Cisco CCNA Chapter 1

  1. A recieving host has failed to recieve all of the segments that it should acknowledge.  What can the host do to improve the reliability of this communications session?

    A. Send a different source port number.

    B. Restart the virtual circuit.

    C. Decrease the sequence number.

    D. Decrease the window size.
    ( D ) - A recieving host can control the transmitter by using flow control (TCP uses Windowing by default).  By decreasing the window size, the receiving host can slow down the transmitting host so the receiving host does not overflow its buffers.
  2. Which fields are contained within IEE Ethernet frame header? ( Choose two)

    A. Source and destination MAC address

    B. Source and destination network address

    C. Source and destination MAC address and source and destination network address

    D. FCS field
    ( A & D ) - An Ethernet frame has source and destination MAC addresses, an Ether-type field to identify the Network layer protocol, the data, and the FCS field that holds the answer to the CRC
  3. Which layer 1 devices can be used to enlarge the area covered by a single LAN segment? (Choose two)

    A. Switch

    B. NIC

    C. Hub

    D. Repeater

    E. RJ-45 transceiver
    ( C & D ) - Not that you really want to enlarge a single collision domain, but a hub (multiport repeater) will provide this for you.
  4. Segmentation of a data stream happens at which layer of the OSI model?

    A. Physical

    B. Data Link

    C. Network

    D. Transport
    ( D ) - The Transport Layer receives large data streams from the upper layers and breaks these up into smaller pieces called segments.
  5. Which of the following describe router finctions? (Choose four)

    A. Packet switching

    B. Collision prevention

    C. Packet filtering

    D. Broadcast domain enlargement

    E. Internetwork communication

    F. Broadcast forwarding

    G. Path selection
    ( A, C, E, & G ) - Routers provide packet switching, packet filtering, internetwork communications, and path selection
  6. Routers operate at layer_____.  Lan switches operate at layer_____. Ethernet hubs operate at layer____.  Word processing operates at layer_____.

    A. 3,3,1,7

    B. 3,2,1, none

    C. 3,2,1,7

    D. 2,3,1,7

    E. 3,3,2, none
    ( B ) - Routers operate at layer 3.  LAN switches operate at layer 2.  Ethernet hubs operate at layer 1.  Word processing applications communicate to the Application layer interface, but do not operate at layer 7, so the answer would be NONE.
  7. When data is encapsulated, which is the correct order?

    A. Data, frame, packet, segment, bit

    B. Segment, data, packet, frame, bit

    C. Data, segment, packet, frame, bit

    D. Data, segment, frame, packet, bit
    ( C ) - The encapsulation method is:

    Data, segment, packet, frame, bit
  8. Why does the data communication industry use the layered OSI reference model? (Choose two)

    A. It devides the network communication process into smaller and simplier components,thus aiding component development, design, and troubleshooting.

    B. It enables equipment from different vendors to use the same electronic components, thus saving research and development funds.

    C. It supports the evolution of multiple competing standards and thus provides business opportunities for equipment manufacturers.

    D. It encourages industry standardization by defining what functions occur at each layer of the model.

    E. It provides a framework by which changes in functionality in one layer require changes in other layers.
    ( A & D ) - The main advantage of a layered model is that it can allow application developers to change aspects of a program in just one layer of the layer model's specifications.  Advantages of using the OSI layered model include, but are not limited to, the following:  It devides the network communications process into smaller and simplier components, thus aiding component development, design, & trouble-shooting;  it allows multiple-vendor development through standardization of networkcomponents; it encourages industry standardization by defining what functions occur at each layer of the model; it allows various types of network hardware and software to communicate; and it prevents changes in one layer from affecting other layers, so it does not hamper development.
  9. What are two purposes for segmaentation with a bridge?

