ccna考試題庫

1、WORD格式QUESTION 37What are twocharacteristicsof RIPv2? (Choosetwo.)A. classful routingprotocolB. variable-lengthsubnet masksC. broadcast addressingD. manual route summarizationE. uses SPF algorithm tocompute pathAnswer: BDExplanation/Reference:A：有類路由協(xié)議，錯誤B：可變長度子網(wǎng)掩碼，正確C：采用播送地址更新，錯誤D：手動路由匯總，正確E: 使用 spf

2、 算法計算路徑，錯誤。QUESTION 38Which two Ethernet fiber-optic modes support distances of greater than 550 meters? A.1000BASE-CXB. 100BASE-FXC. 1000BASE-LXD. 1000BASE-SX專業(yè)資料整理WORD格式E. 1000BASE-ZX Answer: CE Explanation/Reference: A：最長距離 25米B：最長距離 100米C：最長距離 3000米D：最長距離 550米E：最長距離 70 千米QUESTION 39What two thin

3、gs will a router do when running adistance vectorrouting protocol? (Choose two.)A. Send periodicupdatesregardless oftopologychanges.B. Send entire routingtableto allrouters intherouting domain.C. Use theshortest-path algorithmto thedetermine best path.D. Update the routingtablebased on updates fromt

4、heir neighbors.E. Maintainthetopologyofthe entirenetworkinits database.Answer: AD專業(yè)資料整理WORD格式Explanation/Reference:考點：考察距離矢量路由協(xié)議特性A：周期性更新，正確B：發(fā)送整個路由表到整個路由域，錯誤，只發(fā)送給鄰居C：使用 SPF算法，錯誤D：依靠鄰居發(fā)送更新來更新路由表，正確E：在數(shù)據(jù)庫中維護整個網(wǎng)絡的拓撲。錯誤Which commandshows if an access list is assigned to an interface?A. show ip interfac

5、e interface access-listsB. show ip access-lists interface interfaceC. show ip interface interfaceD. show ip access-lists interfaceAnswer: CExplanation/Reference:QUESTION 42Refer to the exhibit. Which rule does the DHCPserveruse when thereisan IP address conflict?專業(yè)資料整理WORD格式A. The address is removed

6、 from the pool untilconflict isresolved.B. The address remains in the pool until theconflict is resolved.C. Only the IPdetectedby Gratuitous ARP isremoved from the pool.the專業(yè)資料整理WORD格式D. Only the IP detected by Ping is removed from the pool.E. The IP will be shown, even after the conflictis resolved

7、.Answer: AExplanation/Reference:show ip dhcp conflict 命令可以查看哪些 ip 地址在使用上有沖突。有沖突的地址不再分配出去。A：地址被刪除直到?jīng)_突解決，正確B: 地址保存直到?jīng)_突解決，錯誤C/D：答案片面。E：當沖突解決后，地址會被顯示。錯誤。QUESTION 44Refer to the exhibit. If number 2 is selected from the setup script, what happens when the user runs專業(yè)資料整理WORD格式setupfrom a privileged promp

8、t?A. Setup is additive and any changes will be added to the config script.B. Setup effectively starts the configuration over as if the router was booted for the first time.C. Setup will not run if an enable secret password exists on the router.D. Setup will not run, because it is only viablewhen no

9、configuration exists on the router.Answer: AExplanation/Reference:0 不保存進入 IOS命令配置模式1 不保存返回設置模式2 保存退出A：設置和改動被保存到配置腳本B：為有效地重新開場配置，如果路由器是第一次啟動的配置。專業(yè)資料整理WORD格式C：如果配置了密碼，設置不會運行D：設置不可用，因為它只能在沒有配置存在時才有效 QUESTION 49Which two statements describe the Cisco implementation of VLANs? (Choose two.) A. VLAN 1 is t

10、he default Ethernet VLAN.B. CDPadvertisements are only sent on VLAN1002. C. By default, the managementVLAN is VLAN1005. D. By default, the switch IP address is in VLAN 1005.E. VLAN 1002 through 1005 are automatically created and cannot be deleted.Answer: AEExplanation/Reference:考點：考察 vlan 知識點。A：缺省都存

