CCNA试题1.What is the correct order for the OSI model? BP=Presentation, S=Session, D=Datalink, Ph=Physical, T=Transport, A= Application, N=NetworkA. P S A PH D N TB. A P S T N D PHC. PH D N T A S PD. P S A T N D PHIt is crucial you not only memorize this and know what each layer does.2. What is encapsulation? CA. Putting the header on an incoming frameB. Putting a header on an incoming segmentC. Putting a header on an outgoing frameD. Putting a header on an outgoing bitThis also includes trailers and can be put on segments, packets, and frames.3. Which layer is most concerned with user applications? AA. ApplicationB. PresentationC. NetworkD. Physical4. Which of the following is de-encapsulation?AA. Stripping the header from a frameB. Putting a header on a segmentC. Putting a header on a frameD. Stripping a frame from a linkThis also includes trailers as in question 2.5. What layer converts data into segments? CA. ApplicationB. PresentationC. TransportD. Physical6. What layer converts data into Packets? AA. NetworkB. ApplicationC. PhysicalD. Data Link7. What layer converts data into Frames? CA. ApplicationB. PhysicalC. Data LinkD. Transport8. What layer converts data into bits? DA. ApplicationB. SessionC. Data LinkD. PhysicalAll of the layers need to convert data into something that they can pass down to the next level, with the exception of the Application layer which hands data to the Presentation layer.The Presentation layer encrypts, and compresses before sending it to the Session layer for it s first conversion.9. Which layer is most concerned with getting datafrom the beginning to the final destination? DA. ApplicationB. PresentationC. SessionD. TransportThe transport layer is most concerned with reliable transportation from one end to the other.10. Which of the following is not a part of the Session layer? BA. Establishing a sessionB. Ensuring error free segmentsC. Ending a sessionD. Keeping the sender and receiver from sending a message at the same time That is the job of the Transport layer.11. Which of the following is not a job for the presentation layer? Choose 2 CDA. Data representationB. CompressionC. Dialog managementD. TransmissionE. EncryptionC is handled by the session layer, andD is handled by the Transport layer12. What does Peer to Peer communication involve? DA. Each layer communication with the layer below itB. Each layer communication with layer above itC. Each layer communicating with adjacent layer in another systemD. Each layer communication with it s corresponding layer in another systemAnswer D.Answer C sounds correct also, but adjacent and corresponding are two different things. The session layer can only communicate with the session layer in another system for example.13. Why does the industry use a layered model?Choose all correct ABCDA. When you enhance one layer it doesn t affect the other layersB. Design and development can be made in a modular fashionC. Network operations can be simplifiedD. Troubleshooting can be simplified.14. Which two of the following are not from the physical layer? ADA. SDLCB. V.35C. HSSID. ISDNE. RS-232Answer A D.SDLC and ISDN are W AN protocols that function at the data link layer15. Which two answers are functions of the OSI model"s network layer? BCA. Sequencing of framesB. Path determinationC. Packet switchingD. Packet sequencingAnswer B C. Sequencing is done at the data link layer. D is fictional.16. What is an example of a MAC address? DA. Az32:6362:2434B. Sj:2817:8288C. GGG:354:665D. A625:cbdf:6525The address is a 48 bit address which requires 12 Hex digits.A hex digit can t be past the letter F. Hex stands for 16. 1-9 and A-F make up numbers that are valid.17. Which of the following is not part of the data link layer? EA. Transports data across the physical linkB. Performs physical addressingC. Performs flow controlD. Determines network topologyE. Terminates a sessionThis is part of the session layer18. Which of the following are data link protocols? ADEA. HDLCB. FTPC. SQLD. ISDNE. Token RingFTP is an application and SQL is a session layer protocol.19. Of the following address AA77:3827:EF54, which of the following is the vendor portion? AA. AA7738B. 27EF54C. AA77D. EF54The vendor code is how you can tell who made the card. The last 6 digits are the physical address.20. Which of the following are examples of layer 3 addressing? ABA. 165.33.4.34B. AA77:3827:EF54C. HHHH:hg:7654D. 76The first is a TCPIP address and the second is an IPX address21. What is considered Layer 3 addressing? BA. Data Link LayerB. Network