1000道CCNA经典试题+答案

1Assystemadministrator,youtypendebugipxsapnandreceive

thefollowinglinesaspartoftheIOSresponse:type0x4,

''HELLO2'',199.0002.0003.0006(451),2hopstype0x4,

HHELLOr\199.0002.0003.0008(451),2hopsWhatdoesn0x4H

signify?

A.ThatisaGetNearestServerresponse.

B.ThatitisaGeneralquery.

C.ThatitisaGeneralresponse.

D.ThatitisaGetNearestServerrequest.

2TomonitorIPigrptraffic,youcanuse"debugIPigrp

transactionMor"debugIPigrpevents”.Howdoyoudisplay

informationaboutIPXroutingupdatepackets?

A.debugrouting

B.debugipxtransaction

C.debugipxroutingactivity

D.debugipxevents

3Tomonitoripxtrafficonanetwork,whatcommandwouldyouuse?

A.debugipxtransaction

B.showipxtraffic

C.showipxevents

D.displayipxtraffic

AnsB

4WhatcommandwouldyouusetofindoutthenamesofNovellservers

onanetwork?

A.showipxserversB.showipxhosts

C.showipxsap

D.showipxnodes.

5Thenipxdelaynumber"commandwillallowanadministratortochangethe

default

settings.Whatarethedefaultsettings?

A.ForLANinterfaces,onetick;forWANinterfaces,sixticks

B.ForLANinterfaces,sixticks;forWANinterfaces,onetick

C.ForLANinterfaces,zeroticks;forWANinterfaces,fiveticks

D.ForLANinterfaces,fiveticks;forWANinterfaces,zeroTicks

AnsAThedefaultis-forLANinterfaces,onetick;forWANinterfaces,sixticks

6Asasystemadministrator,youneedtosetuponeEthernet

interfaceontheCiscoroutertoallowforbothsapandNovell-ether

encapsulations.Whichsetofcommandswillaccomplishthis?

A.interfaceethernet0.1ipxencapsulationNovell-etheripxnetwork9einterface

ethemet

0.2ipxnetwork6c

B.interfaceethernet0ipxencapsulationNovell-etheripxnetwork9einterface

ethernet0

ipxencapsulationsapipxnetwork6c

C.interfaceethernet0.1ipx

encapsulationNovell-etherinterface

ethernet0.2ipxencapsulationsap

D.interfaceethernet0.1ipx

encapsulationNovell-etheripx

network9einterfaceethernet0.2ipx

encapsulationsapipxnetwork6c

AnsD

Thefollowingcommandssetupthesubinterfacestoallowfortwotypesof

encapsulation:

interfaceethernet0.1ipxencapsulationNovell-etheripxnetwork9einterfaceetheme

0.2

ipxencapsulationsapipxnetwork6c

7Whatdoesthe“IPXmaximum-paths2ncommandaccomplish?

A.Itenablesloadsharingon2pathsifthepathsareequalmetric

paths.

B.Itsetsuproutingtogotonetwork2.

C.ItisthedefaultforCiscoIPXloadsharing.

D.Itenablesloadsharingon2pathsifthepathsare

unequalmetricpaths.

AnsAItenablesloadsharingon2pathsifthepathsareequalmetricpaths.The

defaultis1

pathandthemaximumis512paths.

8Youwanttoenablebotharpaandsnapencapsulationononerouter

interface.Howdoyoudothis?

A.Theinterfacecanhandlemultipleencapsulationtypeswithno

extraconfiguration.

B.Assigntwonetworknumbers,oneforeachencapsulationtype.

C.EnableNovell-ethertorunmultipleencapsulationtypes.

D.Botharpaandsnapareenabledbydefaultsoyoudon'thaveto

configureanything.

AnsBToassignmultiplenetworknumbers,youusuallyusesubinterfaces.Asample

configurationfollows:ipxethernet0.1ipxencapsulationnovell-etheripxnetwork9e

interfaceethernet0.2ipxencapsulationsapipxnetwork6c

8Bydefault,CiscoroutersforwardGNSSAPstoremotenetworks.

