LAN Switching and Wireless: CCNA Exploration Companion Guide / Edition 1

by Wayne Lewis

Overview

LAN Switching and Wireless CCNA Exploration Companion Guide

 

Wayne Lewis, Ph.D.

 

LAN Switching and Wireless, CCNA Exploration Companion Guide is the official supplemental textbook for the LAN Switching and Wireless course in the Cisco Networking Academy CCNA® Exploration curriculum version 4. This course provides a comprehensive approach to learning the technologies and protocols needed to design and implement a converged switched network. The Companion Guide, written and edited by a Networking Academy instructor, is designed as a portable desk reference to use anytime, anywhere. The book’s features reinforce the material in the course to help you focus on important concepts and organize your study time for exams.

 

New and improved features help you study and succeed in this course:

• Chapter objectives: Review core concepts by answering the questions listed at the beginning of each chapter.
• Key terms: Refer to the updated lists of networking vocabulary introduced and turn to the highlighted terms in context in each chapter.
• Glossary: Consult the all-new comprehensive glossary with more than 190 terms.
• Check Your Understanding questions and answer key: Evaluate your readiness with the updated end-of-chapter questions that match the style of questions you see on the online course quizzes. The answer key explains each answer.
• Challenge questions and activities: Strive to ace more challenging review questions and activities designed to prepare you for the complex styles of questions you might see on the CCNAexam. The answer key explains each answer.

 

Wayne Lewis is the Cisco Academy Manager for the Pacific Center for Advanced Technology Training (PCATT), based at Honolulu Community College.

 

How To: Look for this icon to study the steps that you need to learn to perform certain tasks.

 

Packet Tracer Activities: Explore networking concepts in activities interspersed throughout some chapters using Packet Tracer v4.1 developed by Cisco. The files for these activities are on the accompanying CD-ROM.

 

Also available for the LAN Switching and Wireless course:

LAN Switching and Wireless, CCNA Exploration Labs and Study Guide

ISBN-10: 1-58713-202-8

ISBN-13: 978-1-58713-202-5

 

Companion CD-ROM

The CD-ROM provides many useful tools and information to support your education:

• Packet Tracer Activity exercise files
• A Guide to Using a Networker’s Journal booklet
• Taking Notes: A .txt file of the chapter objectives
• More IT Career Information
• Tips on Lifelong Learning in Networking

 

This book is part of the Cisco Networking Academy Series from Cisco Press®. Books in this series support and complement the Cisco Networking online curriculum.

 

Product Details

ISBN-13:	9781587132070
Publisher:	Cisco Press
Publication date:	05/14/2008
Series:	Companion Guide Series
Edition description:	New Edition
Pages:	528
Product dimensions:	8.25(w) x 9.50(h) x 1.33(d)

About the Author

Wayne Lewis is the Cisco Academy Manager for the Pacific Center for Advanced Technology Training (PCATT), based at Honolulu Community College (HonCC), and the Legal Main Contact for the CCNA/CCNP/Network Security Cisco Academy Training Center at PCATT/HonCC. Since 1998, Wayne has taught routing and switching, wide area networking, network troubleshooting, network security, wireless networking, IP telephony, and quality of service to instructors from universities, colleges, and high schools in

Australia, Canada, Mexico, Central America, South America, United States, American Samoa, Guam, China, Hong Kong, Taiwan, Indonesia, Singapore, Korea, Japan, Italy, Germany, Netherlands, Sweden, Poland, Hungary, and Great Britain, both onsite and at PCATT/HonCC. Cisco has sent Wayne to several countries to conduct inaugural Networking Academy teacher-training sessions to certify the initial cohorts of instructors and kick off the training centers for these countries. Before teaching networking, Wayne began teaching

at age 20 at Wichita State University, followed by the University of Hawaii and HonCC. In 1992, Wayne received a Ph.D. in math, specializing in finite rank torsion-free modules over a Dedekind domain; he now works on algebraic number theory research in his spare time. Wayne works as a contractor for Cisco , performing project management for the development of network security, CCNA, and CCNP curriculum. He and his wife, Leslie, also run a network consulting company. Wayne enjoys surfing the South Shore of Oahu in

the summer and surfing big waves on the North Shore in the winter.

Read an Excerpt

IntroductionIntroduction

The Cisco Networking Academy is a comprehensive e-learning program that provides students with Internet technology skills. A Networking Academy delivers web-based content, online assessment, student performance tracking, and hands-on labs to prepare students for industry-standard certifications. The CCNA curriculum includes four courses oriented around the topics on the Cisco Certified Network Associate (CCNA) certification.

LAN Switching and Wireless, CCNA Exploration Companion Guide is the official supplement textbook to be used with v4 of the CCNA Exploration LAN Switching and Wireless online curriculum of the Networking Academy.

This book goes beyond earlier editions of the Cisco Press Companion Guides by providing many alternative explanations and examples as compared with the course. You can use the online curriculum as normal and use this companion guide to help solidify your understanding of all the topics through the alternative examples.

