Networking Chapter 2 offers an introduction to the basic operation of network repeaters and hub

Guide to Networking Essentials, Eighth Edition 2-1

Chapter 2

Network Hardware Essentials

At a Glance

Instructor’s Manual Table of Contents

• Overview

• Objectives

• Teaching Tips

• Quick Quizzes

• Class Discussion Topics

• Additional Projects

• Additional Resources

• Key Terms

• Technical Notes for Hands-On Projects

Guide to Networking Essentials, Eighth Edition 2-2

Lecture Notes

Overview

Chapter 2 offers an introduction to the basic operation of network repeaters and hub.

Students learn about the purpose of network switches, as well as how to summarize the

Objectives

• Describe the basic operation of network repeaters and hubs

• Explain the purpose of network switches

Teaching Tips

Network Repeaters and Hubs

2. Discuss the purpose of a repeater, or why a device might be used as a repeater.

Multiport Repeaters and Hubs

1. Explain that a multiport repeater, or hub, will clean a signal as well as regenerate it.

2. Explain the functions of a hub.

• Receives bit signals generated from a connected computer on one of its ports

3. Define network bandwidth as the amount of data that can be transferred on a network

4. Explain why, when devices are connected to a hub, they must wait their turn to

communicate.

6. Use Figure 2-4 to discuss several of the indicator lights that might be found on a typical

hub.

7. Discuss the importance of an uplink port on a hub. Explain that this port can be used to

8. Emphasize the limitations of hubs and point out that they are typically being replaced

with switches.

Teaching

Tip

For additional information about hubs, see

http://wiki.wireshark.org/HubReference.

Network Switches

1. Explain that a switch actually reads a frame, determines which port the destination

Basic Switch Operation

1. Explain how a switch directs traffic to the correct port by using a MAC address.

3. Use Figure 2-5 to illustrate the steps that describe a switch’s operation.

4. Discuss what a switch does with a frame if it doesn’t find the destination MAC address

5. Discuss how a switch can handle several computer conversations at one time, thereby

6. Discuss the advantages inherent in using switches compared to a hub.

7. Discuss some of the indicator lights that could be found on most switches. Point out that

some switches have a dedicated port for up linking to another switch.

Teaching

Tips

Switches also have the ability to perform more advanced tasks such as link

aggregation, or port bonding, to increase link speeds.

Teaching

Tip

For a visual guide in explaining how a MAC address is structured, see

http://upload.wikimedia.org/wikipedia/commons/9/94/MAC-48_Address.svg

Quick Quiz 1

1. What does a repeater do?

2. A multi-port repeater is often referred to as which of the following?

a. Switch

b. Bridge

c. Hub

d. Network Interface Card

3. The amount of data that can be transferred on a network during a specific interval is

known as which of the following?

a. Network bandwidth

b. Network speed rating

c. Line speed rating

d. Duplexing speed

4. True or False: A switch operates just like a hub?

5. How long are MAC addresses?

a. 42 bits

b. 16 hexadecimal characters

c. 4 octets

d. 12 hexadecimal characters

Wireless Access Points

1. Explain the use of access points as a means of wireless distribution. Point out that most

Basic AP Operation

1. Make a comparison of access points to hubs.

2. Point out that the destination device sends an acknowledgement back to the sending

device to indicate that the frame was received.

3. Explain that some wireless configurations require additional handshaking between two

4. Discuss the limitations of wireless, as well as advantages / disadvantages of using a

wireless connection.

Teaching

Tip

Widely available, consumer home routers that provide wireless access are

actually several devices combined into one, including an access point. It might be

helpful to point out some wireless router models as access points.

Guide to Networking Essentials, Eighth Edition 2-6

Network Interface Cards

1. Discuss how network interface cards (NICs) use different types of media, but all have

NIC Basics

1. Describe the process by which a NIC turns a frame into transmittable signals for

whatever media type it is made for.

2. Use Figures 2-10 and 2-11 to demonstrate how a NIC handles incoming and outgoing

data from the network medium.

