思科认证考试(CCNA)考试模拟题集锦(171题)与答案

1、思科认证考试(C C N A)考试模拟题集锦(1-71题)及答案19及答案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 above2. CxNx What is the standard encapsul

2、ation method used by Cisco routers for the Internet Protocol (IP) onit ' s Ethernet interfaces?a) SNAPb) ARPAc) NOVELL-ETHERd) DARPAe) Ethernet_802.33. CxNx What will be the correct command on a Cisco router to set the IP address of an interface assumingyou are at the "router(config-if)#&qu

3、ot; 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 thatapply)a) show ip routeb) show ip addressc) show ip interfaced) show

4、 interfacee) 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 routec) show ip arpd) 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 I P 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' s IP address.c) Where an IP host tries to reso

6、lve 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 thedestination host responds with it ' s IP address.e)The

7、re is no such process.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 above8. RxNx Which of the following are link state Routing Protocols.(Choose all that apply.)a) IPb) OSPFc) R

8、IPd) EIGRPe) IS-IS9. 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-ram10. CxNx Which of the following explains the correct definition of adminis

9、trative distance as it pertainsto 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) The process where a router will distance itself from other routers due to it' s

10、 lack of administrativeexperience.d) 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 priority.takee) The process where a router will pri

11、oritize routing protocols so that in the event two routing protocolshave conflicting next hop addresses, the routing protocol with the highest administrativedistance willpriority.11. ExNx Collisions occur whena) multiple packets are placed on a serial linkb) multiple stations listen for traffic and

12、transmit at the same timec) when multiple tokens are on a ring 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 be

13、ing routed? (Choose all that apply.)a) show ip protocolb) show protocolc) show rund) show starte) 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

14、 access-list will implicitly deny all traffic.d) Access-lists are processed top down.e) All of the above.15. xxNx If the access-group commandis configured on an interface and there is no access-list created which of the following is most correct?a) An error message will appear.b) The command will be

15、 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 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

16、any 55 established"a) telnet sessions will 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 p

17、ermitted 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 most likely be placed close to the destination.b) Standard lists will most likely be

18、 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 following is most correct?a) IP is to TCP. as IPX is to SPX.b) RTMP is to Appletalk as IP RIP

19、 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 not active:a) The packet will time out.b) The packet will be removed by Host

20、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 of question.A - ATMB - BridgingC - Cisco specificE - EthernetF -

21、Frame relayH-HDLCI - FDDIN - ISDNO - OSI modelP - PPPR - RoutingS - SwitchingT - Token ringX - X.25x - Not applicableThe second character represents protocol.A - AppletalkB - Banyan Vines D - DecnetI - IPL - Dial on DemandN-NLSPO - OSPFX - IPXx - Not ApplicableThe third character represents the cert

22、ification 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-up Services Exam #640-405Cisco Internetworking Troubleshooting ( CIT)

23、 Exam #640-406 D - 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 question that will help you gain the CCDA or CCDP certific

24、ation.CCNAt题1-19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 aboveAnswerd) 69Here is a sampling of other port numbers and

25、 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 42)Time service (port 37)NetBIOS Name Server (por

26、t 137)NetBIOS Datagram Server (port )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 encapsulation method used by Cisco routers for the

27、 Internet Protocol (IP) on it ' s Ethernet interfaces?a) SNAPb) ARPAc) NOVELL-ETHERd) DARPAe) Ethernet_802.3Answerb) 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

28、router to set the IP address of an interface assuming you are at the "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

29、mode, the ip address can be set by using the setup mode.Configuring interface EthernetO/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 /2

30、4Take note when using the setup mode the mask is configured using the number 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 routeb) show ip address c) show ip interface d) show interface e) display ip address

31、esAnswerc) show ip interface d) show interface Examples of each of these commands are shown below: Router_A#sh int e0/0Ethernet。/。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, rel

32、y 255/255, load 1/255 Encapsulation ARPA, loopback not set, keepalive set (10 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 d