11、在 vlan1 ，端口都屬于 vlan1 ，正確B：CDP信息只發(fā)送到 vlan1002 ，錯誤，vlan1002 是fddi網(wǎng)絡的 vlan 號。C：缺省情況交換機 IP 配置在 vlan1005 ，錯誤， vlan1005trnet 網(wǎng)絡的 vlan 號。缺省在 vlan1 里面。D：vlan1002-1005 自動生成并不能被刪除，正確，他們都是被保存的特殊 vlan 。專業(yè)資料整理WORD格式QUESTION 56沒有理解什么意思Refer to the exhibit. What does the (*) represent in the output?A. Packet is de

12、stined for a local interface to the router.B. Packet was translated, but no response was received from the distant device.C. Packet was not translated, because no additional ports are available.D. Packet was translated and fast switched to the destination.Answer: DExplanation/Reference:由圖中提示信息可以看出，源

13、為 10.10.0.2 已經(jīng)有個一個轉(zhuǎn)換，所以后續(xù)的數(shù)據(jù)包快速轉(zhuǎn)發(fā)。What are three advantages of VLANs? (Choosethree.)A. VLANsestablishbroadcastdomains in switchednetworks.專業(yè)資料整理WORD格式B. VLANs utilizepacket filtering to enhancenetwork security.C. VLANs provide a method of conserving IPaddresses in large networks.D. VLANs provide alo

14、w-latencyinternetworkingalternative to routed networks.E. VLANs allow access tonetwork servicesbasedon department,notphysical location.F. VLANscan greatlysimplifyadding,moving, orchanging hosts on the network.Answer: AEFExplanation/Reference:A：VLAN在交換網(wǎng)絡中建立播送域，正確B：利用 VLAN的數(shù)據(jù)包過濾，增強網(wǎng)絡的平安性。錯誤，沒有這個特性。C：提

15、供了在大型網(wǎng)絡中的保護IP 地址的方法。錯誤D：提供低延遲互聯(lián)網(wǎng)絡替代路由網(wǎng)絡。錯誤E：vlan 允許基于邏輯劃分的網(wǎng)絡訪問，不是物理位置。正確。F：VLAN可以大大簡化添加，移動或更改網(wǎng)絡上的主機。正確。QUESTION 61專業(yè)資料整理WORD格式An administratorwould liketo configurea switchover a virtualterminalconnectionfrom locationsoutsideof the local LAN. Which of the following arerequiredin order forthe switcht

16、o be configuredfrom a remotelocation? (Choose two.)A. The switch must be configured with an IP address, subnet mask, and default gateway.B. The switch must be connected to a router over a VLAN trunk.C. The switch must be reachable through a port connected to its management VLAN.D. The switch console

17、 port must be connected to the Ethernet LAN.E. The switch managementVLANmust be created and have a membership of at least one switch port.F. The switch must be fully configured as an SNMP agent.Answer: ACExplanation/Reference:要想遠程管理 VLAN，1、交換機配置 IP ，2、路由可達專業(yè)資料整理WORD格式QUESTION 65Which router IOS comm

18、ands can be used to troubleshoot LAN connectivity problems? (Choose three.)A. pingB. tracertC. ipconfigD. show ip routeE. winipcfgF. show interfaces Answer: ADFExplanation/Reference:A：測試連通性D：查看是否有路由F：查看接口是否可用QUESTION 64Which of the following are benefits of VLANs? (Choose three.)A. They increase the

19、 size of collision domains. B. They allow logical grouping of users by function. 允許用戶從邏輯上進展分組專業(yè)資料整理WORD格式C. They canenhance network security.D. They increase the size of broadcast domainswhile decreasing the number of collision domains. E. They increase the number of broadcast domainswhile decreasin

20、g the size of the broadcast domains.F. They simplify switch administration.Answer: BCEExplanation/Reference:考察 VLAN的特點A：增加沖突域的大小，錯誤B：允許邏輯劃分網(wǎng)段，正確C：增強網(wǎng)絡平安，正確。不同vlan 不能直接通信。D：當減少沖突域時增加播送域的大小。錯誤E：減少播送域的大小時增加了播送域個數(shù)。正確。F: 簡化交換機管理。答非所問。QUESTION 71Which characteristics are representative of a link-state rou

