CCNP Self-Study CCNP BSCI Exam Certification Guide

Access Registrar, AccessPath, Are You Ready, ATM Director, Browse with Me, CCDA, CCDE, CCDP, CCIE, CCNA, CCNP, CCSI, CD-PAC, CiscoLink, the Cisco NetWorks logo, the Cisco Powered Network

Trang 1

Cisco Press

201 W 103rd StreetIndianapolis, IN 46290

Cisco Press

CCNP Self-Study CCNP BSCI Exam Certification Guide

Clare Gough

chpt_01.book Page i Thursday, January 9, 2003 4:32 PM

Trang 2

Printed in the United States of America 1 2 3 4 5 6 7 8 9 0

First Printing January 2003

Library of Congress Cataloging-in-Publication Number: 20-02115641

ISBN: 1-58720-078-3

Warning and Disclaimer

This book is designed to provide information about building scalable Cisco networks Every effort has been made to make this book as complete and as accurate as possible, but no warranty or fitness is implied.

The information is provided on an “as is” basis The author, Cisco Press, and Cisco Systems, Inc., shall have neither bility nor responsibility to any person or entity with respect to any loss or damages arising from the information con- tained in this book or from the use of the discs or programs that may accompany it.

lia-The opinions expressed in this book belong to the author and are not necessarily those of Cisco Systems, Inc.

Trademark Acknowledgments

All terms mentioned in this book that are known to be trademarks or service marks have been appropriately capitalized Cisco Press or Cisco Systems, Inc., cannot attest to the accuracy of this information Use of a term in this book should not be regarded as affecting the validity of any trademark or service mark.

Feedback Information

At Cisco Press, our goal is to create in-depth technical books of the highest quality and value Each book is crafted with care and precision, undergoing rigorous development that involves the unique expertise of members from the professional technical community.

Readers’ feedback is a natural continuation of this process If you have any comments regarding how we could improve the quality of this book, or otherwise alter it to better suit your needs, you can contact us through e-mail at feedback@ciscopress.com Please make sure to include the book title and ISBN in your message.

We greatly appreciate your assistance.

Trang 3

Cisco Representative Anthony Wolfenden Cisco Press Program Manager Sonia Torres Chavez Cisco Marketing Communications Manager Tom Geitner Cisco Marketing Program Manager Edie Quiroz

Acquisitions Editor Michelle Grandin

Keith Cline

Steve Gifkins Brent Stewart Martin Walshaw

Steve Wisniewski CD-ROM Question Authors David Barnes

Martin Walshaw CD-ROM Technical Editors Steve Gifkins

Mike Truett

Corporate Headquarters

Cisco Systems, Inc.

170 West Tasman Drive San Jose, CA 95134-1706 USA

http://www.cisco.com Tel: 408 526-4000

800 553-NETS (6387) Fax: 408 526-4100

European Headquarters

Cisco Systems Europe

11 Rue Camille Desmoulins

92782 Issy-les-Moulineaux Cedex 9

France http://www- europe.cisco.com Tel: 33 1 58 04 60 00 Fax: 33 1 58 04 61 00

Americas Headquarters

Cisco Systems, Inc.

170 West Tasman Drive San Jose, CA 95134-1706 USA

http://www.cisco.com Tel: 408 526-7660 Fax: 408 527-0883

Asia Pacific Headquarters

Cisco Systems Australia, Pty., Ltd

Level 17, 99 Walker Street North Sydney

NSW 2059 Australia http://www.cisco.com Tel: +61 2 8448 7100 Fax: +61 2 9957 4350

CCNP, CCSI, CD-PAC, CiscoLink, the Cisco NetWorks logo, the Cisco Powered Network logo, Cisco Systems Networking Academy, Fast Step, FireRunner, Follow Me Browsing,

FormShare, GigaStack, IGX, Intelligence in the Optical Core, Internet Quotient, IP/VC, iQ Breakthrough, iQ Expertise, iQ FastTrack, iQuick Study, iQ Readiness Scorecard, The

iQ Logo, Kernel Proxy, MGX, Natural Network Viewer, Network Registrar, the Networkers logo, Packet, PIX, Point and Click Internetworking, Policy Builder, RateMUX,

ReyMaster, ReyView, ScriptShare, Secure Script, Shop with Me, SlideCast, SMARTnet, SVX, TrafficDirector, TransPath, VlanDirector, Voice LAN, Wavelength Router, Workgroup Director, and Workgroup Stack are trademarks of Cisco Systems, Inc.; Changing the Way We Work, Live, Play, and Learn, Empowering the Internet Generation, are service marks of Cisco Systems, Inc.; and Aironet, ASIST, BPX, Catalyst, Cisco, the Cisco Certified Internetwork Expert Logo, Cisco IOS, the Cisco IOS logo, Cisco Press, Cisco Systems, Cisco Systems Capital, the Cisco Systems logo, Collision Free, Enterprise/Solver, EtherChannel, EtherSwitch, FastHub, FastLink, FastPAD, IOS, IP/TV, IPX, LightStream, LightSwitch, MICA, NetRanger, Post-Routing, Pre-Routing, Registrar, StrataView Plus, Stratm, SwitchProbe, TeleRouter, are registered trademarks of Cisco Systems, Inc or its affiliates in the U.S and certain other countries

