Networking Test 4 Study Guide

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True/False

Indicate whether the statement is true or false.

____ 1. IPX/SPX is considered the protocol suite of the Internet, and it is the most widely used protocol suite in LANs.

____ 2. The Internetwork layer is the layer that handles network configuration and is considered the heart of the TCP/IP protocol suite.

____ 3. The Transport layer uses port numbers to identify the source and destination Application-layer protocol of the data that it contains.

____ 4. The Transport layer is the same in both the OSI model and the TCP/IP model.

____ 5. The maximum transmission unit for Ethernet is 1518 bytes.

Multiple Choice

Identify the choice that best completes the statement or answers the question.

____ 6. The Transport layer deals with which unit of information?

a. frame b. packet c. signal d. segment

____ 7. Which of the following is not a function of the Network Access layer?

a. transmits and receives bit signals b. delivers packets efficiently

c. provides a MAC address for the network interface

d. receives packets form the Internetwork layer and creates the frame ____ 8. In what layer does the NIC operate?

a. Network Access b. Internetwork c. Transport d. Application

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____ 9. In which layer does a router operate?

a. Network Access b. Internetwork c. Transport d. Application

____ 10. Which protocol is responsible for determining the MAC address associated with each IP address and keeping a table of its results?

a. MAC b. DNS c. ARP d. NAT

____ 11. TCP establishes a connection with the destination device using which process?

a. encapsulation b. flow control c. windowing

d. three-way handshake

____ 12. Which of the following is not an Application layer protocol?

a. DNS b. TCP c. DHCP d. SMTP

____ 13. An IP address consists of four octets separated by periods. Which part of this address denotes its class?

a. first octet b. second octet c. third octet d. fourth octet

____ 14. How many host addresses are available on a Class C network?

a. 254 b. 256 c. 65534 d. 65536

____ 15. What is the decimal equivalent to the binary number 11000001?

a. 97 b. 160 c. 161 d. 193

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____ 16. How many bits are in an IPv6 address?

a. 32 b. 48 c. 64 d. 128

____ 17. The last 64 bits of an IPv6 address are the interface identifier. Where is that number derived from?

a. via DHCP b. a static entry c. from an ISP d. the MAC address

____ 18. What is the decimal equivalent to the hexadecimal number D?

a. 13 b. 15 c. 12 d. 10

____ 19. How many bits are available in an IPv6 network for creating subnets when the prefix is /48 and the host ID is 64 bits?

a. 48 b. 16 c. 32 d. 64

____ 20. Which layer is responsible for establishing a connection between the source and destination?

a. Application b. Session c. Transport d. Presentation

____ 21. Which layer of the OSI model is responsible for encryption and decryption?

a. Application b. Presentation c. Session d. Transport ____ 22. What is a PDU?

a. It is an Application layer protocol that handles delivery of messages.

b. It is a unit of measurement for the maximum amount of data that can be transferred.

c. It is the name given to the unit of information used by each layer.

d. It is a Network layer protocol that handles path determination

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____ 23. What information would you find in the header of a Transport layer PDU?

a. destination IP address b. cyclic redundancy check c. source MAC address d. window size

____ 24. At each layer of the OSI model, data is appended to the original message and then sent on to the next lower layer. What is this process called?

a. encapsulation b. deencapsulation c. packetization d. checkpointing

____ 25. What does the Transport layer use to make sure that a message is reassembled correctly on the receiving device?

a. source port number b. window Size

c. destination port number d. sequence number

____ 26. What is the IEEE standard that governs all forms of Ethernet media?

a. 802.11 b. 802.3 c. 802.15 d. 802.2

____ 27. Which is the IEEE standard that sets the standards for wireless networking?

a. 802.16 b. 802.3 c. 802.15 d. 802.11

____ 28. Which layer is responsible for determining the best path a packet should travel across an internetwork?

a. Network b. Transport c. Session d. Data Link

____ 29. One job that a router performs is that of gatekeeper, which means that it can be configured to only allow certain packets access into the network based on a list of rules. What is that process called?

a. media control b. packet forwarding c. access control d. signal bounce

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____ 30. You are working at the help desk and you get a message that a user cannot access the Internet. You open a command prompt, ping the workstation’s IP address, and get a response. You ask the user to try the Internet again. He does so with the same result— no connection. Which type of device is most likely to be the problem?

a. Physical layer device b. Data Link layer device c. Network layer device d. Presentation layer device

____ 31. Which layer has been subdivided into the Logical Link Control sublayer and the Media Access Control sublayer?

a. Physical b. Data Link c. Network d. Transport

____ 32. What layer is responsible for making sure that the data that it sends and receives is in a format that the receiving and sending computers can understand?

a. 7 b. 6 c. 5 d. 4

____ 33. At what layer do NICs operate?

a. Transport b. Data Link c. Physical d. Network

____ 34. Which layer is responsible for the encoding of signals?

a. 3 b. 1 c. 5 d. 7

____ 35. The Transport layer segments data into smaller chunks, the size of which is determined by which of the following?

a. MTU b. LLC c. PDU d. TCP

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Completion

Complete each statement.

