思科认证考试(CCNA)考试模拟题集锦(1_71题)与答案.doc

1、.思科认证考试（）考试模拟题集锦(1-71题) 及答案19 及答案1. OxNx During a TFTP transfer using Cisco Routers what is the numeric value, in decimal, of the destination port field of the User Datagram Protocol (UDP) header? a) 96b) 47c) a random number above 1024d) 69e) none of the above2. CxNx What is the standard encapsulat

2、ion method used by Cisco routers for the Internet Protocol (IP) on it s Ethernet interfaces?a) SNAP b) ARPAc) NOVELL-ETHER d) DARPAe) Ethernet_802.33. CxNx What will be the correct command on a Cisco router to set the IP address of an interface assuming you are at the "router(config-if)#"

3、prompt?a) ip address b) ip address c) ip d) ip e) none of the above4. CxNx Which commands will display the IP addresses of all interfaces on a Cisco Router? (Choose all that apply)a) show ip routeb) show ip addressc) show ip interfaced) show in

4、terfacee) display ip addresses5. CxNx Which of the following commands will display the contents of the ARP cache of your Cisco router? a) show ip arp cacheb) show ip route c) show ip arp d) show arpe) there is no way to display the ARP cache6. CxNx Reverse Address Resolution Protocol (RARP) is the p

5、rocess:a) Where an IP host resolves its IP address by broadcasting its MAC address to the network and a BOOTPserver assigns it an IP address.b) Where an IP host resolves its MAC address by broadcasting to the local network its IP address.c) Where an IP host tries to resolve the MAC address of a dest

6、ination by sending a network broadcast. Thedestination responds to the broadcast with its MAC address.d) Where an IP host resolves a destination IP address by sending a broadcast on the local network and thedestinationhost responds with its IP address.e)There is no such process.7. OxNx Which of the

7、following applications requires the connection-oriented layer four protocol, TCP? (Choose all that apply).a) Telnetb) FTPc) TFTPd) SNMPe) none of the above8. RxNx Which of the following are link state Routing Protocols. (Choose all that apply.)a) IPb) OSPFc) RIPd) EIGRPe) IS-IS9. CxNx Of the followi

8、ng commands, identify the correct one for clearing the IP arp table in memory of the router.a) clear ip arp-cacheb) clear ip arp-tablec) clear arp-cached) clear arp-tablee) clear arp-ram10. CxNx Which of the following explains the correct definition of administrative distance as it pertains to Cisco

9、 s IOS?a) The process by which routers select an administrator for an autonomous system. b) The process where a router will select the best path to a destination network.c) The process where a router will distance itself from other routers due to its lack of administrativeexperience.d) The process w

10、here a router will prioritize routing protocols so that in the event two routing protocolshave conflicting next hop addresses, the routing protocol with the lowest administrative distance will take priority.e) The process where a router will prioritize routing protocols so that in the event two rout

11、ing protocolshave conflictingnexthop addresses,the routingprotocolwiththe highestadministrativedistancewilltakepriority.11. ExNx Collisions occur whena) multiple packets are placed on a serial linkb) multiple stations listen for traffic and transmit at the same timec) when multiple tokens are on a r

12、ing simultaneouslyd) beaconing process takes place12. RINx How many subnets are possible with a Class C address and a subnet mask of 52? a) 32b) 30c) 60d) 62e) 413. RxNx What commands will list all protocols that are currently being routed? (Choose all that apply.) a) show ip protocolb)

13、 show protocolc) show rund) show start.e) All of the above14. xxNx Which of the following are true of access lists?a) Access list should have at least one permit statement.b) The last configured line should always be a permit statement.c) Every access-list will implicitly deny all traffic.d) Access-

14、lists are processed top down.e) All of the above.15. xxNxIfthe access-groupcommandis configuredon an interfaceand thereisno access-listcreatedwhichof the following is most correct?a) An error message will appear.b) The command will be executed and deny all traffic out.c) The command will be executed

