The Ethernet networking technology standard was based on a ring topology.

True / False Questions
 

31. (p. 67) The Ethernet networking technology standard was based on a ring topology.
FALSE

32. (p. 67) All implementations of Ethernet use the same frame type as the original Ethernet networks.
TRUE

33. (p. 69) The MAC address of a node is a unique 48-bit identifying address that comes from the NIC.
TRUE

34. (p. 70) The great popularity of Ethernet networks is due primarily to their ability to secure data frames to prevent interception by unauthorized hackers.
FALSE

35. (p. 69) Since a computer may contain only one NIC, it can have only one unique Layer 2 address.
FALSE

36. (p. 70) An Ethernet frame must have 1500 bytes of data, so padding is used if the actual data is less than this size.
FALSE

37. (p. 71) An Ethernet network uses the CSMA/CD access method.
TRUE

38. (p. 71) If a collision has occurred on an Ethernet network, the cable is restricted to the nodes whose data collided until they have finished retransmitting.
FALSE

39. (p. 68) A repeater also functions as an amplifier.
FALSE

40. (p. 67) The hub of a 10BaseT network analyzes the MAC address to see to which port it should forward the packet.
FALSE

Fill in the Blank Questions
 

41. (p. 67) Originally, Ethernet used __________________ cabling.
coaxial coax

42. (p. 67) The DIX Ethernet standard allowed computers to communicate with each other at a transfer rate of __________________.
10 Mbps

43. (p. 67) __________________ is the organization that now controls Ethernet standards.
IEEE

44. (p. 77) The maximum distance between a hub and a node on a 10BaseFL network is __________________.
2000 meters/2 kilometers

45. (p. 71) In an Ethernet network, the process called __________________ determines which machines may access the wire at any time.
CSMA/CD

46. (p. 69) All Ethernet frames begin with a(n) __________________.
preamble

47. (p. 72) A group of nodes that hear each other's traffic is defined as a(n) __________________.
collision domain

48. (p. 74) The __________________ connector is used for UTP cabling.
RJ-45

49. (p. 77) The maximum speed of a 10BaseFL network is __________________.
10 Mbps

50. (p. 67) Which IEEE subcommittee sets the standards for the CSMA/CD access method used with Ethernet networks?
802.3

51. (p. 77) The signal type of a 10BaseFL network is __________________.
baseband

52. (p. 76) 10BaseT networks use the __________________ hybrid topology.
star-bus

53. (p. 76) With 10BaseT, each node connects to a central __________________.
hub

54. (p. 78) The single point of failure that can down an entire 10BaseT network is the __________________.
hub

55. (p. 75) 10BaseT devices use pins 1 and 2 to __________________ data.
send

56. (p. 67) A(n) __________________ is a device that takes all data frames it receives from one Ethernet segment and retransmits them on another segment.
repeater

57. (p. 67) On a 10BaseT network, the __________________ repeats the signals coming in from one port to all other ports.
hub

58. (p. 74) Most UTP cables come with stranded __________________ fibers to add strength to the cable.
Kevlar

59. (p. 74) A 10BaseT network uses __________________ connectors.
RJ-45

60. (p. 75) Another word for an RJ-45 connector is a(n) __________________.
crimp

61. (p. 75) The __________________ defines the industry standard for correctly wiring an RJ-45 jack for 10BaseT networks.
Telecommunications Industry Association/Electronics Industry Association (TIA/EIA)

62. (p. 80) A(n) ______________ is a device that links network segments to form larger networks but also preserves bandwidth by filtering traffic between segments based on MAC addresses.
bridge

63. (p. 80) Because a bridge works with MAC addresses, you can infer that it operates at the ______________ layer of the OSI model.
Data Link or Layer 2

64. (p. 77) The cabling type that is most difficult to tap into is __________________.
fiber-optic

65. (p. 77) If you want to connect network segments that use different frame formats, you can use a(n) ______________________.
media converter

66. (p. 77) One of the two common connectors for 10BaseFL cabling is the __________________ connector.
SC or ST

67. (p. 68) A 10BaseFL network uses the __________________ signal type.
baseband

68. (p. 77) A bridge creates and maintains a list of ______________ that it updates as network traffic occurs.
MAC addresses

69. (p. 79) In a pinch, you can use a(n) __________________ to connect two computers with no hub between them.
crossover cable

70. (p. 79) Never connect two hubs by their __________________.
uplink ports

Essay Questions
 

71. (p. 67) What company developed the original Ethernet networking technology in 1973? 

