Chapter 5: LANs and WLANs

TRUE/FALSE

1. Because network technology continues to evolve, it is based on a set of fairly unstable concepts.

2. A WAN provides connectivity within a limited geographical area, often within a single building.

3. In a client/server network, a server provides services to other computers called clients.

4. A bus topology connects all devices to a common backbone, which functions as a shared

communications link.

5. The device used to connect your home LAN to the Internet is a type of gateway.

6. A process called handshaking allows two communications devices on a network to negotiate their

communications protocols.

7. The wave on the bottom in the accompanying figure depicts a digital signal.

8. The wave on the top in the accompanying figure depicts an analog signal.

9. MAC addresses are used for some low-level network functions and can also be employed to

establish network security.

10. A packet always travels from the source directly to the destination, never traveling through

intermediate routing devices.

11. IP addresses can be assigned by ISPs or system managers.

12. When two packets collide in an Ethernet network, as illustrated in the accompanying figure, the

two devices wait for random time periods before retransmitting to prevent a collision from

reoccurring.

13. In the accompanying figure, the item on the left simply plugs into a serial port on the outside of the

system unit.

14. In the accompanying figure, the item on the right can be installed in an expansion slot inside the

system unit of a desktop computer.

15. In the accompanying figure, the item on the left can be used with a notebook or desktop computer.

16. Microwaves cannot be aimed in a single direction and have less carrying capacity than radio waves

17. A transceiver is a combination of a transmitter and a receiver.

18. Bluetooth is often used to connect workstations to a LAN.

19. WPA2 makes sure that packets have not been intercepted or tampered with in any way.

20. A cryptographic algorithm is a word, number, or phrase that must be known to encrypt or decrypt a

message.

MODIFIED TRUE/FALSE

1. The Internet is the world’s largest example of a(n) LAN. _________________________

2. In the accompanying figure, the network in the middle is configured in a(n) bus topology.

_________________________

3. In the accompanying figure, the network on the bottom is configured in a(n) string topology.

_________________________

4. In the accompanying figure, the network at the top is configured in a(n) mesh topology.

_________________________

5. The topology located at the middle in the accompanying figure uses a common backbone to

connect all network devices. _________________________

6. High-bandwidth communications systems, such as cable TV and DSL, are sometimes referred to as

narrowband. _________________________

7. The best-known communications protocol is probably SMTP, which regulates Internet data

transport. _________________________

8. As shown in the accompanying figure, the TCP/IP protocol detects packet collisions, deletes the

colliding signals, resets the network, and prepares to retransmit the data.

_________________________

9. Data in a(n) wired network travels without the use of network cables.

_________________________

10. Microwaves are electromagnetic signals that can be aimed in a single direction and have more

carrying capacity than radio waves. _________________________

11. Wi-Fi signals cannot be disrupted by interference from electronic devices operating at the same

frequency. _________________________

12. A wireless ad hoc network uses a centralized broadcasting device, such as a wireless access point

or router. _________________________

13. Computers connected to a LAN are less vulnerable to malicious code than standalone computers.

_________________________

14. The process of converting ciphertext into plaintext is called encryption.

_________________________

15. Public key encryption uses one key to encrypt a message and another key to decrypt it.

_________________________

MULTIPLE CHOICE

1. A network, like the one in the accompanying figure, would be used to ____.

a. connect personal computers within a very limited geographical area, such as a single

building

b. connect several smaller networks together

c. provide high-speed connectivity for a metropolitan area

d. connect devices over a large geographical area

2. Today, most networks, like the one in the accompanying figure, are configured with ____

technology.

a. Token Ring c. Ethernet

b. ARCnet d. FDDI

3. The type of network shown in the accompanying figure is known as a ____.

a. LAN c. MAN

b. WAN d. TAN

4. Which of the following can serve as a node on the network in a LAN?

a. computer c. network device

b. networked peripheral d. all of the above

5. Which of the following is NOT a type of network device?

a. hub c. workstation

b. switch d. router

6. A(n) ____ server stores files and supplies them to workstations upon request.

a. file c. application

b. supply d. index

7. In a peer-to-peer mode, a network ____.

a. contains one or more computers configured with server software

b. contains one or more computers configured with client software

c. allows workstations to share resources, like files and applications

d. has a computer that provides a centralized repository for data

8. In ____ mode, workstations can share responsibility for processing, storage, printing, and

communications tasks.