15、 and permit all traffic out.d) The command will be executed and permit all traffic in and out.e) The command will be executed and deny all traffic in and out.16. xxNx What is the result of the command?" access-list 101 permit tcp any 55 established"a) telnet sessions wi

16、ll be permitted regardless of the source addressb) telnet sessions will be denied regardless of the source addressc) telnet sessions will be denied if initiated from any address other than networkd) telnet sessions will be permitted to the network onlye) telnet sessions will be

17、 denied to the network only17. xxNx Which is generally true of the location of access-lists? (Choose all that apply.)a) Standard lists will most likely be placed close to the destination.b) Standard lists will most likely be placed close to the source.c) Extended lists will most likely be

18、 placed close to the destination.d) Extended lists will most likely be placed close to the source.e) It does not matter.18. RxNx Which of the following is most correct?a) IP is to TCP. as IPX is to SPX.b) RTMP is to Appletalk as IP RIP is to IP.c) NLSP is to IPX as OSPF is to IP.d) a is true.e) b is

19、 true.f) a & b are true.g) c is true.h) b & c are true.i) a, b and c are true.19. ExNx If Host A sends a packet to Host B over ethernet and Host B is not active:a) The packet will time out.b) The packet will be removed by Host A.c) The NVRAM of Host B will remove the packet.d) The packet wil

20、l "die" when it reaches the terminator.e) The packet will be removed by the token monitor.Coding Key and InformationThe first character represents the category of question.A-ATMB - Bridging.C - Cisco specificE - EthernetF - Frame relayH - HDLCI - FDDIN - ISDNO - OSI modelP-PPPR - RoutingS

21、- SwitchingT - Token ringX - X.25x - Not applicableThe second character represents protocol.A - AppletalkB - Banyan VinesD - DecnetI-IPL - Dial on DemandN - NLSPO - OSPFX-IPXx - Not ApplicableThe third character represents the certification that the question will help you prepare for.N - CCNA Exam #

22、640-407P - CCNPAdvanced Cisco Router Configuration (ACRC) Exam 640-403Cisco LAN Switch Configuration (CLSC) Exam #640-404Cisco Monitoring and Troubleshooting Dial-up Services Exam #640-405Cisco Internetworking Troubleshooting ( CIT) Exam #640-406D - CCDA & CCDPCisco Design Specialist Exam #9E0-0

23、04Cisco Internetwork Design#640-025We will reserve the fourth character for future use.As an example, when you come across a question coded "BXDx", it signifies a question that will help you gainthe CCDA or CCDP certification.CCNA试题 1-19 答案1. OxNx During a TFTP transfer using Cisco Routers

24、 what is the numeric value, in decimal, of the destination port field of the User Datagram Protocol (UDP) header?a) 96b) 47c) a random number above 1024d) 69e) none of the aboveAnswerd) 69.Here is a sampling of other port numbers and the application they are associated with. The first 8 of these pro

25、tocols are automatically forwarded through the router by using the helper-address commandTrivial File Transfer (TFTP) (port 69)Domain Name System (port 53)IEN-116 Name Server (port 42)Time service (port 37)NetBIOS Name Server (port 137)NetBIOS Datagram Server (port 138)Boot Protocol (BootP) client a

26、nd server datagrams (port 67)TACACS service (port 49)Simple Mail Transfer Protocol (25)File Transfer Protocol (21)Simple Network Management Protocol (161)2. CxNx What is the standard encapsulation method used by Cisco routers for the Internet Protocol (IP) on it s Ethernet interfaces?a) SNAPb) ARPAc

27、) NOVELL-ETHERd) DARPAe) Ethernet_802.3 Answerb) ARPASNAP is the default encapsulation for a token ring interface NOVELL-ETHER is the default encapsulation for a ipx interface.3. CxNx What will be the correct command on a Cisco router to set the IP address of an interface assuming you are at the &qu