Xerox developed the original Ethernet network technology in 1973.

72. (p. 67) What is the IEEE standard that defines the carrier access method used by Ethernet? 

IEEE 802.3 is the IEEE standard that defines the carrier access method used by Ethernet.

73. (p. 68) Although the terms frame and packet are sometimes used interchangeably, use the OSI model to explain the differences between these two terms. 

Frames are based on MAC addresses at the Data Link layer, Layer 2, of the OSI model. Packets are based on the IP protocol at Layer 3, the Network layer, of the OSI model.

74. (p. 68) Explain two ways that the use of frames improves network communication. 

(1) Frames prevent a machine from monopolizing the shared bus cable.
(2) Frames make the process of retransmitting lost data more efficient, since only the damaged or lost packets must be resent.

75. (p. 70) What is a sniffer program? 

A sniffer is a network diagnostic tool that allows a NIC to process all frames, regardless of whether they are intended for that NIC or not. In the right hands, a sniffer is a valuable diagnostic tool, but in the wrong hands, unscrupulous users may use it to intercept frames.

76. (p. 71) What happens if the frame check sequence at the receiving machine does not match the one calculated by the sending machine? 

If the frame check sequence generated at the receiving machine does not match the one calculated by the sending machine, the receiving machine will discard the frame and request that the sending machine retransmit the frame.

77. (p. 71) What does carrier sense mean on an Ethernet network? 

Carrier sense means that each node that uses the network must examine the cable to determine whether there is any traffic currently on it. If the cable is not in use (free), the node may transmit. If the cable is busy, the node will wait for a brief period and recheck the cable.

78. (p. 71) What does multiple access mean on an Ethernet network? 

In an Ethernet network, the term multiple access means that all machines have equal access to the wire when it is free. Access to the cable is simply on a first-come, first-served basis.

79. (p. 72) What does collision detection mean on an Ethernet network? 

Collision detection means that the sending node must listen to determine if another computer tried to transmit at the same time, thus causing a data collision that resulted in both transmissions being lost.

80. (p. 72) If Ethernet nodes detect that a collision has occurred, what do they do? 

Both nodes stop transmitting immediately. Then each generates a random number that determines the amount of time each will wait until trying to transmit again. If the cable is free, the node that generated the lowest random number will begin its retransmission first. The other node must wait for a free wire before retransmitting.

81. (p. 73) On an Ethernet network, what is the likely result if the collision domain gets too large? 

If a collision domain gets too large, the network will experience traffic problems (numerous collisions) that will cause general network sluggishness.

82. (p. 75) Explain why a 10BaseT Ethernet network cannot send and receive data simultaneously, even though it uses separate pairs of wires to send and receive data. 

A 10BaseT network cannot both send and receive because of the CSMA/CD access method, which restricts access to the cable to just one node at a time.

83. (p. 79) Describe the wiring of a crossover cable in terms of TIA/EIA. 

A crossover cable is wired so that sending and receiving wire pairs are reversed. Therefore, one end of the cable is crimped according to the TIA/EIA 568A standard, and the other end is crimped according to the TIA/EIA 568B standard.

84. (p. 79) What would you need to do to connect two hubs, after determining that neither one has an uplink port? 

To connect two hubs when neither has an uplink port, use a crossover cable, and connect each end to a regular port on each hub.

85. (p. 74) What does "Base" mean in cabling standards such as 10BaseT? 

"Base" in 10BaseT indicates that the cabling uses a baseband signal, which means that it carries only a single signal on the cable.

86. (p. 79) What would happen if a standard Ethernet cable connected two hubs that do not have special ports to interconnect them? 

No communications would take place because both hubs would attempt to send data on the first pair of wires (1 and 2), and would listen for data on the same pair of wires (3 and 6).

