Chapter 5: Ethernet

Question 1

Who was Robert Metcalfe

Answer 1

First person to create the Ethernet in the mid 1970 at Xerox

Question 2

What is Alohanet?

Answer 2

Alohanet was a digital radio network to communicate between campuses in Hawaii. Alohanet was the birthplace of CSMA/CD

Question 3

The first Ethernet standard was publish by who and what year?
(Class notes)

Answer 3

DIX 1980

Question 4

What is 802.3

Answer 4

IEEE 802.3 Ethernet standard which has been updated several times to include new technologies

Question 5

What is DIX?

5.1.2.1

Answer 5

The DIX Ethernet standard which is now referred to Ethernet II

Question 6

What is the difference between 802.3 and Ethernet 2

5.1.2.1

Answer 6

The differences between framing styles are minimal. The most significant difference between the two standards is the addition of a Start Frame Delimiter (SFD) and the change of the Type field to a Length field in the 802.3.

Question 7

What is 802.2?

Answer 7

It defines Logical Link Control (LLC), which is the upper portion of the data link layer of the OSI Model

Question 8

What is 802.3?

Answer 8

defining the physical layer and data link layer’s media access control (MAC) of wired Ethernet.

Question 9

What is CSMA/CD?

Answer 9

In CSMA/Collision Detection (CSMA/CD), the device monitors the media for the presence of a data signal. If a data signal is absent, indicating that the media is free, the device transmits the data. If signals are then detected that show another device was transmitting at the same time, all devices stop sending and try again later

Question 10

What does OUI stand for?

5.1.1.4

Answer 10

Organizationally Unique Identifier (OUI)

Question 11

What is the Organizationally Unique Identifier (OUI)

5.1.1.4

Answer 11

All MAC addresses assigned to a NIC or other Ethernet device must use that vendor’s assigned OUI as the first 3 bytes or 24 bits and a 6 HEX digits

Question 12

What is the structure of the MAC address for an Ethernet Device?
5.1.1.4

Answer 12

The first 24 bits or 6 hex digits makes up the organization identifier and the last 24bit 6 hex digits make the vendors assigned NIC or interface card

Question 13

What is the Address Resolution Protocol (ARP) Broadcast address?
5.1.3.4

Answer 13

FFFF:FFFF:FFFF:FFFF

Question 14

What is the min and max frame length Ethernet II and IEEE 802.3
5.1.2.2

Answer 14

Both the Ethernet II and IEEE 802.3 standards define the minimum frame size as 64 bytes and the maximum as 1518 bytes.

Question 15

What are the 7 Frame fields and their sizes for 802.3?

5.1.2.3

Answer 15

1) The Preamble (7 bytes)
2) Start Frame Delimiter (SFD) (1byte)
3) Destination MAC Address Field (6 bytes)
4) Source MAC Address Field (6 bytes)
5) Length Field (2 bytes)
6) Data Field (46 - 1500 bytes)
7) Frame Check Sequence Field (FCS) (4 Bytes)