The basis for this book, as well as the online curriculum, is to provide the reader with a thorough understanding of LAN switching and wireless technologies beyond that necessary for the CCNA certification exam. The commands and web-based GUI utilities for configuring LAN switching and wireless are not very difficult. The challenge is to understand the operation of these technologies and protocols and their role in the network.

The objective of this book is to explain LAN switching and wireless technologies. Every concept is methodically explained with no assumptions made of the reader's knowledge of LAN switching or wireless technologies. The only exceptions are if a concept is beyondthe scope of this course or is covered in CCNP, and then it is noted within the text.

Readers are encouraged to peruse the resources managed by Wayne Lewis at cisco.honolulu.hawaii.edu. Please e-mail Wayne Lewis at [e-mail] for more information about CCNP and network security instructor training and for access to more resources for this course and other CCNP, IP telephony, QoS, and network security courses.Goal of This Book

First and foremost, by providing a fresh, complementary perspective on the content, this book is intended to help you learn all the required materials of the LAN Switching and Wireless course in the Networking Academy CCNA Exploration curriculum. As a secondary goal, the text is intended as a mobile replacement for the online curriculum for individuals who do not always have Internet access. In those cases, you can instead read the appropriate sections of the book, as directed by your instructor, and learn the same material that is covered in the online curriculum. Another secondary goal is to serve as your offline study material to prepare for the CCNA exam.Audience for This Book

This book's main audience is anyone taking the CCNA Exploration LAN Switching and Wireless course of the Cisco Networking Academy curriculum. Many Academies use this textbook as a required tool in the course, and other Academies recommend the Companion Guides as an additional source of study and practice materials. Book Features

The educational features of this book focus on supporting topic coverage, readability, and practice of the course material to facilitate your full understanding of the course material.Topic Coverage

The following features give you a thorough overview of the topics covered in each chapter so that you can make constructive use of your study time:

• Objectives: Listed at the beginning of each chapter, the objectives reference the core concepts covered in the chapter. The objectives match the objectives stated in the corresponding chapters of the online curriculum; however, the question format in the Companion Guide encourages you to think about finding the answers as you read the chapter.

• "How-to" feature: When this book covers a set of steps that you need to perform for certain tasks, this book lists the steps as a how-to list. When you are studying, the icon helps you easily refer to this feature as you skim through the book.

• Notes, tips, cautions, and warnings: These are short sidebars that point out interesting facts, time-saving methods, and important safety issues.

• Chapter summaries: At the end of each chapter is a summary of the chapter's key concepts. It provides a synopsis of the chapter and serves as a study aid.

Readability

The author has compiled, edited, and in most cases rewritten the material so that it has a more conversational tone that follows a consistent and accessible college-reading level. In addition, the following features have been updated to assist your understanding of the networking vocabulary:

• Key terms: Each chapter begins with a list of key terms, along with a page-number reference from inside the chapter. The terms are listed in the order in which they are explained inside the chapter. This handy reference allows you to find a term, flip to the page where the term appears, and see the term used in context. The Glossary defines all the key terms.

• Glossary: This book contains an all-new Glossary with more than 150 terms.

Practice

Practice makes perfect. This new Companion Guide offers you ample opportunities to put what you learn to practice. You will find the following features valuable and effective in reinforcing the instruction that you receive:

• Check Your Understanding questions and answer key: Updated review questions are presented at the end of each chapter as a self-assessment tool. These questions match the style of questions that you see in the online course. The Appendix, "Check Your Understanding and Challenge Questions Answer Key," provides an answer key to all the questions and includes an explanation of each answer.

• (NEW) Challenge questions and activities: Additional—and more challenging—review questions and activities are presented at the end of chapters. These questions are purposefully designed to be similar to the more complex styles of questions you might see on the CCNA exam. This section might also include activities to help prepare you for the exams. The Appendix provides the answers.

• Packet Tracer activities: Interspersed throughout the chapters, you'll find many activities to work with the Cisco Packet Tracer tool. Packet Tracer allows you to create networks, visualize how packets flow in the network, and use basic testing tools to determine whether the network would work. When you see this icon, you can use Packet Tracer with the listed file to perform a task suggested in this book. The activity files are available in this book's CD-ROM; Packet Tracer software, however, is available through the Academy Connection website. Ask your instructor for access to Packet Tracer.

Labs and Study Guide

The supplementary book LAN Switching and Wireless, CCNA Exploration Labs and Study Guide (ISBN: 1-58713-202-8) by Cisco Press contains all the labs from the curriculum plus additional challenge labs and study guide material. The end of each chapter of this Companion Guide indicates with icons what labs, activities, and Packet Tracer activities are available in the Labs and Study Guide.

• Lab references: This icon notes the hands-on labs created for this chapter in the online curriculum. Within the LAN Switching and Wireless, CCNA Exploration Labs and Study Guide you will find additional study guide material created by the author of that book.

