2021思科認(rèn)證考試試題及答案5篇

2021思科認(rèn)證考試試題及答案5篇第1篇

IGP是內(nèi)部網(wǎng)關(guān)協(xié)議，BGP是外部網(wǎng)關(guān)協(xié)議。

此題為判斷題(對，錯(cuò))。

正確答案：V

在Cisco路由器上串行線路的默認(rèn)的二層封裝協(xié)議是()。

A.CHAP

B.HDLC

C.PPP

D.SLIP

正確答案：B

HDLC是一種面向()的鏈路層協(xié)議。

A.字符

B.比特

C.信兀

D.數(shù)據(jù)包

正確答案：B

Whichoneofthefollowingcharacteristicsistrueregardingtheuseofhubs

andswitches?

A.HubscanhavetheirportsbeconfiguredwithVLANs

B.Usinghubsiscostlywithregardtobandwidthavailability.

C.Switchescannotforwardbroadcasts.

D.Switchesaremoreefficientthanhubsinprocessingframes.

E.Switchesincreasethenumberofcollisiondomainsinthenetwork.

正確答案：E

解析：

Explanation:Switchesincreasesthenumberofcollisionsdomainsinthenetwork.Switch

esthatareconfiguredwithVLANswillreducethesizeofthecollisiondomainsbyincreasin

gthenumberofcollisiondomainsinanetwor^butmakingthemsmallerthanthatofoneb

igJIatnetwork.IncorrectAnswers^.SwitchesarecapableofVLANconfigurations^uth

ubsarenot.B.Hubsaregenerallytheleastcostlymethodpossibletoconnectmultipledev

icestogetherinanetwork.C.Switchesforwardbroadcastsandmulticast^bydefaulttoall

portswithinthesameVLAN.Onlyroutersblockallbroadcasttrafficbydefault.D.Switches

andhubscanbeequallyefficientinprocessingframesjntheory.Inpractice^witchesareg

enerallymoreefficientastheyusuallyhavemoreCPUandmemoryallocatedtothem^nd

aregenerallymuchmoreexpensivethanasimplehub.

WhiletroubleshootinganissueintheEzonexamLANyounoticethata

networkinterfaceporthascollisiondetectionandcarriersensingenabledona

sharedtwistedpairnetwork.Fromthisstatement,whatisknownaboutthe

networkinterfaceport?

A.ThisisanEthernetportoperatingathalfduplex

B.ThisisanEthernetportoperatingatfullduplex

C.ThisisaportonanetworkinterfacecardinaPC

D.Thisis10MB/sswitchport

E.Thisisa100MB/sswitchport

F.Noneoftheabove

正確答案：A

A

RIP路由在()時(shí)間內(nèi)沒有收到更新會標(biāo)記為不可達(dá)路由()

A.90s

B.120S

C.180S

D.240S

正確答案：C

2021思科認(rèn)證考試試題及答案5篇第2篇

HowcouldtheEzonexamcorporationbenefitfromusingVLANsontheir

network?

(Selectthreeanswerchoices.)

A.VLANsallowaccesstonetworkservicesbasedondepartment,not

physicallocation.

B.VLANsutilizepacketfilteringtoenhancenetworksecurity.

C.VLANsprovidealow-latency,highbandwidthinternetworkingalternative.

D.VLANsprovideamethodofcommunicationbetweenIPaddressesinlarge

networks.

E.VLANsestablishsegmentedbroadcastdomainsinswitchednetworks.

F.VLANscangreatlysimplifyadding,moving,orchanginghostsonthe

network.

正確答案：AEF

A,E,F解析：Explanation:

VLANsestablishbroadcastdomainsinswitchednetworks,sobyvirtueofhaving

theoptiontocreatemanyefficientbroadcastdomains,congestionisreduced

andnetworkthroughputisgreatlyenhanced.VLANsallownetworkstobe

dividedbydepartmentorresourceneeds,ratherthenbyphysicallocation.When

peoplemovedepartments,leaveadepartment,orjoinadepartment,

administrationiseasyandconvenientwithafewkeystrokes.

IncorrectAnswers:

B,D.Thesewouldberouterfunctionsatlayer3.SwitchesandVLANsoperateat

layer2oftheOSImodel.

C.TheuseofVLANsmayactuallyincreasethelatencyinsomecases,astraffic

fromoneVLANtotheotherwillneedtoberouted.