A.False

B.True

AnsA

GNSisNovell'sprotocoltoGetNearestServer.Ifthereisaserveronthelocal

network,that

serverwillrespond.Ifthereisnft,theCiscorouterhastobeconfiguredtoforwardthe

CAp

9TopreventServiceAdvertisements(SAPs)fromfloodinga

network,Ciscoroutersdonotforwardthem.Howareservices

advertisedtoothernetworks?

A.EachrouterbuildsitsownSAPtableandforwardsthatevery

60seconds.

B.Eachrouterassignsaservicenumberandbroadcaststhat.

C.SAPsaren*tnecessarywithCiscorouters.

D.CiscoroutersfilteroutallSAPs.

Ans:ACiscoroutersbuildSAPtablesandforwardthetableevery60seconds.All

SAPs

can'tbefilteredevenwith4.xsinceNDSandtimesynchronizationusesSAPs.

10NovelFsimplementationofRIPupdatesroutingtablesevery

seconds.

A.60

B.90

C.10

D.30

AnsANovell'sRIPupdatesroutingtablesevery60seconds,Apple'sRTMPisevery

i八

seconds,routersARPevery60seconds,IGRPsignalevery90seconds,andBanyan

VINES

signalsevery90seconds.

11InNovell'suseofRIP,therearetwometricsusedtomakerouting

decisions.Selectthetwometrics.

A.Ticks.

B.Hops

C.Loops

D.Counts

Ans:A&BItfirstusesticks(whichisabout1/18sec.);ifthereisatie,ituseshops;if

areequal,thenitusesanadministrativelyassignedtiebreaker.

12WhatistheCisconamefortheencapsulationtypeusedonaserial

interface?

A.HDLC

B.SDLC

C.SAP

D.SNAP

13narpanisusedbytheCiscoIOSforwhichencapsulationtypes?

A.Ethernet_II

B.Ethernet_802.3

C.Ethemet_802.2

D.Ethernet_SNAP

AnsANovelFsIPXandCisco'sIOSnametheirprotocolsdifferently.Ciscousessap

for

Ethernet_802.2,Token-Ring,andNovell'sFDDI_802.2.Ciscousessn叩for

Ethernet_SNAP,Token-Ring_SNAP?andFDDI_SNAP.Ciscousesarpafor

Ethernet_II

and,finallytliedefaultisNovell-etherforNovell'sEthernet_802.3.

14''snap''isusedbytheCiscoIOSforwhichencapsulationtypes?

A.Ethernet_SNAP

B.Token-Ring_SNAP

C.FDDI_SNAP

D.Novell-SNAP

E.Novell-FDDI.

Ans:A.B&CNovelFsIPXandCisco*sIOSnametheirprotocolsdifferently.Cisco

usessap

forEthernet_802.2,Token-Ring,andNovelFsFDDT_802.2.Ciscousessnapfor

Ethernet_SNAP,Token-Ring_SNAP,andFDDI_SNAP.Ciscousesarpafor

Ethernet_II

and,finallythedefaultisNovell-etherforNovell'sEthernet_802.3.

15nsapnisusedbytheCiscoIOSforwhichencapsulationtypes?

A.Ethernet_802.2

B.Token-Ring

C.FDDI_SNAP

D.Ethernet_802.3

E.FDDI_802.2

AnsA,B&E

NovelFsIPXandCisco'sIOSnametheirprotocolsdifferently.Ciscousessapfor

Ethernet_802.2,Token-Ring,andNovell'sFDDI_802.2.Ciscousessnapfor

Ethernet_SNAP,Token-Ring_SNAP,andFDD1_SNAP.Ciscousesarpafor

Ethernet_II

and,finallythedefaultisNovell-etherforNovell'sEthemet_802.3.

