ccna考試題庫

1、QUESTION 37What are two characteristics of RIPv2? (Choose two.)A. classful routing protocolB. variable-length subnet 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：采用廣播地址更新，錯誤 D：手動路由匯總，正確 E: 使用 sp

2、f 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-SXE. 1000BASE-ZXAnswer: CEExplanation/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 things will a ro

3、uter do when running a distance vector routing protocol? (Choose two.)A. Send periodic updates regardless of topology changes.B. Send entire routing table to all routers in the routing domain.C. Use the shortest-path algorithmto thedetermine best path.D. Update the routing table based on updates fro

4、m their neighbors.E. Maintain the topology of the entire network in its database.Answer: ADExplanation/Reference: 考點：考查距離矢量路由協(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(hù)整個網(wǎng)絡(luò)的拓?fù)?。錯誤Which commands hows if an access list is assigned to an interface?A. show ip in

5、terface interface access-listsB. show ip access-lists interface interfaceC. show ip interface interfaceD. show ip access-lists interface Answer: CExplanation/Reference:QUESTION 42Refer to the exhibit. Which rule does the DHCP server use when there is anIP address conflictA. The address is removed fr

6、om the pool until the conflict is resolved.B. The address remains in the pool until the conflict is resolved.C. Only the IP detected by Gratuitous ARP is removed from the pool.D. Only the IP detected by Ping is removed from the pool.E. The IP will be shown, even after the conflict is resolved.Answer

7、: 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:地址保留直到?jīng)_突解決，錯誤C/D：答案片面。 E：當(dāng)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 runssetupfrom a privileged prompt?A. Setup is ad

8、ditive 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 viable when no configuration e

9、xists on the router. Answer: AExplanation/Reference:0 不保存進(jìn)入 IOS命令配置模式1 不保存返回設(shè)置模式2 保存退出 A：設(shè)置和改動被保存到配置腳本 B：為有效地重新開始配置， 如果路由器是第一次啟動 的配置。C：如果配置了密碼，設(shè)置不會運行D：設(shè)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 the default Ethernet VLA

10、N.B. CDPa dvertisements are only sent on VLAN1 002.C. By default, the management VLAN is VLAN 1005.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：考查 vlan 知識點。A：缺省都存在 vlan1 ，端口都屬于 vlan1

11、 ，正確 B：CDP信息只發(fā)送到 vlan1002 ，錯誤，vlan1002 是fddi 網(wǎng)絡(luò)的vlan 號。C：缺省情況交換機 IP配置在vlan1005 ，錯誤， vlan1005trnet 網(wǎng)絡(luò)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 們都是被保留的特殊 vlan 。QUESTION 56沒 有理解什么意思Refer to the exhibit. What does the (*) represent in the output?A. Packet is destined for a local interface t

12、o 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，源為已經(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

13、are three advantages of VLANs? (Choose three.)A. VLANse stablish broadcast domains in switched networks.B. VLANs utilize packet filtering to enhance network security.C. VLANs provide a method of conserving IP addresses in large networks.D. VLANs provide a low-latency internetworking alternative to r

14、outed networks .E. VLANs allow access to network services based on department, not physical location .F. VLANs can greatly simplify adding, moving, or changing hosts on the network.Answer: AEFExplanation/Reference:A：VLAN在交換網(wǎng)絡(luò)中建立廣播域，正確 B：利用VLAN的數(shù)據(jù)包過濾，增強網(wǎng)絡(luò)的安全性。 錯誤， 沒有這個特性。C：提供了在大型網(wǎng)絡(luò)中的保護(hù) IP 地址的方法。錯誤D：提

15、供低延遲互聯(lián)網(wǎng)絡(luò)替代路由網(wǎng)絡(luò)。錯誤E：vlan 允許基于邏輯劃分的網(wǎng)絡(luò)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(luò)上的主 機。正確。QUESTION 61 An administrator would like to configure a switch over a virtual terminal connection from locations outsideof the local LAN. Which of the following are required in order for the switch to be configured from

16、a remote location? (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 port must be conne

17、cted to the Ethernet LAN.E. The switch managementV LANm ust be created and have a membership of at least one switch port.F. The switch must be fully configured as an SNMP agent.Answer: AC Explanation/Reference: 要想遠(yuǎn)程管理 VLAN，1、交換機配置 IP ，2、路由可達(dá)QUESTION 65Which router IOS commands can be used to trouble

18、shoot LAN connectivity problems? (Choose three.)A. pingB. tracertC. ipconfigD. show ip routeE. winipcfgF. show interfacesAnswer: 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 size of collision domains.B

19、. They allow logical grouping of users by function. 允許用戶從邏輯上進(jìn)行分組C. They can enhance network security.D. They increase the size of broadcast domains while decreasing the number of collision domains.E. They increase the number of broadcast domains while decreasing the size of the broadcast domains.F.

