Ethernet and Switching

Question 1

At which OSI layer does ethernet function

Answer 1

Data Link Layer (2)

Question 2

What does CSMA/CD stand for

Answer 2

Carrier Sense Multiple Access with Collision Detection

Question 3

Collision Domain

Answer 3

A group of networked devices that will simultaneously detect a voltage spike (when spike is detected all devices stop sending messages).

Question 4

Half duplex communication

Answer 4

One device communicates at a time (walkie talkie).

Question 5

Full duplex communication

Answer 5

Two devices communicate at the same time (telephone) collisions are not possible

Question 6

Modern Collision domain

Answer 6

Half duplex communication between a device and a switch (most modern networks are full duplex).

Question 7

Ethernet II Frame

Answer 7

Mechanism that we use to move data across and ethernet network from 1 device to another.

Question 8

Data packet

Answer 8

A unit of data made into a package that travels along a given network path.

Question 9

Frame

Answer 9

A chunk of data, with a data link layer header

Question 10

Components of an Ethernet Header

Answer 10

Destination MAC address, Source MAC address, Type, FCS

Question 11

Network interface card

Answer 11

The device that connects our PC to an ethernet cable

Question 12

MAC address

Answer 12

Composed of Manufacturer ID and Serial Number. Layer 2 address/identifier specifically tied to a network interface card.

Question 13

Ethernet Header Type Field

Answer 13

Tells us what type of data is being transferred

Question 14

Ethernet FCS

Answer 14

Frame Check Sequence Cyclical Redundancy Check (CRC)

Question 15

Protocol Data Unit

Answer 15

Varies from layer to layer. Entire Frame and Data (payload) that is being transferred

Question 16

Bus Topology

Answer 16

Single wire (rarely seen)

Question 17

Ring Topology

Answer 17

Device connections create a circular path (rarely seen)

Question 18

Star Topology

Answer 18

Each device is connected to a layer 2 device

Question 19

Ethernet switch

Answer 19

Used in wired networks to connect devices using Ethernet cables; allows connected devices to talk to other devices.

Question 20

Mac Address Table

Answer 20

Used by a switch to keep track of port and mac addresses. Creates virtual circuits within the switch to eliminate collisions.

Question 21

Layer 2 Broadcast message

Answer 21

When the destination MAC address of the frame is all F’s the frame is sent out to all active interfaces, except the receiving interface. (Don’t confuse this with layer 3 broadcast addresses that are rarely used).

Question 22

Broadcast Domain

Answer 22

Group of networked devices which will receive a layer 2 broadcast message.

Question 23

Physical addres

Answer 23

Same as a MAC address; sometimes called the hardware address