试思科网络技术验四.docx
《试思科网络技术验四.docx》由会员分享，可在线阅读，更多相关《试思科网络技术验四.docx（14页珍藏版）》请在冰点文库上搜索。
试思科网络技术验四
LAB4CablingLANsandWANs
PART1Repeaters
Objective:
∙Createasimulatednetworktopology
∙ApplyIPaddressestoworkstations
∙Befamiliarwiththefunctionofarepeater
∙UnderstandtheFourRepeaterRule
∙Testthesimulatedtopology
Step1
CreatethetopologyshowninthediagraminPacketTracer.Afterconnectingallthedevices,assigneachPCwithavalidIPaddressandsubnetmask.（YoucanuseanyIPaddressesaslongastheybelongtothesamenetwork.）
Step2
a）ClickontheSimulationtabtostartcreatingascenario.
b）AddapacketandclickonsourcePC0andthenclickondestinationPC1.AddanotherpacketfromPC1toPC2.
c）Clickplaytowatchthesimulation.
d）Takenoteofthetimeittakesforeachpackettoreachitsdestination.（Havingmorerepeatersbetweenworkstationsaddslatencytothepackets.）
Step3
a）Clickonceonthearrowontheleftoftheplaybuttontogobackonesecond（ThenumberintheTimeboxshouldbe“6”）
b）AddapacketfromPC2toPC1.
c）ClickontheTopologytab.RemoveaconnectionthenaddanotherrepeateranywherebetweenSwitch0andPC2.Re-connectthedevices.
d）ClickontheSimulationandhittheplaybuttontowatchthesimulation.（Latencyresultsincollision.）
PART2RepeatersandHubs
Information:
1.Thistopologyconsistsof8hostsalongwith2hubsand1repeaterinthenetwork.
Tips:
a）ThePacketTracer“i”locatedontheupperrightofeachpageanddevicewillgiveinformationpertainingtothatcertaindeviceortopology.
b）Insimulation,the“i”nexttothescenariodropdownlistwillgiveinformationaboutthespecificscenario.
c）Insimulation,clickingonthepacketswillshowOSIlayerinformation.
Procedures:
a）Inthetopologymode,addthree（3）additionalrepeatersbetweenthetwo
（2）hubs.
b）Insimulationmode,createanewscenario.
c）SendapacketfromPC4toPC0andapacketfromPC5toPC1atdifferenttimessothatthepacketswillnotcollide.
d）Beforerunningthesimulation,clickontheindividualpacketsonPC4andPC5toreviewthepacketandOSIinformation.Next,runthesimulation.
e）Afterthefirstsimulation,repeatstep3exceptthepacketsdoescollidethistime.Thenrepeatstep4.
f）AfterthepacketsarrivetoHub1,clickonthepacketthatleavesHub1andpropagatestoRepeater0.
Questions:
a）Whatisthepurposeofahubandrepeaterinthisnetwork?
集线器：
对接收到的信号进行再生整形放大，以扩大网络的传输距离，同时把所有节点集中在以它为中心的节点上；中继器：
主要功能是通过对数据信号的重新发送或者转发，来扩大网络传输的距离。
b）Whattypeofmediumisbeingusedtoconnectthehoststothehubsandtherepeatertothehubs?
twistedpair
c）Howmanycollisiondomain（s）doesthisnetworkcontain?
2个冲突域
PART3Wireless
Information:
1.Thistopologyconsistsofaworkstation,alaptop,aserver,aprinter,andanaccesspoint.Theentirenetworkiswireless.
Tips:
a）ThePacketTracer“i”locatedontheupperrightofeachpageanddevicewillgiveinformationpertainingtothatcertaindeviceortopology.
b）Insimulation,the“i”nexttothescenariodropdownlistwillgiveinformationaboutthespecificscenario.
c）Insimulation,clickingonthepacketswillshowOSIlayerinformation.
Procedures:
a）ReviewScenario2insimulationmode.
b）Takeintoconsiderationthattheconnecteddevicesdoesn’thaveanyideathatthecollisionsareoccurring.
c）Whatifthedevicescontinuesendingpacketstoeachotherindefinitely?