20、They simplify switch administration.Answer: BCE Explanation/Reference: 考查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(luò)安全，正確。不同 vlan 不能直接通信。 D：當(dāng)減少沖突域時增加廣播域的大小。錯誤 E：減少廣播域的大小時增加了廣播域個數(shù)。正確。F: 簡化交換機管理。答非所問。QUESTION 71Which characteristics are representative of a link-state routing protocol? (Choose three.)A. p

21、rovides common view of entire topologyB. exchanges routing tables with neighborsC. calculates shortest pathD. utilizes event-triggered updatesE. utilizes frequent periodic updatesAnswer: ACDExplanation/Reference: 鏈路狀態(tài)路由協(xié)議有協(xié)議特點？A: 提供查看拓?fù)涞拿睿?正確。show ip ospf database B：鄰居之間交換 路由信息 ，錯誤。 交換 LSA C：計算最短路徑

22、，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 the graphic above to determine which of the following are correct .(Choose two.)A. Router John uses a link-state routingprotocol.B. Router John will receive routing updates on the Serial0/0 interface.C. Router John will re

23、ceive routing updates on the Serial0/1 interface.D. Router John will send routing updates out the Serial0/0 interface.E. Router John will send routing updates out theFastEthernet0/0 interface.F. Router John will send routing updates out the Serial0/1 interface.Answer: BDExplanation/Reference: 由圖中幾處畫

24、紅線的地方可知只有 s0/0 發(fā)送和接受 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 and a maximum of 50 host addressesper subnet.Working with only one Class B address, which of the following subnet

25、 masks will support an appropriate addressing scheme ? (Choose two.)A. BEExplanation/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-state protocol use to build and maintain its topologicald

26、atabase? (Choose two.)A. hello packetsB. SAP messages sent by other routersC. LSAs from other routersD. beacons 信息received on point-to-point linksE. routing tables received from other link-state routersF. TTL packets from designated routersAnswer: ACExplanation/Reference: 鏈路狀態(tài)路由協(xié)議如何維護(hù)拓?fù)鋽?shù)據(jù)庫？A：hello 包

27、用于維護(hù)鄰居關(guān)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接受 TTL包，錯誤，答非所問。 QUESTION 80Which statements describe the routing protocol OSPF? (Choose three.)A. It supports VLSM.B. It is used to route between autonomous systems.C. It confines network instability

28、 to one area of the network.D. It increases routing overhead on the network.E. It allows extensive control of routing updates .F. It is simpler to configure than RIP v2. Answer: ACEExplanation/Reference: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(luò)的范圍， 正確。 通過劃分區(qū)域?qū)?現(xiàn)。D：增加了網(wǎng)絡(luò)的開銷，錯誤。 E：允許路由更新控制，正確。F：比

29、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 avoidanceE. load balancingAnswer: ACDExplanation/Reference:流控制有哪些？A：緩存B：直通C：窗口機制D：擁塞避免E：負(fù)載均衡。What can be determined from the line of show ip route output shown in t

30、he exhibit? (Choose two.)注意R =rip 管理距離修改Rout ripDistance 10A. The next routing update can be expected in 35 seconds.B. The IP address is configured on S0/1.C. The IP address is configured on S0/1.D. This route is using the default administrative distance.E. The network is two hops away from this rou

31、ter. Answer: DEExplanation/Reference:考點：考查 RIP的路由條目。通過 RIP學(xué)習(xí)到一條到達(dá) 的路由，下一跳是，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 30 B：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 120 E：正確。QUESTION 93Refer to the exhibit. From RouterA, a network administrator is able to ping the serial interface of RouterB

32、 but unable to ping any of the subnets attached toRouterB. Based on the partial outputs in the exhibit, whatcould be the problem?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

33、 protocol has summarized on the classful boundary.E. EIGRP has been configured with aninvalidautonomous system number.Answer: DQUESTION 97For what two purposes does the Ethernet protocol use physical addresses? (Choose two.)A. to uniquely identify devices at Layer 2B. to allow communication with dev

34、ices on a different networkC. to differentiate a Layer 2 frame from a Layer3 packetD. to establish a priority system to determine which 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 addre

35、ss is unknownAnswer: AEExplanation/Reference: 考點：考查 mac地址的作用。A：在二層唯一確定一臺設(shè)備，正確B：是設(shè)備在不同的網(wǎng)絡(luò)中通信， 錯誤， 不同網(wǎng)絡(luò)通信 需要通過 IP 地址確定。C：區(qū)別二層和三層幀，錯誤。 D：確定設(shè)備的優(yōu)先級，錯誤。沒有這個功能。E：是同一網(wǎng)絡(luò)的不同設(shè)備可以通信，正確 F：當(dāng)不知道遠(yuǎn)程設(shè)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 2 encapsulation information is changed

