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1、Chapter4NetworkLayer.PacketizingatthenetworklayerinvolvesA) EncapsulatingthepayloadatthesourceB) AddsaheaderthatcontainsthesourceanddestinationinformationC) DecapsulatingthepayloadatthedestinationD) Allofthechoicesarecorrect2.Routersinthepatharenotallowedto.A) fragmentthepackettheyreceiveB) decapsul
2、atethepacketC) changesourceordestinationaddressD) Allofthechoicesarecorrectl l J VH/ ABCDThenetworklayerintheIprehensiveerrorandflowcontrol,limitederrorcontrol,butnoflowcontrol,comprehensiveerrorcontrolbutlimitedflowcontrol.Allofthechoicesarecorrect4.Inavirtual-circuitapproach,theforwardingdecisioni
3、sbasedonthevalueofthefieldinthepacketheader.a)b)qd)sourceaddressdestinationaddresslabelNoneofthechoicesarecorrect5.Inadatagramapproach,theforwardingdecisionisbasedonthevalueofthefieldinthepacketheader.A)B)QD)sourceaddressdestinationaddresslabelNoneofthechoicesarecorrect6.Theperformanceofanetworkcanb
4、emeasuredintermsof.A)B)QD)delaythroughputpacketlossallofthechoicesarecorrect7.Transmissiondelay(time)istheratioof.A) transmissionratetopacketlengthB) transmissionratetodistanceC) packetlengthtotransmissionrateD) processingtimetotransmissionrate8.l ) n IHf ABCDPropagationdelay(time)istheratioof.trans
5、missionratetopropagationspeedpropagationspeedtodistancepacketlengthtopropagationspeeddistancetopropagationspeed9.Whentheloadinthenetworkreachesthenetworkcapacity,thepacketdelayandtheA)B)QD)networkthroughputreaches.increasessharply;itsminimumincreasessharply;itsmaximumdecreasessharply;itsminimumdecre
6、asessharply;itsmaximum10.Inopen-loopcongestioncontrol,policiesareapplied.A) topreventcongestionbeforeithappensB) toalleviatecongestionafterithappensC) toeitherpreventcongestionbeforeithappensortoalleviatecongestionafterithappensD) Noneofthechoicesarecorrect11.Thetechniqueisoneoftheopen-loopcongestio
7、npolicyA) backpressureB) chokepacketC) implicitsignaling- a12.heA)B)QD)13.lplA)B)QD)D) Noneofthechoicesarecorrecttechniqueisoneoftheclose-loopcongestionpolicyacknowledgmentpolicychokepacketdiscardingpolicyNoneofthechoicesarecorrectprotocol.connection-orientedunreliableconnection-orientedreliableconn
8、ectionlessunreliableconnectionlessreliable14.AnHLENvalueofdecimal10means.A) thereare10bytesofoptionsB) thereare10bytesintheheaderC) thereare40bytesofoptionsD) thereare40bytesintheheader15.Ifthefragmentoffsethasavalueof100,itmeansthat.A) thedatagramhasnotbeenfragmentedB) thedatagramis100bytesinsizeC)
9、 thefirstbyteofthedatagramisbyte800D) Noneofthechoicesarecorrect16.Whatisneededtodeterminethenumberofthelastbyteofafragment?A) offsetnumberB) totallengthC) bothoffsetnumberandthetotallengthD) Noneofthechoicesarecorrect17.TheIPheadersizeisbyteslong.A) 20to60B) 20C) 60D) Noneofthechoicesarecorrect18.A
10、)B)0D)PacketsintheIPlayerarecalled.segmentsdatagramsframesNoneofthechoicesarecorrect19.Thetotallengthfielddefinesthetotallengthofthedatagram.A) includingtheheaderB) excludingtheheaderC) excludingtheoptionlengthD) Noneofthechoicesarecorrect20.Whenadatagramisencapsulatedinaframe,thetotalsizeofthedatag