16WhichtypeofEthernetframingisusedforTCP/IPand

AppleTalk?

A.Ethernet802.3

B.Ethernet802.2

C.EthernetII

D.EthernetSNAP

AnsDEthernet802.3isusedwithNetWareversions2through3.11,Ethernet802.2is

used

withNetWare3.12andlaterplusOSIrouting,EthernetIIisusedwithTCP/IPand

DECnet,

andEthernetSNAPisusedwithTCP/IPandAppleTalk.

17WhichtypeofEthernetframingisusedforTCP/IPand

DECnet?

A.Ethernet802.3

B.Ethernet802.2

C.EthernetII

D.EthernetSNAP

Ans:CEthernet802.3isusedwithNetWareversions2through3.11,Ethernet802.2

isused

withNetWai'e3.12andlaterplusOSIrouting,EthernetIIisusedwithTCP/IPand

DECnet,

andEthernetSNAPisusedwithTCP/IPandAppleTalk.

18YouareasystemadministratoronaNetWarenetwork,youare

runningNetWare4.11andyoucannotcommunicatewithyourrouter.

Whatisthelikelyproblem?

A.NetWare4.11defaultsto802.2encapsulation.

B.NetWare4.11defaultsto802.3encapsulation

C.CiscoroutersonlyworkwithNetWare3.11.

D.NetWare3.11defaultsto802.2encapsulation.

AnsAThedefaultencapsulationonCiscoroutersisNovellEthernet_802.3and

NetWare

3.12andlaterdefaultsto

802.2encapsulation,3.11andearlierdefaultsto802.3.

19NetWareIPXaddressingusesanetworknumberandanode

number.Whichstatementsaretrue?

A.Thenetworkaddressisadministrativelyassignedandcanbeup

to16hexadecimaldigitslong.

B.Thenodeaddressisalwaysadministrativelyassigned.

C.ThenodeaddressisusuallytheMACaddress.

D.IftheMACaddressisusedasthenodeaddress,thenIPX

eliminatestheuseofARP.

AnsA,C&D

Thenetworkaddresscanbeupto16hexadecimaldigitsinlength.Thenodenumber

is12

hexadecimaldigits.ThenodeaddressisusuallytheMACaddress.AnexampleIPX

address

is4a1d.0000.0c56.de33.Thenetworkpartis4ald.Thenodepartis0000.0c56.de33.

The

networknumberisassignedbythesystemadministratoroftheNovellnetwork.

20WhichNetWareprotocolworksonlayer3-networklayer-ofthe

OSImodel?

A.IPX

B.NCP

C.SPX

D.NetBIOS

AnsAIPX(InternetworkPacketExchange)isaNetWarenetworklayer3protocol

；edfor

transferringinformationonLANs.

21WhichNetWareprotocolprovideslink-staterouting?

A.NLSPB.RIP

C.SAP

D.NCP

Ans:A

NetWai'eLinkServicesProtocol(NLSP)provideslink-staterouting.

SAP(ServiceAdvertisementProtocol)advertisesnetworkservices.

NCP(NetWareCoreProtocol)providesclient-to-server

connectionsandapplications.RIPisadistancevectorrouting

protocol.

22Asasystemadministrator,youwanttodebugigrpbutare

worriedthatthe“debugIPigrptransaction0commandwillflood

theconsole.Whatisthecommandthatyoushoulduse?

A.debugIPigrpevent

B.debugIPigrp-events

C.debugIPigrpsummary

D.debugIPigrpevents

AnsDThe"debugIPigrpevents"isusedtoonlydisplayasummaryofIGRProuting

information.YoucanappendanIPaddressontoeithercommandtoseeonlythe

IGRP

updatesfromaneighbor.

23Whatdoesthefollowingseriesofcommandsaccomplish?

routerigrp71network

routerigrp109

network

A.Itisolatesnetworksand.

B.Itloadsigrpfornetworks109and71.

C.ItdisablesRIP.