    A. To add more broadcast domains

    B. To create more collision domains

    C. To add more bandwidth for users

    D. To allow more broadcasts for users
    ( B & C ) - Bridges break up collision domains, which allow more bandwidth for users.
  10. Which of the following are unique characteristics of half-duplex Ethernet when compared to full-duplex Ethernet? (Choose two)

    A. Half-duplex Ethernet operates in a shared collision domain.

    B. Half-duplex Ethernet operates in a private collision domain.

    C. Half-duplex Ethernet has higher effective throughput.

    D. Half-duplex Ethernet has lower effective throughput.

    E. Half-duplex Ethernet operates in a private broadcast domain.
    ( A & D ) - Unlike full-duplex, half-duplex Ethernet operates in a shared collision domain, and it has a lower effective throughput than full-duplex.
  11. You want to implement a network medium that is not susceptible to EMI.  Which type of cabeling should you use?

    A. Thicknet coax

    B. Thinnet coax

    C. Category 5 UTP cable

     D. Fiber-optic cable
    ( D ) - Fiber-Optic cable provides a more secure, long-distance cable that is not susceptible to EMI interferance at high speeds.
  12. Acknowledgements, sequencing, and flow control are characteristics of which OSI layer?

    A. Layer 2

    B. Layer 3

    C. Layer 4

    D. Layer 7
    ( C ) - A reliable Transport layer connection uses acknowledgements to make sure all the data is transmitted and recieved reliably.  A reliable connection is defined by a virtual circuit that uses achknowledgements, sequencing, and flow control, which are characteristics of the Transport Layer (layer 4).
  13. Which of the following are types of flow control? (Choose all that apply)
    ( A, C, & D) - The common types of flow control are buffering, windowing, and congestion avoidance
  14. Which of the following types of connections can use full-duplex? (Choose three)
    ( B,C, & E ) - Hubs cannot run full-duplex Ethernet.  Full-duplex must be used on a point-to-point connection between two devices capable of running full dupex. Switches and hosts can run full duplex between each other, but hub can run ful duplex.
  15. What is the purpose of flow control?

    A. To ensure that data is retransmitted if an acknowledgement is not recieved

    B. To reassemble segments in the correct order at the destination device

    C. To provide a means for the reciever to govern the amount of data sent by the sender

    D. To regulate the size of each segment
    ( C ) - Flow control allows the recieiving device to control the tramsmitter so the recieving device's buffer does not overflow.
  16. Which three statements are true about the operation of a full-duplex Ethernet network?

    A. There are no collision in Full-Duplex mode.

    B. A dedicated switch port is required for each full-duplex node.

    C. Ethernet hub ports are preconfigured for full-duplex mode.

    D. In a full-duplex environment, the host network card must check for the availability of the network media before transmitting.

    E. The host network card and the switch port must be capable of operating in full-duplex mode.
    ( A, B, & E ) - Full-duplex means you are using both wire pairs simultanously to send and receive data.  You must have a dedicated switch port for each node,  which means you will not have collisions.  both the host network card and the switch port must be capable and set to work in full-duplex mode.
  17. What type of RJ45 UTP cable is used between switches?

    A. Stright-through

    B. Crossover Cable

    C. Crossover cable with a CSU/DSU

    D. Crossover with a router in between the two switches
    ( B ) - To connect two switches together, you would use a RJ45 UTP crossover cable.
  18. How does a host on an Ethernet LAN know when to transmit after a collision has occured? (Choose two)

    A. In a CSMA/CD collision domain, mutiple stations can successfully transmit data sinultanously.

    D. In a CSMA/CD collision domain, stations must wait until the media is not in use before transmitting.

    E. After a collision, all stations run a random backoff algorithm.  When the backoff delay period has expired, all stations have equal priority to transmit data.

    F. After collision, all stations involved run an identical backoff algorithm and then synchronize with each other prior to transmitting data.
    ( B & E ) - Once transmitting stations on an Ethernet segment hear a collision, they send an extended jam signal to ensure that all stations recognize the collision.  After the jamming is complete, each sender waits a predetermined amount of time, plus a random time.  After both timers expire, they are free to transmit, but they must make sure the media is clear before transmitting and that they all have equal priority.
  19. What type of RJ45 UTP cable do you use to connect a PC's COM port to a router or switch console port?