28、ot;router(config-if)#" prompt?a) ip address b) ip address c) ip d) ip e) none of the aboveAnswera) ip address If you are not in the configuration mode, the ip address can be set by using the setup mode.Configuring inte

29、rface Ethernet0/0:Is this interface in use? yes:Configure IP on this interface? yes:IP address for this interface : Number of bits in subnet field 16: 16Class A network is , 16 subnet bits; mask is /24Take note when using the setup mode the mask is configured using the nu

30、mber of subnet bits.4. CxNx Which commands will display the IP addresses of all interfaces on a Cisco Router? (Choose all that apply)a) show ip route.b) show ip addressc) show ip interfaced) show interfacee) display ip addresses Answerc) show ip interfaced) show interfaceExamples of each of these co

31、mmands are shown below:Router_A#sh int e0/0Ethernet0/0 is up, line protocol is upHardware is AmdP2, address is0010.7b15.bd41(bia 0010.7b15.bd41)Internet address is /24MTU 1500 bytes, BW 10000 Kbit,DLY 1000 usec,rely 255/255, load 1/255Encapsulation ARPA, loopback not set,keepalive set (10

32、sec)ARP type: ARPA, ARP Timeout 04:00:00Last input never, output 00:00:06,output hang neverLast clearing of "show interface"counters neverQueueing strategy: fifoOutput queue 0/40, 0 drops;input queue 0/75,0 drops5 minute input rate 0 bits/sec,0 packets/sec5 minute output rate 0 bits/sec,0

33、packets/sec0 packets input, 0 bytes,0 no bufferReceived 0 broadcasts, 0 runts,0 giants,0 throttles, 0 input errors, 0 CRC,0 frame, 0 overrun, 0 ignored,0 abort0 input packets with dribblecondition detected127 packets output, 11802 bytes,0 underruns0 output errors, 0 collisions,2 interface resets0 ba

34、bbles, 0 late collision,0 deferred.0 lost carrier, 0 no carrier0 output buffer failures, 0 outputbuffers swapped outRouter_A#sh ip int e0/0Ethernet0/0 is up, line protocol is upInternet address is /24Broadcast address is 55Address determined bynon-volatile memoryMTU is 1500 by

35、tesHelper address is not setDirected broadcast forwarding is enabledOutgoing access list is not setInbound access list is not setProxy ARP is enabledSecurity level is defaultSplit horizon is enabledICMP redirects are always sentICMP unreachables are always sentICMP mask replies are never sentIP fast

36、 switching is enabledIP fast switching on the sameinterface is disabledIP multicast fast switching is enabledRouter Discovery is disabledIP output packet accounting is disabledIP access violation accounting isdisabledTCP/IP header compression is disabledProbe proxy name replies are disabledGateway D

37、iscovery is disabledPolicy routing is disabledNetwork address translation is disabled5. CxNx Which of the following commands will display the contents of the ARP cache of your Cisco router?a) show ip arp cacheb) show ip routec) show ip arpd) show arpe) there is no way to display the ARP cacheAnswerc

38、) show ip arp Example: Router_A#sh ip arpProtocol Address Age(min) Hardware Address Type InterfaceInternet - 0010.7b15.bd50 ARPA FastEthernet1/0Internet - 0010.7b15.bd41 ARPA Ethernet0/0.6. CxNx Reverse Address Resolution Protocol (RARP) is the process:a) Where an IP host resolves

39、 its IP address by broadcasting its MAC address to the network anda BOOTPserver assigns it an IP address.b) Where an IP host resolves its MAC address by broadcasting to the local network its IP address.c) Where an IP host tries to resolve the MAC address of a destination by sending a network broadca

40、st. Thedestina tion responds to the broadcast with its MAC address.d) Where an IP host resolves a destination IP address by sending a broadcast on the local network and thedestination host responds with its IP address.e)There is no such process.Answera) Where an IP host resolves its IP address by br

