McGraw hill CCENT cisco certified entry networking technician study guide exam 640822 jul 2008 ISBN 0071591141 pdf

CCENT™

®

Cisco Certified
Entry Networking Technician
Study Guide
(Exam 640-822)


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®

CCENT™

Cisco Certified
Entry Networking Technician
Study Guide
(Exam 640-822)
Matthew Walker
Angie Walker
This study/training guide and/or material is not sponsored by, endorsed by, or affiliated
with Cisco Systems, Inc. in any manner. Cisco®, Cisco Systems®, CCDA®, CCNA®, CCDP®,
CCNP®, CCIE®, CCIP®, CCSP®, CCVP®, CCDETM, CCENTTM, the Cisco Systems logo, and
the Cisco Certified Internetwork Expert logo are trademarks or registered trademarks
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trademarks are trademarks of their respective owners. This publication and CD may be
used in assisting students to prepare for an exam. Neither The McGraw-Hill Companies

nor Boson Software warrant that use of this publication and CD will ensure passing
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DOI: 10.1036/0071591141


This book is dedicated to my father, Ronald Walker (1947–2008).
We miss you, Dad.


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ABOUT THE AUTHORS

Matthew Walker is the IA Training Instructor Supervisor and a Sr. IA Analyst at
Dynetics, Inc., in Huntsville, Alabama. An IT education professional for over 15 years,
Matt served as the Director of the Network Training Center and the Curriculum
Lead and Senior Instructor for the local Cisco Networking Academy on Ramstein
AB, Germany. After leaving the US Air Force, Matt served as a Network Engineer
for NASA’s Secure Network Systems, designing and maintaining secured data, voice,
and video networking for the agency. He has written and contributed to numerous
technical training books for Air Education and Training Command, United States
Air Force, and continues to train, and write, certification and college-level IT and
IA Security courses. Matt holds numerous commercial certifications, including
Cisco Certified Network Professional (CCNP), Microsoft Certified System Engineer

(MCSE), CEH (Certified Ethical Hacker), CNDA (Certified Network Defense
Architect), and Certified Pen Test Specialist (CPTS).
Angie Walker is currently the Chief Information Security Officer for the University
of North Alabama, located in beautiful Florence, Alabama. Among the many
positions she has filled over the course of her 20-plus years in Information Technology
and Information Assurance are Manager of the Information Systems Security (ISS)
Office for the Missile Defense Agency (MDA) South, as well as the lead for the
MDA Alternate Computer Emergency Response Team (ACERT). She served as
Superintendent of the United States Air Forces in Europe (USAFE) Communications
and Information Training Center, Superintendent of the 386 Communications
Squadron on Ali Al Saleem AB, Kuwait, and Senior Information Security Analyst
for Army Aviation Unmanned Aircraft Systems. Angie holds several industry
certifications, including CISSP, Network+ and Security+, and a master’s degree in
Information Systems Management. With over nine years of IT and IA educational
experience, she has developed and taught courseware worldwide for the US Air
Force, as well as several computer science courses as an instructor for the University of
Alabama in Huntsville, and Kaplan University in Fort Lauderdale, Florida.

Copyright © 2008 by The McGraw-Hill Companies. Click here for terms of use.


About the Tech Editor
Bobby E. Rogers is a Senior Information Assurance Analyst for Dynetics, Inc.,
in Huntsville, Alabama. In addition to working in the Certification and Accreditation
process for the U.S. government, Bobby also leads penetration testing teams for
Dynetics. Bobby recently retired from the United States Air Force after almost 21 years,
serving as a computer networking and security specialist, and has designed and managed
networks all over the world. He has held several positions of responsibility overseeing
network security in both the Department of Defense and private company networks.
His duties have included perimeter security, client-side security, security policy