• (NEW) Packet Tracer Companion activities: Many of the Hands-on Labs include Packet Tracer Companion Activities where you can use Packet Tracer to complete a simulation of the lab. Look for this icon in the LAN Switching and Wireless, CCNA Exploration Labs and Study Guide for Hands-on Labs that have a Packet Tracer Companion.

• (NEW) Packet Tracer Skills Integration Challenge activities: These activities require you to pull together several skills learned from the chapter to successfully complete one comprehensive exercise. Look for this icon in the LAN Switching and Wireless, CCNA Exploration Labs and Study Guide for instructions on how to perform the Packet Tracer Skills Integration Challenge for this chapter.

A Word About Packet Tracer

Packet Tracer is a self-paced, visual, interactive teaching and learning tool developed by Cisco. Lab activities are an important part of networking education. However, lab equipment can be a scarce resource. Packet Tracer provides a visual simulation of equipment and network processes to offset the challenge of limited equipment. Students can spend as much time as they like completing standard lab exercises through Packet Tracer and have the option to work from home. Although Packet Tracer is not a substitute for real equipment, it allows students to practice using a command-line interface. This "e-doing" capability is a fundamental component of learning how to configure routers and switches from the command line.

Packet Tracer v4.x is available only to Cisco Networking Academies through the Academy Connection website.

The course includes essentially three types of Packet Tracer activities. This book uses an icon system to indicate which type of Packet Tracer activity is available. The icons are intended to give you a sense of the purpose of the activity and the amount of time you need to allot to complete it. The three types of Packet Tracer activities follow:

• Packet Tracer Activity: This icon identifies straightforward exercises interspersed throughout the chapters where you can practice or visualize a specific topic. The activity files for these exercises are available on this book's CD-ROM. These activities take less time to complete than the Packet Tracer Companion and Challenge activities.

• Packet Tracer Companion: This icon identifies exercises that correspond to the hands-on labs of the course. You can use Packet Tracer to complete a simulation of the hands-on lab or complete a similar "lab." The Companion Guide points these out at the end of each chapter, but look for this icon and the associated exercise file in LAN Switching and Wireless, CCNA Exploration Labs and Study Guide for hands-on labs that have a Packet Tracer Companion.

• Packet Tracer Skills Integration Challenge: This icon identifies activities that require you to pull together several skills learned from the chapter to successfully complete one comprehensive exercise. The Companion Guide points these out at the end of each chapter, but look for this icon and the associated exercise file in LAN Switching and Wireless, CCNA Exploration Labs and Study Guide for instructions on how to perform a Packet Tracer Skills Integration Challenge.

How This Book Is Organized

The book covers the major topic headings in the same sequence as the online curriculum for the CCNA Exploration LAN Switching and Wireless course. This book has seven chapters with the same numbers and names as the online course chapters.

For people reading this book without being in the CCNA Exploration LAN Switching and Wireless class, or just using this book for self-study, the sequence of topics in each chapter provides a logical sequence for learning the material presented.

Each chapter has a reference topology that is used to maintain a common framework from which to build upon the LAN switching and wireless concepts. The single topology per chapter allows for better continuity and easier understanding of switching commands, operations, and outputs, as well as web-based GUI utility mastery.

• Chapter 1, "LAN Design," provides an overview of the switched LAN architecture for small- and medium-sized businesses. The concept of converged network services within hierarchical networking is emphasized. You also learn how to select the appropriate switch to implement at each hierarchical layer in the switched LAN topology.

• Chapter 2, "Basic Switch Concepts and Configuration," reviews and reinforces the underlying concepts included within the IEEE 802.3 LAN standard and introduces the role of an Ethernet switch within a LAN. The basic configuration of switches to support voice, video, and data transmission is introduced, as well as basic network management options and rudimentary security measures.

• Chapter 3, "VLANs," provides an introduction to types of VLANs, port membership within VLANs, and VLAN trunking. VLANs are the logical basis upon which switched LANs are built. Configuring, verifying, and troubleshooting VLANs are discussed.

• Chapter 4, "VTP," examines the VLAN trunking protocol. VTP automates many of the VLAN configuration options in a switched LAN, but requires a good conceptual understanding of how the Layer 2 protocol operates. The underlying operation of VTP and VTP pruning are explored, followed by detailed guidance on VTP configuration.

• Chapter 5, "STP," provides a detailed analysis of the original IEEE 802.1D spanning-tree protocol (STP) and the improved IEEE 802.1w rapid spanning-tree protocol (RSTP). The operation of STP is complex and requires a careful, measured approach, which is provided herein. Compared to the underlying operation of STP, the configuration of 802.1D and 802.1w is relatively straightforward. Both 802.1D and 802.1w result in a logical, loop-free, Layer 2 topology with physical redundancy.

• Chapter 6, "Inter-VLAN Routing," explores three methods of inter-VLAN routing: one router interface per VLAN, router-on-a-stick, and multilayer switching. The configuration of the first two methods on access layer switches is detailed. Verification and troubleshooting inter-VLAN routing scenarios round out the chapter.

