Network Technology - Ethernet Switching

Ethernet operates in which 2 layers?

• Data link layer

• Physical layer

• Network layer

• Transport layer

Ethernet uses which 2 sub-layers in the Data Link layer to operate?

• LLC Sublayer

• MAC Sublayer

• NIC Sublayer

• ARP Sublayer

Which of the following is/are correct?

Expect more than 1 answer.

• LLC Sublayer handles communication between Network and Physical layers

• MAC Sublayer handles encapsulation and Media access control

• LLC Sublayer adds information which identifies the network layer protocol being used

• MAC Sublayer does not provide flow control

What is/are right about MAC Sublayer?

Expect more than 1 answer.

• Forms an Ethernet frame

• The Ethernet frame includes Source and Destination MAC addresses

• The Ethernet frame includes Frame Check Sequence (FCS) for error detection

• MAC Sublayer DOES NOT include specifications for different Ethernet communications standards over various types of media

What is/are correct about the Ethernet Frame fields?

Expect more than 1 answer.

• Minimum Ethernet frame size is 64 bytes

• Maximum Ethernet frame size is 1518 bytes, excluding preamble

• Frames above 1500 bytes are supported by most Fast Ethernet and Gigabit Ethernet switches and NICs.

• Frames below 64 bytes are called Collision fragment or Runt frame, and they are discarded

Hexadecimal number for 10 is _______

• A

• X

• B

• C

Hexadecimal number for 11 is _______

• A

• B

• C

• X

Hexadecimal number for 32 is _______

Note: Binary for 32 is 0010 0000

• 20

• 30

• 10

• 23

Answer explanation

Binary for 32 is 0010 0000

0010 ---> 2

0000 --->0

Therefore 20

What is/are TRUE about MAC address?

Expect more than 1 answer.

• It has 48-bit

• Represented with 12 hexadecimal digits

• First 24 bits is known as OUI and it is unique to the manufacturer

• There is only 1 way to writing MAC address

Answer explanation

Different ways to write MAC address:

Examples:

Using dash:

00-60-2F-3A-07-BC

Using colon:

00:60:2F:3A:07:BC

Using periods:

0060.2F3A.07BC

What of the following is incorrect about Frame Processing?

• All networked devices have a unique MAC address

• Frame header contains Source and Destination MAC addresses

• NIC reads the destination MAC address in the frame and see if it matches its own MAC Address

• If MAC address does not match the MAC address of the NIC, the NIC then passes the frame up the OSI layer.