21、ting protocol? (Choose three.)A. provides common view of entire topologyB. exchanges routing tables with neighborsC. calculates shortest path專業(yè)資料整理WORD格式D. utilizes E. utilizesevent-triggered updates frequent periodic updates專業(yè)資料整理WORD格式Answer: ACDExplanation/Reference:鏈路狀態(tài)路由協(xié)議有協(xié)議特點？A: 提供查看拓撲的命令，正確。

22、show ip ospf database B：鄰居之間交換路由信息，錯誤。交換 LSAC：計算最短路徑，正確。D：利用觸發(fā)更新，正確E：利用周期更新，錯誤。QUESTION 73Use the output from the router shown in thegraphicabove to determine which of the followingare correct .(Choose two.)專業(yè)資料整理WORD格式A. Router John uses a link-state routing protocol.B. Router John willreceiverouti

23、ngupdates on theSerial0/0 interface.C. Router John willreceiveroutingupdates on theSerial0/1 interface.D. Router John willsend routingupdatesouttheSerial0/0 interface.E. Router John willsend routingupdatesoutthe專業(yè)資料整理WORD格式FastEthernet0/0 interface.F. Router John willsend routingupdates out theSeria

24、l0/1 interface.Answer: BDExplanation/Reference:由圖中幾處畫紅線的地方可知只有s0/0發(fā)送和承受路由信息。QUESTION 742的次方問題A national retail chain needs to design an IP addressing schemeto support a nationwide network. Thecompany needs a minimum of 300 sub-networks anda maximum of 50 host addressesper subnet.Working with only on

25、e Class B address, which ofthe following subnet masks will supportanappropriateaddressing scheme ? (Choose two.)A. 255.255.255.0B. 255.255.255.128C. 255.255.252.0D. 255.255.255.224E. 255.255.255.192專業(yè)資料整理WORD格式F. 255.255.248.0 Answer: BE Explanation/Reference:需要至少 300個子網(wǎng)，每個子網(wǎng)至少 50臺主機。使用一個B類地址來劃分。A：最

26、多有 256個子網(wǎng)，錯誤C：只有 64個子網(wǎng)D：每個子網(wǎng)只有 30個可用 IPF：只有 32 個子網(wǎng)QUESTION 79What information does a router running alink-stateprotocoluse to buildand maintainitstopologicaldatabase? (Choose two.)A. hello packetsB. SAP messages sent by other routersC. LSAs from other routersD. beacons 信息 receivedon point-to-pointli

27、nksE. routingtablesreceivedfrom other link-stateroutersF. TTL packets fromdesignated routersAnswer: AC專業(yè)資料整理WORD格式Explanation/Reference:鏈路狀態(tài)路由協(xié)議如何維護拓撲數(shù)據(jù)庫？A：hello 包用于維護鄰居關系，正確。B：錯誤，沒有這個概念。C：通過其他路由器的 LSA，正確。D：從點到點鏈路接收，錯誤。答案片面E：從其他路由器接收路由表，錯誤。相互間不直接發(fā)送路由表。F：從 DR承受 TTL包，錯誤，答非所問。QUESTION 80Which statement

28、s describe the routing protocol OSPF? (Choose three.)A. It supports VLSM.B. Itis used to route between autonomous systems .C. Itconfinesnetwork instabilityto one area ofthe network.D. Itincreasesroutingoverhead on the network.E. It allows extensive control of routingupdates .F. It is simpler to conf

29、igure than RIP v2.Answer: ACEExplanation/Reference:專業(yè)資料整理WORD格式A：支持 VLSM，正確B：在 AS之間使用，錯誤。在 AS內(nèi)部使用C：限制了不穩(wěn)定網(wǎng)絡的X圍，正確。通過劃分區(qū)域?qū)崿F(xiàn)。D：增加了網(wǎng)絡的開銷，錯誤。E：允許路由更新控制，正確。F：比 RIPv2 更容易配置，錯誤，答非所問。Which of the following are types of flow control ? (Choose three.)A. bufferingB. cut-throughC. windowingD. congestion avoidan

