NET 121b: Essentials of Networking

Review for Second Test
  1. What is the difference between a network connectivity device and an internetwork connectivity device? Give an example of each.

  2. What device is more commonly used in place of hubs?

  3. What is the purpose of a bridge? Why is a bridge useful?

  4. What kind of address is used by a bridge? What other network device is typically associated with this kind of address?

  5. How many repeaters are allowed on a coaxial Ethernet network?

  6. How many repeaters are allowed on a token ring network?

  7. What is an IEEE solution to bridging loop problems?

  8. What is the purpose of a router? What are two kinds of addresses routers need to know about?

  9. What is a Distance Vector protocol? What are some reasons that might make it a poor choice for a router?

  10. What is a Link State protocol? Why might it be a better protocol than a protocol that uses Distance Vector methods?

  11. What is the count to infinity problem? What kind of router protocols could suffer from it?

  12. What is a hop? Are more or fewer preferable, all other factors being equal?

  13. What is packet encapsulation? Why might you have to encapsulate a protocol?

  14. Name three protocols that are not routable.

  15. What is the difference between 1 Kbps and 1 Mbps?

  16. What is POTS? What is the maximum data transfer rate you might be able to attain on it, in a good system?

  17. What is modem? Is it a networking or internetworking device?

  18. What is the bandwidth of an ISDN B channel? How many B channels would an American customer on Basic Rate expect to have?

  19. What does DSL stand for? What are the three DSL variants listed? Which one can use the data line for voice service as well as data?

  20. Why would a customer want to subscribe to a satellite data service?

  21. What could be a likely cause of interference with Wi-Fi service in a typical home? What other wireless technology uses the same frequency as many Wi-Fi devices?

  22. What is an RRAS service?

  23. What dial-up protocols might a Remote Access Server need to use if you are expecting users to dial in to a modem installed in it?

  24. What is a RADIUS server? How does it improve service for dial-up network users?

  25. The text lists several security protocols for dial-up lines. Which does it consider the most secure? Which does it state as "not considered secure"?

  26. Where are the T data carrier standards available? The J standards? Compare the data transfer rate of a T-1 and a J-1 line.

  27. What humidity is recommended for computer rooms in your text?

  28. Why are magnetic fields disruptive to computer systems?

  29. What are some steps you can take to minimize electrostatic discharge?

  30. What class would a computer fire fall into?

  31. What precaution should be taken if you must run data cables near fluorescent lights?

  32. When troubleshooting a network card, how do you check what properties are bound to it?

  33. What kinds of trouble could the lights on a NIC tell you about?

  34. What kind of trouble could be caused by network cable problems?

  35. What is an obvious sign of trouble with a switch port?

  36. Assume you are troubleshooting a network problem. Where should you go to investigate if the trouble:
    1. is reported by only one user on the network?
    2. is reported by users on one floor of your building?
    3. is reported by users in several buildings?

  37. What is a crossover cable? What is it used for?

  38. Why would you use a tone generator when troubleshooting?

  39. What kind of problem do you troubleshoot with a Time Domain Reflectometer?

  40. What are the four steps in DIReCtional troubleshooting?

  41. List five things a network troubleshooter might need in a tool kit.

  42. Why is network documentation useful to a troubleshooter?

  43. What command is commonly used on a Windows workstation to view the most important settings for a NIC?

  44. What are some protocols that are typically used on WANs?

  45. Many companies have T1 lines to the Internet. How does T1 bandwidth compare to common bandwidths on most LANs?

  46. What are two meanings of the word "port", in relation to the topics in this course?

  47. What ports are assigned to these protocols: FTP, Telnet, DNS, HTTP, SMTP.

  48. What are the protocols listed above used for?

  49. How many bytes are in a standard (IPv4) IP address? How many bits does that make? What does "dotted octet" mean?

  50. What are the five network classes called? How many bytes are used by the network part of the address in each class?

  51. How many layers are in the Department of Defense networking model? What are they?

  52. How do the layers of the DoD model map to the layers of the OSI/RM?

  53. Which layer of each model contains protocols that are considered reliable?

  54. What is the largest number that can be expressed in a single byte? What does this number look like, expressed in base 2 (binary) notation?

  55. If you see an address in binary notation, which byte will tell you what class this address belongs to? How can you tell the class of the address by looking at this byte?

  56. What is the address that is defined as the Local Host? What would an address mean that has all host bits set to 0s? How about all host bits set to 1s?

  57. What is the formula for computing the number of usable subnets when borrowing any given number of host bits?

  58. If your routers support CIDR, they will receive addresses like In this example, what do the characters /23 mean to the router?

  59. What is the tracert utility used for? What phrase does the name of the utility stand for?

  60. What is the ping utility used for? What does it require as an argument (the part of the command the follows the word "ping")?

  61. What are two variations that can be used with the ipconfig command in a network that uses DHCP?

  62. When should you use winipcfg instead of ipconfig?

  63. What kind of information can you get from nslookup as well as from ping? How is nslookup different?

  64. What are file services? What protocol typically is used for file service on a TCP/IP network?

  65. What is message service? What protocol is typically used by email in a TCP/IP network?

  66. What formula tells you how many hosts can be placed on each subnet you create?

  67. Examine this problem, and answer each question using the methods from the text or from my notes.
    Required number of subnets: 100
    Required number of hosts/subnet:400
    Classful network address:
    What is the required subnet mask?
    What is the actual number of possible subnets with that mask?
    What is the actual number of possible hosts per subnet?

  68. Examine this problem, and answer each question using the methods from the text or from my notes.
    Given subnet mask:
    Classful network address:
    What is the CIDR notation for this mask?
    What is the actual number of possible subnets with that mask?
    What is the actual number of possible hosts per subnet?