思科认证考试试题及答案5卷

思科认证考试试题及答案5卷第1卷

子网/22有（）个可用的IP地址

A.1022

B.1024

C.256

D.254

正确答案：A

备份路由器IOS的命令是：（）

A.copyflashtftp

B.copyrunning-configtftp

C.copyIOStftp

D.copystartup-configtftp

正确答案：A

CDPisbeingusedthroughouttheEzonexamnetwork.Whataretworeasons

whytheEzonexamnetworkadministratorwoulduseCDP?（Choosetwo）

A.Todeterminethestatusofnetworkservicesonaremotedevice

B.ToobtaintheIPAddressofaconnecteddeviceinordertotelnettothe

device

C.Toverifythetypeofcableinterconnectingtwodevices

D.ToverifyLayer2connectivitybetweentwodeviceswhenLayer3fails

E.ToobtainVLANinformationfromdirectlyconnectedswticehs

F.Todeterminethestatusoftheroutingprotocolsbetweendirectly

connectedrouters

G.Tosupportautomaticnetworkfailoverduringoutages

正确答案：BD

B,D

信息传送时，RIP使用什么度量值来确定最佳路径()

A.带宽

B.跳数

C.管理距离

D.每个数据包发送的变量

正确答案：B

YouareworkingasanetworktechnicianatEzonexamUniversity,whenyou

getacallfromtheEngineeringFaculty.They'recomplainingthatthey'rereceiving

obsoleteinformationfromtheBusinessFaculty'snetworktrafficbroadcasts.

WhatcanyoudotocontaintheBusinessFaculty'sbroadcastwhilestill

keepingitconnectedtotheinternetandtheenterpriseservicesoftheUniversity?

(Selectallvalidanswerchoices)

A.Usehalfandfull-duplexEthernetontheEngineeringDepartmentLAN

B.EstablishaVTPdomaintominimizetheobsoletetraffic

C.ChangetheswitchIPaddressoftheswitch

D.CreateseparateVLANsandsubnetsforthetwodepartmentsandroute

betweenthetwo

E.ProvidegreaterbandwidthtotheEngineeringDepartmentLAN

F.Placethebusinessdepartmentonaseparatesubnetandroutebetween

networks

正确答案：DF

D,F解析：Explanation:

Inordertopreventthebroadcastandlinklevelmulticasttrafficseparated

betweenthedepartments,theyneedtobeisolatedatlayertwo.Thiscanbe

accomplishedintwoways.ThefirstistocreateseparateVLANsandplaceeach

departmentintoadifferentone.Thesecondmethodwouldbetoseparatethe

twodepartmentsintotwocompletelydifferentnetworks,androutebetween

them.

IncorrectAnswers:

A.Mixingtheuseofhalfandfullduplexwillmakenodifferencetothenumberof

broadcastssent.

B.TrunkingisonlyusefulinnetworksthatalreadycontainVLANs.

C.Thiswillmakenodifference,asalluserswillstillbecontainedwithinthesame

IPsubnet

E.Theamountofbandwidthinvolvedwillnothaveanyimpactontheamountof

broadcaststhataresentandreceived.

思科认证考试试题及答案5卷第2卷

交换机上VLAN的功能描述中，正确的是（）

A.可以减少广播域的个数

B.可以减少广播对网络性能的影响

C.可以减少冲突域的个数

D.可以减小冲突域的容量

正确答案：B

AfterconnectingaPCtoanavailableportonaswitch,youfindthatthePC

cannotaccessanyoftheresourcesontheLAN.NootherPC'sconnectedtothe

switchappeartobehavinganyissues.Whatisthemostlikelycauseforthis

problem?

A.Therouterlacksaroutingtableentryforthenewhost

B.ThehostswitchportisassignedtotheincorrectVLAN

C.ThehostMACaddressisincorrectlyconfigured

D.ASTPinstanceforthenewhosthasnotbeeninitialized

E.TheswitchdoesnothavetheMACaddresshardcodedintheCAMtable.