    A. Straight-through

    B. Crossover cable

    C. Crossover cable with a CSU/DSU

    D. Rolled
    ( D ) - To connect to a router or a switch console port, you would use an RJ45 UTP rolled cable.
  20. You have the following binary number:


    What are the deciaml & hexadecimal equivalents?

    A. 69 / 0x2102

    B. 183 B7

    C. 173 / A6

    D. 83 / 0xC5
    ( B ) - You must be able to take a binary number and convert it into both decimal & hexadecimal. 

    183 & B7
  21. Which layer chooses and determines the availability of communicating partners along with the resources necessary to make the connection, coordinates partnering applications, and forms a consensus on procedures for controlling data integrity and error recovery?
    Application Layer (software designer chooses)
  22. Which layer is responsibile for converting data packets from the Data Link Layer into electrical signals? 
    Physical Layer
  23. At which layer is routing implemented, enabling connections and path selection between two end systems?
    Network Layer (layer 3)
  24. Which layer defines how data is formatted, presented, encoded, and converted for use on the network?
    Presentation  Layer (layer 6)
  25. Which layer is responsible for creating, managing, and terminating sessions between applications?
    Session Layer (layer 5)
  26. Which layer ensures the trustworthy transmission of data accross a physical link and is primarily concerned with physical addressing, line descipline, network topology, error notification, order delivery of frames, and flow control?
    PDUs at the Data Link Layer
  27. Which layer is used for reliable communication between nodes over the network and provides mechanisms for establishing, maintaining, and terminating vitual circuits; transport-fault detection and recovery; and contolling the flow ofinormation?
    Transport Layer (layer 4)
  28. Which layer provides logical addressing that routers will use for path determination?
    Network Layer (layer 3)
  29. Which layer specifies voltage, wire speed, and pinout cables and moves bits between device?
    Physical Layer (layer 1)
  30. Which layer combines bits into bytes and bytes into frames, uses MAC addressing, and provides error detection?
    Data Link Layer (layer 2)
  31. Which layer is responsible for keeping data from different applications seperate on the network?
    Session Layer (layer 5)
  32. Which layer is represented by frames?
    Data Link Layer (layer 2)
  33. Which layer is represented by segments?
    Transport Layer (layer 4)
  34. Which layer is represented by packets?
    Network Layer (layer 3)
  35. Which layer is represented by bits?
    Physical Layer (layer 1)
  36. Put the following in order of encapsulation:

    Segments, packets, frames, bits
  37. Which layer segments and reassembles data into a data stream?
    Transport Layer (layer 4)
  38. Which layer provides the physical transmission of the data and handles error notification, network topology, and flow control?
    Data Link Layer (layer 2)
  39. Which layer manages device addressing, tracks the location of devices on the network, and determines the best way to move data?
    Network Layer (layer 3)
  40. What is the bit length and expression form of a MAC address?
    48 bits (6 bytes * 8 bits) express as a hexadecimal
  41. This device sends and recieves information about the network layer
    A router
  42. This layer create virtual circuits before transmitting between two end stations?
    Transport Layer (layer 4)
  43. This layer uses service access points.
    The Data Link Layer (layer 2) using LLC sub-layer
  44. This device uses hardware addresses to filter a network.
    A Bridge or a Switch
  45. Ethernet is defined at these layers.
    At the Data Link & Physical Layers
  46. This layer supports flow control and sequencing.
    The Transport Layer (layer 4)
  47. This device can measure the distance to a remote network.
    A router
  48. Logical addressing is used at this layer.
    The Network Layer (layer 3)
  49. Hardware addresses are defined at this layer.
    The Data Link Layer (layer 2) using the MAC sub-layer
  50. This device creates one big collision domain and one large broadcast domain.
    A hub
  51. This device creates smaller collision domains, but the network is still one large broadcast domain.
    A switch or a bridge
  52. This device can never run full duplex.
    A hub
  53. This device breaks up collision domains and broadcast domains.
    A Router
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Cisco CCNA Chapter 1