11、rammustbelessthanthel %)/ 1 H ABCDMUTMATMTUNoneofthechoicesarecorrect21.AnIPv4addressisnormallyrepresentedinbaseindotted-decimalnotation.A) 16B) 256C) 10D) Noneofthechoicesarecorrectintoclasses.5Noneofthechoicesarecorrect23.ThenumberofaddressesassignedtoanorganizationinclasslessaddressingA) canbeany
12、numberB) mustbeamultipleof256C) mustbeapowerof2D) Noneofthechoicesarecorrect24.Thefirstaddressassignedtoanorganizationinclasslessaddressing.A) mustbeevenlydivisiblebythenumberofaddressesintheorganizationB) mustbedivisibleby128C) mustbelongtooneoftheA,B,orCclassesD) Noneofthechoicesarecorrect25lnA)B)
13、QD)subnetting,thenumberofaddressesineachsubnetmust.beapowerof2beamultipleof128bedivisibleby128Noneofthechoicesarecorrect26.WhatisthedefaultprefixlengthforclassAinCIDRnotation?9816NoneofthechoicesarecorrectA)B)Q627.WhatisthedefaultprefixlengthforclassBinCIDRnotation?9816Noneofthechoicesarecorrecta)b)
14、qd)28.WhatA)B)QisthedefaultprefixlengthforclassCinCIDRnotation?24816D)Noneofthechoicesarecorrect29.DHCPisa(an)layerprotocol,applicationtransportnetworkdata-linkA)B)QD)30.InDHCBtheclientusesportandtheserverusesport,anephemeral;awell-knownawell-known;awell-knownawell-known;anephemeralNoneofthechoicesa
15、recorrectA)B)QD)31.DHCPusestheservicesof.UDPTCPIPNoneofthechoicesarecorrecta)b)c)d32.allowsasitetouseasetofprivateaddressesforinternalcommunicationandasetofglobalInternetaddressesforcommunicationwiththerestoftheworld.A) DHCPB) NAC) IMCPD) Noneofthechoicesarecorrect33.Theideaofaddressaggregationwasde
16、signedtoalleviatetheincreaseinroutingtableentrieswhenaddressing.classfulclasslessclassfulorclasslessNoneofthechoicesarecorrectS/l/uUABCD34.TheuseofhierarchyinroutingtablescanreduceincreaseneitherreducenorincreaseNoneofthechoicesarecorrectthesizeoftheroutingtables.A)B)QD)35.ICMPisa(an)layerprotocol.A
17、) application-layerprotocolthathelpsTCP/IPatthenetworklayerB) transport-layerprotocolthathelpsTCP/IPatthenetworklayerC) network-layerprotocol.D) data-linklayerprotocolthathelpsTCP/IPatthenetworklayer36.WhichofthefollowingistrueaboutICMPmessages?l ) nF,adefinesthelinksofanetwork,networklinkrouterlink
18、summarylinktonetworkNoneofthechoicesarecorrect55A)B)QD)isaninterdomainroutingprotocolusingpathvectorrouting.BGPRIPOSPFNoneofthechoicesarecorrect56.Aone-to-allcommunicationbetweenonesourceandallhostsonanetworkisclassifiedasacommunication.A)unicastB)0D)multicastbroadcastNoneofthechoicesarecorrect57.Ao
19、ne-to-manycommunicationbetweenonesourceandaspecificgroupofhostsisclassifiedasacommunication.A)B)QD)unicastmulticastbroadcastNoneofthechoicesarecorrect58.Aone-to-onecommunicationbetweenonesourceandonedestinationisclassifiedasacommunication.l ). 1ABCDunicastmulticastbroadcast59mA)B)QD)Noneofthechoices
20、arecorrect,therouterforwardsthereceivedpacketthroughonlyoneofitsinterfaces,unicastingmulticastingbroadcastingNoneofthechoicesarecorrect60.Inmulticastrouting,eachinvolvedrouterneedstoconstructapathtreeforeachgroup.A) averageB) longestC) shortestD) Noneofthechoicesarecorrect61.Inthetreeapproachtomulti
