5&6. Ethernet LAN Switching

Question 1

Hexadecimal C = Decimal […]

Answer 1

12

Question 2

Ethernet header ‘Source’ = […] byte(s)

Answer 2

6

Question 3

By default, a dynamic MAC address will be removed from the MAC address table after [time] of inactiv

Answer 3

5 minutes

Question 4

Ethernet header ‘Preamble’ = […] bytes(s)

Answer 4

7

Question 5

What is the only field in an Ethernet trailer?

Answer 5

Frame Check Sequence

Question 6

What is the bit pattern of one byte in the Ethernet preamble?

Answer 6

10101010

Question 7

What is the bit pattern of the Ethernet SFD

Answer 7

10101011

Question 8

What is the Ethernet Type value for IPv6? (in hexadecimal)

Answer 8

0x86DD

Question 9

What does ‘FCS’ in an Ethernet frame stand for?

Answer 9

Frame Check Sequence; Checks if the data is corrupted by performing CRC.

Question 10

What does a switch do with an unknown unicast frame?

Answer 10

Floods it out all ports (except the one it was received on)

Question 11

A value of […] or less in the Type/Length field indicates Length.

Answer 11

1500

Question 12

What is the total size of the Ethernet header + trailer? = […] bytes

Answer 12

26

Question 13

Which field of an Ethernet header is used for synchronization?

Answer 13

Preamble

Question 14

A value of […] or greater in the Type/Length field indicates Type.

Answer 14

1536

Question 15

Which field of an Ethernet frame does a switch use to learn and populate its MAC address table?

Answer 15

Source MAC address

Question 16

The first 3 bytes of a MAC address are the […]

Answer 16

OUI (Organizationally Unique Identifier)

Question 17

What is the Ethernet Type value for IPv4? (in hexadecimal)

Answer 17

0x0800

Question 18

What are the 5 fields of an Ethernet header?

Answer 18

Preamble, SFD, Destination, Source, Type/Length

Question 19

What is the size of the Ethernet header + trailer? (no Preamble + SFD)

Answer 19

18 bytes

Question 20

What is the minimum size of an Ethernet frame? (Header + Payload + Trailer)

Answer 20

64 bytes

Question 21

What is the minimum size of an Ethernet payload?

Answer 21

46 bytes

Question 22

What protocol is used to discover the Layer 2 address of another device?

Answer 22

ARP (Address Resolution Protocol)

Question 23

What are the two messages used in ARP?

Answer 23

ARP Request

ARP Reply

Question 24

What is the broadcast MAC address?

Answer 24

FFFF.FFFF.FFFF

Question 25

What is the command to view the ARP table on a Windows, macOS, or Linux computer?

Answer 25

arp-a

Question 26

The process of addresses being cleared from the MAC Address table after 5 minutes of inactivity is known as

Answer 26

Aging

Question 27

Clear all dynamic MAC addresses from the MAC Address Table:

SW1# […]

Answer 27

clear mac address-table dynamic

Question 28

View the MAC Address Table:

SW1# […]

Answer 28

show mac address-table

Question 29

Clear all entries for a specific dynamic MAC address from the MAC Address Table:
SW1# […]

Answer 29

clear mac address-table dynamic address mac-address

Question 30

Clear all dynamic MAC addresses on a specific interface from the MAC Address Table:
SW1# […]

Answer 30

clear mac address-table dynamic interface interface-id

Question 31

What is the Ethernet Type code for an ARP packet?

Answer 31

0x0806

Question 32

Command to show the ARP table on a Cisco device:

Answer 32

show arp