a. peer-to-peer c. star

b. mesh d. client/server

9. A ____ topology features a central connection point for all workstations and peripherals.

a. mesh c. bus

b. star d. ring

10. The physical arrangement of devices in a network is referred to as its physical ____.

a. topography c. logology

b. logography d. topology

11. In a ____ topology, network nodes are connected in a closed circle.

a. circle c. ring

b. closed d. star

12. A tree topology ____.

a. is a blend of star and ring networks

b. consists of multiple star networks connected into a bus configuration by a backbone

c. does not offer flexibility for expansion

d. is no longer used

13. In the accompanying figure, which physical topology is NOT represented?

a. bus c. ring

b. mesh d. star

14. A ____ is a generic term for any device or software code used to join two networks.

a. NIC c. node

b. gateway d. networked peripheral

15. A ____ is a physical path or a frequency used for signal transmissions.

a. logical channel c. connecting link

b. communications channel d. node link

16. High-bandwidth communications systems are sometimes referred to as ____.

a. quickband c. narrowband

b. broadband d. Internet 2

17. Dial-up Internet access is an example of a(n) ____ communications system.

a. broadband c. narrowband

b. slowband d. Internet 2

18. Two devices on a network might have to negotiate their communications protocols through a

process called ____.

a. handshaking c. realization

b. synchronization d. introduction

19. The telephone network uses a technology called ____, which establishes a dedicated, private link

between telephones for the duration of a call.

a. packet switching c. bus switching

b. circuit switching d. ring switching

20. In the technology referred to as ____, a message is divided into several parcels that can be routed

independently to their destination.

a. packet switching c. circuit switching

b. handshaking d. protocol

21. A protocol known as ____ is designed to automatically distribute IP addresses.

a. DHCP c. CSMA/CD

b. packet switching d. a piconet

22. Which of the following is NOT an advantage of using a wired network?

a. Increased security c. Simple to configure

b. Fast access d. Limited mobility

23. A wired network is one that uses ____ to connect network devices.

a. NICs c. cables

b. radio frequency waves d. infrared light

24. Most wired networks in homes, schools, and businesses use Ethernet technology that is defined by

____ standards.

a. IEEE 802.3u c. IEEE 802.3ba

b. IEEE 802.3 d. IEEE 802.3ae

25. Current Ethernet standards allow extensive flexibility in network ____ to meet the needs of small

and large installations.

a. resolution c. addressing

b. topology d. infrastructure

26. On an Ethernet, a ____ is broadcast to every device but is accepted only by the device to which it

is addressed.

a. code c. band

b. packet d. node

27. ____ takes care of situations in which two network devices attempt to transmit packets at the same

time.

a. IEEE c. HomePNA

b. CSMA/CD d. HomeWi-Fi

28. The original Ethernet standard carried data over a coaxial cable bus topology at ____.

a. 10 Mbps c. 10 Gbps

b. 100 Mbps d. 100 Gbps

29. What is the IEEE designation for the Gigabit Ethernet standard?

a. IEEE 802.3 c. IEEE 802.3u

b. IEEE 802.3ae d. IEEE 802.3z

30. Ethernet networks ____.

a. are difficult to implement, manage, and maintain

b. use a nonproprietary technology, making Ethernet equipment available from a variety of

vendors

c. do not offer much flexibility in network topology

d. are not compatible with Wi-Fi wireless networks

31. A network ____ sends data only to the devices specified as the destination.

a. switch c. hub

b. port d. keylogger

32. Which of the following is NOT true about the speed of Ethernet routers?

a. Ethernet routers are available at 10/100 Mbps or Gigabit speeds.

b. If you have a 10/100 Mbps router and several of the network computers have Gigabit

Ethernet adapters, the Gigabit adapters will receive data at the Gigabit rate.

c. If you have a Gigabit router and all the network computers have Gigabit Ethernet adapters,

data will flow over all network connections at Gigabit speeds.

d. If some computers have Gigabit adapters, whereas others have 10/100 Mbps adapters, a

Gigabit router will ship data at a speed that corresponds to each adapter.