21、casting,eachrouterneedstocreateaseparatetreeforeachsource-group.n 11/ / l ABCDgroup-sharedsource-baseddestination-basedNoneofthechoicesarecorrect62.TheMulticastOpenShortestPathFirst(MOSPF)routingusesthetreeapproach.A) source-basedB) group-sharedC) destination-basedD) Noneofthechoicesarecorrect63.The
22、A)B)0D)MulticastOpenShortestPathFirst(MOSPF)protocolisanextensionoftheOSPFprotocolthatmulticastroutingtocreatesource-basedtrees.Theprotocolisbasedonrouting,distancevectorlinkstatepathvectorNoneofthechoicesarecorrect64.path from the source to theroA)B)QD)InRPEarouterforwardsonlythecopythathastraveled
23、theshortestlongestaverage65.RPF eliminates the forwarding backwarding floodingNone of the choicesin the flooding process.a)b)qd)are correctNoneofthechoicesarecorrect66.RPBcreatesashortestpathtreefromthesourcetoeachdestination,a)b)c)dunicastmulticastbroadcastNoneofthechoicesarecorrect67.RPBguarantees
24、thateachdestinationreceivesofthepacket.A) onlyonecopyB) nocopiesC) multiplecopies-8 13 O )- ) O 6lnp A B C DD) NoneofthechoicesarecorrectJthemulticastpacketmustreachonlythosenetworksthathaveactivemembersforthatRPFRPBRPMNoneofthechoicesarecorrect69.addspruningandgraftingtotocreateamulticastshortestpa
25、thtreethatsupportsdynamicmembershipchanges.A) RPM;RPBB) RPB;RPMC) RPF;RPMD) Noneofthechoicesarecorrect70.isanimplementationofmulticastdistancevectorrouting.Itisasource-basedroutingprotocol,basedonRIRA) MOSPFB) DVMRPC) CBTD) Noneofthechoicesarecorrect71.DVMRPisaroutingprotocol,basedonRIP.A)B)QD)sourc
26、e-basedgroup-shareddestination-basedNoneofthechoicesarecorrect72.A)B)QD)Pruningandgraftingarestrategiesusedin.RPFRPBRPMNoneofthechoicesarecorrect73.PIM-DMisusedwhenthenumberofrouterswithattachedmembersisrelativetothenumberofroutersintheinternet.A)B)QD)largesmallmoderateNoneofthechoicesarecorrect74.P
27、IM-SMisusedwhenthenumberofrouterswithattachedmembersisrelativetothenumberofroutersintheinternet.a)b)qd)largesmallmoderateNoneofthechoicesarecorrect75.bits long.AnIPv6addressisn J* / l ABCD326412825676.AnIPv6addressconsistsofbytes(octets);A)4B)0D)816Noneofthechoicesarecorrect77.Inhexadecimalcolonnota
28、tion,a128-bitaddressisdividedintosections,eachhexadecimaldigitsinlength.A)B)QD)8;28;38;4Noneofthechoicesarecorrect78.AnIPv6addresscanhaveuptohexadecimaldigits.A)B)QD)1632879mA)B)QD)NoneofthechoicesarecorrectIPv6,thefieldinthebaseheaderrestrictsthelifetimeofadatagram,versionpriorityhoplimitNoneofthec
29、hoicesarecorrect80.TheinIPv6isdesignedtoprovidespecialhandlingforaparticularflowofdata.A) flowlabelB) nextheaderC) hoplimitD) Noneofthechoicesarecorrect81.WhentwocomputersusingIPv6wanttocommunicatebutthepacketmustpassthroughanIPv4region,whichtransitionstrategyshouldbeused?A)B)QD)tunnelingheadertrans
30、lationeithertunnelingorheadertranslationNoneofthechoicesarecorrect82.WhenthemajorityoftheInternethasmovedtotheIPv6butsomestilluseIPv4,whichtransitionstrategyshouldbeused?A)B)QD)tunnelingheadertranslationeithertunnelingorheadertranslationNoneofthechoicesarecorrect83.A)B)QD)TheprotocolsICMPv6.ARPandIGMPICMPandIGMPICMRARRandIGMPNoneofthechoicesarecorrectinversion4arecombinedintoonesingleprotocol.BCCAA BCAABCACAB ACABCABBAC DBABB BABCACCBCA ABCDCBCBDCCBADBCDCCABACBBBBAABCAACBAACBABAD