development, security training, penetration testing, and computer crime investigation.
As a trainer, he has taught a wide variety of IT-related subjects in both makeshift
classrooms in tents in the desert and formal training centers. He also has taught a
wide variety of courses as a part-time contractor for several nationally known training
centers and a major university. Bobby is an accomplished author, having written
numerous IT articles in various publications and training materials for the U.S. Air
Force, and has authored several training videos on a wide variety of IT security topics.
He is also a regular security article contributor for several online IT sites.
He has a Bachelor of Science degree in Computer Information Systems from
Excelsior College, and two Associates in Applied Science degrees from the
Community College of the Air Force. Bobby’s professional IT certifications include:
A+, Security+, ACP, CCNA, CCAI, CIW, CIWSA, MCP+I, MCSA (Windows
2000 & 2003), MCSE (Windows NT4, 2000, & 2003), MCSE: Security (Windows
2000 & 2003), CISSP, CHFI, CIFI, CPTS, and CEH.

Copyright © 2008 by The McGraw-Hill Companies. Click here for terms of use.


CONTENTS AT A GLANCE

1

Networking 101

..............................................................

1

2

TCP/IP

.......................................................................

31

3

Network Media and Devices

4

Ethernet Fundamentals

5

Switching: Moving Data Inside Your Network

6

Routing Essentials and IP Addressing

................................................

69

.....................................................

101

...........................

129

......................................

155

7

IP Address Subnetting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

191

8

Interfacing with Cisco Devices

.............................................

229

9

Cisco Switch Configuration

................................................

271

10

Cisco Router Configuration

................................................

315

11

WANs and WLANs

.........................................................

363

12

Applications, Security, and Troubleshooting

A

About the CD
Glossary
Index

..............................

403

................................................................

455

.......................................................................

461

. . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

495

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CONTENTS

Foreword . . . . . .................................................... xvii
Preface . . . . . . .....................................................
xix
Acknowledgments ................................................. xxv
Introduction . ..................................................... xxvii

1

2

Networking 101 ................................................

1

Network Essentials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Network Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Network Topologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Network Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The OSI Reference Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functions and Advantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Network Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Protocol Data Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
✓ Two-Minute Drill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Q&A Self Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Self Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2
2
5
8
11
11
12
17
19
23
25

28

TCP/IP ...........................................................

31

TCP/IP and OSI Reference Model Comparison . . . . . . . . . . . . . . . . . . . . . . . . . .
TCP/IP History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comparing the Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Application Layer Functions and Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DNS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DHCP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercise 2-1: Viewing TCP/IP Protocols in Action . . . . . . . .
Transport Layer Functions and Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TCP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
UDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Port Numbers and Multiplexing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

32
32
33
34
34
37
39
42
46
47
50

51

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CCENT Cisco Certified Entry Networking Technician Study Guide

3

4

Internet and Network Access Layer Functions and Protocols . . . . . . . . . . .
IP and ICMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Network Access Layer Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
✓ Two-Minute Drill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Q&A Self Test . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Self Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

53
54
56
59
62
66

Network Media and Devices .................................

69

Network Media . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Media Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Copper Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fiber Cabling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Network Devices . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
NICs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transceivers, Repeaters, and Hubs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bridges and Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Routers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Security Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Putting It All Together . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
✓ Two-Minute Drill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Q&A Self Test . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Self Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

70
70
71
77
79
79
80
81
85
87
88
92
94
98

Ethernet Fundamentals ...................................... 101
Ethernet History . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ethernet Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Frame Types and Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Media Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Data Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ethernet Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
✓ Two-Minute Drill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Q&A Self Test . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Self Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5

102
103
103
107
112
116
121
122
126

Switching: Moving Data Inside Your Network ............. 129
Switch Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Physical Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Switch Initialization Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

130

130
133


Contents

Duplex and Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Switch Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Switch Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Switch Installation and Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Looping and STP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VLANs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
✓ Two-Minute Drill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Q&A Self Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Self Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6