33. If Windows displays the ____ icon and indicates the network is connected, it is ready for use.

a. Network Neighborhood c. My LANs

b. My Network Places d. Local Area Connection

34. Most wireless networks transport data as ____ signals.

a. infrared c. microwave

b. satellite d. RF (radio frequency)

35. Which of the following is a disadvantage of using a wireless network when compared to a wired

network?

a. speed c. security

b. range d. all of the above

36. Which of the following is NOT true?

a. When lots of computer game players compete against each other over a LAN, a fast, wired

network is desirable.

b. Wireless LANs are faster for intra-LAN operations, such as exchanging files and sharing

printers.

c. Even the slowest wireless LAN technologies are faster than most Internet services.

d. Despite interference, wireless networks are fast enough for most applications.

37. Wireless signal range can be limited by ____.

a. the type of signal c. transmitter strength

b. the physical environment d. all of the above

38. The most popular wireless LAN technology is ____.

a. WUSB (Wireless USB) c. Bluetooth

b. Wi-Fi d. WiMAX

39. Which of the following does NOT impact signal strength on a wireless network?

a. distance from a transmitter c. transmitter strength

b. obstacles that interfere with the signal d. encryption

40. Which of the following is true about Bluetooth?

a. It requires cables to connect electronic devices.

b. It has a very long transmission range of over 500 feet.

c. It is used exclusively to connect workstations to a LAN.

d. It forms networks automatically when two or more devices are within range.

41. A Wi-Fi network transmits data as radio waves over ____ frequencies.

a. 2.4 MHz or 5.8 MHz c. 2.4 GHz or 5.8 GHz

b. 1.2 MHz or 2.4 MHz d. 1.2 GHz or 2.4 GHz

42. Wi-Fi encompasses all of the following standards EXCEPT ____.

a. 802.11b c. 802.11n

b. 802.11g d. 802.11p

43. ____ technology improves the speed and range of a LAN by using two or more antennae to

essentially send multiple sets of signals between network devices.

a. WiMAX c. Zigbee

b. MIMO d. MAN

44. Which of the following is NOT true about Wi-Fi standards?

a. IEEE 802.11b is the original standard.

b. All of the standards are cross compatible.

c. They are compatible with Ethernet.

d. IEEE 802.11n is faster than, but compatible with, b and g.

45. In a wireless ____ network, devices broadcast directly to each other.

a. ad-hoc c. embedded

b. infrastructure d. SSID

46. Which of the following is NOT true?

a. Using groupware, several people on a LAN can work together on a single document.

b. Purchasing a single software copy for an entire LAN is always allowed under the terms of

a single-user license agreement.

c. LANs can provide authorized users with access to data stored on network servers or

workstations.

d. Sharing networked hardware and/or software can reduce costs.

47. Which of the following is NOT true?

a. When a network malfunctions, all of the resources you access over the network are

unavailable until the network is repaired.

b. LANs are vulnerable to unauthorized access from many sources and locations.

c. LANs are less vulnerable than standalone computers to malicious code.

d. Wireless LANs can be tapped from a specially equipped computer in a car that is being

driven by a hacker.

48. A ____ server is a computer whose primary purpose is to be a repository for files that can be

accessed by network workstations.

a. file c. document

b. print d. backup

49. To configure a file server, open a browser from any workstation, enter the file server’s ____

address, and provide the administrator ID and password.

a. TCP c. LAN

b. network d. IP

50. To set up a print server, connect it to the printer’s ____ port and access the configuration settings

using your browser.

a. FireWire c. serial

b. USB d. ASP

51. A printer with built-in networking does not have to be attached to a workstation or a print server

because it has its own ____.

a. LAN c. 802.11 standard

b. network adapter d. Wi-Fi cable

52. On Macs, you can view the number of packets sent, received, and dropped from your network

connection using the ____ application.

