Accessing the WAN
CCNA Exploration Companion Guide
Bob Vachon
Rick Graziani
Accessing the WAN, CCNA Exploration Companion Guide is the official supplemental textbook for the Accessing the WAN course in the Cisco Networking Academy CCNA Exploration curriculum version 4. This course discusses the WAN technologies and network services required by converged applications in enterprise networks. The Companion Guide, written and edited by Networking Academy instructors, 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 focus 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 250 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 CCNA exam. The answer key explains each answer.
Bob Vachon is the coordinator of the Computer Systems Technology program and teaches networking infrastructure courses at Cambrian College in Sudbury, Ontario, Canada. Bob has worked and taught in the computer networking and information technology field for 25 years and is a scholar graduate of Cambrian College.
Rick Graziani teaches computer science and computer networking courses at Cabrillo College in Aptos, California. Rick has worked and taught in the computer networking and information technology field for 30 years.
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 Accessing the WAN Course
Accessing the WAN,
CCNA Exploration
Labs and Study Guide
ISBN-10: 1-58713-201-X
ISBN-13: 978-1-58713-201-8
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. The products in this series support and complement the Cisco Networking Academy online curriculum.
Sprache
Verlagsort
Verlagsgruppe
Zielgruppe
Für höhere Schule und Studium
Maße
Höhe: 210 mm
Breite: 236 mm
Dicke: 34 mm
Gewicht
ISBN-13
978-1-58713-205-6 (9781587132056)
Copyright in bibliographic data and cover images is held by Nielsen Book Services Limited or by the publishers or by their respective licensors: all rights reserved.
Schweitzer Klassifikation
Bob Vachon
is the coordinator of the Computer Systems Technology program at Cambrian College in Sudbury, Ontario, Canada, where he teaches networking infrastructure courses.
He has worked and taught in the computer networking and information technology field since 1984. He is a scholar graduate of Cambrian College, and he received the prestigious
Teaching Excellence Award in 1997. Vachon has been a Cisco Networking Academy instructor since 1999 and has been CCNP certified since 2002. He has worked with Cisco
as team lead, author, CCNP certification assessment developer, and subject matter expert on a variety of projects, including CCNA, CCNP, and global partner training courses. He
enjoys playing the guitar and being outdoors, either working in his gardens or white-water canoe tripping.
Rick Graziani teaches computer science and computer networking courses at Cabrillo College in Aptos, California. He has worked and taught in the computer networking and
information technology fields for almost 30 years. Before that, he worked in IT for various companies, including Santa Cruz Operation, Tandem Computers, and Lockheed Missiles
and Space Corporation. He holds an M.A. in computer science and systems theory from California State University Monterey Bay. Graziani also does consulting work for Cisco and
other companies. When he is not working, he is most likely surfing. He is an avid surfer who enjoys longboarding at his favorite Santa Cruz surf breaks.
Chapter 1 Introduction to WANs 1
Objectives 1
Key Terms 1
Introducing Wide-Area Networks (WANs) 3
What Is a WAN? 3
Why Are WANs Necessary? 5
The Evolving Enterprise 5
Businesses and Their Networks 5
Small Office (Single LAN) 6
Campus (Multiple LANs) 6
Branch (WAN) 8
Distributed (Global) 9
The Evolving Network Model 11
The Hierarchical Design Model 11
The Enterprise Architecture 13
WAN Technology Concepts 17
WAN Technology Overview 17
WAN Physical Layer Concepts 18
WAN Data Link Layer Concepts 23
WAN Switching Concepts 26
WAN Connection Options 29
WAN Link Connection Options 29
Dedicated Connection Link Options 31
Circuit-Switched Connection Options 32
Packet-Switched Connection Options 35
I nternet Connection Options 38
Choosing a WAN Link Connection 44
Summary 48
Labs 49
Check Your Understanding 50
Challenge Questions and Activities 54
Chapter 2 PPP 55
Objectives 55
Key Terms 55
Introducing Serial Communications 56
How Does Serial Communication Work? 56
Serial Communication Standards 59
TDM 61
Demarcation Point 66
Data Terminal Equipment and Data Communications Equipment 67
HDLC Encapsulation 72
Configuring HDLC Encapsulation 75
Troubleshooting Serial Interfaces 76
PPP Concepts 83
Introducing PPP 83
PPP Layered Architecture 84
PPP Frame Structure 87
Establishing a PPP Session 88
Establishing a Link with LCP 89
NCP Explained 95
PPP Configuration Options 97
PPP Configuration Commands 98
Verifying a Serial PPP Encapsulation Configuration 101
Troubleshooting PPP Encapsulation 102
PPP Authentication Protocols 108
Password Authentication Protocol 109
Challenge Handshake Authentication Protocol (CHAP) 110
PPP Encapsulation and Authentication Process 112
Configuring PPP with Authentication 115
Troubleshooting a PPP Configuration with Authentication 118
Summary 120
Labs 120
Check Your Understanding 122
Challenge Questions and Activities 126
Chapter 3 Frame Relay 127
Objectives 127
Key Terms 127
Introduction 128
Basic Frame Relay Concepts 128
Introducing Frame Relay 128
Virtual Circuits 134
Frame Relay Encapsulation 140