136
137
139
139
140
142
146
148
152

Routing Essentials and IP Addressing ...................... 155
Routing Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Routing Logic and Data Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Routed and Routing Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
An Introduction to IP Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IP Address Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IP Address Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IP Address Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
✓ Two-Minute Drill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Q&A Self Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Self Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7

xiii

156
157
162
168
168
171
174
183
185
189

IP Address Subnetting ........................................ 191
Foundation Skills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Binary Math . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Boolean AND Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercise 7-1: Binary Math Skills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Subnet Essentials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subnet Definition and Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subnet Mask Creation Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subnet Masks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Decoding Subnet Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Applying Subnet Masks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subnetting Tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercise 7-2: Decoding and Applying Subnet Information . . .
✓ Two-Minute Drill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Q&A Self Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Self Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

192
192
197
198
199
200
202
206
206
208
210
214
220
223
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Interfacing with Cisco Devices .............................. 229
The IOS and Configuration Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Boot Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Cisco IOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuration Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Access Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercise 8-1: Router Connection
Methods—HyperTerminal and Telnet . . . . . . . . . . . . . . . . . . . . . . . .
The CLI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CLI Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CLI Help Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercise 8-2: Basic CLI Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comparing the Router and Switch CLI . . . . . . . . . . . . . . . . . . . . . . . . .
✓ Two-Minute Drill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Q&A Self Test . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Self Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9

230
230
234
238
241
244

249
249
252
257
258
263
265
269

Cisco Switch Configuration .................................. 271
About Cisco Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Physical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Initial Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using the System Configuration Dialog . . . . . . . . . . . . . . . . . . . . . . . . .
Basic Configuration Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Securing the Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Passwords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
exec-timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercise 9-1: Basic Switch Configuration . . . . . . . . . . . . . . . . . . . .
Configuring SSH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercise 9-2: SSH Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interface Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VLAN1 and the Switch IP Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Speed, Duplex, and Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VLAN Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercise 9-3: Interface and VLAN Configuration . . . . . . . . . .
Port Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

272

272
274
275
276
278
281
282
285
285
287
289
290
291
292
294
297
299


Contents

xv

✓ Two-Minute Drill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Q&A Self Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Self Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

305
309
313

10 Cisco Router Configuration .................................. 315
First Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
About Cisco Routers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Physical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuration Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Initial Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercise 10-1: Basic Router Configuration . . . . . . . . . . . . . . . . . .
Configure Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercise 10-2: Static Route Configuration . . . . . . . . . . . . . . . . . .
Dynamic Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Routing Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring RIPv2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercise 10-3: Configuring RIP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring an Internet Access Router . . . . . . . . . . . . . . . . . . . . . . . . . .
✓ Two-Minute Drill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Q&A Self Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Self Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

316
316
321
324
325
327
329
333
334
336
337

341
342
354
357
361

11 WANs and WLANs ............................................ 363
Wide Area Networking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WAN Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Point-to-Point Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Packet Switched Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remote Access Technologies
....................................
WAN Configuration Extras . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wireless Networking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing Wireless Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wireless Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
✓ Two-Minute Drill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Q&A Self Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Self Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

364
365
368
371
374
378
380
380

384
386
394
397
401


xvi

CCENT Cisco Certified Entry Networking Technician Study Guide

12 Applications, Security, and Troubleshooting ............... 403
Application Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Application Needs and Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
telnet (SSH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercise 12-1: telnet Sessions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Network Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Threats and Attacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mitigations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Host Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Switch and Router Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercise 12-2: Using CDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
✓ Two-Minute Drill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Q&A Self Test . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Self Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A

404
404
407
409
410
410
414
417
418
423
426
430
445
448
452

About the CD .................................................. 455
System Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing and Running the Boson NetSim LE and BEE . . . . . . . . . . . . . . . . .
Boson NetSim LE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BEE and Practice Exams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electronic Book . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CertCams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Help . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal Installation(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Book Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Boson Software Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

456
456

456
457
458
458
458
459
459
459

Glossary ............................................................... 461
Index ................................................................... 495