D.Itdisablesallroutingprotocols.

AnsAItisolatesnetworkandandassociatesautonomoussystems

109

and71withIGRP.IGRPdoesnotdisableRIP.bothcanbeusedatthesametime.

24Inthecommandnrouterigrp109"whatdoes109signify?

A.anautonomoussystem

B.anynetworknumberwhichtherouterisattachedtoC.theallowablelengthofthe

routingtable

D.thenetworksocketnumber

AnsATheCiscoIOSglobalconfigurationcommand"routerigrpxxx°isusedto

configure

theInteriorGatewayRoutingProtocol.Inthiscase,the109iscalledtheprocess-id,

which

canalsobeusedforanautonomoussystemnumber.

25IGRPsupportsafeaturethatallowstraffictobe

distributedamongupto6(4default)pathstoprovidegreater

overallthroughputandreliability.Whatisthiscalled?

A.unequal-costloadbalancing

B.equal-costloadbalancing

C.proportionateloadbalancing

D.lowcostloadbalancing

AnsAAnunequal-costloadbalancingisusedtoprovidealternatepathsfordata

distributiononaninternetwork.Ciscodevelopedthismethodtouseunusedorunder

utilizedlinkstoincreasebandwidthandnetworkavailability.

26IGRPusesflashupdates,poisonreverseupdates,holddowntimes,

andsplithorizon.Howoftendoesitbroadcastitsroutingtable

updates?

A.90seconds

B.10seconds

C.30seconds

D.45seconds

AnsA

27ThecommandnshowIPprotocolndisplayswhichinformation?

A.routingtimers

B.networkinformation

C.contentsoftheIProutingtable

D.informationaboutallknownnetworkandsubnetworks

AnsA&B

"showIPprotocol"displaysroutingtimersandnetwork

information.nshowIProute"displaystheroutingtablewith

informationaboutallknownnetworksandsubnetworks.

28WhenusingRIP,routingupdatesarebroadcastevery

seconds.

A.30

B.10

C.60

D.90

Ans:ANovell'sRIPupdatesroutingtablesevery60seconds,Apple'sRTMPisevery

10

seconds,routersARPevery60seconds,DECnethostsandIGRPsignalevery15

seconds,

andBanyanVINESsignalsevery90seconds.

29Anautonomoussystemcanonlyexistifallroutersinthatsystem

meetwhichcriteria?

A.interconnected

B.runthesameroutingprotocol

C.assignedsameautonomoussystemnumber

D.runIGRPonly

E.runRIPonly

AnsA,B&CAnautonomoussystemisasetofroutersandnetworksunderthesame

administration.Eachroutermustbeinterconnected,runthesameroutingprotocol,

and

assignedthesameautonomoussystemnumber.ThenetworkInformationCenter

(NIC)

assignsauniqueautonomoussystemnumbertoenterprises.

30Adefaultrouteisanalogoustoa.

A.defaultgateway

B.staticroute

C.dynamicroute

D.one-wayroute

Ans:AAdefaultrouteisanalogoustoadefaultgateway.Itisusedtoreducethe

lengthof

routingtablesandtoprovidecompleteroutingcapabilitieswhenaroutermightnot

know

theroutestoallothernetworks.

31Routerscanlearnaboutdestinationsthroughstaticroutes,default,

ordynamicrouting.Bydefault,arouterwilluseinformationderived

from,

A.IGRP

B.RIP

C.IP

D.TCP

AnsAThequalityofinformationisrated:Connectedinterface0Staticroute1IGRP

100

RIP120Unknown255Thelowerthevalue,themorereliablethesourcewith255

signifyinginfonnationthattherouterwillignore.So,therouterwilluseIGRP,rated

aiiuu,

beforeIP,ratedal

120.

32Youareloggedintoarouter,whatcommandwouldshow

youtheIPaddressesofroutersconnectedtoyou?

