Data link layer

Question 1

What are the two sublayers in layer 4 and what are their functions

Answer 1

LLC - Logical link layer. It communicates between the networking software in the upper layers and the physical hardware in the lower layers

MAC - media access control. It is responsible for media access control and data encapsulation

Question 2

What are the 4 basic layer 2 functions

Answer 2

1. Accepts a frame from the network medium
2. De-encapsulates the frame to expose the new de-encapsulated packet
3. Re-encapsulate it into a new frame
4. Forward the new frame on the medium of the next network segment

Question 3

Characteristic of MAC address

Answer 3

1. An Ethernet MAC address consists of a 6 hexadecimal vendor OUI code followed by a 6 hexadecimal vendor-assigned value.
2. An Ethernet MAC address is a 48-bit address expressed using 12 hexadecimal digits. Because a byte equals 8 bits, we can also say that a MAC address is 6 bytes in length.