a. Infrastructure Console c. Dedicated Application Server

b. RTS Utility d. Network Utility

53. Symptoms of network problems include which of the following?

a. intermittent outages

b. slow response time

c. non-availability of network services to all workstations

d. all of the above

54. ____ occurs when hackers intercept signals by cruising through a business district or neighborhood

with a Wi-Fi enabled notebook computer.

a. LAN driving c. LAN chalking

b. LAN jacking d. LAN encryption

55. Wireless ____ scrambles the data transmitted between wireless devices and then unscrambles the

data only on devices that have a valid key.

a. polymorphism c. protected access

b. concatenation d. encryption

56. The original wireless encryption was called ____.

a. WEP c. WPA2

b. WPA d. WSA

57. ____, also referred to as personal mode, is a type of WPA used on most home networks.

a. WSA c. WEP2

b. WEP d. PSK

58. A(n) ____ is the basis for scrambling and unscrambling the data transmitted between wireless

devices.

a. active link c. PSK

b. wireless network key d. algorithm

59. ____ transforms a message in such a way that its contents are hidden from unauthorized readers.

a. Encryption c. Concatenation

b. Encapsulation d. Polymorphism

60. A message that has not been encrypted is referred to as ____.

a. ciphertext c. keytext

b. plaintext d. weak text

61. An encrypted message is referred to as ____.

a. keytext c. ciphertext

b. strong text d. plaintext

62. The process of converting ciphertext into plaintext is called ____.

a. right-texting c. war driving

b. decryption d. AES

63. A ____ is a procedure for encrypting or decrypting a message.

a. nexus c. cryptographic index

b. cryptographic algorithm d. message

64. A ____ is a word, number, or phrase that must be known to encrypt or decrypt a message.

a. cryptographic index c. cryptographic key

b. rank d. message

65. Computers may break a code by using a(n) ____, which consists of trying all possible keys.

a. brute force attack c. symmetric attack

b. encapsulated effort d. signal-based effort

66. In ____ key encryption, the key used to encrypt a message is also used to decrypt the message.

a. balanced c. PKE

b. symmetric d. PGP

67. ____ encryption uses one key to encrypt a message but another key to decrypt the message.

a. Symmetric c. Asymmetric

b. Public key d. Brute force

68. ____ software may be used by personal computer users when they want to encrypt e-mail or other

documents.

a. SMTP c. HTTP

b. PGP d. URL

69. ____ is a crucial technology for e-commerce and e-mail.

a. Symmetric key encryption c. Public key encryption

b. Network security key d. all of the above

70. With PGP, to whom do you send the private key?

a. People whom you have authorized to send you plaintext messages

b. People whom you have authorized to send you encrypted messages

c. Anyone with whom you expect to have e-mail correspondence

d. No one

Case-Based Critical Thinking Questions

Case 5-1

Thomas is a network expert, having mastered the finer points of network structure, topology, and

geographical scope. He has built many different types of networks at home, school, and work.

71. Thomas is designing a wired home network with six nodes for a friend. His friend has asked that

the network be configured such that, if one link fails, the rest of the network will still function.

Which of the following topologies will Thomas most likely choose?

a. tree c. ring

b. bus d. star

72. Thomas’ friend has indicated that he plans to use a file sharing system, like BitTorrent, although it

will operate on a small scale. What term best describes the network that Thomas and his friend will

construct?

a. MAN c. peer-to-peer

b. WAN d. client/server

73. Thomas has taken a freelance job working for a local ISP (Internet Service Provider), and he wants

to review the technologies relevant to the work he will do for this enterprise. Given the geographic

area served by the ISP extends about 40 miles, which would be the most relevant to Thomas’

efforts?

a. WANs c. PANs

b. LANs d. MANs

74. Thomas has been asked by a friend to overhaul an existing network so that it is more robust. She

wants each device on the network to connect to all of the other devices on the network. Which

network topology will Thomas most likely use?

a. star topology c. mesh topology

b. bus topology d. ring topology

Case-Based Critical Thinking Questions

Case 5-2

Esteban has decided to install a computer network in his home. He knows he can choose wired or

wireless and that there are differences in transmission speed and security.