A.showcdpneighborsdetail

B.showrun

C.showneighbors

D.showcdp

AnsA

33Asasystemadministrator,youperformanextendedpingatthe

privilegedEXECprompt.Aspartofthedisplay,youseenSetDFbit

inIPheader?[yes]:nWhatwouldhappenifyouanswerednoatthe

prompt.

A.Thisletstherouterfragmentthepacket.

B.Ittellstherouternottofragmentthepacket.

C.Thisletstherouterdirectthepackettothedestinationitfinds

initsroutingtable.

D.Ittelltheroutertosendthepackettothenexthoprouter.

AnsA"SetDFbitinIPheader?”isaresponsetoanextendedpingattherouter.If

you

answeryes(thedefault)therouterwillnotfragmentthepacket.Ifyouanswerno,the

router

willfragmentthepacket.

34Youhavetyped"ping”andgetthefollowingdisplay:Type

escape

sequencetoabort.Sending5,100-byteICMPEchoesto,

timeoutis2seconds:

!!!!

Whatdoesthesignify?

A.Thatonemessagetimedout.

B.Thatallmessagesweresuccessful.

C.Thatonemessagewassuccessful.

D.Thatonemessagecompletedinundertheallotted

timeframe.

AnsA

Thepossibleresponsesfromthepingcoinmandare:

!Successfulreceiptofanechoreply..Timed

outwaitingforareplyUDestination

unreachableCCongestion-experienced

packetIPinginteiTupted?Packettype

unknown&PacketTTLexceeded

35Whichcommand,thatisusedtotestaddressconfiguration,uses

Time-To-Live(TTL)valuestogeneratemessagesfromeachrouter.

A.trace

B.ping

C.telnet

D.bootp

Ans:ATheCiscoIOSEXECcommandntrace[protocol][destination]"isusedto

discover

routesthatpacketswilltraveltotheirdestinationhosts.TraceusesTTL(Timeto

Live)

valuestoreportdestinationrouteinformation.

36Whatdoesthecominand“IPname-server55”

accomplish?

A.Itsetsthedomainnamelookuptobealocalbroadcast.

B.Thisisanillegalcommand.

C.Itdisablesdomainnamelookup.

D.Thecommandisnowdefunctandhasbeenreplacedby"IP

server-nameipany”

AnsABydefaultDNSisenabledonarouterwithaserveraddressof

55.

whichprovidesforalocalbroadcast.

37Asasystemadministrator,youneedtoprovideyourrouterswithaDomain

Name

System(DNS)server.HowmanyDNSserverscanyouspecifywithone

command?

A.6

B.1

C.2

D.4

AnsAYoucanonlyspecifysixnameserversinonecommand.Thesyntaxis"IP

name-serverserver-address1[[server-address2]...server-address6].Youmustalso

enable

DNS.

38HowwouldyouconfigureonehostnamethatpointstotwoIP

addresses?

A.IPhostjacob

B.IPjacob

C.IPhostjacob

D.IPhostduplicate"all”

AnsAThecorrectsyntaxisIPhostname[TCP-port-number]address[address]

So,

nIPhostP1R11.0,0.5"isthecorrectchoice.nIPhostjacob"only

pointsthe

hostnamejacobtooneIPaddress-.

39Thefollowingselectionsshowthecommandpromptandtheconfigurationof

theIP

networkmask.Whichtwoarecorrect?

A.Router#termIPnetmask-format{bitcountIdecimalIhexadecimal}

B.Router(config-if)#IPnetmask-format{bitcountIdecimalIhexadecimal}

C.Router(config-if)#netmask-format{bitcountIdecimalIhexadecimal}

D.Router#ipnetmask-format{bitcountIdecimalIhexadecimal}

AnsA&BRouter#termIPnetmask-fonnat{bitcountIdecimalIhexadecimal}and

Router(config-if)#IPnetmask-format{bitcountIdecimalIhexadecimal}arecorrect.

canconfigurethemaskforthecurrentsessionandyoucanconfigureitforaspecific

line.