All other brands, names, or trademarks mentioned in this document or Web site are the property of their respective owners The use of the word partner does not imply a partnership

Cisco Systems has more than 200 offices in the following countries Addresses, phone numbers, and fax numbers are listed on

the Cisco Web site at www.cisco.com/go/offices

Argentina • Australia • Austria • Belgium • Brazil • Bulgaria • Canada • Chile • China • Colombia • Costa Rica • Croatia • Czech Republic • Denmark • Dubai, UAE • Finland • France • Germany • Greece • Hong Kong • Hungary • India • Indonesia • Ireland Israel • Italy • Japan • Korea • Luxembourg • Malaysia • Mexico • The Netherlands • New Zealand • Norway • Peru • Philippines Poland • Portugal • Puerto Rico • Romania • Russia • Saudi Arabia • Scotland • Singapore • Slovakia • Slovenia • South Africa • Spain Sweden

• Switzerland • Taiwan • Thailand • Turkey • Ukraine • United Kingdom • United States • Venezuela • Vietnam

• Zimbabwe chpt_01.book Page iii Thursday, January 9, 2003 4:32 PM

Trang 4

iv

About the Author

Clare Gough, CCIE No 2893, has been a certified Cisco Systems instructor for the ICRC, ACRC, CIT, CLSC, and CID courses She holds a master's degree in education and a master’s degree in information systems Over the last 15 years, she has developed and taught a variety of networking and internetworking courses throughout the world for Digital Equipment Company and various Cisco training partners She moved from England in 1991 and now lives in San Francisco with her family.

About the Technical Reviewers

Jorge Aragon, CCIE No 5567, is a network engineer with Perot Systems Corporation (PSC) in Dallas, Texas He holds a bachelor of science degree in electrical engineering from the National Polytechnic Institute in Mexico, and has a master of science degree in telecommunications from the University of Pittsburgh He also holds an MCSE certification and several Cisco specializations Jorge is part of the PSC Global Infrastructure team, where he designs, implements, and troubleshoots LAN and WAN networks for clients in multiple industries across the globe He enjoys spending time with his wife and children, reading, jogging, and practicing martial arts Jorge can be reached

at jorge.aragon@ps.net.

Steve Gifkins is a CCIE and CCSI of four and five years, respectively He is based in the United Kingdom, where he runs his own independent Cisco-only consulting and training business He is married with no children, and his hobbies include anything to do with outdoor life Having retired with a knee injury from playing active sports such as squash, rugby, and soccer, he has taken up new hobbies in horse eventing and show jumping In addition, he enjoys skiing and hill scrambling.

Tim Sammut, CCIE No 6642, is a senior network engineer for ExtraTeam, a Cisco partner in San Francisco, fornia Tim has served in key project roles involving technologies from LAN switching to security to SNA integra- tion and has helped many organizations, ranging from 100 to 130,000 users, make the most of their network investment Tim also holds the CISSP, CCIE Security, MCNE, and MCSE certifications.

Cali-Brent Stewart is a Cisco instructor for Global Knowledge As a Global Knowledge employee, he participated in the development of ICND, BSCI, BCMSN, BCRAN, and CIT for Internet-based delivery and served as SME (Subject Matter Expert) for the CD-based ICND and CIT titles He is currently participating in the BSCI 2.0 update as the lab development engineer Prior to working for Global Knowledge, Brent owned an ISP and worked as an IT consultant Brent holds the CCNP and CCDP certifications.

Martin Walshaw, CCIE No 5629, CCNP, CCDP, is a systems engineer working for Cisco Systems in the enterprise line of business in South Africa His areas of specialty are multiservice (voice and video) as well as security, which keeps him busy both night and day During the last 12 years or so, Martin has dabbled in many aspects of the IT industry, ranging from programming in RPG III and Cobol to PC sales When Martin is not working, he likes to spend all his available time with his wife, Val, and his son, Joshua Without their patience, understanding, and support, projects such as this would not be possible.

Steve Wisniewski is CCNP certified and has a master of science degree from Stevens Institute of Technology in telecom management Steve works for Lehman Brothers as a senior implementation specialist implementing Cisco switches and routers He has also previously edited several other Cisco books and authored a book titled Network Administration for Prentice Hall Steve lives in East Brunswick, New Jersey, with his wife, Ellen.

