Table Of ContentIntroduction to Networks
Companion Guide
Cisco Networking Academy
Cisco Press
800 East 96th Street
Indianapolis, Indiana 46240 USA
ii Introduction to Networks Companion Guide
Cisco Networking Academy Publisher
Paul Boger
Copyright© 2014 Cisco Systems, Inc.
Associate Publisher
Published by:
Dave Dusthimer
Cisco Press
800 East 96th Street
Business Operation
Indianapolis, IN 46240 USA Manager, Cisco Press
Jan Cornelssen
All rights reserved. No part of this book may be reproduced or transmitted in any form
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any information storage and retrieval system, without written permission from the pub- Mary Beth Ray
lisher, except for the inclusion of brief quotations in a review.
Managing Editor
Printed in the United States of America
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First Printing December 2013
Development Editor
Library of Congress Cataloging-in-Publication data is on file. Ellie C. Bru
ISBN-13: 978-1-58713-316-9 Project Editor
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ISBN-10: 1-58713-316-4
Copy Editor
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Warning and Disclaimer
Technical Editor
This book is designed to provide information about the Cisco Networking Academy Aubrey Adams
Introduction to Networks course. Every effort has been made to make this book as
complete and as accurate as possible, but no warranty or fitness is implied. Editorial Assistant
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The information is provided on an “as is” basis. The authors, Cisco Press, and Cisco
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iii
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iv Introduction to Networks Companion Guide
About the Contributing Authors
Mark A. Dye
Mark is the lead network engineer for Kwajalein Range Services at Ronald Reagan
Ballistic Missile Defense Test Site on Kwajalein, Marshall Islands. He is responsible
for the network team that provides design, deployment, and operation of all the
missile test range data networks across ten islands as well as three continental U.S.
locations.
He has previously worked as subject matter expert and content team lead for the
Cisco Academy Program as well as an author for multiple Cisco Network Academy
Fundamentals online courses. He worked to develop and review courseware and
assessments for both the Academy and certification programs.
For more than 20 years, Mark served as technology manager for The Bevill Center
for Advanced Manufacturing Technology of Alabama Technology Network. He
developed and implemented comprehensive network strategies for intranet and
Internet, including policies, administrative procedures, network security, and
interconnectivity. He also implemented and taught Cisco Networking Academy
Fundamentals of Wireless LANs, Fundamentals of Network Security, and CCNA
and CCNP courses at The Bevill Center for instructors and students.
Allan D. Reid
Allan is a professor and program supervisor at Centennial College in Toronto,
Ontario, Canada, where he teaches courses in networking, network security, virtu-
alization, and cloud computing. He is the lead for the Centennial College ASC/ITC
and has been teaching the academy curriculum since one of the earliest versions.
Allan has authored multiple books and online courses for the Cisco Academy pro-
gram, where he is a subject matter expert and content team lead. He works as part of
the core team to develop state-of-the-art assessments and courseware.
Outside of his academic responsibilities, Allan has been active in the computer and
networking fields for more than 30 years and is currently a principal in a company
involved in the design, installation, and management of network solutions for small-
to medium-sized companies.
v
Contents at a Glance
Introduction xxvi
Chapter 1: Exploring the Network 1
Chapter 2: Configuring a Network Operating System 59
Chapter 3: Network Protocols and Communications 115
Chapter 4: Network Access 161
Chapter 5: Ethernet 231
Chapter 6: Network Layer 283
Chapter 7: Transport Layer 341
Chapter 8: IP Addressing 391
Chapter 9: Subnetting IP Networks 465
Chapter 10: Application Layer 515
Chapter 11: It’s a Network 551
Appendix A: Answers to the “Check Your Understanding” Questions 627
Glossary 641
Index 654
vi Introduction to Networks Companion Guide
Contents
Introduction xxvi
Chapter 1 Exploring the Network 1
Objectives 1
Key Terms 1
Introduction (1.0.1.1) 3
Globally Connected (1.1) 4
Networking Today (1.1.1) 4
Networks in Our Daily Lives (1.1.1.1) 4
Technology Then and Now (1.1.1.2) 5
The Global Community (1.1.1.3) 6
Networks Support the Way We Learn (1.1.1.4) 7
Networks Support the Way We Communicate (1.1.1.5) 8
Networks Support the Way We Work (1.1.1.6) 10