FOREWORD

From Boson Software
The Cisco CCENT certification requires that you learn and master a number of
skills. As you read this book, incorporating Boson NetSim into your learning process
will help you successfully complete the CCENT certification. The Boson NetSim
Limited Edition (LE) included with this book will get you started on your way, and
additional capability from the full edition is available after purchasing an upgrade.
Boson NetSim will help you with the practical hands-on portion of your
education, and it ensures that you not only understand the concepts of routing and
switching but that you can actually configure and implement routing and switching
on Cisco devices. Once you feel you have mastered both the theory and the practical
labs, you can test your knowledge using the exams included with this book and
the CD. You may also purchase ExSim-Max practice exams from Boson, available
at . ExSim-Max is the most realistic practice exam on the
market with questions that are well-written, technically accurate, and completely
representative of those on the actual exam. With ExSim-Max, you can be sure you

are ready to pass the real exam.
Boson NetSim is the most advanced network simulator on the market for learning
how to configure a Cisco router and Catalyst switch. Boson NetSim will not only
help you become CCENT certified, it will actually help you learn and understand
how to configure routers, switches, and networks.
The Boson NetSim LE can be upgraded to the full edition for CCENT at any
time at (with a valid activation code from your
qualifying McGraw-Hill book). Upgrading enables all other Boson NetSim labs,
commands, telnet, and advanced features. Don’t forget to complete your study with
ExSim-Max practice exams. Thank you very much, and best wishes in your future
studies!
Boson Software


xvii
Copyright © 2008 by The McGraw-Hill Companies. Click here for terms of use.


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PREFACE

O

f course, the primary focus of our book is to help you achieve the Cisco Certified
Entry-level Network Technician certification—but there’s more to it than that. We’ve
provided all the background and technical knowledge in this book that you’ll need to
be successful on the exam, as well as a few exercises and hands-on projects to increase your odds.
Hopefully, though, we’ll also succeed in two other, secondary but just as important, goals.

First, after reading through this we’d be happy to see you emboldened with
confidence. Yes, we whole-heartedly believe, and would like to make sure you know,
YOU CAN DO IT! Sure, certifications are hard—they’re supposed to be; if they
were easy, everyone would do it—but this isn’t something you’re not capable of. This
book was written in the same manner we learned the information—in a simple, easy
and, yes, fun fashion. Look at it this way: If a couple of yahoos from Alabama, with
four kids and two full-time jobs, can figure this stuff out, you should do just fine.
Secondly, after all is said and done, we sure hope you don’t stop. CCENT is
a great certification, but it’s not the end-all be-all. Instead, it should be a great
beginning for you. After you pass—and you know you will—follow it up with
personal practice, hands-on experience, and study. Put into play what you’ve been
studying for all this time and prove you know it. Then, of course, start on your next
certification—the CCNA.
After you’ve completed the CCENT certification by passing the Interconnecting
Cisco Network Devices (ICND) v1 640-822 exam, you’ll be (literally) halfway to
a CCNA certification. The ICNDv2 640-816 exam covers the second half of the
CCNA body of knowledge and is more Cisco IOS configuration-, and device-,
centric. An excellent resource for studying for “part 2” is the Cisco Certified Network
Associate (CCNA) Study Guide (McGraw-Hill) by Richard Deal.

In This Book
This book covers all the exam objectives posted on Cisco’s web site concerning the
CCNA 640-822 exam. Each chapter explores one or more of the main objectives
in this list. You’ll also find much repetition from chapter to chapter since some
objectives are covered across multiple chapters. The Introduction offers a breakdown
of Cisco’s objectives and which chapter of this book covers each objective.

xix
Copyright © 2008 by The McGraw-Hill Companies. Click here for terms of use.