36. An IP address is composed of two parts, one is the ____________ ID and one is the host ID.

37. ____________are sets of rules and procedures that dictate communication and behavior.

38. ___________ is a way of breaking a large address space into more, smaller, address spaces.

39. The four layers of the TCP/IP protocol suite are Application, ____________, Internetwork, and Network Access.

40. An address that can only be used on the internal network and cannot be used to access the Internet is called a ____________ address.

41. The ____________ reference model is a general framework for networking systems that uses a layered approach to reduce its complexity.

42. The ____________ layer is the bottom layer, whose job it is to convert bits into signals and vice versa.

43. The process of stripping the header and trailer from a PDU is called ____________.

44. The PDU at the Data Link layer is called a ____________.

45. The ____________ layer of the TCP/IP model combines the top three layers of the OSI model into one layer.

Matching

a. ARP b. APIPA c. CIDR d. DNS e. DHCP f. IMAP g. NAT h. POP3 i. TCP j. UDP

____ 46. method of IP addressing that allows more efficient use of IP addresses

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____ 47. dynamically configures IP address

____ 48. protocol in which e-mail is downloaded to the host computer ____ 49. Transport layer protocol that is connectionless

____ 50. translates private IP address to public IP address ____ 51. resolves IP address to MAC address

____ 52. Transport layer protocol that is connection-oriented and reliable

____ 53. type of address that is automatically assigned when no DHCP server can be contacted

____ 54. protocol in which only e-mail headers are downloaded to the host until the message is opened ____ 55. resolves computer names to IP addresses

Short Answer

56. What are four tasks or responsibilities of the Internetwork layer?

57. Briefly describe ARP, include the meaning of its acronym and the layer in which it functions.

58. Explain how Tracert uses an ICMP packet and the TTL value to map the path to an IP address.

59. How does TCP provide flow control and reliability?

60. Briefly describe the three-way handshake that TCP uses to establish a connection.

61. What does APIPA stand for, and what does it do?

62. What is the function of DNS, and at which layer does it operate?

63. Briefly describe an IP address.

64. A range of addresses is reserved for private addressing in each class. What are those ranges?

65. What is the difference between TCP and UDP?

66. What are the benefits to using a layered approach?

67. List the layers of the OSI model from the top down, along with their counterparts in the TCP/IP model.

68. Name the PDU at each layer of the OSI model.

69. What does “802” refer to in the IEEE 802 standard?

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71. How does window size provide flow control?

72. What does the Data Link layer do with a frame after it receives it?

73. What is encoding, and where does it take place?

74. In regards to the OSI Reference Model, what is peer communication?

75. What are the sublayers of the Data Link layer, and what do they do?

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Networking Test 4 Study Guide Answer Section

TRUE/FALSE

1. ANS: F PTS: 1 REF: Page 208

2. ANS: T PTS: 1 REF: Page 213

MULTIPLE CHOICE

6. ANS: D PTS: 1 REF: Page 209

7. ANS: B PTS: 1 REF: Page 213

8. ANS: A PTS: 1 REF: Page 210

10. ANS: C PTS: 1 REF: Page 216

15. ANS: D PTS: 1 REF: Pages 239-242

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COMPLETION

36. ANS: network

PTS: 1 REF: Page 214 37. ANS: Protocols

PTS: 1 REF: Page 208 38. ANS: Subnetting

PTS: 1 REF: Page 236 39. ANS: Transport

PTS: 1 REF: Page 209 40. ANS: private

PTS: 1 REF: Page 233 41. ANS: OSI

PTS: 1 REF: Page 262 42. ANS: Physical

PTS: 1 REF: Page 274 43. ANS: deencapsulation

PTS: 1 REF: Page 268 44. ANS: frame

PTS: 1 REF: Page 273 45. ANS: Application

PTS: 1 REF: Page 265

MATCHING

47. ANS: E PTS: 1 REF: Page 227

48. ANS: H PTS: 1 REF: Page 226

49. ANS: J PTS: 1 REF: Page 222

50. ANS: G PTS: 1 REF: Page 234

52. ANS: I PTS: 1 REF: Page 222

54. ANS: F PTS: 1 REF: Page 226

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SHORT ANSWER

56. ANS:

It is responsible for routing packets through the internetwork. It uses ARP to find MAC addresses from IP addresses. It is responsible for delivering packets efficiently. It is responsible defining and verifying source and destination IP addresses.

57. ANS:

ARP stands for Address Resolution Protocol, and it functions in the Internetwork layer. ARP’s job is to find the MAC address of a device given its IP address.

58. ANS:

Tracert sends an ICMP to the IP address with a TTL value of 1. When the first router receives the packet it decrements the TTL to 0, discards the packet, and sends a TTL-expired packet to the sending computer. When the sending computer receives the TTL-expired packet, it notes the address of the first router. Then it sends a second packet with a TTL of 2. This time the packet gets to the second router, is discarded, and the second router sends a TTL-expired packet. When Tracert receives this response, it notes the address of the second router. This continues until the packet reaches the intended IP address.