41、oadcasting its MAC address to the network and a BOOTPserver assigns it an IP address.Choice C describes Address Resolution Protocol (ARP). A host never has to resolve its own MAC address. TheMAC address is burned into the NetworkInterface card. When the host isbooted the MAC addresswill be loadedint

42、o memory.7. OxNx Which of the following applications requires the connection-oriented layer four protocol, TCP?(Choose all that apply)a) Telnetb) FTPc) TFTPd) SNMPe) none of the above Answera) Telnetb) FTPTFTP and SNMP use layer 4 UDP.8. RxNx Which of the following are link state Routing Protocols.

43、(Choose all that apply.)a) IPb) OSPF c) RIP d) EIGRPe) IS-IS Answerb) OSPFe) IS-ISA link state routing protocol advertises, to it s neighbors, the state of the link when the state of the link changes.A distance vector routing protocol advertises its routing table periodically.9. CxNx Of the followin

44、g commands, identify the correct one for clearing the IP arp table in memory of the router.a) clear ip arp-cacheb) clear ip arp-table.c) clear arp-cached) clear arp-tablee) clear arp-ram Answerc) clear arp-cacheIf you have changed an ip address or a NIC card on a host you might use this command to r

45、eset the cache.10. CxNx Which of the following explains the correct definition of administrative distance as it pertains to Cisco s IOS?a) The process by which routers select an administrator for an autonomous system.b) The process where a router will select the best path to a destination network.c)

46、 The process where a router will distance itself from other routers due to its lack of administrativeexperience.d) The process where a router will prioritize routing protocols so that in the event two routing protocolshave conflicting next hop addresses, the routing protocol with the lowest administ

47、rative distance will takepriority.e) The process where a router will prioritize routing protocols so that in the event two routing protocolshave conflicting next hop addresses, the routing protocol with the highest administrative distance will take priority.Answerd) The process where a router will p

48、rioritize routing protocols so that in the event two routing protocolshave conflicting next hop addresses, the routing protocol with the lowest administrative distance will take priority.Cisco uses administrative distances (AD) to measure the reliability of the routing protocol. The lower the (AD) t

49、he more reliable the protocol.Router_C#sh ip routeCodes: C - connected, S - static,I - IGRP, R - RIP,M - mobile, B - BGPD - EIGRP, EX - EIGRP external, O - OSPF,IA - OSPF inter areaN1 - OSPF NSSA external type 1, N2 - OSPFNSSA external type 2E1 - OSPF external type 1,E2 - OSPF external type 2,E-EGPi

50、 - IS-IS, L1 - IS-IS level-1,L2 - IS-IS level-2, * -candidate defaultU - per-user static route, o - ODRGateway of last resort is not set/24 is subnetted, 2 subnetsC is directly connected,Serial1C is directly connected,Serial0I /8 100/8576 via ,.00:00

51、:09, Serial1100/8576 via , 00:00:19,Serial0The 100 in bold is the administrativedistance for IGRP.A partial list of administrative distances is included below:Protocol ADEIGRP 90IGRP 100OSPF 110RIP 120BGP 180If a router hears a IP RIP and a IGRP update for the same network the router will

52、discard the rip information. IP RIP uses hop count as it s metric, while IGRP uses a composite metric including bandwidth and load, speed is the primary consideration.11. ExNx Collisions occur whena) multiple packets are placed on a serial linkb) multiple stations listen for traffic and transmit at

53、the same timec) when multiple tokens are on a ring simultaneouslyd) beaconing process takes placeAnswerb) multiple stations listen for traffic and transmit at the same timeCollisionsis a term thatisused in an ethernetenvironment.Ethernetcan be describedas a listenthen transmitscenario.Firsta stationwilllistenfortrafficifno trafficissensed then a transmissionwilltakeplace.If two stations transmit at the same time collisions will occur. The first station to detect the collision sends out