3. Explain why NIC’s are assigned MAC addresses.

a. These addresses must be unique, or communication on the network no longer

4. Introduce students to a broadcast MAC address.

a. A MAC address of FF:FF:FF:FF:FF:FF is reserved for broadcasts, and cannot be

5. Explain that most NICs have a link status indicator and an activity indicator.

Selecting a NIC

1. Discuss with students that when selecting a NIC to install in a computer, there are a

number of factors to consider:

a. What bus type should be used? Several are available, such as PCI and PCIe.

NIC Drivers

1. Students should learn that NIC drivers, in most cases, will be automatically installed or

2. Demonstrate how to verify that a NIC is installed using the Network & Internet Status

Wireless NICs

1. Discuss the prevalence of wireless NICs in mobile devices.

3. Discuss what information is needed in order to connect to a wireless network.

a. You must know the service set identifier (SSID). Most wireless routers available

b. You might also be prompted for a security key or a username and password.

Teaching

Tip

If you have a wireless device, or preferably a workstation / laptop with wireless,

try doing a wireless survey around your area. Show students just how prevalent

wireless technology is! Netspot is a common tool for doing a wireless survey,

and can be found at https://www.netspotapp.com/

Quick Quiz 2

1. What is the main difference between a wireless access point and a hub?

2. Before a computer can transmit data to the AP, it must first send which of the following

messages to let the AP know it intends to transmit data?

a. Broadcast

b. Request to Send (RTS)

c. Beacon

d. SSID

3. What is the name of the address that is built into every NIC?

4. A frame with a destination MAC address composed of all binary 1s or FF-FF–FF–FF–

FF-FF in hexadecimal is known as which of the following?

a. Unicast frame

b. Anycast frame

c. Multicast frame

d. Broadcast frame

Guide to Networking Essentials, Eighth Edition 2-8

5. What information must you have in order to connect to a wireless network?

a. Name of the switch

b. SSID

c. MAC address of the router

d. MAC address of the switch

Teaching

Tip

To see more information about the 802.11 wireless standards, visit

https://www.networkworld.com/article/3238664/80211-wi–fi-standards-and-

speeds-explained.html

Routers

1. Discuss the role of routers in delivering packets or information to other non-locally

connected networks. Use Figures 2-15 and 2-16 in your discussion.

2. Be sure to point out the key properties and features of a router versus a switch:

a. Routers connect LANs, switches connect computers

Routers Connect LANs

1. Explain that in order to communicate between two different LANs or networks with

2. Use Figures 2-17 and 2-18 to compare a large LAN connected by switches to three

Routers Create Broadcast Domains

1. Use Figure 2-19 to explain how and why a router will create broadcast domains.

Guide to Networking Essentials, Eighth Edition 2-9

Routers Work with IP Addresses and Routing Tables

1. Describe how a router maintains a table of addresses to direct networking traffic.

3. Explain that a default route tells a router where to send a packet with a destination

network that can’t be found in the routing table.

5. Mention that the router may send a message to the sending station informing it that the

network is unreachable.

6. Describe a default gateway as the address configured in a computer’s IP address

7. Point out to students that this chapter explains the basic operation of the most common

Quick Quiz 3

1. True or False: Routers are devices that enable multiple LANs to communicate with one

another by forwarding packets from one LAN to another.

2. The scope of devices to which broadcast frames are forwarded is known as which of the

following?

a. Default gateway

b. Interface

c. Broadcast domain

d. Default route

3. What is another name for a port on routers?

4. Which of the following tells a router where to send a packet with a destination network

that can’t be found in the routing table?

Guide to Networking Essentials, Eighth Edition 2-10

a. Default gateway

b. Interface

c. Broadcast domain

d. Default route

Class Discussion Topics

2. What might prevent wireless technology from being used extensively in an enterprise?

Additional Projects

1. If Cisco equipment is available, set up two switches with connections to each other,

Additional Resources

1. Collision domains vs. Broadcast domains

4. What is a Wireless Access Point?

5. How Routers Work

Key Terms

For explanations of key terms, see the Glossary for this text.

Guide to Networking Essentials, Eighth Edition 2-11

➢ hub

➢ network bandwidth

➢ network interface card

➢ (NIC)

➢ promiscuous mode