思科认证考试考试模拟题集锦及答案

1、思科认证考试（CCNA ）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 encaps

2、ulation method used by Cisco routers for the Internet Protocol (IP) onit s Ethernet interfaces?a) SNAPb) ARPAc) NOVELL-ETHERd) DARPAe)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 router(config-if)# prompt?a) ip addressb) ip

3、addressc) ipd) ipe) 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 interfacee) display ip addresses5. CxNx Which of the following commands will display the

4、 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 cache6. CxNx Reverse Address Resolution Protocol (RARP) is the process:a) Where an IP host resolves it s IP address by broadcasting it s MAC address to t

5、he network and a BOOTPserver assigns it an IP address.b) Where an IP host resolves it s MAC address by broadcasting to the local network it s IP address.c) Where an IP host tries to resolve the MAC address of a destination by sending a network broadcast. The destination responds to the broadcast wit

6、h it s MAC address.d) Where an IP host resolves a destination IP address by sending a broadcast on the local network and the destination host responds with it s IP address.e) There is no such process.7. OxNx Which of the following applications requires the connection-oriented layer four protocol, TC

7、P?(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 following commands, identify the correct one for clearing the IP arp table in memory of t

8、he 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 s IOS?a) The process by which routers select an administrator for an autonomous s

9、ystem.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 it s lack of administrativeexperience.d) The process where a router will prioritize routing protocols so that in the event two routing p

10、rotocols have 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 routing protocolstakehave conflicting next hop addresses, the routing protocol with t

11、he highest administrative distance will priority.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 ring simultaneouslyd) beaconing process takes place12. RINx How many sub

12、nets are possible with a Class C address and a subnet mask ofa) 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) show protocolc) show rund) show starte) All of the above14. xxNx Which of the following a

13、re 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-lists are processed top down.e) All of the above.which15. xxNx If the access-group commandi

14、s configured on an interface and there is no access-list created of 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 and permit all traffic out.d) The command will be executed and permit all traffic

15、 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 establisheda) telnet sessions will be permitted regardless of the source addressb) telnet sessions will be denied regardless of the source addressc)

16、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 denied to the network only17. xxNx Which is generally true of the location of access-lists? (Choose all that apply.)a) Standard lists will

17、 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 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 followin

18、g 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 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

19、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 will 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

20、of question.A - ATMB - BridgingC - Cisco specificE - EthernetF - Frame relayH - HDLCI - FDDIN - ISDNO - OSI modelP - PPPR - RoutingS - SwitchingT - Token ringX -x - Not applicableThe second character represents protocol.A - AppletalkB - Banyan VinesD - DecnetI - IPL - Dial on DemandN - NLSP O - OSPF

21、 X - IPX x - Not Applicable The third character represents the certification that the question will help you prepare for. N - CCNA Exam #640-407P - CCNPAdvanced Cisco Router Configuration (ACRC) Exam 640-403Cisco LAN Switch Configuration (CLSC) Exam #640-404Cisco Monitoring and Troubleshooting Dial-

22、up Services Exam #640-405Cisco Internetworking Troubleshooting ( CIT) Exam #640-406D - CCDA & CCDPCisco Design Specialist Exam #9E0-004Cisco 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 questi

23、on that will help you gain the CCDA or CCDP certification.CCNA试题1-19答案1. OxNx During a TFTP transferusing Cisco Routers what is the numeric value, in decimal, of the destinationport field of the User Datagram Protocol (UDP) header?a) 96b) 47c) a random number above 1024d) 69e) none of the aboveAnswe

24、rd) 69Here is a sampling of other port numbers and the application they are associated with. The first 8 of these protocols are automatically forwarded through the router by using the helper-address command Trivial File Transfer (TFTP) (port 69)Domain Name System (port 53)IEN-116 Name Server (port 4

25、2)Time service (port 37)NetBIOS Name Server (port 137)NetBIOS Datagram Server (port 138)Boot Protocol (BootP) client and 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

26、 encapsulation method used by Cisco routers for the Internet Protocol (IP) on it s Ethernet interfaces?a) SNAPb) ARPAc) NOVELL-ETHERd) DARPAe)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 t

27、he correct command on a Cisco router to set the IP address of an interface assuming you are at the router(config-if)# prompt?a) ip addressb) ip addressc) ipd) ipe) none of the aboveAnswera) ip addressIf you are not in the configuration mode, the ip address can be set by using the setup mode.Configur

28、ing interface 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 number of subnet bits.4. C

29、xNx 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 interfacee) display ip addressesAnswerc) show ip interfaced) show interfaceExamples of each of these commands are shown below:Rou

30、ter_A#sh int e0/0Ethernet0/0 is up, line protocol is upHardware is AmdP2, address isaddress is 1500 bytes, BW 10000 Kbit,DLY 1000 usec,rely 255/255, load 1/255Encapsulation ARPA, loopback not set,keepalive set (10 sec)ARP type: ARPA, ARP Timeout 04:00:00Last input never, output 00:00:06,output hang

31、neverLast clearing of show interfacecounters 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 packets/sec0 packets input, 0 bytes,0 no bufferReceived 0 broadcasts, 0 runts,0 giants,0 throttles

32、, 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 babbles, 0 late collision,0 deferred0 lost carrier, 0 no carrier0 output buffer failures, 0 outputbu