Trang 5

Dedication

This book is dedicated to David and Jack, who make everything worthwhile.

chpt_01.book Page v Thursday, January 9, 2003 4:32 PM

Trang 6

The technical editors, Steve Gifkins, Martin Walshaw, Jorge Aragon, and Steve Wisniewski, were extremely ough Their careful attention to detail and constructive advice improved this book immeasurably I would particu- larly like to thank Jorge Aragon and Steve Wisniewski who went the extra mile by testing configurations and producing output screens.

thor-I would also like to thank Wendell Odom, who led me into the art of book writing and has ever generously shared his expertise.

Of course, I am immensely grateful to my husband, David, for his support, in spite of the long hours demanded by this book, and to our small son, Jack, for making me laugh and see the joy of life.

Trang 7

Contents at a Glance

Chapter 1 Cisco Certifications, the BSCI Exam, and This Book’s Features 3

Chapter 2 Managing Scalable Network Growth 27

Chapter 4 IP Routing Principles 157

Chapter 5 Using OSPF in a Single Area 205

Chapter 6 Using OSPF Across Multiple Areas 283

Chapter 7 Configuring the Integrated IS-IS Protocol 339

Chapter 8 Using EIGRP in Enterprise Networks 423

Chapter 9 Connecting to Other Autonomous Systems—The Basics of BGP-4 483

Chapter 10 Implementing and Tuning BGP for Use in Large Networks 539

Chapter 11 Controlling Routing Updates Across the Network 593

Chapter 12 Scenarios for Final Preparation 665

Appendix A Answers to Quiz Questions 771

Appendix B Sample Configurations 843

Index 903

chpt_01.book Page vii Thursday, January 9, 2003 4:32 PM

Trang 8

viii

Contents

Chapter 1 Cisco Certifications, the BSCI Exam, and This Book’s Features 3

Goals of This Book 4This Book’s Intended Audience 5Prerequisites to Reading the Book 5Overview of Cisco Certifications 6Exams Required for Certification 8What’s on the BSCI Exam 9Cisco BSCI Exam Outline File Excerpts from Cisco.com 9Author’s Note About Exam Content 12

Topics in This Book 13How to Use This Book to Pass the Exam 15I’ve Taken BSCI—Now What? 17I’ve Taken the Cisco Networking Academy Courses—Now What? 17I’m New to Internetworking with Cisco, and I Will Not Be Taking the BSCI Course—Now What? 18

I’ve Learned a Lot About CCNP Topics Through Experience, But I Will Not Be Taking the BSCI Course—Now What? 19The Features of This Book 20

Command Syntax Conventions 20References and Suggested Reading 21Strategies for The Exam Day 21Icons Used in This Book 22Conclusion 24

Chapter 2 Managing Scalable Network Growth 27

How to Best Use This Chapter 27

“Do I Know This Already?” Quiz 28Foundation Topics 32

Introduction to Corporate Networks—Growth, Scalability, and Congestion 32Key Requirements of a Network 33

Reliability 33

Trang 9

Responsiveness 33Efficiency 34Adaptability/Serviceability 34Accessibility/Security 34Factors That Increase Network Traffic 35Identifying the Problems Created by Network Congestion 35Traffic Analysis and Network Design 35

Problems Created by Network Congestion 36Excessive Traffic 36

Physical Problems of Ethernet 36Dropped Packets 37

Retransmission of Packets 37Incomplete Routing Tables 37Incomplete Server Lists 38The Spanning-Tree Protocol Breaks 38Runaway Congestion 39

Symptoms of Congestion 39Applications Time Out 40Clients Cannot Connect to Network Resources 40Network Death Results 40

Creating a Network That Meets the Key Requirements 40Cisco’s Hierarchical Design 41

Why Scaling Reduces Congestion 41How Hierarchical Is Hierarchical? 41The Functions of Each Layer 41The Access Layer 42

The Distribution Layer 42The Core Layer 42General Design Rules for Each Layer 42

IP Access Lists: Alleviating Congestion with Cisco Routers 43Cisco Proprietary Solutions 44

Managing Network Congestion for IP 44The Implementation of IP Access Lists 44

IP Access List Overview 45Standard IP Access Lists 45Extended IP Access Lists 46Guidelines for Writing Access Lists 48Verifying Filter Configuration 49

chpt_01.book Page ix Thursday, January 9, 2003 4:32 PM

Trang 10

x

Uses of IP Access Lists 51Security Using Access Lists 51Controlling Terminal Access 51Configuration 52

Traffic Control Through Routing Updates 52Prioritization 54

Types of Prioritization 54Reducing Network Traffic: Alternatives to Access Lists 55Null Interface 55

Configuration of Null Interfaces 55Internet Example 55

Intranet Example 56CPU Considerations and Additional Methods for Controlling Network Traffic 57Fast, Autonomous, and Silicon Switching 58