• Chapter 7, "Basic Wireless Concepts and Configuration," provides a quick introduction to all the important elements necessary to understand wireless technologies and standards. A web-based GUI is used to configure wireless routers in constructing the LAN/WLAN reference topology for the chapter. Common troubleshooting issues specific to wireless LANs are explored.

• The Appendix, "Check Your Understanding and Challenge Questions Answer Key," provides the answers to the Check Your Understanding questions that you find at the end of each chapter. It also includes answers for the Challenge Questions and Activities that conclude most chapters.

• The Glossary provides a compiled list of all the key terms that appear throughout this book.

About the CD-ROM

The CD-ROM included with this book provides many useful tools and information to support your education:

• Packet Tracer Activity files: These are files to work through the Packet Tracer Activities referenced throughout the book, as indicated by the Packet Tracer Activity icon.

• Taking Notes: This section includes a .txt file of the chapter objectives to serve as a general outline of the key topics of which you need to take note. The practice of taking clear, consistent notes is an important skill not only for learning and studying the material but for on-the-job success as well. Also included in this section is "A Guide to Using a Networker's Journal" PDF booklet providing important insight into the value of the practice of using a journal, how to organize a professional journal, and some best practices on what, and what not, to take note of in your journal.

• IT Career Information: This section includes a student guide to applying the toolkit approach to your career development. Learn more about entering the world of Information Technology as a career by reading two informational chapters excerpted from The IT Career Builder's Toolkit: "Communication Skills" and "Technical Skills."

• Lifelong Learning in Networking: As you embark on a technology career, you will notice that it is ever-changing and evolving. This career path provides new and exciting opportunities to learn new technologies and their applications. Cisco Press is one of the key resources to plug into on your quest for knowledge. This section of the CD-ROM provides an orientation to the information available to you and tips on how to tap into these resources for lifelong learning.

About the Cisco Press Website for This Book

Cisco Press may provide additional content that can be accessed by registering your individual book at the ciscopress.com website. Becoming a member and registering is free, and you then gain access to exclusive deals on other resources from Cisco Press.

To register this book, go to http://www.ciscopress.com/bookstore/register.asp and log in to your account or create a free account if you do not have one already. Then enter the ISBN located on the back cover of this book.

After you register the book, it will appear on your Account page under Registered Products, and you can access any online material from there.

© Copyright Pearson Education. All rights reserved.