33、ffers swapped outRouter_A#sh ip int e0/0Ethernet0/0 is up, line protocol is upInternet address is address is determined by non-volatile memoryMTU is 1500 bytesHelper address is not setDirected broadcast forwarding is enabledOutgoing access list is not setInbound access list is not setProxy ARP is en

34、abledSecurity level is defaultSplit horizon is enabledICMP redirects are always sentICMP unreachables are always sentICMP mask replies are never sentIP fast switching is enabledIP fast switching on the same interface is disabledIP multicast fast switching is enabledRouter Discovery is disabledIP out

35、put packet accounting is disabledIP access violation accounting isdisabledTCP/IP header compression is disabledProbe proxy name replies are disabledGateway Discovery is disabledPolicy routing is disabledNetwork address translation is disabled5. CxNx Which of the following commands will display the c

36、ontents 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) show ip arpExample:Router_A#sh ip arpProtocol Address Age(min) Hardware Address Type InterfaceInternet - ARPA FastEthernet1/0Internet - ARPA

37、Ethernet0/06. CxNx Reverse Address Resolution Protocol (RARP) is the process:a) Where an IP host resolves it s IP address by broadcasting it s MAC address to the network and a BOOTP server assigns it an IP address.b) Where an IP host resolves it s MAC address by broadcasting to the local network it

38、s IP address.c) Where an IP host tries to resolve the MAC address of a destination by sending a network broadcast. Thedestination responds to the broadcast with it s MAC address.d) Where an IP host resolves a destination IP address by sending a broadcast on the local network and the server assigns i

39、t an IP address.destination host responds with it e)There is no such process. Answera) Where an IP host resolves its IP address.s IP address by broadcasting it s MAC address to the network and a BOOTPChoice C describes A ddress Resolution Protocol (ARP). A host never has to resolve it s own MAC addr

40、ess. The MAC address is burned into the Network Interface card. When the host is booted the MAC address will be loaded into 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

41、aboveAnswera) Telnetb) FTPTFTP and SNMP use layer 4 UDP.8. RxNx Which of the following are link state Routing Protocols.(Choose all that apply.)a) IPb) OSPFc) RIPd) EIGRPe) IS-ISAnswerb) OSPFe) IS-ISA link state routing protocol advertises, to it s neighbors, the state of the link when the state of

42、thelink changes.A distance vector routing protocol advertises its routing table periodically.9. CxNx Of the following 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-ra

43、mAnswerc) clear arp-cacheIf you have changed an ip address or a NIC card on a host you might use this command to reset 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 administ

44、rator 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 it s lack of administrativeexperience.d) The process where a router will prioritize routing protocols so that i

45、n the event two routing protocols have 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 routing protocolstakehave conflicting next hop addresses, th

46、e routing protocol with the highest administrative distance will priority.Answerd) The process where a router will prioritize routing protocols so that in the event two routing protocols have conflicting next hop addresses, the routing protocol with the lowest administrative distance will take prior

47、ity.Cisco uses administrative distances (AD) to measure the reliability of the routing protocol. The lower the (AD) the 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 area

48、N1 - OSPF NSSA external type 1, N2 - OSPFNSSA external type 2E1 - OSPF external type 1,E2 - OSPF external type 2,E - EGPi - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate defaultU - per-user static route, o - ODR Gateway of last resort is not set is subnetted, 2 subnets C is directly c

49、onnected, Serial1C is directly connected,Serial0I 100/8576 via00:00:09, Serial1100/8576 via 00:00:19,Serial0The 100 in bold is the administrative distance for IGRP.A partial list of administrative distances is included below:Protocol AD EIGRP 90 IGRP 100 OSPF 110 RIP 120 BGP 180If a router hears a I

50、P RIP and a IGRP update for the same network the router will 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

51、linkb) multiple stations listen for traffic and transmit at 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 timeCollisions is a term that is used in an ethernet environment. Ethern

52、et can be described as a listen then transmit scenario. First a station will listen for traffic if no traffic is sensed then a transmission will take place. If two stations transmit at the same time collisions will occur. The first station to detect the collision sends out a jamming signal to alert

53、all stations a collision has occurred. At this point these stations set up a random interval timer when the timer expires re-transmission will occur.Token ring is a token passing process a station can transmit only when he has the token. There never can be multiple tokens on the ring. Early token re

54、lease allows up to two data frames to be transmitted on a token ring LAN at the same time. Collisions do not occur on a token ring.Because of the point to point nature of serial links collisions do not occur.Beaconing is a term used in a token passing environment.12. RINx How many subnets are possib

55、le with a Class C address and a subnet mask ofa) 32b) 30c) 60d) 62e) 4 Answerd) 62 The above mask is using 6 bits to describe subnets. The formula used to determine the number of subnets (not including the all 0 s or all 1 s subnet) is 2n - 2 were n is the number of subnet bits. This is the number t

56、o use when configuring a ip address with the setup dialog.13. RxNx What commands will list all protocols that are currently being routed? (Choose all that apply.)a) show ip protocolb) show protocolc) show rund) show starte) All of the above Answerb) show protocolc) show runShow ip protocol will show just the ip routing protocols that are currently configured. Show start may or may not show the current routed protocols.Below is the output of show protocolRouter_B#show protocolGlobal values: Internet Protocol routing is enabledAppletalk routing is enabledBRI0 is admini