16 марта 2010 г.

ICND1/Chapter 1/ Review Questions with Answers

Вопросы и ответы из Chapter 1 книги  Cisco Press "Interconnecting Cisco Network Devices, Part 1 (ICND1): CCNA Exam 640-802 and ICND1 Exam 640-822" для повторения перед экзаменом.

1. Which three statements about networks are accurate? (Choose three.)
a. Networks transmit data in many kinds of environments, including homes, small businesses, and   large enterprises.
b. A main office can have hundreds or even thousands of people who depend on network access to do their jobs.
c. A network is a connected collection of devices that can communicate with each other.

2. What is the purpose of a router?
a. To interconnect networks and choose the best paths between them

3. What is the purpose of a switch?
c. To serve as the endpoint in the network, sending and receiving data

4. What is the purpose of network interconnections?
d. To provide network attachment to the end systems and intelligent switching of the data within the local network

5. Which resource is not sharable on a network?
a. memory

6. Which three of the following are common network applications? (Choose three.)
a. e-mail
b. collaboration
d. databases

7. Match each network characteristic to its definition.
_D_1. speed
_G_2. cost
_C_3. security
_A_4. availability
_E_5. scalability
_B_6. reliability
_F_7. topology
a. Indicates how easily users can access the network
b. Indicates how dependable the network is
c. Indicates the protection level of the network itself and the data that is transmitted
d. Indicates how fast data is transmitted over the network
e. Indicates how well the network can accommodate more users or data transmission requirements
f. Indicates the structure of the network
g. Indicates the general price of components, installation, and maintenance of the network

8. Which statements about physical networking topologies are accurate? (Choose two.)
a. A physical topology defines the way in which the computers, printers, network devices, and other devices are connected.
b. There are two primary categories of physical topologies: bus and star.

9. Which statement about logical topologies is accurate?
c. A logical topology describes the paths that the signals travel from one point on a
network to another.

10. Match each topology type to its correct description.
_B_1. All of the network devices connect directly to each other in a linear
fashion.
_A_2. All of the network devices are directly connected to one central point with
no other connections between them.
_D_3. All of the devices on a network are connected in the form of a circle.
_C_4. Each device has a connection to all of the other devices.
_E_5. At least one device maintains multiple connections to other devices.
_F_6. This design adds redundancy to the network.
a. star
b. bus
c. mesh
d. ring
e. partial-mesh
f. dual-ring

11. Which two statements about wireless networks are accurate? (Choose two.)
a. Instead of cables, wireless communication uses RFs or infrared waves to transmit data.
b. To receive the signals from the access point, a computer needs to have a wireless adapter card or wireless NIC.
c. For wireless LANs, a key component is a router, which propagates signal distribution.
d. Wireless networks are not very common, and generally only large corporations use them.

12. What is the main threat to a closed network?
d. Misuse by employees

13. Which two factors have recently influenced the increase in threats from hackers? (Choose two.)
b. Hacker tools have become more sophisticated.
d. Hacker tools require less technical knowledge to use.

14. Which of the following four attacks are classified as access attacks? (Choose two.)
a. Password attacks
c. Trojan horse

15. Which two statements about the purpose of the OSI model are accurate? (Choose two.)
a. The OSI model defines the network functions that occur at each layer.
b. The OSI model facilitates an understanding of how information travels throughout
a network.

16. Match each OSI layer to its function.
_E_1. physical
_C_2. data link
_A_3. network
_D_4. transport
_G_5. session
_B_6. presentation
_F_7. application
a. Provides connectivity and path selection between two host systems that might be located on geographically separated networks
b. Ensures that the information sent at the application layer of one system is readable by the application layer of another system
c. Defines how data is formatted for transmission and how access to the network is controlled
d. Segments data from the system of the sending host and reassembles the data into a data stream on the system of the receiving host
e. Defines the electrical, mechanical, procedural, and functional specifications for activating, maintaining, and deactivating the physical link between end systems
f. Provides network services to the applications of the user, such as e-mail, file transfer, and terminal emulation
g. Establishes, manages, and terminates sessions between two communicating hosts and also synchronizes dialogue between the presentation layers of the two hosts and manages their data exchange

17. Arrange the steps of the data encapsulation process in the correct order.
_F_1. Step 1
_C_2. Step 2
_A_3. Step 3
_B_4. Step 4
_E_5. Step 5
_D_6. Step 6
_G_7. Step 7
_H_8. Step 8
a. The presentation layer adds the presentation layer header (Layer 6 header) to the data. This then becomes the data that is passed down to the session layer.
b. The session layer adds the session layer header (Layer 5 header) to the data. This then becomes the data that is passed down to the transport layer.
c. The application layer adds the application layer header (Layer 7 header) to the user data. The Layer 7 header and the original user data become the data that is passed down to the presentation layer.
d. The network layer adds the network layer header (Layer 3 header) to the data. This then becomes the data that is passed down to the data link layer.
e. The transport layer adds the transport layer header (Layer 4 header) to the data This then becomes the data that is passed down to the network layer.
f. The user data is sent from an application to the application layer.
g. The data link layer adds the data link layer header and trailer (Layer 2 header and trailer) to the data. A Layer 2 trailer is usually the frame check sequence, which is used by the receiver to detect whether the data is in error. This then becomes the data that is passed down to the physical layer.
h. The physical layer then transmits the bits onto the network media.

