Lesson 3 - Chapter 2: Ethernet

Question 1

What is a protocol?

Answer 1

a set of rules to follow/communication standard

(using certain language/shared vocabulary and rules that make communication between devices easier)

Question 2

The standards that define everything needed to get data from one computer to another is called what?

Answer 2

Ethernet

Question 3

What are Ethernet flavors?

Answer 3

The improvements made to Ethernet over the years, and the variety of ways that Ethernet is implemented

Question 4

Most modern Ethernet networks employ 1 of what 4 speeds?

Answer 4

1. Ethernet (10BaseT)
2. Fast Ethernet (100BaseT)
3. Gigabit Ethernet (1000BaseT)
4. 10 Gigabit Ethernet (10GBaseT)

Question 5

For the Ethernet network speeds (1000BaseT for example), what does the number indicate and its measurement? What does “Base” mean? (2)

Answer 5

The “1000” means the Ethernet speed measured in Mbps.
The “Base” means baseband, which uses the entire bandwidth of the cable to carry Ethernet data

Question 6

What’s the difference between baseband and broadband?

Answer 6

Baseband - uses the entire bandwidth of the cable to carry Ethernet data
Broadband - allows multiple data streams to share the medium

Question 7

What type of Ethernet cables would you find in a typical home or small business network?

Answer 7

Unshielded Twisted Pair (UTP) cables

Question 8

What are UTP cables?

Answer 8

cables that carry data on twisted pairs of copper wires

Question 9

In “100BaseT” Ethernet speed, what does the T stand for?

Answer 9

Twisted, as in UTP

Question 10

Instead of T, what letter would Ethernet cables use if they use fiber optic cable instead?

Answer 10

Since T = Twisted (UTP), fiber uses other letters like FX

Question 11

What is a network’s topology?

Answer 11

describes how the network components are connected to each other (physical or logical)

Question 12

What’s the difference between physical and logical topology?

Answer 12

physical topology - how each component is physically cabled to another
logical topology - describes how data flows through the network

Question 13

What are the 4 types of physical topologies?

Answer 13

1. star
2. bus
3. mesh
4. ring

Question 14

What does a switch provide?

Answer 14

A switch provides a common point of connection for network devices

Question 15

How many ports do consumer-level switches have?

Answer 15

4-8 ports

Question 16

How many ports do business-level switches have?

Answer 16

32 or more

Question 17

Can multiple switches be chained together?

Answer 17

yes

Question 18

What’s the most popular network topology in use today?

Answer 18

the physical star (hosts connect to a central box like a switch, data passes through the box to travel around)

Question 19

What logical topology is in use today?

Answer 19

Since the earliest Ethernet networks used a physical bus topology, the physical arrangements have changed but logically Ethernet still uses a bus topology to transfer data

Question 20

Early Ethernet star topology networks used a hub instead of a switch. What’s a hub?

Answer 20

(stupid repeaters)
anything sent in one port automatically went out to all the other connected ports (hosts)

Question 21

How are switches and hubs different?

Answer 21

hubs = stupid repeaters
switches = smart repeaters (memorize the MAC addresses of all connected devices and only send signals to the correct host)

Question 22

The connection between a computer and a switch is called?

Answer 22

a segment

Question 23

Can you use a splitter on an Ethernet cable in a star bus topology like with cable TV and other network types?

Answer 23

No because the switch assumes that the data that’s incoming is coming from a single source (so you can’t split the source)

Question 24

What’s a benefit of the star bus topology?

Answer 24

the entire network doesn’t go down if a single cable breaks (but it would if the central switch failed)

Question 25

Ethernet segments are limited to how many meters (or less)?

Answer 25

100 meters (or less) = roughly 300ish feet

Question 26

What are the 2 types of switches?

Answer 26

1. managed
2. unmanaged

Question 27

What’s the difference between a managed and unmanaged switch?

Answer 27

unmanaged = a smart device that automatically is configured to allow devices to communicate via MAC addresses (tl;dr connection device)

managed = configuration options available at the switch’s IP address and software for extra features

Question 28

VLANS are a type of what kind of switch?

Answer 28

Virtual Lans are a type of managed switch

Question 29

What can you use VLANs for?

Answer 29

Break up/segment a single physical network into 2+ distinct networks

(computers within the same VLAN can talk to each other, but not outside it)

Question 30

What is PoE?

Answer 30

Power over Ethernet enables a single cable to act as both data and an electrical conduit to a device

(useful for deploying security cams with no AC outlet nearby, just connect to a compatible WAP or switch)

Question 31

What feature in a switch supports PoE?

Answer 31

power injector

Question 32

How can you add PoE functionality to a switch or router that doesn’t natively support it?

Answer 32

by adding a midspan injector

Question 33

What are the 3 standards for PoE?

Answer 33

1. 802.3af (oldest, Type 1, 15.4 watts, VoIP, WiFi)
2. 802.3at (Type 2, 30 watts, video IP phones, tilt cameras, alarms)
3. 802.3bt (Type 3, 60 watts, IP cameras, laptops, video IP phones)
4. 802.3bt (Type 4, 100 watts, same as 3)