正确答案：B

解析:Explanation:VirtualLANsbreakupbroadcastdomainsinalayer-

twoswitchedinternetwork.IfahostisinadifferentVLANthenthenetworkservicesitneed

stouse,thepacketsmustgothrougharouter.Ifroutingdoesnottakeplace,thePCwillbeu

nabletocommunicatewithanyotherdevicesnotinthesameVLAN.AnswerBisthebestan

swerforthisquestion.IncorrectAnswers:A.ThePCisunabletocommunicatewithotherL

ANusers.Norouterneedstoevenbeinstalledforthistowork.C,E.TheMACaddressofthe

PCdoesnotneedtobeenteredmanuallyintotheswitch.Theswitchwilldynamicallylearn

oftheMACaddressofthePC.D.TheSTPalgorithmdoesnotneedtohaveanyendhostinfo

rmationaddedinorderforittowork.

与动态路由协议相比，静态路由有哪些优点?()

A.带宽占用少

B简单

C.路由器能自动发现网络拓扑变化

D.路由器能自动计算新的路由

正确答案：AB

BothbridgesareswitchesarebeingusedthroughouttheEzonexamLAN.

Whichofthefollowingstatementsaretrueregardingbridgesandswitchesinthis

network?

(Choose3)

A.Switchesareprimarilysoftwarebasedwhilebridgesarehardwarebased.

B.Switchesusuallyhaveahighernumberofportsthanmostbridges.

C.Bridgesarefrequentlyfasterthanswitches.

D.Bridgesdefinebroadcastdomainswhileswitchesdefinecollisiondomains.

E.BothbridgesandswitchesforwardLayer2broadcasts.

F.BothbridgesandswitchesmakeforwardingdecisionsbasedonLayer2

addresses.

正确答案：BEF

B,E,F

Barney是子网/24中一个具有IP地址的主机。以下哪些操作

时标准IPACL可配置来执行的()

A.匹配准确的源IP地址

B.使用一个access-list命令匹配IP地址到,而不匹配其他IP

地址

C.使用一access-list命令匹配Barney的子网中的所有IP地址,而不匹配其

他IP地址

D.仅匹配包的目标IP地址

正确答案：AC

思科认证考试试题及答案5卷第3卷

AnewswitchisbeinginstalledintheEzonexamnetworkandyouhavebeen

assignedthetaskofconnectingittoanexistingswitch.Indoingthis,youwantto

setuptheVLANTrunkingProtocolsothatVLANinformationcanbepassed

betweentheswitches.Whichofthefollowingmustyoudotoaccomplishthis?

(Chooseallthatapply).

A.YoumustseteachendofthetrunklinetoIEEE802.Ieencapsulation.

B.YoumustsetthesameVTPmanagementdomainnameonboth

switches.

C.Youmustsetallportsonthetwoswitchesasaccessports.

D.YoumustconfigureoneoftheswitchesasaVTPserver.

E.Youmustusearollovercabletoconnectthetwoswitches.

正确答案：BD

解析：

Explanation:ThefollowingdescribeswhatisneededinordertocorrectlysetupVTP:Incor

rectAnswers:A.TheencapsulationcanbeeitherISLor802.1Q,andneedtomatchateache

ndofthetrunk.C.PortsmustonlybeassignedtoVLANS.Oncethatisdoneandthetrunkisu

pandrunning,theVLANinformationwillbepassedbetweentheswitches.E.AregularCA

T5cableisusedtoconnecttheswitches,assumingl0/100Ethernetisused.

Youareexperiencingintermittentissuesrelatingtocongestionwithinthe

Ezonexamnetwork.WhatarethepossiblecausesofcongestiononthisLAN?

(Chooseallthatapply)

A.Abroadcastdomainwithtoomanyhosts.

B.Fullduplexoperation.

C.Broadcaststorms.

D.Multicasting.

E.NetworkSegmentation.

F.Lowbandwidth.

正确答案：ACF

A,C,F解析：Explanation:

ALANsegmentwithtoomanyhostscanmeanthattherearealargenumberof

stationscontendingforbandwidth.Itcanalsomeananincreaseinthenumberof

collisionsonthesegment,whichcancausefurthercongestionissues.