30、ceE. load balancing Answer: ACD Explanation/Reference:流控制有哪些？A：緩存B：直通C：窗口機制D：擁塞防止E：負載均衡。專業(yè)資料整理WORD格式What can be determined from the line of show iprouteoutputshown in the exhibit?(Choose two.)專業(yè)資料整理WORD格式注意 R =rip Rout rip Distance 10管理距離修改專業(yè)資料整理WORD格式A. The next routing update can be expected in 35

31、 seconds.B. The IP address 10.10.10.6 is configured on S0/1.C. The IP address 10.10.10.8 is configured on S0/1.D. This route is using the default administrative distance.E. The 10.10.10.8 network is two hops away fromthis router.Answer: DEExplanation/Reference:專業(yè)資料整理WORD格式考點：考察 RIP的路由條目。通過 RIP學習到一條到

32、達10.10.10.8 的路由，下一跳是 10.10.10.6 ，出接口是 s/1 。A：錯誤。 rip 更新周期為 30s，正常計時器不會超過 30B：錯誤，這個 ip 是對端接口 ipC：錯誤。 s0/1 的ip 無法得知D：正確， rip 缺省的管理距離是 120E：正確。QUESTION 93Refer to the exhibit. From RouterA, a network administrator is able to ping the serial interface of RouterBbut unable to ping any of the subnets atta

33、ched to RouterB. Based on the partial outputs in the exhibit, whatcould be the problem?專業(yè)資料整理WORD格式A. EIGRP does not support VLSM.B. The EIGRP network statements areincorrectlyconfigured.C. The IP addressing on the serial interface of RouterA is incorrect.D. The routing protocol has summarized on th

34、e classful boundary.E. EIGRP has been configured with aninvalid專業(yè)資料整理WORD格式autonomous system number.Answer: DQUESTION 97For what two purposes does the Ethernet protocol use physical addresses? (Choose two.)A. to uniquely identify devices at Layer 2 B. to allow communication with devices on a differe

35、nt networkC. to differentiate a Layer 2 frame from a Layer 3 packetD. to establish a priority system to determinewhich device gets to transmit firstE. to allow communication between different devices on the same networkF. to allow detection of a remote device when its physical address is unknown Ans

36、wer: AEExplanation/Reference:考點：考察 mac地址的作用。A：在二層唯一確定一臺設備，正確B：是設備在不同的網(wǎng)絡中通信，錯誤，不同網(wǎng)絡通信需要通過 IP 地址確定。專業(yè)資料整理WORD格式C：區(qū)別二層和三層幀，錯誤。D：確定設備的優(yōu)先級，錯誤。沒有這個功能。E：是同一網(wǎng)絡的不同設備可以通信，正確F：當不知道遠程設備的物理地址時可以查詢，錯誤。不能跨網(wǎng)段。QUESTION 98As a frame leaves a Layer 3 device, the Layer 2encapsulation information ischanged from what itw

37、aswhen it entered the device.For what two reasonscan this happen? (Choose two.)A. The data is moving from 10BASE-TX to 100BASE-TX.B. The WAN encapsulation type has changed. C. The data format has changed from analog to digital.D. The source and destination hosts are in the same subnet.E. The source

38、and destinationMACaddresses havechanged.Answer: BEExplanation/Reference:專業(yè)資料整理WORD格式考點：數(shù)據(jù)包轉(zhuǎn)發(fā)過程。當數(shù)據(jù)包離開三層設備時，二層封裝哪些信息改變了。A：從 10M網(wǎng)絡到 100M網(wǎng)絡，錯誤。帶寬改變不會改變數(shù)據(jù)包封裝。B：廣域網(wǎng)封裝改變，正確。如從HDCL變成 PPPC：數(shù)據(jù)格式從模擬型號變成數(shù)據(jù)信號，錯誤，物理層的信號方式變化不會影響二層數(shù)據(jù)格式。D：錯誤。E：原蜜 MAC改變，正確。QUESTION 99Which two statements are trueregardingEIGRP?(Choo