75. Esteban decides to install a wireless network. Which LAN technology will he most likely choose?

a. Bluetooth c. Infrared

b. WUSB d. Wi-Fi

76. Esteban plans to use a router to not only connect the network devices together but also to connect

to the Internet. He knows that he will have to configure the router by ____.

a. changing the router password c. activating encryption

b. entering the SSID d. all of the above

77. After additional research, Esteban decides that he wants to create a wired network using existing

telephone wiring. What kind of network will he create?

a. Ethernet network c. HomePNA network

b. Powerline network d. Wi-Fi network

Case-Based Critical Thinking Questions

Case 5-3

You have just secured a new job with a new firm that is very security conscious. You’ve been

instructed to learn as much as possible about encryption to ensure the confidentiality of customer

transactions as well as electronic communications about new research and development projects.

78. After researching this topic, you find that encryption can be used in all of the following ways

EXCEPT ____.

a. securing credit card numbers transferred from shoppers’ computers to e-commerce sites

b. scrambling data sent over wired or wireless networks to prevent intrusions

c. scrambling the contents of e-mail messages to maintain privacy

d. decrypting computer archives so that the data they contain is unusable if the archive is lost

or compromised

79. As part of your research, you find that the longer the key, the longer it will take a devious

competitor to crack the code. You also find that most encryption today uses a ____ key, and so you

decide to use an encryption key of that size.

a. 56-bit c. 128-bit

b. 64-bit d. 256-bit

80. You decide to use public key encryption to protect e-commerce transactions. Once the browser

uses the public key it receives from the server to encrypt the credit card information, who can

decrypt the message?

a. you

b. any user you authorize in the firm

c. any hacker who intercepts the transaction

d. the Web server with access to the private key

COMPLETION

1. Each device that is connected to a network is referred to as a(n) ____________________.

2. A(n) ____________________ is any device that contains network circuitry to directly connect to a

network.

3. A(n) ____________________ server handles jobs sent to network printers.

4. The arrangement of devices in a network is referred to as its ____________________.

5. A communications ____________________, or link, is a physical path or a frequency used for

signal transmission.

6. High-bandwidth communications systems are sometimes referred to as ____________________.

7. The bandwidth of a digital channel is usually measured in ____________________ per second

(bps).

8. In the context of networks, the communications ____________________ refers to the set of rules

for efficiently transmitting data from one network node to another.

9. Transmission signals can be disrupted by interference called ____________________, which has

the potential to corrupt data.

10. A(n) ____________________ is a parcel of data that is sent across a computer network.

11. ____________________ switching essentially establishes a private link between one telephone

and another for the duration of a call.

12. A(n) ____________________ address is a series of numbers, such as 204.127.55.1, used to

identify a network device.

13. Most wireless networks transport data using ____________________ signals.

14. A Bluetooth network is sometimes called a(n) ____________________.

15. A wireless ____________________ performs the same function as a hub or router in a wired

Ethernet network by broadcasting signals to any devices with compatible Wi-Fi cards.

16. A(n) ____________________ is the name of a wireless network.

17. You can use ____________________ to assign a drive letter to a storage device located on a

different network workstation.

18. If you use the ____________________ operating system, it automatically detects available LANs

any time you turn on a workstation.

19. To set up a print server, connected to the printer’s USB port and access the

____________________ settings using your browser.

20. ____________________ jacking is when hackers cruise through a business district or

neighborhood with a Wi-Fi enabled notebook computer to intercept signals.

MATCHING

Identify the letter of the choice that best matches the phrase or definition.

a. cryptographic key g. communications protocol

b. ciphertext h. bandwidth

c. gateway i. MAC address

d. node j. collision

e. narrowband k. packet

f. infrared light l. RF signals

1. A generic term for any device or software code used to join two networks

2. Systems with less capacity, such as dial-up Internet access

3. A set of rules for efficiently transmitting data from one network node to another

4. Occurs when two network devices on an Ethernet attempt to transmit packets at the same time

5. Also called radio waves

6. The transmission capacity of a communications channel

7. A word, number, or phrase that must be known to decrypt or encrypt a message

8. Carries data signals only for short distances and with a clear line of sight

9. A parcel of data that is sent across a computer network

10. An encrypted message

11. Each connection point on a network

12. A unique number assigned to a network interface card when it is manufactured