LayerC. Application LayerD. None of thesePhysical is Layer 1, then data link, and then Network. This is the same layer that routers are on. A22. What layer are Bridges on?A. Data LinkB. PhysicalC. ApplicationD. TransportBridges segment networks but are not able to determine addresses like the network layer does.23. Repeaters are on what layer? CA. TransportB. SessionC. PhysicalD. ApplicationAll repeaters can do is boost a signal. An active hub is a good example of a repeater. A switching hub is a good example of layer 3 addressing, since switches go by network addresses and IPX addresses rather than just boost signals. Bridges can only read mac addresses, and not the full IPX or TCPIP addresses.24. Which of the following are considered routing protocols? ADA. OSPFB. IPC. IPXD. EIGRPE. Token RingAnswers B and C are routed protocols, whereas A and D are the protocols that do the routing. This is easily confused. You can remember it by thinking that the routing protocols that haul the routed protocols are like a tug ship pulling a barge. The barge is full of data.25. Which two of the following are considered connection oriented communication? ADA. Setup and maintenance procedures are performed to ensure message delieveryB. A physical circuit exists between two communicating devicesC. It is a best effort type of communicationD. A virtual connection exists between the twoB is not a necessity, andC is not accurate. TCP is connection oriented and UDP is not26. Which of the following are not WAN protocols? Choose 2 CDA. Frame RelayB. A TMC. EthernetD. FDDIE. ISDNEthernet and FDDI are LAN protocols.27. Which of the following will allow you to view NVRAM s contents? AEA. show configurationB. show protocolsC. show versionD. show running-configE. show startup-configAnswer A E. These show the backup configuration stored in NVRAM. The other anwsers allow youto view RAM.28. Which of the following contains the OS image? AA. FlashB. NVRAMC. RAMD. InterfacesROM will be used if Flash is unavailable. NVRAM is the backup configuration, and RAM is the active configuration29. Which of the following indicates the router is in privilege mode? AA. Router#B. Router>C. Router-D. Router* Answer B shows the router in user mode.30. What does "show cdp neighbors" not show? Neighbors___C______A. device idC. ios versionD. port type and number31. Which of the following will show you the clock? DA. cl?B. Cl ?C. Clock?D. Clock ?By typing this the router will finish the command and show the clock.32. CDP operates at which layer? DA. TransportB. NetworkC. Data linkD. PhysicalCDP allows a network device to exchange frames with other directly connected networked devices.33. Which command does not show two devices are not routing packets between them successfully? ACDA. pingB. show interfaceC. traceD. telnetAnswer A C D. With these commands you can tell whether or not you have communication. Show interface just verifies there is a connection34. What keystrokes shows the possible commands in privilege mode? ABA. helpB. hC. ctrl+hD. ?Answers A and B will give a brief description when typed, and C is not valid.35. Which two items contain versions of the router s configuration file? BCA. flashB. nvramC. ramD. romA and D contain the OS.36. Which of the following commands will allow you to review the contents of RAM?A. show configuration BCDC. show versionD. show running-configE. show startup-configA and E allow you to see NVRAM.37. Which of the following will allow you to add, modify, or delete commands in the startup configuration file? DA. show startup-configB. show running-configC. configure terminalD. configure memoryAnswer C allows you to change items in the running configuration file38. Which command would be used to restore a configuration file to RAM? ____A____TFTP running-configA. router#copyB. router>copyC. router*copyD. router^copyYou must be in privilege mode when executing this, which is why you see the # sign.39. Which of the following commands will display the running configuration file to a terminal? AA. show running-configB. show router-configC. router#show flashD. router>show versionIt can only be shown in privilege mode.40. If you need to copy the currently executing configuration file into NVRAM,which command would you use? CA. router#copy startup-config running-configB. router#copy startup-config TFTPC. router#copy running-config startup-configD. router>copy startup-config running-configAnswers ABC show that the router is in privilege mode which is necessary to complete this action, but only C shows the correct syntax.。