39、se two.)A. Passive routes簡單的說就是：能被路由器路由的協(xié)議。例如： IP、IPX 、APPLE TALK 等 are in the process of being calculated by DUAL.B. EIGRPsupports VLSM, route summarization, and routing update authentication.C. EIGRPexchanges full routing table information with neighboring routers with every update.D. If the feasi

40、ble successor has a higheradvertised distance than the successor route, it becomes the專業(yè)資料整理WORD格式primary route.E. A query process is used to discover a replacement for a failed route if a feasible successor is notidentifiedfrom the currentroutinginformation.Answer: BEExplanation/Reference:A：被動路由在路由

41、進程中由dual 計算，錯誤。B：至此 VLSM，路由匯總，認證，正確C：每次更新都發(fā)送全部的路由信息，錯誤，增量更新。D：如果可行后繼路由器有一個比后繼路由器高的通告距離，它會成為主路由條目，錯誤。E：如果不存在FS，使用查詢進程去發(fā)現(xiàn)替代失效的路由信息，正確。What is anappropriateuse of a default route?A. to providerouting to a local web serverB. to provide routingfrom an ISP to a stub networkC. to provide routing that willo

42、verridetheconfigured dynamic routing protocolD. to provideroutingto a destinationthatis notspecifiedin the routing table and which isoutside the local專業(yè)資料整理WORD格式networkAnswer: DExplanation/Reference:考點：考察缺省路由的特點A：提供路由到本地 web效勞器，錯誤B：提供從 ISP到末節(jié)網(wǎng)絡的路由，錯誤C：提供優(yōu)先于動態(tài)路由協(xié)議的路由，錯誤。根據(jù)最長匹配原那么，缺省路由最后才匹配。D：正確QUEST

43、ION 103Refer to the exhibit.A junior network engineerhas preparedthe exhibited configuration file.What twostatementsare trueof the planned configurationfor interface fa0/1? (Choose two.)專業(yè)資料整理WORD格式A. The two FastEthernet interfaces will requireNATconfiguredon two outsideserialinterfaces.B. Address

44、translation on fa0/1 is not requiredfor DMZ Devices to access the Internet.C. The fa0/1 IP addressoverlapswith the spaceused by s0/0.D. The fa0/1 IP address isinvalidfor the IPsubnet on which it resides.E. Internethosts maynot initiateconnectionstoDMZ Devices through the configuration that isshown.A

45、nswer: BE專業(yè)資料整理WORD格式Explanation/Reference:DMZ使用公網(wǎng)地址，不需要做 NAT，圖中 ACL第二條錯將 DMZ做了 NAT，因此造成不能訪問QUESTION 111Refer to the exhibit. Some 2950 series switchesare connected to the conference area of thecorporateheadquarters network . The switchesprovidetwo tothree jacks per conference room to host laptopcon

46、nections foremployees who visit theheadquarters office. When large groups ofemployees come fromotherlocations,thenetwork administratoroftenfindsthathubs have been connected to walljacksin theconferenceareaalthough the portson theaccesslayer switches were notintendedto supportmultipleworkstations.Wha

47、t actioncould thenetwork administratortaketo preventaccess by multiple laptops through asingle專業(yè)資料整理WORD格式switch port and still leave the switch functional for its intended use?A. Configure static entries in the switch MAC address table to include the range of addresses used byvisiting employees.B.

48、Configure an ACL to allow only a single MACaddress to connect to the switch at one time.C. Use the mac-address-table 1 globalconfiguration command to limit each port to onesource MACaddress.專業(yè)資料整理WORD格式D. Implement Port Securityon allinterfacesanduse the port-securitymaximum1 commandto limitportacce

49、ss to a single MAC address.E. Implement Port Securityon allinterfacesanduse the port-securitymac-address stickycommandtolimit access to a single MAC address. F. Implement Port Security at global configuration mode and use the port-security maximum 1 commandto allow each switch only one attached hub.Answer: DExplanation