quis chapter 5 CCNA

1. A Layer 2 switch is used to switch incoming frames from a 1000BASE-T port to a port connected to a 100Base-T network. Which method of memory buffering would work best for this task?
   shared memory buffering  *
Refer to curriculum topic: 5.2.2
With shared memory buffering, the number of frames stored in the buffer is restricted only by the size of the entire memory buffer and not limited to a single port buffer. This permits larger frames to be transmitted with fewer dropped frames. This is important to asymmetric switching, which applies to this scenario, where frames are being exchanged between ports of different rates. With port-based memory buffering, frames are stored in queues that are linked to specific incoming and outgoing ports making it possible for a single frame to delay the transmission of all the frames in memory because of a busy destination port. Level 1 cache is memory used in a CPU. Fixed configuration refers to the port arrangement in switch hardware.


2. What is the decimal equivalent of the hexadecimal value of 3F?
  63 *
Refer to curriculum topic: 5.1.2
In order to convert a hexadecimal number to decimal, consider that the digit to the far right represents the 1s column where values 0 through F can appear.  A hexadecimal value of A equals the decimal number 10. B equals 11, and so on through F equaling 15. The value of F in the number F equals 15. Next consider the value of 3 in the hexadecimal number of 3F. That place holder is the 16s column. Multiple the number 3 times 16 for a total of 48. Add 48 to 15 for the grand total of 63. Hexadecimal 3F equals a decimal value of 63.?

3. Which action is taken by a Layer 2 switch when it receives a Layer 2 broadcast frame?
  It sends the frame to all ports except the port on which it received the frame. *
Refer to curriculum topic: 5.2.1
When a Layer 2 switch receives a frame with a broadcast destination address, it floods the frame to all ports except the port on which it received the frame.

 4. Which two functions or operations are performed by the MAC sublayer? (Choose two.)
  It is responsible for Media Access Control.  *
  It adds a header and trailer to form an OSI Layer 2 PDU. * 
Refer to curriculum topic: 5.1.1
The MAC sublayer is the lower of the two data link sublayers and is closest to the physical layer. The two primary functions of the MAC sublayer are to encapsulate the data from the upper layer protocols and to control access to the media.


5.Fill in the blank using a number.
The minimum Ethernet frame size is........... bytes. Anything smaller than that should be considered a "runt frame."
Answer 1:
64 *
Refer to curriculum topic: 5.1.1
Ethernet II and IEEE 802.3 standards define the minimum frame size as 64 bytes and the maximum as 1518 bytes.

 6. When a switch configuration includes a user-defined error threshold on a per-port basis, to which switching method will the switch revert when the error threshold is reached?
  store-and-forward  *
Refer to curriculum topic: 5.2.2
When the store-and-forward switching method is used, the switch receives the complete frame before forwarding it on to the destination. In contrast, a cut-through switch forwards the frame once the destination Layer 2 address is read.


7.
i209358v1n1_209358.png


Refer to the graphic. H2 has sent a broadcast message to all of the hosts. If host H1 wants to reply to the broadcast message, which statement is true?

 H1 sends a unicast message to H2, and the switch forwards it directly to H2. *
Refer to curriculum topic: 5.2.1
Since H2 has just sent a broadcast message to all hosts, the MAC address for H2 is already in the switch MAC table. A unicast message from H1 to H2 will therefore be forwarded by the switch directly to H2.


8. When the store-and-forward method of switching is in use, what part of the Ethernet frame is used to perform an error check?
  CRC in the trailer. *
Refer to curriculum topic: 5.2.2
The cyclic redundancy check (CRC) part of the trailer is used to determine if the frame has been modified during transit.? If the integrity of the frame is verified, the frame is forwarded. If the integrity of the frame cannot be verified, then the frame is dropped.


9. i209881v1n2_209881.png


Refer to the exhibit. What is the destination MAC address of the Ethernet frame as it leaves the web server if the final destination is PC1?
  00-60-2F-3A-07-CC *
Refer to curriculum topic: 5.3.1
The destination MAC address is used for local delivery of Ethernet frames. The MAC (Layer 2) address changes at each network segment along the path. As the frame leaves the web server, it will be delivered by using the MAC address of the default gateway.


10. Fill in the blank.
The binary number 0000 1010 can be expressed as........... in hexadecimal.
Answer 1:
A *
Refer to curriculum topic: 5.1.2
The binary number 0000 1010 can be expressed as 0A in hexadecimal.


11. What type of address is 01-00-5E-0A-00-02?
  an address that reaches a specific group of hosts *
Refer to curriculum topic: 5.1.2
The multicast MAC address is a special value that begins with 01-00-5E in hexadecimal. It allows a source device to send a packet to a group of devices.


12. Fill in the blank.
On Ethernet networks, the hexadecimal address FF-FF-FF-FF-FF-FF represents the...........
 MAC address.
Answer 1:
Broadcast
Refer to curriculum topic: 5.1.2
On Ethernet networks, the broadcast MAC address is 48 binary ones displayed as hexadecimal FF-FF-FF-FF-FF-FF.


13. What is the primary purpose of ARP?
  resolve IPv4 addresses to MAC addresses *
Refer to curriculum topic: 5.3.2


14. Refer to the exhibit. PC1 issues an ARP request because it needs to send a packet to PC3. In this scenario, what will happen next?
  RT1 will send an ARP reply with its own Fa0/0 MAC address. *
Refer to curriculum topic: 5.3.2
When a network device has to communicate with a device on another network, it broadcasts an ARP request asking for the default gateway MAC address. The default gateway (RT1) unicasts an ARP reply with the Fa0/0 MAC address.


15. Fill in the blank.
The Ethernet........... sublayer is responsible for communicating directly with the physical layer.
Answer 1:
MAC
Refer to curriculum topic: 5.1.1
Ethernet at the data link layer is divided into two sublayers - the MAC and the LLC sublayers. The LLC sublayer is responsible for communicating with the upper layers, and the MAC sublayer communicates directly with the physical layer.