40WhenconfiguringthesubnetmaskforanIPaddress,which

formatscanbeused?A.dotted-decimal.

B.HexadecimalC.Bit-count

D.Octal

E.Binary

41Youaregiventhefollowingaddress:7/25.Determine

thesubnetmask,addressclass,subnetaddress,andbroadcast

address.

A.255.255.255,128,B,,27

B.28,C,,27

C.28,C,27,

D.24,C,,27

42Youaregiventhefollowingaddress:3/30.

Determinethesubnetmask,addressclass,subnetaddress,and

broadcastaddress.

A.52,B,2,5

B.52,C,2,5

C.52,B,5,2

D.48,B,2,5

AnsA

43Youaregiventhefollowingaddress:/21.Determine

thesubnetmask,addressclass,subnetaddress,andbroadcast

address.

A.,A,,55

B.,B,,55

C.,A,55,

D.,A,,55

44YouhaveanIPhostaddressof21andasubnetmask

of48.Whatisthebroadcastaddress?

A.27

B.20

C.21

D.22

AnsATheeasiestwaytocalculatethisistosubtract

48(subnetmask)from55,thisequals7.Convertthe

address

21tobinai-y-11001001110111100000010101111001.Convertthemask

48tobinary-11111111111111111111111111111000.ANDthem

togethertoget:11001001110111100000010101111000or20.

20

isthesubnetaddress,add7tothisaddressfor27orthebroadcastaddress.

21through26arethevalidhostaddresses.

45Giventheaddress20andthesubnetmaskof

.Howmanyhostsareavailable?

A.254

B.510

C.126

D.16,372

AnsA

172.16.2120isastandardClassBaddresswithasubnetmaskthatallows254hosts.

You

areanetworkadministratorandhavebeenassignedtheIPaddressof.

You

needtohave20subnetswith5hostspersubnet.Thesubnetmaskis48.

46Whichaddressesarevalidhostaddresses?

A.7

B.8

C.6

D.9

E.1

AnsA,B&DSubnetaddressesinthissituationareallinmultiplesof8.Inthis

example,

6isthesubnet,1isthebroadcastaddress.Therestarevalid

hostIDs

onsubnet6.

47YouareanetworkadministratorandhavebeenassignedtheIP

addressof.Youneedtohave20subnetswith5hostsper

subnet.Whatsubnetmaskwillyouuse?

A.48

B.28

C.92

D.40

AnsAByborrowing5bitsfromthelastoctet,youcan.have30subnets.Ifyou

borrowed

only4bitsyoucouldonlyhave14subnets.Theformulais(2tothepowerofn)-2.By

bon*owing4bits,youhave(2x2x2x2)-2=14.Byborrowing5bits,youhave

(2x2x2x2x2)-2=30.Toget20subnets,youwouldneedtoborrow5bitssothesubnet

mask

wouldbe

48.

48YouaregiventheIPaddressof60withasubnetmask

of.Whatisthenetworkaddressinbinary?

A.1010110000010000

B.0000001010100000

C.1010110000000000

D.1110000011110000

Ans:ATofindthenetworkaddress,converttheIPaddresstobinary-10101100

0001000000000001010100000-thenANDeditwiththesubnetmask-11111111

111111110000000000000000.Therestis10101100000100000000000000000000,

whichisindecimal.Thefirstoctetrulestatesthattheclassofanaddress

canbe

deteiTninedbythenumericalvalueofthefirstoctet.

49WhichaddressesareINCORRECTLYpairedwiththeirclass?

A.128to191,ClassB

B.192to223ClassB

C.128to191,ClassC

D.192to223,ClassC

AnsB&CAddressclassesare:1to126,ClassA;128to191,ClassB,192to223,

224to239.ClassD;and240to255,ClassE.Thefirstoctetrulestatesthattheclass

ofan

addresscanbedeterminedbythenumericalvalueofthefirstoctet.