Asimulationcanbeseenbycreatingpacketsbetweenthedevicessothatmultiplecollisionshappenoneafteranother.Thinkofthelatencythistypeofsituationcreates.
Questions:
a）Whattypesofsignalsarewirelessconnectionscapableof?
语音和数据信号
b）Inwhatwaysareaccesspointsrelatedordifferentcomparedtoothernetworkingdevicessuchashubsandswitches?
般俗称为网络桥接器，顾名思义即是当作传统的有线局域网络与无线局域网络之桥梁，因此任何一台装有无线网卡之PC均可透过AP去分享有线局域网络甚至广域网络之资源。
除此之外，AP本身又兼具有网管之功能，可针对接有无线网络卡之PC作必要之控管。
c）Whatsecurityissue（s）ariseswhenusingwirelessconnectivity?
非授权用户的接入、信息泄露、信号干扰、伪装地址和拦截对话、高级攻击
d）Inwhatsituationsdoeswirelessconnectivityhaveanadvantageoverwiredandviceversa?
安装便捷、使用灵活、易于扩展
PART4BridgesandSwitches
Information:
1.Thistopologyconsistsof14hostsalongwith4switchesand2bridgesinthenetwork.
Tips:
a）ThePacketTracer“i”locatedontheupperrightofeachpageanddevicewillgiveinformationpertainingtothatcertaindeviceortopology.
b）Insimulation,the“i”nexttothescenariodropdownlistwillgiveinformationaboutthespecificscenario.
c）Insimulation,clickingonthepacketswillshowOSIlayerinformation.
d）Insimulation,clickingonthebridgesandswitcheswillloaduptheMACaddresstables.
Procedures:
a）Inthetopologymode,Switch0’sFastEthernetport6isdisabled.Asaresult,thelinkbetweenSwitch0andBridge0isdown.
b）Stillintopologymode,clickonSwitch0andthenclickonFastEthernetport6.Enabletheportbyturningiton.
c）Nowgointosimulationmode.Asyoumaynoticethelinkthatwasjustenabled,hasjustdisableditself.ThiseffectisduetotheloopthatiscreatedinthetopologyandtheSpanningTreeProtocolpreventsthisloopfromoccurring.
d）SendapacketfromhostXctohostXX.Analyzethepaththepackettakes.SincethelinkfromSwitch0andBridge0isdowntopreventaloop,Switch3mustsendthepackettoBridge1whosendsittoSwitch2,whothensendsittoSwitch0andfinallyendingupathostXX.
e）Now,intopologymode,removetwoofthebridgesandcreateaconnectionbetweentheisolatednetworksegmentssothatpacketscanbesentamongstthem.
Questions:
a）Whatisthepurposeofabridgeandswitchinthistopology?
网桥：
网桥的功能在延长网络跨度上类似于中继器，然而它能提供智能化连接服务，即根据帧的终点地址处于哪一网段来进行转发和滤除。
交换机：
交换机的主要功能包括物理编址、网络拓扑结构、错误校验、帧序列以及流控。
b）WhichOSIlayer（s）doesabridgeandswitchworkon?
数据链路层
c）Whatarethebenefitsofusingbridgesandswitchescomparedtorepeatersandhubs?
集线器的某个端口工作的时候其他所有端口都有名收听到信息，容易产生广播风暴。
当网络较大的时候网络性能会受到很大的影响，换机就能够起到这种作用，当交换相工作的时候只有发出请求的端口和目的端口之间相互响应而不影响其他端口，那么交换机就能够隔离冲突域和有效地抑制广播风暴的产生。
集线器不管有多少个端口，所有端口都共享一条带宽，在同一时刻只能有两个端口传送数据，其他端口只能等待；同时集线器只能工作在半双工模式下。
而对于交换机而言，每个端口都有一条独占的带宽，当两个端口工作时并不影响其他端口的工作，同时交换机不但可以工作在半双工模式下也可以工作在全双工模式下。
d）Howmanycollisiondomain（s）doesthisnetworkcontain?