59. ANS:

TCP sets a maximum number of bytes to transmit before it must receive an acknowledgment of receipt from the receiving station. If it does not receive an acknowledgement within a certain period, it assumes an error has occurred and begins to retransmit the data since the last acknowledgement was received.

60. ANS:

When a client computer makes a request, TCP begins the session by sending the receiving computer, which is typically a server, a SYN segment. If the server is not busy, then it sends back an ACK-SYN packet

acknowledging the creation of the session. Then the client computer sends back an ACK segment to finalize the connection.

61. ANS:

APIPA stands for Automatic Private IP Addressing. APIPA provides a computer with an IP address when the computer cannot contact a DHCP server.

62. ANS:

DNS allows computers to contact other computers using a familiar name instead of a hard-to-remember IP address. DNS keeps records of which name corresponds to which IP address in a DNS cache so that a frequently accessed address can be resolved quickly. DNS is an Application layer protocol.

PTS: 1 REF: Pages 227-228

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63. ANS:

An IP address is a 32-bit number divided into 4, 8-bit octets that are separated by periods, which is called dotted decimal notation. The first octet denotes the class of the IP address. Each octet can have a value from 0 to 255. The address has two parts—one is the network ID and the other is the host ID. The network portion of the address is determined by the subnet mask.

64. ANS:

For Class A, all addresses beginning with 10 For Class B, addresses from 172.16 to 172.31

For Class C, addresses from 192.168.0 to 192.168.255 PTS: 1 REF: Page 233

65. ANS:

TCP and UDP are both Transport layer protocols, but TCP is considered reliable and UDP is considered unreliable. TCP is connection-oriented, which means that it forms a connection before it transmits data, thereby ensuring that the recipient is ready and waiting. The sender also waits for acknowledgements after sending data. This behavior makes it reliable. UDP is connectionless, so it sends data and doesn’t wait to see whether anyone is listening; no acknowledgements are involved in the communication.

66. ANS:

In a layered approach, each layer is only responsible for a specific task instead of the end-to-end

communication. Therefore, when a problem occurs, it is easier to pinpoint the layer that is affected and then troubleshoot only that issue. In addition, by using a layered approach, upgrades in technology can be to individual layers without affecting the others.

67. ANS:

Application—Application Presentation—Application Session—Application Transport—Transport Network—Internetwork Data Link—Network Access Physical—Network Access

68. ANS:

The PDU for the Application, Presentation, and Session layers is data. The PDU at the Transport layer is a segment, at the Network layer is a packet, and at the Data Link layer is a frame. The final PDU is in the form of bits at the Physical layer.

69. ANS:

It is the project name that was given to the standard that defines all physical elements of networking communications. It represents the year and the month that the project began—February of 1980.

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70. ANS:

The window size is a negotiated amount between the transmitting and receiving devices that sets the amount of data that can be transferred before an acknowledgement must be sent and received.

71. ANS:

When the window size is reached and no acknowledgement is received, then the transmitting device assumes there is a problem and begins to retransmit. If this happens, the window size is reduced, thus causing the transmitting device to send a smaller amount of data and relieving the load on the receiving device.

72. ANS:

First, it checks the destination MAC address to make sure that it is intended for itself. Then it calculates the CRC and compares it to the incoming frame’s CRC to make sure that the values are the same. Next, it strips off the header and trailer information. Then the resulting packet is sent up to the Network layer.

73. ANS:

Encoding is a process performed by the Physical layer that takes the frame from the Data Link layer and changes it into 1s and 0s to be transmitted onto the medium. The type of signal that it is changed into is dependent on the type of media.

74. ANS:

Peer communication refers to the way that each layer on a transmitting computer communicates with the same layer on the receiving computer, just as though they were in direct contact.

75. ANS:

The first layer is the Logical Link Control sublayer, and it is responsible for handling some kinds of error recovery and flow control. The second layer is the Media Access Control sublayer, and it is responsible for providing the MAC address. It also controls the way in which a device will access the network.

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_____ 1.F

_____ 2.T

_____ 3.T

_____ 4.T

_____ 5.T

_____ 6.D

_____ 7.B

_____ 8.A

_____ 9.B

_____ 10.C

_____ 11.D

_____ 12.B

_____ 13.A

_____ 14.A

_____ 15.D

_____ 16.D

_____ 17.D

_____ 18.A

_____ 19.B

_____ 20.B

_____ 21.B

_____ 22.C

_____ 23.D

_____ 24.A

_____ 25.D

_____ 26.B

_____ 27.D

_____ 28.A

_____ 29.C

_____ 30.C

_____ 31.B

_____ 32.B

_____ 33.B

_____ 34.B

_____ 35.A

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_____ 47.E _____ 48.H _____ 49.J _____ 50.G _____ 51.A _____ 52.I _____ 53.B _____ 54.F _____ 55.D