87. (p. 77) In what basic way is a 10BaseT network different from a 10BaseFL network? 

While a 10BaseT network uses UTP cabling, a 10BaseFL network uses fiber-optic cabling.

88. (p. 79-80) Describe a problem with an Ethernet hub that using an Ethernet switch solves. 

The problem with an Ethernet hub that replacing it with an Ethernet switch solves is that on a hub the total speed of the network is 10 Mbps, and only one conversation can take place at a time. Therefore, when more than two computers wish to communicate, it reduces the effective bandwidth of each conversation. A switch solves this problem, because, rather than send all incoming frames out all the other ports (as a hub does), a switch only sends signals to the destination port. Therefore, each conversation gets the entire 10-Mbps bandwidth.

89. (p. 74) What will happen if the hub in a 10BaseT network loses power? 

If a 10BaseT hub loses power, the entire segment will stop working.

90. (p. 75) Why are the wires color-coded in a UTP cable? 

The wires in a UTP cable are color-coded so that they can be crimped in the proper order in an RJ-45 connector.

91. (p. 75) What is the difference between the TIA/EIA 568A and 568B wiring standards for 10BaseT networks? 

The green and orange pairs are swapped between the two wiring standards, while the blue and brown pairs stay in the same place. Said another way, the wires connected to pins 1 and 2 are swapped with the wires connected to pins 3 and 6.

92. (p. 75) Describe an RJ-45 connector and explain how it is used. 

An RJ-45 connector has four pairs of wires (8 pins) and is used for connecting copper cabling, such as UTP.

93. (p. 80) Is a bridge regarded as an intelligent device? Why or why not? 

Yes, a bridge is an intelligent device because it filters and forwards traffic based on an analysis of MAC addresses.

94. (p. 75) For a cable with RJ-45 connectors to be used to connect a node to a 10BaseT network hub, what must be true about the pins on each end of the connectors? 

For a cable with RJ-45 connectors to be used to connect a node to a 10BaseT network hub, the pins on each RJ-45 connector must match.

95. (p. 78) If you are using a regular cable to connect two hubs that both have uplink ports, describe which ports you should use to connect the able to the two hubs. 

To connect two hubs that both have uplink ports, you connect one end of the cable to the uplink port on one of the hubs, and then connect the other end of the cable to a regular port on the second hub.

96. (p. 80) What does filter mean when you say a bridge filters and forwards traffic? 

When referencing Ethernet bridges, filtering traffic means that the bridge stops it from crossing from one network to the next. The bridge examines the destination MAC address of each frame. If the destination node is on the same network segment as the source and can be delivered locally, the bridge stops the frames from passing to another segment. If the address indicates that the destination is on a different network segment from the source, the bridge forwards the traffic, allowing the frames to pass to another network segment.

97. (p. 80) Describe the behavior of an Ethernet bridge, comparing it to a repeater. 

A newly installed Ethernet bridge initially behaves exactly like a repeater, passing frames from one segment to another. Unlike a repeater, the bridge changes this behavior once it has learned the MAC addresses of each port. After that, it filters traffic, meaning it stops traffic belonging on one connected network from crossing to the other network, and forwards only traffic that it has learned belongs on the other network.

98. (p. 81) Explain what happens, as far as collisions, when multiple Ethernet segments connect to each other through hubs. 

When multiple Ethernet segments connect to each other with hubs, they still comprise the same collision domain. Therefore, it is possible to have a greater number of collisions, causing general network sluggishness.

99. (p. 79) Describe what things you should remember when connecting hubs. 

When connecting hubs remember to only daisy-chain hubs, take time to figure out the uplink ports, and be aware that if you connect hubs incorrectly, no damage will occur—they just won't work.

100. (p. 69-71) What are the seven basic pieces of information contained in an Ethernet frame? 

The seven basic pieces of information contained in an Ethernet frame are:

(1) the Preamble
(2) the MAC address of the recipient
(3) the MAC address of the sender
(4) the type of data
(5) the data itself
(6) a pad
(7) a frame check sequence