Cisco Express Forwarding 58Placement of Client/Server 59Design Principles of a Client/Server Network 59

IP Helper Address 59Configuration of IP Helper Address 60Enhanced Interior Gateway Routing Protocol 60Tunneling into IP 61

Configuration of Tunneling into IP 63Conclusion 64

Foundation Summary 65Chapter Glossary 68

Q & A 69Scenarios 74Scenario 2-1 74Scenario 2-2 76Scenario 2-3 76Scenario Answers 77Scenario 2-1 Answers 77Scenario 2-2 Answers 78Scenario 2-3 Answers 79

Trang 11

Chapter 3 IP Addressing 83

Introduction: What Is a Layer 3 Address and How Does It Affect My Life? 88Case Study 88

The Need for Layer 3 Addressing 88

A Definition of a Layer 3 Address 89Network Structures and Data Flow 89The Network and How It Is Addressed 89

A Confusion of Network Terminology 89Network Terms Explained 90

A Definition of a Layer 3 Network 90 Network Characteristics 90

An IP Address 91Why IP? 91

IP Network Terminology 91Network and Host Addressing 92The Internet Mask 92

The Internet Authoritative Bodies 93

An Example of Bit Allocation in a Network Address 94The Subnet Mask 94

Where to Place the Network Boundary 94The Logical AND 95

The AND Operation Rules 95Familiar Rules in IP Subnetting 96The Newer Subnet Rules 97

IP Addressing Summary 98Prefix Routing/CIDR 98

A Definition of Prefix Routing/CIDR 98Problems with IP Addressing and the Internet 99CIDR as a Solution 99

Summary of CIDR 100

An Example of the Use of CIDR 100

An Example of CIDR in Use in the Case Study 101Advantages of Prefix Routing/CIDR 101

Variable-Length Subnet Masks 103

An Example of VLSM 103Routing Protocols That Support VLSM 103Rules for VLSM 104

The Advantages of Using VLSM 104

chpt_01.book Page xi Thursday, January 9, 2003 4:32 PM

Trang 12

xii

Case Study: Addressing the Network 105Bit Allocation, the Subnet Rule, and VLSM 107Allocating VLSM Addresses 107

Summarization 109The Advantages of Summarization 112Reducing the Size of the Routing Table 112Simplification 112

Hiding Network Changes 112Network Growth 112

Other Solutions to Address Exhaustion 113Configuring Summarization 113

Automatic Summarization 113Manual Summarization 113Discontiguous Networks 114Considerations for Summarization with Discontiguous Networks 115Case Study 115

Alternatives to Summarization 115Optimizing the IP Address Space 116Assigning IP VLSM Subnets for WAN Connections 116Designing IP Networks 118

Keys Points to Remember When Designing an IP Network 120Private Addresses on the Internet 123

Connecting to the Outside World 125The Main Features of NAT 127Conclusion 129

Foundation Summary 130

IP Addressing Summary 130Summary of CIDR 130

An Example of the Use of CIDR 131Rules for VLSM 132

Advantages of Summarization 132Chapter Glossary 133

Q & A 136Scenarios 142Scenario 3-1 142Scenario 3-2 144Scenario 3-3 144Scenario Answers 146

Trang 13

Scenario 3-1 Answers 146Scenario 3-2 Answers 150Scenario 3-3 Answers 153

Chapter 4 IP Routing Principles 157

Introduction: What Is a Routing Protocol? 162Case Study 162

What Is a Routing Protocol? 162The Definition of a Routing Protocol 163The Purpose of a Routing Protocol 163How the Routing Protocol Works 163Routing and Routed 163

The Network Field 164The Purpose of the Network Field 164How the Network Field Is Used 165The Outgoing Interface Field 165The Purpose of the Outgoing Interface Field 165The Metric Field 165

The Next Hop Field 166The Purpose of the Next Hop Field 166The show ip route Command 167

How the Routing Table Is Kept Current and Correct 168Switching Versus Routing 169

The Routing Function 169The Switching Function 170Types of Routing Protocols 171Distance Vector and Link-State Routing Protocols 172Distance Vector Routing Protocols 173

The Distance Vector Routing Metrics 173Link-State Routing Protocols 174

The Meaning of Link State 175Learning About the Network 175Learning About a Change in the Network 175Updating Local Network Tables 176

Path Selection 176Interior and Exterior Routing Protocols 176Interior Routing Protocols 176

Exterior Routing Protocols 176

chpt_01.book Page xiii Thursday, January 9, 2003 4:32 PM

Trang 14

xiv

RIP Version 1 177IGRP 178

OSPF 179Key Attributes of OSPF 180Path Selection Between Routing Protocols 181Administrative Distance 181

Convergence 183RIPv1 Convergence 183IGRP Convergence 184EIGRP Convergence 184OSPF Convergence 185Conclusion 185