50WhichaddressesareINCORRECTLYpairedwiththeirclass?

A.1to126,ClassA

B.128to191,ClassA

C.1to126,ClassB

D.128to191,ClassB

Ans:B&C.Addressclassesare:1to126,ClassA;128to191,ClassB,192to223,

,ClassD;and240to255.ClassE.Thefirstoctetrulestatesthatthe

anaddresscanbedeterminedbythenumericalvalueofthefirstoctet.

51WhichaddressesareINCORRECTLYpairedwiththeirclass?

A.240-255,ClassD

B.240-255,ClassE

C.224-239,ClassD

D.224-239,ClassE

AnsA&DAddressclassesare:1to126,ClassA;128to191,ClassI

224to239,ClassD;and240to255,ClassE.

52WhichIPAddressClassisINCORRECTLYpairedwithitsrangeof

networknumbers?

A.ClassAaddressesincludethrough

B.ClassAaddressesincludethrough

C.ClassBaddressesincludethrough

D.ClassCaddressesincludethrough

E.ClassDaddressesincludethrough

AnsAClassAaddressesincludethrough

ClassBaddressesincludethroughClassCaddresses

includethroughClassDaddressesincludethrough

53WhichIPAddressClasscanhave16millionsubnetsbut

support254hosts?

A.ClassC

B.ClassA

C.ClassB

D.ClassD

AnsAPossibleSubnetsIPAddressClassPossibleHosts254A16M.64KB64K

16MC

254

54WhichIPAddressClasscanhave64,000subnetswith64,000hosts

persubnet?

A.ClassBB.ClassA

C.ClassC

D.ClassD

AnsAIPAddressClassPossibleSubnetsPossibleHosts254AI6M64KB64K

16MC

254

55TherearetwoprocessestopairMACaddresswithIP

addresses.WhichprocessfindsanIPaddressfromaMAC

address?

A.RARP

B.ARP

C.RIP

D.IGRP

AnsAARP(AddressResolutionProtocol)mapsanIPaddresstotheMACaddress,

RARP

(ReverseAddressResolutionProtocol)mapstheMACaddresstotheIPaddress.ARP

and

RARPworkattheinternetlayeroftheInternetModelorthenetworklayeroftheOSI

model.

56Whentherouterrunsoutofbufferspace,thisiscalled

A.SourceQuench

B.Redirect

C.InformationRequest

D.LowMemory

AnsASourcequenchistheprocesswherethedestinationrouter,orend

internetworking

devicewill"quench"thedatefromthe"source",orthesourcerouter.Thisusually

happens

whenthedestinationrouterrunsoutofbufferspacetoprocesspackets.

57WhichprotocolcarriesmessagessuchasdestinationUnreachable,

TimeExceeded,ParameterProblem,SourceQuench,Redirect,Echo,

EchoReply,Timestamp,InformationRequest,InformationReply,

AddressRequest,andAddressReply?

A.ICMP

B.UDP

C.TCP

D.TFTP

E.FTP

AnsAICMP(InternetControlMessageProtocol)isanetworklayerinternetprotocol

describedinRFC#792.ICMPreportsIPpacketinfomiationsuchasdestination

Unreachable,TimeExceeded,ParameterProblem,SourceQuench,Redirect,Echo,

Echo

Reply,Timestamp,InformationRequest,InformationReply,AddressRequest,and

Address

Reply.

58TwooftheprotocolsthatcanbecarriedintheProtocolfieldof

anIPpacketare?