Table of Contents

Chapter 1 LAN Design 1

Objectives 1

Key Terms 1

Switched LAN Architecture 2

The Hierarchical Network Model 2

Access Layer 2

Distribution Layer 3

Core Layer 3

A Hierarchical Network in a Medium-Sized Business 4

Benefits of a Hierarchical Network 4

Principles of Hierarchical Network Design 6

Network Diameter 7

Bandwidth Aggregation 8

Redundancy 9

What Is a Converged Network? 10

Legacy Equipment 10

Advanced Technology 11

New Options 12

Separate Voice, Video, and Data Networks 13

Matching Switches to Specific LAN Functions 15

Considerations for Hierarchical Network Switches 15

Traffic Flow Analysis 15

User Community Analysis 17

Data Stores and Data Servers Analysis 19

Topology Diagrams 20

Switch Features 22

Switch Form Factors 22

Switch Performance 24

Power over Ethernet and Layer 3 Functionality 26

Switch Features in a Hierarchical Network 28

Access Layer Switch Features 28

Distribution Layer Switch Features 30

Core Layer Switch Features 31

Switches for Small and Medium Sized Business (SMB) 33

Catalyst Express 500 33

Catalyst 2960 34

Catalyst 3560 35

Catalyst 3750 36

Catalyst 4500 36

Catalyst 4900 37

Catalyst 6500 38

Comparing Switches 39

Summary 40

Labs 40

Check Your Understanding 41

Challenge Questions and Activities 44

Chapter 2 Basic Switch Concepts and Configuration 45

Objectives 45

Key Terms 45

Introduction to Ethernet/802.3 LANs 46

Key Elements of Ethernet/802.3 Networks 46

CSMA/CD 46

Ethernet Communications 47

Duplex Settings 49

Switch Port Settings 50

Switch MAC Address Table 51

Design Considerations for Ethernet/802.3 Networks 52

Bandwidth and Throughput 52

Collision Domains 53

Broadcast Domains 54

Network Latency 54

Network Congestion 55

LAN Segmentation 55

LAN Design Considerations 56

Forwarding Frames Using a Switch 58

Switch Forwarding Methods 59

Symmetric and Asymmetric Switching 60

Memory Buffering 60

Layer 2 and Layer 3 Switching 62

Switch Management Configuration 63

Navigating Command-Line Interface Modes 63

GUI-Based Alternatives to the CLI 65

Using the Help Facility 68

Accessing the Command History 70

Switch Boot Sequence 71

Prepare to Configure the Switch 72

Basic Switch Configuration 72

Management Interface 73

Default Gateway 74

Duplex and Speed 75

HTTP Access 76

MAC Address Table Management 77

Verifying Switch Configuration 78

Basic Switch Management 80

Backing Up and Restoring Switch Configuration Files 80

Using a TFTP Server with Switch Configuration Files 82

Clearing Switch Configuration Information 84

Configuring Switch Security 85

Configuring Password Options 85

Securing Console Access 85

Securing Virtual Terminal Access 87

Securing Privileged EXEC Access 88

Encrypting Switch Passwords 89

Password Recovery 90

Login Banners 92

Configure Telnet and SSH 93

Configuring Telnet 93

Configuring SSH 94

Common Security Attacks 96

MAC Address Flooding 96

Spoofing Attacks 100

CDP Attacks 101

Telnet Attacks 102

Security Tools 103

Configuring Port Security 105

Securing Unused Ports 110

Summary 111

Labs 111

Check Your Understanding 112

Challenge Questions and Activities 117

Chapter 3 VLANs 121

Objectives 121

Key Terms 121

Introducing VLANs 122

Defining VLANs 122

Benefits of VLANs 124

VLAN ID Ranges 126

Types of VLANs 126

Voice VLANs 131

Network Application Traffic Types 133

Switch Port Membership Modes 136

Controlling Broadcast Domains with VLANs 138

VLAN Trunking 143

VLAN Trunks 144

IEEE 802.1Q Frame Tagging 145

Native VLANs 147

Trunking Operation 148

Trunking Modes 149

Configure VLANs and Trunks 151

Configure a VLAN 152

Managing VLANs 155

Managing VLAN Memberships 158

Configure a Trunk 160

Troubleshooting VLANs and Trunks 164

Common Problems with Trunks 165

A Common Problem with VLAN Configurations 171

Summary 173

Labs 173

Check Your Understanding 174

Challenge Questions and Activities 178

Chapter 4 VTP 181

Objectives 181

Key Terms 181

VTP Concepts 182

What Is VTP? 182

Benefits of VTP 184

VTP Components 184

VTP Operation 186

Default VTP Configuration 186

VTP Domains 188

VTP Advertising 190

VTP Configuration Revision Number 192

VTP Advertisement Types 193

VTP Modes 197

VTP Server-to-Client Behavior 198

VTP Server-to-Transparent-to-Client Behavior 199

VTP Pruning 201

VTP Pruning in Action 202

Configure VTP 204

Configuring VTP 204

Steps to Configuring VTP 206

Troubleshooting VTP Configurations 212

Incompatible VTP Versions 212

VTP Password Issues 212

Incorrect VTP Domain Name 213

All Switches Set to VTP Client Mode 214

VTP Troubleshooting Example 215

Managing VLANs on a VTP Server 217

Summary 219

Labs 219

Check Your Understanding 220

Challenge Questions and Activities 224

Chapter 5 STP 227

Objectives 227

Key Terms 227

Redundant Layer 2 Topologies 229

Redundancy 229

Issues with Redundancy 234

Broadcast Storms 238

Duplicate Unicast Frames 240

Real-World Redundancy Issues 241

Loops in the Wiring Closet 242

Loops in Cubicles 243

Introduction to STP 244

Spanning-Tree Algorithm (STA) 244

STP Topology 245

Port Types in the Spanning-Tree Algorithm 247

Root Bridge 248

Best Paths 249

STP BPDU 252

BPDU Process 253

Bridge ID 258

Configure and Verify the BID 261

Port Roles 263

Configure Port Priority 265

Port Role Decisions 266

STP Port States and BPDU Timers 268

Cisco PortFast 271

STP Convergence 273

Step 1. Elect a Root Bridge 273

Verify Root Bridge Election 274

Step 2. Elect Root Ports 276

Verify Root Port Election 278

Step 3. Elect Designated and Nondesignated Ports 279

Verify Designated and Nondesignated Port Election 283

STP Topology Change 285

PVST+, RSTP, and Rapid PVST+ 286

Cisco and IEEE STP Variants 287

Per-VLAN Spanning-Tree (PVST) Overview 287

Per-VLAN Spanning-Tree Plus (PVST+) Overview 287

Rapid Spanning-Tree Protocol (RSTP) Overview 288

Multiple Spanning-Tree Protocol (MSTP) Overview 288

PVST+ 288

Configure PVST+ 291

RSTP 294

RSTP BPDU 295

Edge Ports 296

Link Types 297

RSTP Port States and Port Roles 298

RSTP Proposal and Agreement Process 301