要啟用LACP并將交換機(jī)端口加入端口信道L可使用下面哪兩個(gè)命令之一?()

A.Switch(config)#interfaceport-channell

B.Switch(config)#channel-group1modeactive

C.Switch#interfaceport-channel1

D.Switch(config-if)#channel-group1modeactive

答案：AD

Whyisfull-duplexEthernetsuperiortoitssingle-duplexcounterpart?(Select

twoanswerchoices.)

A.Itusesinexpensivehubs

B.Itoperateswithoutcollisions

C.Itoperatesonswitches

D.Itprovidesfasterdatatransfer

E.Itutilizesfewerwiringpairs

正確答案：BD

解析：Explanation:

FullduplexEthernetallowsconcurrentsendingandreceiving,whichallowsthe

fullbandwidthtobeusedforbothsendingandreceiving.Theresultisacollision

freenetworkwithincreasedthroughput.

IncorrectAnswers:

A,C.Theseareincorrectbecausefullduplexdoesn'trequirehubsorswitches.Full

duplexoperationcanbeusedonswitchandrouterports,aswellasPChosts.

E.Thisisincorrectbecausefullduplexactuallyusesmorewiringpairs.Infull

duplex,bothwirepairsareused.Halfduplexusesonlyasinglepair.

關(guān)于靜態(tài)NAT，下面()說法是正確的。

A.靜態(tài)NAT轉(zhuǎn)換在缺省情況下24小時(shí)后超時(shí)

B.靜態(tài)NAT轉(zhuǎn)換從地址池中分配

C.靜態(tài)NAT將內(nèi)部地址一對一靜態(tài)映射到內(nèi)部全局地址

D.CISCO路由器缺省使用了靜態(tài)NAT

正確答案：C

CDPisbeingusedthroughouttheEzonexamnetwork.Whataretworeasons

whytheEzonexamnetworkadministratorwoulduseCDP?(Choosetwo)

A.Todeterminethestatusofnetworkservicesonaremotedevice

B.ToobtaintheIPAddressofaconnecteddeviceinordertotelnettothe

device

C.Toverifythetypeofcableinterconnectingtwodevices

D.ToverifyLayer2connectivitybetweentwodeviceswhenLayer3fails

E.ToobtainVLANinformationfromdirectlyconnectedswticehs

F.Todeterminethestatusoftheroutingprotocolsbetweendirectly

connectedrouters

G.Tosupportautomaticnetworkfailoverduringoutages

正確答案：BD

B,D

對于以下ACL語句描述正確的是()

RI(config)#ipaccess-liststandardTELNET

RI(config-stdFacl)#permit192.168.4.20.0.0.0

Rl(c^ifig)#lineyty04

Rl(config_1ine)#access-classTELNETin

A.只允許192.168.4.2的數(shù)據(jù)流穿過Rl

B只允許192.168.4.2對Rl進(jìn)行TELNET

C.只允許192.168.4.2對Rl進(jìn)行TELNET并拒絕其它流量

D.只允許192,168.4.0/24網(wǎng)段的數(shù)據(jù)流穿過R1

正確答案：B

2021思科認(rèn)證考試試題及答案5篇第3篇

在大型網(wǎng)絡(luò)中選擇OSPF而不選擇RIP的原因是()

A.更快的路由收斂

B.需要更少的路由器內(nèi)存

C.需要更少的CPU的資源

D.更優(yōu)的選路，路由無環(huán)路

正確答案：AD

下列哪些內(nèi)部路由協(xié)議支持VLSM()

A.RIP-1

B.RIP-2

C.EIGRP

D.OSPF

E.IS-IS

正確答案：BCDE

Afterworkingonarouter,someproblemsariseandyouwishtoviewthe

commandsthatyourecentlyentered.WhichIOScommandopensthehistory

bufferanddisplaysthemostrecentlyenteredcommands?

A.Showhistory

B.Showbuffers

C.Showtypedcommands

D.Showterminalbuffer

E.Showcommand

F.Noneoftheabove

正確答案：A

A解析：Explanation:

Therouterwillbufferpreviouslyenteredcommands.Bydefault,the"show

history"commandwilldisplaytheprevioustencommandsthatwereentered.To

seethecontentsofthebufferyouentertheshowhistorycommand.

IncorrectAnswers:

B.Thiscommandwillshowthememorybufferinformation

C,D.Theseareinvalidcommands.