xx

CCENT Cisco Certified Entry Networking Technician Study Guide

In Every Chapter
Each chapter has several components designed to effectively communicate the
information you’ll need for the exam:
■ Every chapter begins with the Certification Objectives. These identify the

major topics within each section on the exam, dealing with the chapter topic.
Using these objective headings will help you keep track of where you are with
your studies.
■ Practice Exercises, step-by-step exercises providing hands-on experience,

are found in chapters with configuration objectives. While some chapters
require only knowledge and comprehension levels, other objectives require
you to know how a specific configuration option is entered into the switch or
router. These practice exercises are designed to reinforce the chapter verbiage
and provide insight into the skills that are likely to be an area of focus on the
exam. The information covered in these exercises is not simply for reading
purposes—you’ll be required to perform configuration on a variety of scenario
and simulation questions on the exam. Don’t fail to prepare for them by
simply reading over the practice exercises—practice them and be very, very
comfortable with their focus. These exercises will always work with the
simulator product, produced by Boson and provided with this book, but they
can be used anywhere. Practice as much as you can with the simulator and
with real equipment, should you have the opportunity.
■ On the Job entries are found throughout all the chapters and are designed to

point out information and tips that will be helpful both in your day-to-day
responsibilities and in studying for the exam. Please note that while these notes
provide insights, tips, and otherwise interesting tidbits of information, they are
also sometimes used to reinforce testable material. Don’t dismiss them as simply
“neat”—some of the mistakes and real-world issues described in these notes
may prove the difference in correctly answering a question or two on the exam!
■ Exam Watch notes highlight specific information within the section on

which to focus your studies. Do not rely on them totally, but be sure to read
over them before the exam.
■

Remember the benefits
and disadvantages of static routing, and
commit Table 6-2 to memory.

An Inside the Exam entry is provided at the
end of each chapter and basically summarizes
the important aspects of the chapter
in regards to the exam. Tips and tricks
mentioned in this section will definitely help
you understand what to expect on the test.


Preface

✓■
Q&A ■

xxi

The Two-Minute Drill is a full summary of the chapter, condensed and
organized for quick last-minute review.
The Self Test section at the end of each chapter offers questions similar to those
found on the certification exams. Answers and explanations of both correct and
incorrect choices are provided to assist in understanding the material.

Some Pointers
This may seem strange to say, since we wrote this book and hope everyone in the
networking arena gets a copy, but we’ll say it anyway: First and foremost, do not rely
on this book alone to pass your CCENT exam. There’s not a book on the planet
that, by itself, will fully prepare you for the test. Read this book, using the pointers
we provide here to guide your study, but never forget to practice, practice, practice.
The benefit of hands-on real-world experience in preparing you for the exam is
immeasurable. This book is, we humbly feel, a great guide to follow in preparing for
the exam, but you’ll definitely need plenty of practice outside its pages to succeed.
Once you finish reading this book, be sure to do a thorough review of everything:
1. Reread all the Two-Minute Drills. These will serve as an excellent “cram”
session just before the exam.
2. Reread all the Exam Watch notes. Knowing the information to satisfy each
knowledge objective is one thing, but it’s only part of the battle. To be truly
successful, you’ll need to know what to expect on the exam itself. Reading the
Exam Watch notes will give you insights into how the information will be
presented on the exam, and what to expect. If you know this upfront, you won’t
be surprised on the exam, and your confidence will contribute to your success.
3. Retake the Self Test sections at the back of each chapter. Immediately after
reading the chapter, give the accompanying Self Test a shot. Then, after
you’re done with the entire book, go back and take each Self Test again.
Facing all the questions at one time is very similar to the exam itself, and will
help with your study. Please note that simply memorizing these questions and

answers will NOT help you on the exam. The Self Test questions are similar
to what you’ll see, but they’re not exact replicas.
4. Use the Exam Test Engine on the CD. The test engine, provided by Boson
Software on the CD accompanying this book, provides plenty of questions
to prepare you for the exam. You can choose to quiz yourself on all questions,
much like the exam itself, or target your study by focusing on a single category.