Configuring Rapid PVST+ 309

Design STP for Trouble Avoidance 312

Minimize the Number of Blocked Ports 313

Use Layer 3 Switching 314

Keep STP Even if It Is Unnecessary 316

Keep Traffic off of the Management VLAN 316

Troubleshoot STP Operation 316

PortFast Configuration Error 317

Network Diameter Issues 318

Summary 320

Labs 320

Check Your Understanding 321

Challenge Questions and Activities 327

Chapter 6 Inter-VLAN Routing 331

Objectives 331

Key Terms 331

Inter-VLAN Routing 332

Introducing Inter-VLAN Routing 332

One-Router-Interface-per-VLAN 332

Router-on-a-Stick 334

Layer 3 Switch 336

Interfaces and Subinterfaces 337

One-Router-Interface-per-VLAN 338

Router-on-a-Stick 341

Considerations for Inter-VLAN Routing Methods 345

Configuring Inter-VLAN Routing 347

Configure Inter-VLAN Routing 347

Configure Router-on-a-Stick Inter-VLAN Routing 351

Troubleshooting Inter-VLAN Routing 356

Switch Configuration Issues 356

Switch Cisco IOS Commands for Troubleshooting 359

Router Configuration Issues 360

Router Cisco IOS Commands for Troubleshooting 361

IP Addressing Issues 362

IP Addressing Cisco IOS Verification Commands 364

Summary 366

Labs 366

Check Your Understanding 367

Challenge Questions and Activities 373

Chapter 7 Basic Wireless Concepts and Configuration 377

Objectives 377

Key Terms 377

The Wireless LAN 379

Why Use Wireless? 379

Wireless LANs 380

Comparing a WLAN to a LAN 381

Wireless LAN Components 383

Wireless LAN Standards 383

Wi-Fi Certification 386

Wireless Infrastructure Components 387

Wireless NICs 387

Wireless Access Points 388

Wireless Routers 390

Wireless Operation 391

Configurable Wireless Parameters 391

Wireless Topologies 393

Wireless Association 396

Planning the Wireless LAN 399

Wireless LAN Security 402

Threats to Wireless Security 402

Rogue Access Points 402

Man-in-the-Middle Attacks 403

Denial of Service 404

Wireless Security Protocols 405

Authenticating the Wireless LAN 407

Wireless Encryption 408

Controlling Access to the WLAN 409

Configure Wireless LAN Access 410

Configuring the Wireless Access Point 410

Configuring Basic Wireless Settings 413

Configuring Wireless Security 415

Configuring a Wireless NIC 418

Scan for SSIDs 418

Select the Wireless Security Protocol 420

Verify Connectivity to the WLAN 423

Troubleshooting Simple WLAN Problems 424

A Systematic Approach to WLAN Troubleshooting 424

Solve Access Point Radio and Firmware Issues 426

Channel Settings 426

RF Interference 429

Access Point Placement 431

Authentication and Encryption 434

Summary 436

Labs 436

Check Your Understanding 437

Challenge Questions and Activities 441

Appendix Check Your Understanding and Challenge Questions

Answer Key 445

Glossary 461

Preface

Introduction

The Cisco Networking Academy is a comprehensive e-learning program that provides students with Internet technology skills. A Networking Academy delivers web-based content, online assessment, student performance tracking, and hands-on labs to prepare students for industry-standard certifications. The CCNA curriculum includes four courses oriented around the topics on the Cisco Certified Network Associate (CCNA) certification.

LAN Switching and Wireless, CCNA Exploration Companion Guide is the official supplement textbook to be used with v4 of the CCNA Exploration LAN Switching and Wireless online curriculum of the Networking Academy.

This book goes beyond earlier editions of the Cisco Press Companion Guides by providing many alternative explanations and examples as compared with the course. You can use the online curriculum as normal and use this companion guide to help solidify your understanding of all the topics through the alternative examples.

The basis for this book, as well as the online curriculum, is to provide the reader with a thorough understanding of LAN switching and wireless technologies beyond that necessary for the CCNA certification exam. The commands and web-based GUI utilities for configuring LAN switching and wireless are not very difficult. The challenge is to understand the operation of these technologies and protocols and their role in the network.

The objective of this book is to explain LAN switching and wireless technologies. Every concept is methodically explained with no assumptions made of the reader's knowledge of LAN switching or wireless technologies. The only exceptions are if a concept is beyond the scope of this course or is covered in CCNP, and then it is noted within the text.

Readers are encouraged to peruse the resources managed by Wayne Lewis at cisco.honolulu.hawaii.edu. Please e-mail Wayne Lewis at [e-mail] for more information about CCNP and network security instructor training and for access to more resources for this course and other CCNP, IP telephony, QoS, and network security courses.

Goal of This Book

First and foremost, by providing a fresh, complementary perspective on the content, this book is intended to help you learn all the required materials of the LAN Switching and Wireless course in the Networking Academy CCNA Exploration curriculum. As a secondary goal, the text is intended as a mobile replacement for the online curriculum for individuals who do not always have Internet access. In those cases, you can instead read the appropriate sections of the book, as directed by your instructor, and learn the same material that is covered in the online curriculum. Another secondary goal is to serve as your offline study material to prepare for the CCNA exam.

Audience for This Book

This book's main audience is anyone taking the CCNA Exploration LAN Switching and Wireless course of the Cisco Networking Academy curriculum. Many Academies use this textbook as a required tool in the course, and other Academies recommend the Companion Guides as an additional source of study and practice materials.

Book Features

The educational features of this book focus on supporting topic coverage, readability, and practice of the course material to facilitate your full understanding of the course material.

