川大软院计网选择题答案Chapter4(含答案)

1、CHAPTER4:NETWORKLAYER1.Whichofthefollowinggroupsbelongstonetworklayerprotocol?_D_A.IP,TCPandUDPB.ARP,IP,andUDPC.FTP,IMAPandIPD.ICMP,BGP,andRIP2.The3-PDUisnamedas_C_A.messageB.packetC.datagramD.segment3.Inadatagramnetwork,theforwardingdecisionisbasedonthevalueofthe_Bfieldinthepacketheader.A.sourceadd

2、ressB.destinationaddressC.labelD.Noneofthechoicesare4.HOLblockinghappenson_A_A.inputportB.outputportC.switchingfabricsD.allofabove5.Ifnofreebuffersinrouter,thearrivingpacketswillbe:AA.droppedB.queuedC.returnedD.marked6.DuringnormalIPpacketforwardingatarouter,whichofthefollowingpacketfieldsareupdated

3、?_C_A.SourceIPaddressB.DestinationIPaddressC.ChecksumD.Destinationportnumber7.WhichofthefollowingIPaddressdoesnbtelongtothe/25network?_D_A.B.1C.20D.298.YouaregivenanIPnetworkofandtoldthatyouneedtoseparatethisnetworkintosubnetworksthatcansupportamaximumof30hostspersubnet.Thiswillhelpalleviatecongesti

4、ononthenetwork.Whatsubnetmaskcanyouusetocreatethesubnetsnecessarytomeetthegivencriteria?_C_A.B.28C.24D.409.AnIPdatagramof1500bytes(20byteofIPheaderplus1480bytesofIPpayload)arrivesatarouterandmustbeforwardedtoalinkwithanMTUof500bytes.Thustherouterhastofragmentthedatagram.Tothelastfragment,thevalueofo

5、ffsetshouldbe_D_A.1440B.1000C.186D.18010.IPisa_C_protocol.A.connection-orientedunreliableB.connection-orientedreliableC.connectionlessunreliableD.connectionlessreliable11.WhichICMPmessagetypeisthebasisfortheTracerouteutility?BA.EchoRequestB.TTLexpiredC.HostUnreachableD.FragmentReassemblyTimeExceed12

6、.Routersinthepatharenotallowedto_B_.A.fragmentthepackettheyreceiveB.changesourceordestinationaddressC.decapsulatethepacketD.Allofthechoicesarecorrect13._B_allowsasitetouseasetofprivateaddressesforinternalcommunicationandasetofglobalInternetaddressesforcommunicationwiththerestoftheworld.A.DHCPB.NATC.

7、ICMPD.Noneofthechoicesarecorrect14.HowmanybitsarethereinIPv6?_C_A.32B.64C.128D.25615.InCIDRnotation,whichofthefollowingnetworkscontainshost?CA./22B./21C./23D./2416.WhatisthelimitedbroadcastaddresscorrespondingtothenodewiththefollowingIPaddress:9?DA.55B.55C.55D.Noneoftheabove17.InclassfulIPaddressing

8、,howmanynetworkbitsdoes6have?AA.8B.16C.24D.3218.WhatisthebroadcastIPaddressfor28/26?DA.28B.27C.3D.9119.Whatsanetwork?FromIPaddressperspectivetheycanphysicallyreacheachotherwithoutinterveningrouterandthedeviceinterfaceswith:CA.sameIPaddressB.sameTCPport#C.samenetworkpartofIPaddressD.samehostpartofIPa

9、ddress20.TheInternetsnetworklayerhasthreemajorcomponents,thefirstcomponentistheIPprotocol,thesecondcomponentistheroutingprotocol,thefinalcomponentis_.DA.forwardingB.addresstranslationC.checkD.ICMP21.IPaddressingassignsanaddressto50/29,thenetworkaddressforthisnetworkis_.A（）A.48B.50C.D.22.Therearetwo1

10、6-bitintegers:1110011001100110,1101010101010101.TheirchecksumisA_.A.0100010001000011B.1011101110111100C.1111111111111111D.100000000000000023.Theuseofhierarchyinroutingtablescan_A_thesizeoftheroutingtables.A.reduceB.increaseC.neitherreducenorincreaseD.Noneofthechoicesarecorrect24.Whichofthefollowingp

11、rotocoldoesntbinetlroan-gAStoroutingprotocol?_B_A.RIPB.BGPC.OSPFD.IRAP25.Whichofthefollowingprotocolbelongstointra-ASroutingprotocol?_A_A.RIPB.BGPC.DV(DistanceVector)D.LS(LinkState)26.InOSPFnetwork,a_B_belongstobothanareaandthebackbone.A.internalrouterB.areaborderrouterC.boundaryrouterD.backbonerouter27._A_isaninter-domainroutingprotocolusingpathvectorrouting.A.BGPB.RIPC.OSPFD.Noneofthechoicesarecorrect28.RIPusestheservicesof_C_.A.TCPB.IPC.UDPD.Noneofthechoicesarecorrect29.TheRoutingInformationProtocol(RIP)isanintra-domainroutingbasedon_A_routing.A.distancevectorB.l