Foundation Summary 186Chapter Glossary 189

Q & A 193Scenarios 198Scenario 4-1 198Scenario 4-2 200Scenario Answers 202Scenario 4-1 Answers 202Scenario 4-2 Answers 203

Chapter 5 Using OSPF in a Single Area 205

Introduction: What Is OSPF? 211Case Study 211

OSPF Terminology 212OSPF Neighbors 214OSPF Network Topologies 214The Hello Packet 216

Adjacent OSPF Neighbors 217Advantages of Having Neighbors 218The Designated Router 218

Trang 15

Backup Designated Routers 218Why Have Designated Routers? 219Electing the Designated and Backup Designated Routers 219How OSPF Builds Its Routing Table 221

A Router Joins the Network 221

A Change in the Network 221Building the Routing Table on a New OSPF Router 222Finding Neighbors with the Exchange Process 222Discovering Routes 224

The Topology Database 226How the Topology Table Updates the Routing Table 226

A Change in the Network, Maintaining the Topological Database and the Routing Table 227

Learning a New Route 227Choosing the Shortest Path First and Building the Routing Table 230The Metric 230

Information Needed in the Routing Table 231OSPF Across Nonbroadcast Multiaccess Networks 231Which Topology to Choose? 232

Subinterfaces 232Configuring OSPF in a Single Area 234Required Commands for Configuring OSPF on an Internal Router 234Enabling The OSPF Routing Protocol 235

The OSPF network Command 235Options for Configuring OSPF on an Internal Router 237The Loopback Interface and the Router ID 237Changing the Default Metric Using the cost Command 238Determining the Designated Router Using the priority Command 240

A Working Configuration of OSPF on a Single Router 240Configuring OSPF over an NBMA Topology 242

Configuring OSPF in NBMA Mode 242Configuring OSPF in Point-to-Multipoint Mode 244Design Points for the Point-to-Multipoint Mode 244Configuring OSPF in Broadcast Mode 244

Configuring OSPF in Point-to-Point Mode on a Frame Relay Subinterface 245Checking the Configuration of OSPF on a Single Router 246

The show ip ospf Command 247The show ip ospf database Command 248The show ip ospf interface Command 250The show ip ospf neighbor Command 252The show ip protocols Command 255The show ip route Command 257

chpt_01.book Page xv Thursday, January 9, 2003 4:32 PM

Trang 16

xvi

Conclusion 257Foundation Summary 258Routing Table 261Learning a New Route 261Command Summaries 263Chapter Glossary 264

Chapter 6 Using OSPF Across Multiple Areas 283

OSPF in a Multiple Area Network 289Case Study 289

Why Multiple Areas? 289How to Determine Area Boundaries 290Problems with OSPF in a Single Area 290OSPF Areas 291

OSPF Within an Area 291Router Types 291

The Link-State Advertisements 293The ABRs and ASBR Propagation of LSAs 294OSPF Path Selection Between Areas 295

Calculating the Cost of a Path to Another Area 296The Path to Another Area 296

The Path to Another AS 296The Different Types of Areas 297

Trang 17

The OSPF area range Command for an ABR 304The OSPF Summarization Command for an ASBR 305The OSPF Command for a Stub Area 307

The OSPF Command for a Totally Stubby Area 308The OSPF Command for the Cost of a Default Route Propagated into the Area 310

Configuring a Virtual Link 311

A Working Configuration of OSPF on a Multiarea Network 314Checking the Configuration of OSPF on a Multiarea Network 315The show ip ospf border-routers Command 316

The show ip ospf virtual-links Command 317Conclusion 318

Foundation Summary 319OSPF Routers 319Link-State Advertisements 320Routing Table Codes 320Command Summaries 321

chpt_01.book Page xvii Thursday, January 9, 2003 4:32 PM

Trang 18

xviii

Chapter 7 Configuring the Integrated IS-IS Protocol 339

How Best to Use This Chapter 339

Introduction to Integrated IS-IS 344IS-IS Terminology 345

Similarities Between Integrated IS-IS and OSPF 350Differences Between OSPF and Integrated IS-IS 351ISO Addressing for Integrated IS-IS 354

NETs and NSAP 356Rules of ISO Addressing 356Example of a NET Address 356Integrated IS-IS Hierarchical Structure 357The Level 1 Router 357

The Level 2 Router 358The Level 1-2 Router 358Basic Principles of Area Routing 358Integrated IS-IS Networks and Interfaces 360Establishing Adjacencies on a Point-to-Point Link 362Establishing Adjacencies on a Broadcast Link 362Establishing Adjacencies on a Nonbroadcast Multiaccess (NBMA) Link 363Network Layer Protocols Used in Integrated IS-IS 363