Broadcaststormsaretheresultofalargenumberofbroadcastssentoverthe

LAN.Becauseeachstationlistenstothesebroadcastmessages,congestioncan

occurquickly.Finally,lowbandwidthcansimplymeanthattheLANcannot

processalloftheLANtrafficthatisbeingsent.ThiscanmeanthatTCPsessions

areretransmitted,whichcanleadtoadditionalcongestion.

IncorrectAnswers:

B.Thiscanalleviatecongestion,asdatacanbesentandreceivedatthesame

time.Inaddition,collisionsarenotpossibleinafullduplexLAN.

D.Multicastingcanactuallyalleviatecongestionissues,assinglestreamsof

informationcanreachmultiplehostsatthesametime,insteadofusingaseries

ofpointtopoint

connections.

E.SegmentationbreaksupalargeLANintomultiple,smallerLANS.Thiswill

meanfewerhostsperbroadcastdomain.

介质lOOBaseT的最大传输距离是：（）

A.IOm

B.lOOm

C.lOOOm

D.500m

正确答案：B

WhichOSIlayerheadercontainstheaddressofadestinationhostthatison

anothernetwork?

A.Application

B.Presentation

C.Session

D.Transport

E.Network

F.Datalink

G.Physical

正确答案：E

E解析：Explanation:

Onlynetworkaddresscontainsthisinformation.Totransmitthepacketsthe

senderusesnetworkaddressanddatalinkaddress.Butthelayer2address

representsjusttheaddressofthenexthopdeviceonthewaytothesender.Itis

changedoneachhop.Networkaddressremainsthesame.

YouareanadministratoroftheEzonexamswitchednetworkandyourgoalis

toreducesomeoftheadministrativeoverheadonyournetwork.Youplanon

achievingthisbyconfiguringanewVLANforeachdepartmentintheEzonexam

network.

However,youneedtosharetheVLANinformationacrossnumerous

switches.Whichofthefollowingwouldallowyouaccomplishthis?

A.STP

B.GVRP

C.SNMP

D.VTP

E.DHCP

F.Noneoftheabove

正确答案：D

D解析：Explanation:

TheVTP(VLANTrunkingProtocol)isaCiscoLayer2messagingprotocolthat

managestheaddition,deletion,andrenamingofVLANsonanetwork-widebasis.

ItallowsforVLANinformationtospanmultipleswitcheswithintheswitch

domain.

IncorrectAnswers:

A.STPisaswitchingprotocolbutitisusedforpreventingnetworkloops.

B.GVARPisanactualprotocolusedinswitchadministration,butitbeyondthe

scopeofwhataCCNAisexpectedtoknow.

C.SNMPisaprotocolusedformanagingandmonitoringnetworks

E.DHCPistheDynamicHostConfigurationProtocol,whichallowsforPC'sto

obtaintheirIPaddressdynamicallyuponbootingupzalongwiththeirDNSand

defaultgatewayinformation.

思科认证考试试题及答案5卷第4卷

TheLANneedsareexpandingattheEzonexamcorporateoffice,whichis

quicklygrowing.YouareinstructedtoenlargetheareacoveredbyasingleLAN

segmentontheEzonexamnetwork.

Whichofthefollowingarelayer1devicesthatyoucanuse?(Chooseallthat

apply.)

A.Aswitch

B.Arouter

C.Anetworkadaptercard

D.Ahub

E.Arepeater

正确答案：DE

解析:Explanation:

Ahubsimplyrepeatstheelectricalsignalandmakesnoattempttointerpretthe

electricalsignal(layer1)asaLANframe.(Layer2).So,ahubactuallyperforms

OSIlayer1functions,repeatinganelectricalsignal,whereasaswitchperforms

OSIlayer2functions,actuallyinterpretingEthernetheaderinformation,

particularlyaddresses,tomakeforwardingdecisions.Hubscanbeusedto

increasethenumberofstationsthatcanbesupportedonaLAN.

Becausetherepeaterdoesnotinterpretwhatthebitsmean,butdoesexamine

andgenerateelectricalsignals,arepeaterisconsideredtooperateatLayer1.