18. At which layer does de-encapsulation first occur?
b. data link

19. Match each layer with the function it performs in peer-to-peer communication.
_B_1. network layer
_A_2. data link layer
_C_3. physical layer
a. Encapsulates the network layer packet in a frame
b. Moves the data through the internetwork by encapsulating the data and attaching a header to create a packet
c. Encodes the data link frame into a pattern of 1s and 0s (bits) for transmission on the medium (usually a wire)

20. What is the function of a network protocol?
a. Uses sets of rules that tell the services of a network what to do

21. Match each TCP/IP stack layer to its function.
_D_1. Provides applications for file transfer, network troubleshooting, and Internet activities, and supports the network
_B_2. Defines how data is formatted for transmission and how access to the network is controlled
_A_3. Defines the electrical, mechanical, procedural, and functional specifications for activating, maintaining, and deactivating the physical linkbetween end systems
_C_4. Provides routing of data from the source to a destination by defining the packet and addressing scheme, moving data between the data link and transport layers, routing packets of data to remote hosts, and performing fragmentation and reassembly of data packets
_E_5. Provides communication services directly to the application processes running on different network hosts
a. physical layer
b. data link layer
c. Internet layer
d. transport layer
e. application layer

22. Which area of the OSI model and the TCP/IP stack is most diverse?
a. network layer

23. How many bits are in an IPv4 address?
b. 32

24. In a Class B address, which of the octets are the host address portion and are assigned locally?
d. The third and fourth octets are assigned locally.

25. The address 172.16.128.17 is of which class?
b. Class B

26. Which of the following statements is true of a directed broadcast address?
c. A directed broadcast address is an address that has all 1s in the host field.

27. Which two of these addresses are private IP addresses? (Choose two.)
a. 10.215.34.124
b. 172.16.71.43

28. Which three statements about IP are accurate? (Choose three.)
a. IP is a connectionless protocol.
b. IP uses relational addressing.
f. IP delivers data on a best-effort basis.

29. Which three statements about TCP are accurate? (Choose three.)
b. TCP is a connection-oriented protocol.
d. TCP packets are numbered and sequenced so that the destination can reorder packets and determine if a packet is missing.
f. Upon receipt of one or more TCP packets, the receiver returns an acknowledgement to the sender indicating that it received the packets.

30. Which characteristic is similar between TCP and UDP?
a. Operates at Layer 4 (transport layer) of the OSI model and the TCP/IP stack

31. When a single computer with one IP address has several websites open at once, this is called _____.
b. session multiplexing

32. TCP is best for which two of the following applications? (Choose two.) (Understanding TCP/IP’s Transport and Application Layers)
a. E-mail
c. Downloading

33. Which three of the following characteristics apply to UDP? (Choose three.)
a. Packets are treated independently.
c. Packet delivery is not guaranteed.
d. Lost or corrupted packets are not resent.

34. Which two of the following characteristics apply to TCP? (Choose two.)
c. Lost or corrupted packets are resent.
d. TCP segment contains a sequence number and an acknowledgment number.

35. Proprietary applications use which kind of port?
c. Registered ports

36. Ports that are used only for the duration of a specific session are called _____.
a. dynamically assigned ports

37. The source port in both a UDP header and a TCP header is a _____.
d. 16-bit number of the calling port

38. Which field in a TCP header ensures that data arrives in correct order?
b. Sequence number

39. In a TCP connection setup, the initiating device sends which message?
c. Send SYN

40. Acknowledgment and windowing are two forms of _____.
a. flow control

41. Windowing provides which of the following services?
d. The sender can transmit a specified number of unacknowledged segments.

42. Sequence numbers and acknowledgment numbers are found where?
b. TCP header

43. What organization is responsible for Ethernet standards?
b. IEEE

44. What are three characteristics of Ethernet 802.3? (Choose three.)
a. Based on the CSMA/CD process
c. Specifies the physical layer (Layer 1)
e. Specifies the MAC portion of the data link layer (Layer 2)

45. Which statement about an Ethernet address is accurate?
d. Both the destination and source addresses consist of a 6-byte hexadecimal number.

46. Which statement about MAC addresses is accurate?
a. A MAC address is a number in hexadecimal format that is physically located on the NIC.

47. Which statement about NICs is accurate?
b. The NIC communicates with the network through a serial connection and communicates with the computer through a parallel connection.

48. Which minimum category of UTP is required for Ethernet 1000BASE-T?
d. Category 5e
49. Match the UTP categories to the environments in which they are most commonly used.
_D_1. Category 1
_F_2. Category 2
_G_3. Category 3
_E_4. Category 4
_A_5. Category 5
_B_6. Category 5e
_C_7. Category 6
a. Capable of transmitting data at speeds up to 100 Mbps
b. Used in networks running at speeds up to 1000 Mbps (1 Gbps)
c. Consists of 4 pairs of 24-gauge copper wires, which can transmit data at speeds up to 1000 Mbps
d. Used for telephone communications; not suitable for transmitting data
e. Used in Token Ring networks; can transmit data at speeds up to 16 Mbps
f. Capable of transmitting data at speeds up to 4 Mbps
g. Used in 10BASE-T networks; can transmit data at speeds up to 10 Mbps
50. Which three characteristics pertain to UTP? (Choose three.)
b. An insulating material covers each of the individual copper wires in UTP cable.
c. The wires in each pair are wrapped around each other.
d. There is limited signal degradation from EMI and RFI.

6 комментариев:

Анонимный комментирует...

че-то не понял а зачем это? в книге есть правильные ответы в конце

Dave комментирует...

Это для того чтобы перед экзаменом читать. Для того чтобы некоторые понятия и термины очень хорошо помнить.

Анонимный комментирует...

В этом посте есть неправильные ответы. Например: 22, 28

Dave комментирует...

С 22-м согласен. Это была невнимательность с моей стороны. А вот в 28-м я не могу понять что неправильно. На мой взгляд все ок. Поделитесь соображениями, если не трудно...

Анонимный комментирует...

а в pdf можно?

Dave комментирует...

[Ctrl]+a, [Ctrl]+C, [Ctrl]+v -> doPDF

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