The Format of the Hello Packet 365The Format of the LSP 367

The Format of the SNP 368TLVs 369

Integrated IS-IS Operation 371The Update Process 372Sending and Receiving an LSP 372Determining Whether the LSP in the Database Is Valid 374The Decision Process 375

Metrics or Cost 376The Forwarding Process 377The Receive Process 377Integrated IS-IS Design Considerations 377Area Design of Integrated IS-IS Routers 377Route Summarization 379

Integrated IS-IS NBMA Modeling Solutions in a Switched WAN Network 379

Trang 19

Configuring Integrated IS-IS 380Changing the Router from Level 1-2 381Configuring Summarization 384

Configuring NBMA 386Verifying the Integrated IS-IS Operation 389The show clns neighbors Command 391The show clns interface Command 393The show isis database Command 396The show isis database detail Command 397Troubleshooting the Integrated IS-IS Operation 399The show isis spf-log Command 400

The debug Commands 401Conclusion 402

Foundation Summary 403The ISO Address Format (NSAP) 403

Q & A 406Scenarios 411Scenario 7-1 411Scenario 7-2 412Scenario Answers 415Scenario 7-1 Answers 416Scenario 7-2 Answers 420Suggested Further Reading 421

Chapter 8 Using EIGRP in Enterprise Networks 423

Introduction: EIGRP in an Enterprise Network 429Case Study 429

EIGRP Defined 429Operation of EIGRP 430How EIGRP Works 431The Hello Protocol 434Becoming a Neighbor 434

chpt_01.book Page xix Thursday, January 9, 2003 4:32 PM

Trang 20

xx

The Neighbor Table 434The Topology Table 436EIGRP Metrics 438The DUAL Finite-State Machine 439Updating the Routing Table in Passive Mode with DUAL 440Updating the Routing Table in Active Mode with DUAL 441Choosing a Successor 442

Scaling EIGRP 449Reasons for a Poorly Scaled EIGRP Network 449Symptoms of a Poorly Scaled EIGRP Network 449Solutions to EIGRP Scaling Issues 450

Design Issues Particular to EIGRP 450The Routing Table 451

Configuring EIGRP 451The Required Commands for Configuring EIGRP 452The Optional Commands for Configuring EIGRP 454Summarization with EIGRP 454

Load Balancing in EIGRP 454Bandwidth Control 456EIGRP Defaults in Bandwidth Utilization 456EIGRP and the Use of the bandwidth Command in WANs 457Rules in Configuring Bandwidth over an NBMA Cloud 457The Use of the bandwidth-percent Command 458

Configuring EIGRP for IPX 459Configuring EIGRP for AppleTalk 461Verifying the EIGRP Operation 461The show ip eigrp neighbors Command 462The show ip eigrp topology Command 463The show ip eigrp traffic Command 464The debug Commands 465

Conclusion 466Foundation Summary 467Chapter Glossary 468

Trang 21

Chapter 9 Connecting to Other Autonomous Systems—The Basics of BGP-4 483

Introduction: BGP-4 and Communicating with other Autonomous Systems 488Case Study 488

BGP-4 Operation 489

An Autonomous System Defined 490Characteristics of BGP-4 491Overview of the BGP-4 Operation 491Message Types 492

Synchronization 494Benefits of the Synchronization Rule 494CIDR and Route Aggregation 496

BGP-4 Policy-Based Routing 497Rules of Policy Routing 497Disadvantages of Policy Routing 499BGP-4 Attributes 500

The Next-Hop Attribute and a Broadcast Multiaccess Network 503The Next-Hop Attribute and a Nonbroadcast Multiaccess Network 505Route Selection Process 505

Basic Configuration Commands to Connect to Another Autonomous System 507Starting the Routing Process 508

Defining the Networks to Be Advertised 508Identifying Neighbors and Defining Peer Groups 508Forcing the Next-Hop Address 508

Disabling Synchronization 509Aggregating Routes 509Managing and Verifying the BGP-4 Configuration 510When to Use BGP-4 511

When Not to Use BGP-4 511Alternative Methods of Connecting to an ISP 512Conclusion 513

Foundation Summary 514The Key Features of BGP-4 514Chapter Glossary 520

Q & A 522Scenarios 527

chpt_01.book Page xxi Thursday, January 9, 2003 4:32 PM

Trang 22

xxii

Scenario 9-1 527Scenario 9-2 528Scenario 9-3 529Scenario Answers 532Scenario 9-1 Answers 532Scenario 9-2 Answers 533Scenario 9-3 Answers 534

Chapter 10 Implementing and Tuning BGP for Use in Large Networks 539

Introduction—Communicating with Other Autonomous Systems with BGP-4 544Case Study 544

Designing and Configuring a Scalable BGP-4 Network 545Why Does BGP-4 Require a Fully Meshed Network? 546Why Is a Fully Meshed Network a Problem? 546Route Reflectors: The Solution to a Fully Meshed IBGP-4 Network 547Designs That Avoid a Fully Meshed IBGP-4 Network 548

