoforwardpacketsbetweendifferentnetworks.3.TheTCPprotocolisconnectionlessanddoesnotguaranteedatadelivery.4.TheHTTPprotocoloperatesonthetransportlayeroftheOSImodel.5.AVLANisalogicalgroupingofswitchportsthatcanspanmultiplephysicalswitches.6.TheSTP(SpanningTreeProtocol)preventsloopsinaredundantnetworktopology.7.ThedefaultgatewayistheIPaddressofthelocalrouterforadevice.8.IPv6addressesare128bitslongandusehexadecimalnotation.9.TheDNS(DomainNameSystem)translatesdomainnamestoIPaddresses.10.AswitchoperatesatthedatalinklayerandforwardspacketsbasedonMACaddresses.二、单选题（每题2分，共20分）1.WhichofthefollowingisacharacteristicoftheTCPprotocol?A.Connection-orientedandreliableB.ConnectionlessandunreliableC.Connection-orientedandunreliableD.Connectionlessandreliable2.WhatisthemaximumnumberofsubnetsthatcanbecreatedfromaClassCnetworkusinga/26mask?A.2B.4C.8D.163.WhichlayeroftheOSImodelisresponsibleforlogicaladdressing?A.PhysicallayerB.DatalinklayerC.NetworklayerD.Transportlayer4.WhatisthedefaultTTL(TimetoLive)valueforanIPpacket?A.10B.20C.30D.645.WhichofthefollowingisavalidIPv6address?A.B.2001:0db8:85a3:0000:0000:8a2e:0370:7334C.D.6.WhatisthepurposeoftheARP(AddressResolutionProtocol)?A.TotranslatedomainnamestoIPaddressesB.ToresolveIPaddressestoMACaddressesC.ToroutepacketsbetweennetworksD.TomanageVLANs7.Whichofthefollowingisacharacteristicofahub?A.BroadcastsdatatoallconnecteddevicesB.ForwardsdatabasedonMACaddressesC.RoutespacketsbetweennetworksD.Provideslogicalsegmentationofanetwork8.WhatisthedefaultportnumberforHTTP?A.21B.23C.80D.4439.WhichofthefollowingisaLayer2broadcaststorm?A.ExcessiveARPrequestsB.MultipledevicesattemptingtoconnectsimultaneouslyC.AlargenumberofbroadcastpacketsfloodingthenetworkD.Adenial-of-serviceattack10.WhatisthepurposeoftheSTP(SpanningTreeProtocol)?A.TooptimizenetworkperformanceB.TopreventloopsinredundanttopologiesC.TomanageVLANsD.Toprovidelogicaladdressing三、多选题（每题2分，共20分）1.Whichofthefollowingarefunctionsofthetransportlayer?A.End-to-endcommunicationB.RoutingpacketsbetweennetworksC.FragmentationandreassemblyD.Errordetection2.WhatarethecomponentsofanIPv6address?A.8groupsof4hexadecimaldigitsB.Acolon(:)separatorC.AsubnetmaskD.Aprefixlength3.WhichofthefollowingarecommonTCPportnumbers?A.80(HTTP)B.443(HTTPS)C.23(Telnet)D.22(SSH)4.WhatarethebenefitsofusingVLANs?A.ImprovedsecurityB.ReducedbroadcasttrafficC.SimplifiednetworkmanagementD.Increasedbandwidth5.Whichofthefollowingarecharacteristicsofaswitch?A.OperatesatLayer2B.ForwardspacketsbasedonMACaddressesC.ProvideslogicalsegmentationD.Broadcastsdatatoallports6.Whatarethefunctionsofthenetworklayer?A.LogicaladdressingB.RoutingpacketsC.FragmentationD.Errordetection7.Whichofthefollowingaretypesofnetworktopologies?A.StarB.BusC.RingD.Mesh8.WhatarethecomponentsofanIPaddress?A.NetworkportionB.HostportionC.SubnetmaskD.Defaultgateway9.Whichofthefollowingareprotocolsusedinthetransportlayer?A.TCPB.UDPC.ICMPD.HTTP10.Whatarethefunctionsofthedatalinklayer?A.PhysicaladdressingB.FrameformationC.ErrordetectionD.Routingpackets四、案例分析（每题6分，共18分）CaseStudy1:AcompanyhasaClassCnetworkwiththeIPaddress.Theyneedtocreate4subnetswithatleast20hostspersubnet.1.Whatsubnetmaskshouldtheyuse?2.WhataretheIPaddressrangesforeachsubnet?3.Whatisthedefaultgatewayforthefirstsubnet?CaseStudy2:Anetworkengineerisdesigningaredundanttopologyusingtwoswitchesconnectedbyalink.TheyneedtopreventloopsusingSTP.1.WhatisthepurposeofSTPinthisscenario?2.HowdoesSTPchoosetherootbridge?3.WhatisthedefaultSTPtimeoutvalue?CaseStudy3:AcompanyisimplementingVLANstosegmenttheirnetwork.TheyhavetwoVLANs:VLAN10(sales)andVLAN20(engineering).1.HowdoesaswitchforwardpacketsbetweenVLANs?2.Whatisthepurposeofaninter-VLANrouter?3.HowcanVLANsimprovenetworksecurity?五、论述题（每题11分，共22分）1.ExplainthedifferencesbetweenTCPandUDPprotocols.Includetheirusecasesandkeycharacteristics.2.DescribethestepsinvolvedintheARPresolutionprocess.WhyisARPimportantinanetwork?---标准答案及解析一、判断题1.√2.×(RoutersuseIPaddressesforrouting)3.×(TCPisconnection-orientedandreliable)4.×(HTTPoperatesontheapplicationlayer)5.√6.√7.√8.√9.√10.√二、单选题1.A2.B3.C4.A5.B6.B7.A8.C9.C10.B三、多选题1.A,C,D2.A,B,D3.A,B,D4.A,B,C5.A,B,C6.A,B,D7.A,B,C,D8.A,B9.A,B10.A,B,C四、案例分析CaseStudy1:1.Subnetmask:40(/28)2.Subnetranges:-/28to5-6/28to1-2/28to7-8/28to33.Defaultgateway:CaseStudy2:1.STPpreventsloopsbyblockingredundantpathsinaredundanttopology.2.TherootbridgeischosenbasedonthelowestMACaddress.3.DefaultSTPtimeout:30seconds(hellotime:2seconds,forwarddelay:15seconds).CaseStudy3:1.AswitchforwardspacketsbetweenVLANsusinganinter-VLANrouteroraLayer3switch.2.Aninter-VLANrouterallowscommunicationbetweendifferentVLANs.3.VLANsimprovesecuritybyisolatingtrafficbetweensegments.五、论述题1.DifferencesbetweenTCPandUDP:TCP(TransmissionControlProtocol)isaconnection-oriented,reliableprotocolthatensuresdatadelivery.Itusessequencenumbersandacknowledgmentstomanagedataflow.Usecasesinclud