xxii

CCENT Cisco Certified Entry Networking Technician Study Guide

Categories roughly match the chapter outline of the book, to help mark
your progression. Additionally, you can also purchase extra tests from Boson
Software at their web site (www.boson.com).
5. Do all the Practice Exercises in each of the chapters. You will be required to perform
configuration and troubleshooting on simulators during the exam. While
CCENT doesn’t go overboard with these, you’ll definitely need to be familiar
with all the configuration commands and steps included in this text. Use the
exercises in the book to reinforce concepts and prepare for the exam.
Additionally, feel free to experiment on your own—especially if you have access
to equipment. Interject problems to working environments and note various
troubleshooting techniques you can use to fix the problem. The configuration
of devices is a big part of the exam, but troubleshooting and examining
configuration files for errors will play a large role in your success or failure.
6. There may be some simulation questions on the CCENT exam. In simulation
questions, you’ll be required to perform basic configuration and troubleshooting
tasks on a Cisco router and/or switch. Therefore, it is important that you
have good configuration skills. Use the Practice Exercises to hone your
configuration skills! You may come across a simulation scenario presenting

a flawed configuration on the exam. The more you practice with the exercises
and Boson’s NetSim, the easier it will be to spot these configuration errors right
off the bat.

Practice Exams and the Simulator
Hands-on practice and real-world experience are essential in your preparation for
the exam. The practice exercises and simulator built for this book are designed with
exactly that in mind—giving you hands-on experience and an opportunity to practice
to your heart’s delight. The network provided in the simulator should allow you ample
opportunity to see all the command and configuration options in action. The network
is displayed in Figure 1, with addressing for all exercises spelled out in Figure 2.
This network provides every configuration option covered in the book. As
you go through the practice exercises, refer to Figures 1 and 2 to “see” how your
configuration should be applied. Additionally, don’t just rely on the exercises, as
written, for your study. Feel free to create your own configurations on each device.
Use all the show and debug commands you want to see the IOS in action. Finally,
after configuring the network to function, purposely change configuration options to
see the results. Using the practice exercises and your own creativity on this network
will greatly increase your odds of passing the exam.


Preface

FIGURE 1

A simulator
network for
practice exercises

PC-1

xxiii

PC-3

Fast
Ethernet
2960-2
Switch

Serial Point-to-Point
(T-line or DirectConnected in a Lab)

2960-1
Fast
Switch Fast
Ethernet
Ethernet
2800-1
Router

Fast
Ethernet

Fast
Ethernet

2960-4
Switch

2800-2
Router

Fast
Ethernet

2960-3
Switch
Fast
Ethernet

PC-4

PC-2

IP:
192.168.1.11
Mask:
255.255.255.0
Gateway: 192.168.1.1

FIGURE 2

Addressing for
the network
topology used
for the practice
exercises

PC-3

PC-1
MAC:

00-00-11-AA-BB-CC

IP:
192.168.2.10
Mask:
255.255.255.0
Gateway: 192.168.3.1
MAC:

00-00-33-AA-BB-CC

Fast
Ethernet
2960-1
192.168.1.2/24

FA0/2
FA0/1

FA0/2
FA0/1

FA0/1

FA0/2
2960-2

192.168.1.4/24

FA0/3

FA0/3

FA0/2

FA0/1

FA0/3

2800-1
FA0/0: 192.168.1.1/24
S1/0: 172.16.0.1/24 (DCE)

2960-4
192.168.2.2/24

FA0/3
2800-2
FA0/0: 192.168.2.1/24
S1/0: 172.16.0.254/24 (DTE)

2960-3
192.168.1.3/24

PC-2

IP:

192.168.1.10
Mask:
255.255.255.0
Gateway: 192.168.1.1
MAC:

00-00-22-AA-BB-CC

PC-4

IP:
192.168.2.11
Mask:
255.255.255.0
Gateway: 192.168.3.1
MAC:

00-00-44-AA-BB-CC


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