A.TCP

B.UDP

C.FTP

D.TFTP

AnsA&BThefollowingaretliefieldsinanIPsegment,theirlength,andtheir

definitions:

VERS(Versionnumber-16bits)HLEN(Numberof32-bitwordsintheheader-4

bits)

TypeofServer(Howthedatagramshouldbehandled-32bits)TotalLength(Total

length

ofheaderanddata-32bits)Identification(Providefragmentationofdatagramsto

allow

differentMTUsintheinternet-4bits)Flags(Providefragmentationofdatagramsto

allow

differentMTUsintheinternet-4bits)FragOffset(Providefragmentationof

datagramsto

allowdifferentMTUsintheinteniet-6bits)TTL(Time-To-Live-6bits)Protocol

(Upperlayerprotocolsendingthedatagram-16bits)HeaderChecksum)Integrity

checkon

theheader-16bits)SourceIPAddress(32bits)DestinationIPAddress(32bits)IP

Options(networktesting,debugging,securityandothers

-4bits)Data(4bits).

59WherewouldnetworktestingbeincludedinanIPpacket?

A.IPOptionsfieldB.Identificationfield

C.TypeofServicefield

D.Reservationfield

AnsAThefollowingarethefieldsinanIPsegment,theirlength,andtheir

definitions:

VERS(Versionnumber-16bits)HLEN(Numberof32-bitwordsintheheader-4

bits)

TypeofServer(Howthedatagramshouldbehandled-32bits)TotalLength(Total

length

ofheaderanddata-32bits)Identification(Providefragmentationofdatagramsto

allow

differentMTUsintheinternet-4bits)Flags(Providefragmentationofdatagramsto

allow

differentMTUsintheinternet-4bits)FragOffset(Providefragmentationof

datagramsto

allowdifferentMTUsintheinternet-6bits)TTL(Time-To-Live-6bits)Protocol

(Upperlayerprotocolsendingthedatagram-16bits)HeaderChecksum)Integrity

checkon

theheader-16bits)SourceIPAddress(32bits)DestinationIPAddress(32bits)IP

Options(networktesting,debugging,securityandothers

-4bits)Data(4bits).

60WhatfieldtellstheInternetlayerhowtohandleanIPpacket?

A.TypeofService

B.Identification

C.Flags

D.FragOffset

AnsAThefollowingarethefieldsinanIPsegment,theirlength,andtheir

definitions:

VERS(Versionnumber-16bits)HLEN(Numberof32-bitwordsintheheader-4

bits)

TypeofSei*ver(Howthedatagramshouldbehandled-32bits)TotalLength(Total

length

ofheaderanddata-32bits)Identification(Providefragmentationofdatagramsto

allow

differentMTUsintheinternet-4bits)Flags(Providefragmentationofdatagramsto

allow

differentMTUsintheinternet-4bits)FragOffset(Providefragmentationof

datagramsto

allowdifferentMTUsin由einternet-6bits)TTL(Time-To-Live-6bits)Protocol

(Upperlayerprotocolsendingtliedatagram-16bits)HeaderChecksum)Integrity

checkon

theheader-16bits)SourceIPAddress(32bits)

DestinationIPAddress(32bits)

IPOptions(networktesting,debugging,securityandothers

-4bits)Data(4bits).

61WhichfieldsofanIPpacketprovideforfragmentationof

datagramstoallowdifferingMTUsintheinternet?

A.Identification

B.Flags

C.FragOffset

D.TypeofService

E.TotalLength

AnsA,B&CThefollowingarethefieldsinanIPsegment,theirlength,andtheir

definitions:VERS(Versionnumber-16bits)HLEN(Numberof32-bitwordsinthe

header

-4bits)TypeofServer(Howthedatagramshouldbehandled-32bits)TotalLength

(Total

lengthofheaderanddata-32bits)Identification(Providefragmentationofdatagrams

to

allowdifferentMTUsintheinternet-4bits)Flags(Providefragmentationof

datagramsto

allowdifferentMTUsintheinternet-4bits)FragOffset(Providefragmentationof

datagramstoallowdifferentMTUsintheinternet-6bits)TTL(Time-To-Live-6

bits)

Protocol(Upper!ayerprotocolsendingthedatagram-16bits)Header

Checksum)lntegrity

checkontheheader-16bits)SourceIPAddress(32bits)