Ethernet LAN Switching

Question 1

SFD

Answer 1

Start Frame Delimiter
Signifies the end if the Preamble
It is not used to provide receiver clock synchronization

Question 2

Type

Answer 2

The type field indicates the type of packet encapsulated within the frame

Question 3

FCS

Answer 3

Frame Check Sequence
Used to detect errors that occurred during transmission

Question 4

Preamble

Answer 4

Preamble is a series of 1’s and 0’s (7bytes of 10101010) which allows the receiving device to synchronize its receive clock

Question 5

Length

Answer 5

Length field indicates the length of the encapsulated packet

Question 6

Destination MAC Address

Answer 6

It does not populate mac address

Question 7

Source Mac Address

Answer 7

A switch uses the source mac address field to populate its MAC address table. It associates the source MAC address with the interface on which the frame was received. This allows the switch to learn how to reach other devices on the network

Question 8

Known unicast

Answer 8

MAC address is already in the switch mac address table.
No need to flood the frame.

Question 9

Unknown unicast

Answer 9

Switch doesn’t know how to reach destination so it floods the frame of all interfaces except the one it was received on.

Question 10

Minimum ethernet frame payload

Answer 10

46 bytes

Question 11

ARP

Answer 11

Address Resolution Protocol
used to find out destination’s MAC address