How Route Reflectors Operate 549Controlling BGP-4 Traffic 556

How Prefix Lists Work 557How Prefix Lists Are Processed 558How to Configure a BGP-4 Prefix List 558Creating a Prefix List 558

Prefix List Examples 559Verifying the Prefix List Configuration 559Redundant Connections into the Internet—Multihoming 560Multiple Connections into the Internet 561

Receiving Routing Information from the Internet 561Determining the BGP-4 Path by Tuning the Attributes 564Commands to Tune BGP-4—Using the Local Preference and Weight Attributes 564Verifying the Configuration of Attributes 567

Redistribution Between the IGP and BGP-4 570Advertising Routes from an IGP into BGP-4 571Advertising Routes from a BGP-4 into an IGP 571

Do ISPs Need to Redistribute Paths from BGP-4 into the IGP? 571Redistribution from BGP-4 into an IGP in an Organizational Network 572

Trang 23

Conclusion 573Foundation Summary 574Route Reflectors 575Prefix Lists 576Routing Updates from Multihomed Connections to the Internet 577BGP-4 show Commands 578

Chapter Glossary 579

Chapter 11 Controlling Routing Updates Across the Network 593

Introduction: Controlling the Routing Updates Using Redistribution and Filtering 599Case Study 599

Redistribution Between Routing Protocols 599Controlling Routing Updates 601

Reasons to Control Routing Updates 603The Main Features of Redistribution 604Default Redistribution Between Routing Protocols 604Why Use Multiple Routing Protocols? 606

The Reason for Using One Routing Protocol 607Problems of Configuring Multiple Routing Protocols 607Path Selection Within a Routing Protocol 608

Path Selection Between Routing Protocols 610Avoiding Routing Loops When Redistributing 612Redistribution and Problems with Network Convergence 613

chpt_01.book Page xxiii Thursday, January 9, 2003 4:32 PM

Trang 24

xxiv

Configuring Redistribution 614Generic Steps Required for Redistribution 614Redistribution Configuration Syntax 615The Default or Seed Metric 617When to Configure the Administrative Distance 619The Passive Interface 621

Static Routes 621Default Routes 623Controlling Routing Updates with Filtering 625Redistribution Examples 627

Redistribution Example 1 628Redistribution Example 2 629Redistribution Example 3 632Policy-Based Routing Using Route Maps 633Uses for Route Maps 634

Characteristics of Route Maps 634 The Route Map Command Syntax 635Policy-Based Routing Using Route Maps 636Characteristics of Policy Routing 637The Benefits of Policy Based Routing 637Disadvantages of Policy Routing 638Criteria by Which Policy-Based Routes Are Determined 638How Policy-Based Routing Works Using Route Maps 638The Route Map Statements 639

Configuring Route Maps for Policy Routing 640The match Commands for Policy Routing with Route Maps 640Configuration Notes 643

Route Maps, Policy Routing, and Route Switching 643How to Ensure That Packets Are Switched at Speed (Fast) 643Verifying, Maintaining, and Troubleshooting the Redistribution Implementation 644traceroute 644

Extended ping 645Specific Commands for Monitoring Policy-Routing Configurations 645Conclusion 646

Foundation Summary 647Methods of Controlling Routing Updates 647Automatic Redistribution Between Routing Protocols 648Default Administrative Distance 649

The Logic Used in Distribute Lists 649Chapter Glossary 650

Trang 25

Chapter 12 Scenarios for Final Preparation 665

Further Study for Final Preparation 665How to Best Use This Chapter 666Scenarios 667

Scenario 12-1 667Scenario 12-2 668Scenario 12-3 669Scenario Answers 671Scenario 12-1 Answers 671Scenario 12-2 Answers 673Scenario 12-3 Answers 675Three-Part Scenarios 678Scenario 12-4 678Scenario 12-4, Part A—Planning 678Solutions to Scenario 12-4, Part A—Planning 683Scenario 12-4, Part B—Configuration 687Solutions to Scenario 12-4, Part B—Configuration 688Scenario 12-4 Part C—Verification and Questions 689Solutions to Scenario 12-4, Part C—Verification and Questions 720Scenario 12-5 724

Scenario 12-5, Part A—Planning 724Solutions to Scenario 12-5, Part A—Planning 726Alternative Methods of Transition to Another Routing Protocol 726Transitioning to EIGRP from the Outer Edges of the Network 727Summarization in EIGRP 727

Redistribution in EIGRP 727Preventing Route Loops 728

chpt_01.book Page xxv Thursday, January 9, 2003 4:32 PM

Trang 26

xxvi

Scenario 12-5, Part B—Configuration 728Solutions to Scenario 12-5, Part B—Configuration 728Scenario 12-5 Part C—Verification and Questions 731Solutions to Scenario 12-5, Part C—Verification and Questions 765