20个冲突域
PART5Buildingapeertopeernetwork
Objective:
∙Createasimplepeer-to-peernetworkbetweentwoPCs
∙ApplyIPaddressestoworkstations
∙Testconnectivityinthesimulatedtopology
Step1
a）CreatethetopologyshowninthediagraminPacketTracer.
b）Afterconnectingthedevices,assigneachPCwithanIPaddressaccordingtotheinformationinthetablebelow:
Computer
IPAddress
Subnetmask
PC–0
192.168.1.1
255.255.255.0
PC–1
192.168.1.2
255.255.255.0
Step2
e）ClickontheSimulationtabtostartcreatingascenario.
f）AddapacketfromPC0toPC1.
g）ClickplaytotesttheconnectivitybetweenthePCs.
Step3
a）Clickonthetopologytab.
b）ClickonPC0andsetittohalfduplex（defaultisonautonegotiate）.
c）DothesameforPC1.
d）ClickontheSimulationtab.
e）AddapacketfromPC1toPC0.
f）Clickplaytowatchthesimulation.
g）Notethatcollisionoccursonahalfduplexconnection（dataistransmittedinonedirectionatatime）whentwoworkstationssendasignalatthesametime.
Step3
a）Clickonthetopologytab.
b）ClickonPC0andsetittofullduplex.
c）DothesameforPC1.
d）ClickontheSimulationtab.
e）Clickplaytowatchthesimulation.
f）Notethatcollisiondoesnotoccuronafullduplexconnection（dataistransmittedintwodirectionssimultaneously）.
PART6Buildingahub-basednetwork
Objective:
∙CreateasimplenetworkwithtwoPCsusingahub
∙ApplyIPaddressestoworkstations
∙Testconnectivityinthesimulatedtopology
Step1
a）CreatethetopologyshowninthediagraminPacketTracer.
b）Afterconnectingthedevices,assigneachPCwithanIPaddressaccordingtotheinformationinthetablebelow:
Computer
IPAddress
Subnetmask
PC–0
192.168.1.1
255.255.255.0
PC–1
192.168.1.2
255.255.255.0
Step2
a）ClickontheSimulationtabtostartcreatingascenario.
b）AddapacketfromPC0toPC1.
c）Clickplaytowatchthesimulation.
Step3
a）Clickonthetopologytab.
b）AddanotherPCandconnectittothehub.AssignitwithanIPaddressof192.168.1.3andasubnetmaskof255.255.255.0.
c）Clickonthesimulationtabandclickplaytowatchthesimulationagain.（Hubsdon’tfiltertraffic.Theyforwardpacketstoeachworkstationthatisconnectedtothem.）
d）AddapacketfromPC0toPC1andPC2toPC0.
e）Clickplaytowatchthesimulation.（Sincehubsdon’tfiltertraffic,theypermitcollisionstooccur.）
PART7Buildingaswitch-basednetwork
Objective:
∙CreateasimplenetworkwithtwoPCsusingaswitch
∙ApplyIPaddressestoworkstations
∙Testconnectivityinthesimulatedtopology
Step1
a）CreatethetopologyshowninthediagraminPacketTracer.
b）Afterconnectingthedevices,assigneachPCwithanIPaddressaccordingtotheinformationinthetablebelow:
Computer
IPAddress
Subnetmask
PC–0
192.168.1.1
255.255.255.0
PC–1
192.168.1.2
255.255.255.0
Step2
a）ClickontheSimulationtabtostartcreatingascenario.
b）AddapacketfromPC0toPC1.
c）Clickplaytowatchthesimulation.
d）ClickontheswitchtoviewitsMACtable.（PC0andPC1’sMACaddressesareinthetable.）
Step3
a）Clickonthetopologytab.
b）AddanotherPCandconnectittotheswitch.AssignitwithanIPaddressof192.168.1.3andasubnetmaskof255.255.255.0.
c）Clickonthesimulationtabandclickplaytowatchthesimulationagain.（Switcheschoosetheporttowhichthedestinationdeviceisconnected.Theyforwardapacket
升级会员 