Networks Support the Way We Play (1.1.1.7) 10
Providing Resources in a Network (1.1.2) 11
Networks of Many Sizes (1.1.2.1) 12
Clients and Servers (1.1.2.2, 1.1.2.3) 13
Peer-to-Peer (1.1.2.4) 13
LANs, WANs, and the Internet (1.2) 14
Components of a Network (1.2.1, 1.2.1.1) 15
End Devices (1.2.1.2) 16
Intermediary Network Devices (1.2.1.3) 16
Network Media (1.2.1.4) 17
Network Representations (1.2.1.5) 18
Topology Diagrams (1.2.1.6) 19
LANs and WANs (1.2.2) 21
Types of Networks (1.2.2.1) 21
Local-Area Networks (1.2.2.2) 22
Wide-Area Networks (1.2.2.3) 22
The Internet (1.2.3, 1.2.3.1) 22
Intranet and Extranet (1.2.3.2) 23
Internet Access Technologies (1.2.4.1) 25
Connecting Remote Users to the Internet (1.2.4.2) 25
Connecting Businesses to the Internet (1.2.4.3) 27
The Network as a Platform (1.3) 28
The Converging Network (1.3.1.1) 29
Planning for the Future (1.3.1.2) 30
vii
The Supporting Network Architecture (1.3.2.1) 31
Fault Tolerance in Circuit-Switched Networks (1.3.2.2) 32
Fault Tolerance 32
Circuit-Switched Connection-Oriented Networks 33
Fault Tolerance in Packet-Switched Networks (1.3.2.3) 34
Packet-Switched Networks 34
Scalable Networks (1.3.2.4) 35
Scalability 35
Providing QoS (1.3.2.5) 37
Quality of Service 37
Providing Network Security (1.3.2.6) 39
Security 39
The Changing Network Environment (1.4) 41
Network Trends (1.4.1) 41
New Trends (1.4.1.1) 41
Bring Your Own Device (BYOD) (1.4.1.2) 43
Online Collaboration (1.4.1.3) 43
Video Communication (1.4.1.4) 44
Cloud Computing (1.4.1.5) 46
Data Centers (1.4.1.6) 47
Technology Trends in the Home (1.4.2.1) 48
Powerline Networking (1.4.2.2) 49
Wireless Broadband (1.4.2.3) 50
Wireless Internet Service Provider (WISP) 50
Wireless Broadband Service 50
Security Threats (1.4.3.1) 50
Security Solutions (1.4.3.2) 51
Cisco Network Architectures (1.4.4.1) 52
CCNA (1.4.4.2) 53
Summary (1.5) 54
Practice 55
Class Activities 55
Labs 55
Packet Tracer Activities 55
Check Your Understanding 56
Chapter 2 Configuring a Network Operating System 59
Objectives 59
Key Terms 59
viii Introduction to Networks Companion Guide
Introduction (2.0.1) 60
Introduction to Cisco IOS (2.0.1.1) 60
IOS Boot Camp (2.1) 61
Cisco IOS (2.1.1) 61
Operating Systems (2.1.1.1) 61
Purpose of OS (2.1.1.2) 63
Location of the Cisco IOS (2.1.1.3) 63
IOS Functions (2.1.1.4) 64
Accessing a Cisco IOS Device (2.1.2) 65
Console Access Method (2.1.2.1) 65
Telnet, SSH, and AUX Access Methods (2.1.2.2) 66
Terminal Emulation Programs (2.1.2.3) 67
Navigating the IOS (2.1.3) 67
Cisco IOS Modes of Operation (2.1.3.1) 68
Primary Modes (2.1.3.2) 69
Global Configuration Mode and Submodes (2.1.3.3) 69
Navigating Between IOS Modes (2.1.3.4, 2.1.3.5) 71
The Command Structure (2.1.4) 72
IOS Command Structure (2.1.4.1) 73
Cisco IOS Command Reference (2.1.4.2) 75
Context-Sensitive Help (2.1.4.3) 76
Command Syntax Check (2.1.4.4) 78
Hot Keys and Shortcuts (2.1.4.5) 79
IOS Examination Commands (2.1.4.6) 83
The show version Command (2.1.4.7) 83
Getting Basic (2.2) 86
Host Names (2.2.1) 86
Why the Switch (2.2.1.1) 86
Device Names (2.2.1.2) 87
Host Names (2.2.1.3) 87
Configuring Host Names (2.2.1.4) 88
Limiting Access to Device Configurations (2.2.2) 89
Securing Device Access (2.2.2.1) 89
Securing Privileged EXEC Access (2.2.2.2) 90
Securing User EXEC Access (2.2.2.3) 91
Encrypting Password Display (2.2.2.4) 92
Banner Messages (2.2.2.5) 94
Saving Configurations (2.2.3) 96
Configuration Files (2.2.3.1) 96
Capturing Text (2.2.3.2) 98
Address Schemes (2.3) 100
Ports and Addresses (2.3.1) 100
ix
IP Addressing of Devices (2.3.1.1) 100
Interfaces and Ports (2.3.1.2) 101
Addressing Devices (2.3.2) 102
Configuring a Switch Virtual Interface (2.3.2.1) 102
Manual IP Address Configuration for End Devices
(2.3.2.2) 103
Automatic IP Address Configuration for End Devices
(2.3.2.3) 104
IP Address Conflicts (2.3.2.4) 105
Verifying Connectivity (2.3.3) 106
Test the Loopback Address on an End Device (2.3.3.1) 106
Testing the Interface Assignment (2.3.3.2) 107
Testing End-to-End Connectivity (2.3.3.3) 108
Summary (2.4) 109
Practice 110
Class Activities 110
Labs 111
Packet Tracer Activities 111
Check Your Understanding 111
Chapter 3 Network Protocols and Communications 115
Objectives 115
Key Terms 115
Introduction (3.0.1.1) 116
Rules of Communication (3.1) 116
The Rules (3.1.1) 117
What Is Communication? (3.1.1.1) 117
Establishing the Rules (3.1.1.2) 118
Message Encoding (3.1.1.3) 119
Message Formatting and Encapsulation (3.1.1.4) 120
Message Size (3.1.1.5) 121
Message Timing (3.1.1.6) 121
Message Delivery Options (3.1.1.7) 122
Network Protocols and Standards (3.2) 123
Protocols (3.2.1) 123
Protocols: Rules That Govern Communications
(3.2.1.1) 123
Network Protocols (3.2.1.2) 124
Interaction of Protocols (3.2.1.3) 125