RepeaterscanbeusedtophysicallyextendtheLANtogreaterdistances.

YouareaseniornetworkadministratoratEzonexam,andwhileperforming

thepasswordrecoveryprocedureonyour2500seriesCiscorouter,youtypein

thefollowingcommand:

o/r0x2142

Whatisthepurposeofthiscommand?

A.Itisusedtorestarttherouter.

B.ItisusedtobypasstheconfigurationinNVRAM.

C.ItisusedtoenterROMMonitormode.

D.Itisusedtoviewthelostpassword.

E.Itisusedtosavethechangestotheconfiguration.

正确答案：B

解析:Explanation:

Theo/r0x2142commandchangesthevalueofconfig-registerto2142inaCisco

2500seriesrouter,sothattheRouterignorestheNVRAMcontentsandrevertsto

theinitialsetupconfigurationmodewhenitboots.

Whyisfull-duplexEthernetsuperiortoitssingle-duplexcounterpart?(Select

twoanswerchoices.)

A.Itusesinexpensivehubs

B.Itoperateswithoutcollisions

C.Itoperatesonswitches

D.Itprovidesfasterdatatransfer

E.Itutilizesfewerwiringpairs

正确答案：BD

解析：Explanation:

FullduplexEthernetallowsconcurrentsendingandreceiving,whichallowsthe

fullbandwidthtobeusedforbothsendingandreceiving.Theresultisacollision

freenetworkwithincreasedthroughput.

IncorrectAnswers:

A,C.Theseareincorrectbecausefullduplexdoesn'trequirehubsorswitches.Full

duplexoperationcanbeusedonswitchandrouterports,aswellasPChosts.

E.Thisisincorrectbecausefullduplexactuallyusesmorewiringpairs.Infull

duplex,bothwirepairsareused.Halfduplexusesonlyasinglepair.

要在交换机上运行802.1W,可使用哪个命令来启用该协议?()

A.Switch(config)#spanning-treemoderapid-pvst

B.Switch#spanning-treemoderapid-pvst

C.Switch(config)#spanning-treemode802.lw

D.Switch#spanning-treemode802.1w

答案：A

属于私有IP段的是()

A.-55

B.-55

C.-55

D.-55

E.-55

正确答案：ABD

思科认证考试试题及答案5卷第5卷

在大型网络中选择OSPF而不选择RIP的原因是()

A.更快的路由收敛

B.需要更少的路由器内存

C.需要更少的CPU的资源

D.更优的选路，路由无环路

正确答案：AD

下面哪一项正确描述了路由协议()

A.允许数据包在主机间传送的一种协议

B.定义数据包中的格式和用法的一种方式

C.通过执行一个算法来完成路由选择的一种协议

D指定MAC地址和IP地址捆绑的方式和时间的一种协议

正确答案：C

YouaregivenaPC,arouter,andacable.Selectthecorrectcombinationthat

willallowyoutologintorouterVE1locallyusingaterminalemulationprogram

suchasHyperTerminal.

A.ConnectthePC'sCOMporttotherouter'sconsoleportusingastraight-

throughcable.

B.ConnectthePC'sCOMporttotherouter'sconsoleportusingarollover

cable.

C.ConnectthePC'sCOMporttotherouter'sEthernetportusingastraight-

throughcable.

D.ConnectthePC'sEthernetporttotherouter'sEthernetportusinga

rollovercable.

E.ConnectthePC'sEthernetporttotherouter'sEthernetportusinga

straight-throughcable.

F.Noneoftheabove

正确答案：B

B解析：Explanation:

ToconnecttheRouterinConsoleporttoconfigureusingHyperTerminal,you

requiredtheRolloverCable,whichconnectsthePC'sCOMporttotherouter's

Consoleport.

IncorrectAnswers:

A,C,E:StraightCablesareusedfor:Hosttoswitch,SwitchtoRouter.

D:RollovercablesareusedforConsole/COMconnections,notforIPtrafficover

the

Ethernetports.

WhatisthemaximumnumberofIPaddressesthatcanbeassignedtohosts

onaEzonexamsubnetthatusesthe24subnetmask?

A