Frame Relay Topologies 141
Frame Relay Address Mapping 145
Configuring Frame Relay 152
Enabling Frame Relay Encapsulation 153
Configuring Static Frame Relay Maps 156
Advanced Frame Relay Concepts 159
Solving Reachability Issues 159
Frame Relay Subinterfaces 161
Paying for Frame Relay 162
Frame Relay Flow Control 166
Configuring Advanced Frame Relay 168
Configuring Frame Relay Subinterfaces 168
Verifying Frame Relay Operation 171
Troubleshooting Frame Relay Configuration 178
Summary 180
Labs 181
Check Your Understanding 182
Challenge Questions and Activities 188
To Learn More 188
Chapter 4 Network Security 189
Objectives 189
Key Terms 189
Introduction to Network Security 190
Why Is Network Security Important? 190
Common Security Threats 199
Types of Network Attacks 206
General Mitigation Techniques 219
The Network Security Wheel 226
The Enterprise Security Policy 229
Securing Cisco Routers 232
Router Security Issues 232
Applying Cisco IOS Security Features to Routers 235
Securing Router Network Services 250
Vulnerable Router Services and Interfaces 250
Securing Routing Protocols 256
Locking Down Your Router with Cisco AutoSecure 263
Using Cisco SDM 264
Cisco SDM Overview 264
Configuring Your Router to Support SDM 265
Starting SDM 267
The SDM Interface 269
Cisco SDM Wizards 272
Locking Down a Router with SDM 272
Secure Router Management 275
Maintaining Cisco IOS Software Images 275
Managing Cisco IOS Images 276
Managing Cisco IOS Images 283
Backing Up and Upgrading a Software Image 284
Recovering Software Images 288
Troubleshooting Cisco IOS Configurations 294
Recovering a Lost Password 297
Summary 301
Labs 301
Check Your Understanding 302
Challenge Questions and Activities 308
Chapter 5 ACLs 309
Objectives 309
Key Terms 309
Using ACLs to Secure Networks 310
A TCP Conversation 310
Packet Filtering 313
What Is an ACL? 316
ACL Operation 318
Types of Cisco ACLs 322
How a Standard ACL Works 323
Numbering and Naming ACLs 323
Where to Place ACLs 324
General Guidelines for Creating ACLs 327
Configuring Standard ACLs 327
Entering Criteria Statements 327
Configuring a Standard ACL 328
ACL Wildcard Masking 332
Applying Standard ACLs to Interfaces 339
Editing Numbered ACLs 343
Creating Standard Named ACLs 345
Monitoring and Verifying ACLs 346
Editing Named ACLs 347
Configuring an Extended ACL 348
Extended ACLs 349
Configuring Extended ACLs 351
Applying Extended ACLs to the Interfaces 353
Creating Named Extended ACLs 355
Configure Complex ACLs 357
What Are Complex ACLs? 357
Dynamic ACLs 358
Reflexive ACLs 360
Time-Based ACLs 363
Troubleshooting Common ACL Errors 364
Summary 368
Labs 368
Check Your Understanding 369
Challenge Questions and Activities 375
Chapter 6 Teleworker Services 377
Objectives 377
Key Terms 377
Business Requirements for Teleworker Services 379
The Business Requirements for Teleworker Services 379
The Teleworker Solution 380
Broadband Services 384
Connecting Teleworkers to the WAN 384
Cable 385
DSL 391
Broadband Wireless 396
VPN Technology 401
VPNs and Their Benefits 402
Types of VPNs 405
VPN Components 407
Characteristics of Secure VPNs 408
VPN Tunneling 409
VPN Data Confidentiality and Integrity 410
IPsec Security Protocols 416
Summary 419
Labs 419
Check Your Understanding 419
Challenge Questions and Activities 423
Chapter 7 IP Addressing Services 429
Objectives 429
Key Terms 429
Introduction 431
DHCP 431
Introduction to DHCP 432
DHCP Operation 432
BOOTP and DHCP 435
Configuring a Cisco Router as a DHCP Server 440
Configuring a DHCP Client 447
DHCP Relay 449
Configuring a DHCP Server Using SDM 453
Troubleshooting DHCP Configuration 456
Scaling Networks with NAT 460
What Is NAT? 462
Benefits and Drawbacks of Using NAT 468
Configuring Static NAT 470
Configuring Dynamic NAT 471
Configuring NAT Overload for a Single Public IP Address 473
Configuring NAT Overload for a Pool of Public IP Addresses 475
Configuring Port Forwarding 477
Verifying NAT and NAT Overload 479
Troubleshooting NAT and NAT Overload Configuration 483
IPv6 485
Reasons for Using IPv6 489
IPv6 Addressing 493
IPv6 Transition Strategies 499
Cisco IOS Dual Stack 500
IPv6 Tunneling 502
Routing Configurations with IPv6 503
Configuring IPv6 Addresses 506
Configuring RIPng with IPv6 508
Summary 512
Labs 512
Check Your Understanding 514
Challenge Questions and Activities 522
Chapter 8 Network Troubleshooting 525
Objectives 525
Key Terms 525
Establishing the Network Performance Baseline 526
Documenting Your Network 526
Network Documentation Process 533
Why Is Establishing a Network Baseline Important? 535
Steps for Establishing a Network Baseline 535
Troubleshooting Methodologies and Tools 541
A General Approach to Troubleshooting 541
Using Layered Models for Troubleshooting 541
General Troubleshooting Procedures 544
Troubleshooting Methods 545
Gathering Symptoms 548
Troubleshooting Tools 551
Review of WAN Communications 560
WAN Communications 560
Steps in WAN Design 561
WAN Traffic Considerations 562
WAN Topology Considerations 564
WAN Connection Technologies 567
WAN Bandwidth Considerations 568
Common WAN Implementations Issues 569
WAN Troubleshooting from an ISP's Perspective 570
Network Troubleshooting 571
Physical Layer Troubleshooting 573
Data Link Layer Troubleshooting 577
Network Layer Troubleshooting 584
Transport Layer Troubleshooting 586
Application Layer Troubleshooting 589
Summary 595
Labs 595
Check Your Understanding 596
Challenge Questions and Activities 600
Appendix 601
Glossary 637