交換機(jī)工作在OSI七層模型的哪一層()

A.物理層

B.數(shù)據(jù)鏈路層

C.網(wǎng)絡(luò)層

D.傳輸層

正確答案：B

Showcdpinterface命令是用于顯示以下哪一項(xiàng)的（）

A.CDP的時(shí)間值和接口狀態(tài)

B.鄰居路由器的接口配置

C.鄰居設(shè)備的IP地址

D.CDP保持時(shí)間

正確答案：A

擴(kuò)展ACL和標(biāo)準(zhǔn)ACL的區(qū)別（）。

A.標(biāo)準(zhǔn)的ACL在禁止和允許方面比擴(kuò)展的ACL更高的精度

B.擴(kuò)展的ACL核查數(shù)據(jù)包的源地址和目標(biāo)地址和端口號

C.他們都可以查端口號

D.他們都可以查特殊協(xié)議和其他參數(shù)

正確答案：B

2021思科認(rèn)證考試試題及答案5篇第4篇

把訪問權(quán)限表應(yīng)用到路由器端口的命令是：（）

A.permitaccess-list101out

B.ipaccess-group101out

C.applyaccess-list101out

D.access-class101out

正確答案：B

OSI七層模型中，"段”是哪一層數(shù)據(jù)封裝的名稱（）

A.物理層

B.數(shù)據(jù)鏈路層

C.網(wǎng)絡(luò)層

D.傳輸層

正確答案：D

下列對RIP的配置中，合法的命令是（）

A.routerrip100network10.12.0.0

B.routerrip100network10.0.0.0

C.routerripnetwork10.12.0.0

D.routerrip100network10.0.0.0

正確答案：C

ThecorporateheadofficeofEzonexamhasateleconferencingsystemthat

usesVOIP(voiceoverIP)technology.ThissystemusesUDPasthetransportfor

thedatatransmissions.IftheseUDPdatagramsarriveattheirdestinationoutof

sequence,whatwillhappen?

A.UDPwillsendanICMPInformationRequesttothesourcehost.

B.UDPwillpasstheinformationinthedatagramsuptothenextOSIlayer

intheorderthattheyarrive.

C.UDPwilldropthedatagrams.

D.UDPwillusethesequencenumbersinthedatagramheadersto

reassemblethedatainthecorrectorder.

E.UDPwillnotacknowledgethedatagramsandwaitforaretransmissionof

thedatagrams.

正確答案：B

解析：Explanation:

VOIPsystemsutilizeUDPbecauseitisfasteranduseslessoverhead.Inaddition,

thereliabletransportmechanismusedinTCPisuselesstoVOIPbecauseifa

packetgetsdroppedandneedstoberesent,itwillbealreadytoolate.

UDPprovidesaserviceforapplicationstoexchangemessages.UnlikeTCP,UDPis

connectionlessandprovidesnoreliability,nowindowing,andnoreorderingof

thereceiveddata.However,UDPprovidessomefunctionsofTCP,suchasdata

transfer,segmentation,andmultiplexingusingportnumbers,anditdoessowith

fewerbytesofoverheadandwithlessprocessingrequired.UDPdatatransfer

differsfromTCPdatatransferinthatnoreorderingorrecoveryisaccomplished.

ApplicationsthatuseUDParetolerantoflostdata,ortheyhavesomeapplication

mechanismtorecoverdataloss.

Youneedtodescribethevarioustypesofflowcontroltoyourco-workers.

Whichofthefollowingaretypesofflowcontrolthatcanbeusedinanetwork?

(Choosethree)

A.Congestionavoidance

B.Windowing

C.Cut-through

D.Buffering

E.LoadBalacing

F.FastForward

正確答案：ABD

A,B,D

請參見圖示1040.0網(wǎng)絡(luò)發(fā)生故障哪種機(jī)制可防止R2接收有關(guān)1040.0網(wǎng)絡(luò)

的錯(cuò)誤更新信息（）

10.1.0010.2.0.010.3.0.010.4.0.0

A.水平分割

B抑制計(jì)時(shí)器

C.路由毒化

D.觸發(fā)更新

正確答案：A

2021思科認(rèn)證考試試題及答案5篇第5篇

TYPE（類型）字段是思科在HDLC包頭字段中額外添加的。

此題為判斷題（對，錯(cuò)）。

正確答案：V

WhichofthefollowingatruestatementsregardingtheuseofVLANsto

segmentanetwork?(Selectthree)

A.Theyincreasethesizeofcollisiondomains

B.Theyallowlogicalgroupingofusersbyfunction.

C.Theycanenhancenetworksecurity.

D.Theyincreasethesizeofthebroadcastdomainwhiledecreasingthe

numberofcollisiondomains.

E.Theyincreasethenumberof