Topic Coverage

The following features give you a thorough overview of the topics covered in each chapter so that you can make constructive use of your study time:

• Objectives: Listed at the beginning of each chapter, the objectives reference the core concepts covered in the chapter. The objectives match the objectives stated in the corresponding chapters of the online curriculum; however, the question format in the Companion Guide encourages you to think about finding the answers as you read the chapter.

• "How-to" feature: When this book covers a set of steps that you need to perform for certain tasks, this book lists the steps as a how-to list. When you are studying, the icon helps you easily refer to this feature as you skim through the book.

• Notes, tips, cautions, and warnings: These are short sidebars that point out interesting facts, time-saving methods, and important safety issues.

• Chapter summaries: At the end of each chapter is a summary of the chapter's key concepts. It provides a synopsis of the chapter and serves as a study aid.

Readability

The author has compiled, edited, and in most cases rewritten the material so that it has a more conversational tone that follows a consistent and accessible college-reading level. In addition, the following features have been updated to assist your understanding of the networking vocabulary:

• Key terms: Each chapter begins with a list of key terms, along with a page-number reference from inside the chapter. The terms are listed in the order in which they are explained inside the chapter. This handy reference allows you to find a term, flip to the page where the term appears, and see the term used in context. The Glossary defines all the key terms.

• Glossary: This book contains an all-new Glossary with more than 150 terms.

Practice

Practice makes perfect. This new Companion Guide offers you ample opportunities to put what you learn to practice. You will find the following features valuable and effective in reinforcing the instruction that you receive:

• Check Your Understanding questions and answer key: Updated review questions are presented at the end of each chapter as a self-assessment tool. These questions match the style of questions that you see in the online course. The Appendix, "Check Your Understanding and Challenge Questions Answer Key," provides an answer key to all the questions and includes an explanation of each answer.

• (NEW) Challenge questions and activities: Additional—and more challenging—review questions and activities are presented at the end of chapters. These questions are purposefully designed to be similar to the more complex styles of questions you might see on the CCNA exam. This section might also include activities to help prepare you for the exams. The Appendix provides the answers.

• Packet Tracer activities: Interspersed throughout the chapters, you'll find many activities to work with the Cisco Packet Tracer tool. Packet Tracer allows you to create networks, visualize how packets flow in the network, and use basic testing tools to determine whether the network would work. When you see this icon, you can use Packet Tracer with the listed file to perform a task suggested in this book. The activity files are available in this book's CD-ROM; Packet Tracer software, however, is available through the Academy Connection website. Ask your instructor for access to Packet Tracer.

Labs and Study Guide

The supplementary book LAN Switching and Wireless, CCNA Exploration Labs and Study Guide (ISBN: 1-58713-202-8) by Cisco Press contains all the labs from the curriculum plus additional challenge labs and study guide material. The end of each chapter of this Companion Guide indicates with icons what labs, activities, and Packet Tracer activities are available in the Labs and Study Guide.

• Lab references: This icon notes the hands-on labs created for this chapter in the online curriculum. Within the LAN Switching and Wireless, CCNA Exploration Labs and Study Guide you will find additional study guide material created by the author of that book.

• (NEW) Packet Tracer Companion activities: Many of the Hands-on Labs include Packet Tracer Companion Activities where you can use Packet Tracer to complete a simulation of the lab. Look for this icon in the LAN Switching and Wireless, CCNA Exploration Labs and Study Guide for Hands-on Labs that have a Packet Tracer Companion.

• (NEW) Packet Tracer Skills Integration Challenge activities: These activities require you to pull together several skills learned from the chapter to successfully complete one comprehensive exercise. Look for this icon in the LAN Switching and Wireless, CCNA Exploration Labs and Study Guide for instructions on how to perform the Packet Tracer Skills Integration Challenge for this chapter.

A Word About Packet Tracer

Packet Tracer is a self-paced, visual, interactive teaching and learning tool developed by Cisco. Lab activities are an important part of networking education. However, lab equipment can be a scarce resource. Packet Tracer provides a visual simulation of equipment and network processes to offset the challenge of limited equipment. Students can spend as much time as they like completing standard lab exercises through Packet Tracer and have the option to work from home. Although Packet Tracer is not a substitute for real equipment, it allows students to practice using a command-line interface. This "e-doing" capability is a fundamental component of learning how to configure routers and switches from the command line.

Packet Tracer v4.x is available only to Cisco Networking Academies through the Academy Connection website.

The course includes essentially three types of Packet Tracer activities. This book uses an icon system to indicate which type of Packet Tracer activity is available. The icons are intended to give you a sense of the purpose of the activity and the amount of time you need to allot to complete it. The three types of Packet Tracer activities follow:

• Packet Tracer Activity: This icon identifies straightforward exercises interspersed throughout the chapters where you can practice or visualize a specific topic. The activity files for these exercises are available on this book's CD-ROM. These activities take less time to complete than the Packet Tracer Companion and Challenge activities.