36、from what it waswhen it entered the device. For what two reasons can 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 todigital.D. The source and destination hosts are in thesame subnet.E

37、. The source and destination MACa ddresses have changed.Answer: BEExplanation/Reference: 考點：數(shù)據(jù)包轉(zhuǎn)發(fā)過程。當(dāng)數(shù)據(jù)包離開三層設(shè)備時， 二層封裝哪些信息改變了。A：從10M網(wǎng)絡(luò)到 100M網(wǎng)絡(luò)，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 HDC變L 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 trueregarding

38、 EIGRP?(Choose 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. EIGRPs upports VLSM, route summarization, and routing update authentication.C. EIGRPe xchanges full routing table information with neighboring routers with every update.D.

39、 If the feasible successor has a higher advertised distance than the successor route, it becomes the primary route.E. A query process is used to discover a replacement for a failed route if a feasible successor is not identified from the current routing information. Answer: BEExplanation/Reference:

40、A：被動路由在路由進(jìn)程中由 dual 計算，錯誤。 B：至此 VLSM，路由匯總，認(rèn)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(jìn)程去發(fā)現(xiàn)替代失效的 路由信息，正確。What is an appropriate use of a default route?A. to provide routing to a local web serverB. to provide routing from an ISP to a stub networkC. to provi

41、de routing that will override the configured dynamic routing protocolD. to provide routing to a destination that is not specified in the routing table and which is outside the local networkAnswer: DExplanation/Reference: 考點：考查缺省路由的特點A：提供路由到本地 web服務(wù)器，錯誤 B：提供從 ISP到末節(jié)網(wǎng)絡(luò)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

42、配原則，缺省路由最后才匹配。D：正確QUESTION 103Refer to the exhibit. A junior network engineer has prepared the exhibited configuration file.What twostatements are true of the planned configuration for interface fa0/1? (Choose two.)A. The two FastEthernet interfaces will requireNATc onfigured on two outside serial i

43、nterfaces.B. Address translation on fa0/1 is not required for DMZ Devices to access the Internet.C. The fa0/1 IP address overlaps with the space used by s0/0.D. The fa0/1 IP address is invalid for the IPsubnet on which it resides.E. Internet hosts may not initiate connections to DMZ Devices through

44、the configuration that is shown.Answer: BEExplanation/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 switches are connected to the conference area of the corporate headquarters network . The switches provide two to three jacks per conf

45、erence room to host laptop connections for employees who visit the headquarters office. When large groups of employees come from other locations, the network administrator often finds that hubs have been connected to wall jacks in the conference area although the ports on the access layer switches w

46、ere not intended to support multiple workstations.What action could the network administrator take to prevent access by multiple laptops through a singleswitch port and still leave the switch functional for its intended use?A. Configure static entries in the switch MAC address table to include the r

47、ange of addresses used by visiting employees.B. Configure an ACL to allow only a single MAC address to connect to the switch at one time.C. Use the mac-address-table 1 global configuration command to limit each port to one source MAC address.D. Implement Port Security on all interfaces and use the p

48、ort-security maximum1 commandt o limit port access to a single MAC address.E. Implement Port Security on all interfaces and use the port-security mac-address sticky command to limit access to a single MAC address.F. Implement Port Security at global configuration mode and use the port-security maxim

49、um 1 commandto allow each switch only one attached hub.Answer: DExplanation/Reference: 考點：考查交換機端口安全。題目想實現(xiàn)限制一個端 口只接入一臺設(shè)備。A：配置靜態(tài) mac地址表。錯誤。無法達(dá)到限制效果。 B：配置 ACL允許同一個時刻僅一個 mac地址連接到交換 機。錯誤。C：在全局配置模式使用 mac-address-table 命令限制 每個端口一個源 mac地址。錯誤，無法實現(xiàn)。D： 在所有端口使用 port security 和 maximum1 限制一個端口允許一個 mac地址 ，正確。E：部署

50、 port security 和 port-security mac-address sticky 命令，錯誤，無法實現(xiàn)。F：在所有端口使用 port security 和 maximum1 限制一 個端口允許一個 hub，錯誤，一個 hub下面可以接多臺 PC。Running both IPv4 and IPv6 on a router simultaneously is known as what?A. 4to6 routingB. 6to4 routingC. binary routingD. dual-stack routingE. NextGen routingAnswer: DExplanation/Reference: 考點：考查 IPv4 和IPv6共存。同時使用 IPv