33、rops5 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, 0 input errors, 0 CRC,0 frame, 0 overrun, 0 ignored, 0 abort0 input packets with dribble condition detected127 pack

34、ets 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 output buffers swapped outRouter_A#sh ip int e0/0Ethernet。/。is up, line protocol is upInternet address is /24Br

35、oadcast address is 55Address determined bynon-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 enabledSecurity level is defaultSplit horizon is enabledICMP redirects

36、 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 output packet accounting is disabledIP access violation accounting isdi

37、sabledTCP/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 contents of the ARP cache of your Cisco router? a) show ip arp cache

38、b) show ip route c) show ip arp d) 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 - 0010.7b15.bd50 ARPA FastEthernet1/0Internet - 0010.7b15.bd41 ARPA Ethernet0/06. C

39、xNx 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 B OOTP server assigns it an IP address.b) Where an IP host resolves it ' s MAC address by broadcasting to the local network

40、 it' s IP address.c) Where an IP host tries to resolve the MAC address of a destination by sending a network broadcast. The destinatio n 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

41、 destination host responds with it ' s IP address.e)There is no such process.Answere) 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.Choice C describes Address Resolution Protocol (ARP). A host nev

42、er has to resolve it' s own MAC address. TheMAC 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)

43、Telnet b) FTP c) TFTP d) 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. (Choose all that apply.)a) IPb) OSPFc) RIPd) EIGRPe) IS-IS Answer b) OSPF e) IS-IS A link state routing protocol advertises, to it'

44、; s neighbors, the state of the link when the state of 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-t

45、ablec) clear arp-cached) clear arp-tablee) clear arp-ramAnswerc) 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 pertainsto Cisco &#

46、39; 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 it' s lack of administrativeexperience.d) The p

47、rocess 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 priority.e) The process where a router will prioritize routing protocols so that in the event

48、 two routing protocolshave conflicting next hop addresses, the routing protocol with the highest administrativedistance will takepriority.Answerf) The process where a router will prioritize routing protocols so that in the event two routing protocols have conflicting next hop addresses, the routing

49、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) the more reliable the protocol.Router_C#sh ip routeCodes: C - connected, S - static,I - IGRP, R - RIP,M - mobile, B - BGP

50、D - 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 - IS-IS, L1 - IS-IS level-1,L2 - IS-IS level-2, * -candidate defaultU - per-user static route, o - ODRGateway of las

51、t resort is not set/24 is subnetted, 2 subnetsC is directly connected,Serial1C is directly connected,Serial0I /8 100/8576 via ,00:00:09, Seriall100/8576 via , 00:00:19,Serial。The 100 in bold is the administrativedistance for IGRP.A partial

52、list of administrative distances is included below:Protocol ADEIGRP 90IGRP 100OSPF 110RIP 120BGPIf a router hears a IP 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 bandw

53、idth 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 the same timec) when multiple tokens are on a ring simultaneouslyd) beaconing process takes placeAnswerb) multiple st

54、ations listen for traffic and transmit at the same timeCollisionsis a term that is used in an ethernet environment. Ethernet can be described as a listen then transmitscenario.First a stationwill listen for traffic if no traffic is sensed then a transmission will take place.If two stations transmit

55、at the same time collisions will occur. The first station to detect the collision sends out a jamming signal to alert 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 pro

56、cess a station can transmit only when he has the token. There never can bemultiple tokens on the ring. Early token release allows up to two data frames to be transmitted on a tokenring LAN at the same time. Collisions do not occur on a token ring.Because of the point to point nature of serial links

57、collisions do not occur.Beaconing is a term used in a token passing environment.12. RINx How many subnets are possible with a Class C address and a subnet mask of 52?a) 32b) 30c) 60d) 62e) 4Answerd) 62The above mask is using 6 bits to describe subnets. The formula used to determine the number of subnets (notincluding th e all 0 ' s or all 1' s subnet) is 2n - 2 were n is the number of subnet bits. This is the number to use when configuring a ip address with the setup dialog.13. RxNx What commands wi