• Packet Tracer Companion: This icon identifies exercises that correspond to the hands-on labs of the course. You can use Packet Tracer to complete a simulation of the hands-on lab or complete a similar "lab." The Companion Guide points these out at the end of each chapter, but look for this icon and the associated exercise file in LAN Switching and Wireless, CCNA Exploration Labs and Study Guide for hands-on labs that have a Packet Tracer Companion.

• Packet Tracer Skills Integration Challenge: This icon identifies activities that require you to pull together several skills learned from the chapter to successfully complete one comprehensive exercise. The Companion Guide points these out at the end of each chapter, but look for this icon and the associated exercise file in LAN Switching and Wireless, CCNA Exploration Labs and Study Guide for instructions on how to perform a Packet Tracer Skills Integration Challenge.

How This Book Is Organized

The book covers the major topic headings in the same sequence as the online curriculum for the CCNA Exploration LAN Switching and Wireless course. This book has seven chapters with the same numbers and names as the online course chapters.

For people reading this book without being in the CCNA Exploration LAN Switching and Wireless class, or just using this book for self-study, the sequence of topics in each chapter provides a logical sequence for learning the material presented.

Each chapter has a reference topology that is used to maintain a common framework from which to build upon the LAN switching and wireless concepts. The single topology per chapter allows for better continuity and easier understanding of switching commands, operations, and outputs, as well as web-based GUI utility mastery.

• Chapter 1, "LAN Design," provides an overview of the switched LAN architecture for small- and medium-sized businesses. The concept of converged network services within hierarchical networking is emphasized. You also learn how to select the appropriate switch to implement at each hierarchical layer in the switched LAN topology.

• Chapter 2, "Basic Switch Concepts and Configuration," reviews and reinforces the underlying concepts included within the IEEE 802.3 LAN standard and introduces the role of an Ethernet switch within a LAN. The basic configuration of switches to support voice, video, and data transmission is introduced, as well as basic network management options and rudimentary security measures.

• Chapter 3, "VLANs," provides an introduction to types of VLANs, port membership within VLANs, and VLAN trunking. VLANs are the logical basis upon which switched LANs are built. Configuring, verifying, and troubleshooting VLANs are discussed.

• Chapter 4, "VTP," examines the VLAN trunking protocol. VTP automates many of the VLAN configuration options in a switched LAN, but requires a good conceptual understanding of how the Layer 2 protocol operates. The underlying operation of VTP and VTP pruning are explored, followed by detailed guidance on VTP configuration.

• Chapter 5, "STP," provides a detailed analysis of the original IEEE 802.1D spanning-tree protocol (STP) and the improved IEEE 802.1w rapid spanning-tree protocol (RSTP). The operation of STP is complex and requires a careful, measured approach, which is provided herein. Compared to the underlying operation of STP, the configuration of 802.1D and 802.1w is relatively straightforward. Both 802.1D and 802.1w result in a logical, loop-free, Layer 2 topology with physical redundancy.

• Chapter 6, "Inter-VLAN Routing," explores three methods of inter-VLAN routing: one router interface per VLAN, router-on-a-stick, and multilayer switching. The configuration of the first two methods on access layer switches is detailed. Verification and troubleshooting inter-VLAN routing scenarios round out the chapter.

• Chapter 7, "Basic Wireless Concepts and Configuration," provides a quick introduction to all the important elements necessary to understand wireless technologies and standards. A web-based GUI is used to configure wireless routers in constructing the LAN/WLAN reference topology for the chapter. Common troubleshooting issues specific to wireless LANs are explored.

• The Appendix, "Check Your Understanding and Challenge Questions Answer Key," provides the answers to the Check Your Understanding questions that you find at the end of each chapter. It also includes answers for the Challenge Questions and Activities that conclude most chapters.

• The Glossary provides a compiled list of all the key terms that appear throughout this book.

About the CD-ROM

The CD-ROM included with this book provides many useful tools and information to support your education:

• Packet Tracer Activity files: These are files to work through the Packet Tracer Activities referenced throughout the book, as indicated by the Packet Tracer Activity icon.

• Taking Notes: This section includes a .txt file of the chapter objectives to serve as a general outline of the key topics of which you need to take note. The practice of taking clear, consistent notes is an important skill not only for learning and studying the material but for on-the-job success as well. Also included in this section is "A Guide to Using a Networker's Journal" PDF booklet providing important insight into the value of the practice of using a journal, how to organize a professional journal, and some best practices on what, and what not, to take note of in your journal.

• IT Career Information: This section includes a student guide to applying the toolkit approach to your career development. Learn more about entering the world of Information Technology as a career by reading two informational chapters excerpted from The IT Career Builder's Toolkit: "Communication Skills" and "Technical Skills."

• Lifelong Learning in Networking: As you embark on a technology career, you will notice that it is ever-changing and evolving. This career path provides new and exciting opportunities to learn new technologies and their applications. Cisco Press is one of the key resources to plug into on your quest for knowledge. This section of the CD-ROM provides an orientation to the information available to you and tips on how to tap into these resources for lifelong learning.

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