Appendix A Answers to Quiz Questions 771

Chapter 2 771Chapter 2 “Do I Know This Already?” Quiz Answers 771Chapter 2 “Q&A” Answers 774

Chapter 7 806

“Do I Know This Already?” Quiz 806Chapter 7 “Q&A” Answers 808Chapter 8 813

Chapter 8 “Do I Know This Already?” Quiz Answers 813Chapter 8 “Q&A” Answers 815

Trang 27

Appendix B Sample Configurations 843

Configuration 1—OSPF and Dialup Links 844Commands Showing the Configuration 1 Working Network 848Configuration 2—BGP-4 and Route Maps 850

Commands Showing the Configuration 2 Working Network 853

Appendix C Glossary 859

Index 903

chpt_01.book Page xxvii Thursday, January 9, 2003 4:32 PM

Trang 29

C H A P T E R 1

Cisco Certifications, the BSCI

Exam, and This Book’s Features

The Cisco Certified Network Professional (CCNP), Cisco Certified Design Professional (CCDP), and Cisco Certified Internetworking Professional (CCIP) certifications are becoming increasingly popular These certifications have as their foundation the Cisco Certifed Network Associate (CCNA) certification and these profesional-level certifications form the second rung in the ladder to the coveted Cisco Certified Internetwork Expert (CCIE) certification The BSCI exam (#640-901) is one of the exams that you must pass to become a CCNP, CCDP, or CCIP This book will help you prepare for that exam

Professional-level certification opens doors to career opportunities and is a prerequisite for other Cisco certifications as well Generally, passing the BSCI exam means that you have mastered the concepts and implementation skills necessary to build a complex IP network

of Cisco routers

NOTE You must pass the BSCI exam (among other exams) to achieve either the CCNP, CCDP, or

CCIP certification The CCNP, CCDP, and CCIP certifications are often referred to as the

professional-level certifications throughout this book wherever the information at hand applies to CCNP, CCDP, and CCIP For more information on the differences among the three professional-level certifications and the latest on Cisco exams and certifications, begin at the Cisco Career Certification page (www.cisco.com/en/us/learning/le3/

learning_career_certifications_and_learning_paths_home.html) at the Cisco.com website

The BSCI exam is a computer-based exam, with multiple-choice, fill-in-the-blank, and in-order style questions The exam can be taken at any Sylvan Prometric testing center (1-800-829-NETS, www.2test.com) You should check with Sylvan Prometric for the exact length of the exam (Be aware that when you register for the exam, you might be told to allow a certain amount of time to take the exam that is longer than the testing time indicated

list-by the testing software when you begin This is because Sylvan Prometrics wants you to allow for some time to get settled and take the tutorial on the testing engine.)

chpt_01.book Page 3 Thursday, January 9, 2003 4:32 PM

Trang 30

4 Chapter 1: Cisco Certifications, the BSCI Exam, and This Book’s Features

The BSCI exam is not an easy exam This is to say that you cannot simply read one book and

expect to pass it In fact, the exam is surprisingly difficult; this is so that Cisco can be sure that

everyone who passes the test thoroughly understands the subject matter on a conceptual level

and is not just good at exams More importantly, Cisco is very interested in making sure that

passing proves that you have the skills to actually implement the features, not just talk about

them The exam is difficult in subject matter and also in format You can expect multiple-choice

questions—some with multiple answers You can also expect questions requiring you to pick

the correct answer from output screens and configurations

Another difficult aspect of the exam format is that you are not allowed to go back and change

an answer Those CCNP/CCDP/CCIP candidates who are unsure about the question will be

forced to guess rather than have an extra 15 minutes to think about it at the end of the exam

Those who really know most of the answers will be rewarded by Cisco’s attempts to preserve

the integrity of the CCNP/CCDP/CCIP certification The professional-level certification will

mean to everyone that you are highly qualified at the subject at hand

Although this is a difficult exam, networking professionals can expect to pass if they meet the

prerequisites and spend the proper amount of time on training, on-the-job experience, and

study As with most certification exams, you might not pass the first time Taking the exam a

second time, however, might be easier because you have an idea of what to expect

There are many questions on the BSCI exam that you might already know through your

professional background and experiences, if you meet the prerequisites This book offers you

the opportunity to solidify and build on that knowledge as you make your final preparations to

take the BSCI exam The concepts and commands covered on the exam are not secrets locked

in some vault—the information is available in many places and forms, including this book So,

although the exam is difficult, passing is certainly attainable with study

Goals of This Book

The goals for this book became somewhat obvious to me after considering the exam itself, as

well as the Cisco exam philosophy The first goal came straight from Cisco, who asked that I

write a book that not only helps you pass the exam, but that also ensures that you really

understand the concepts and implementation details The second goal of this book is that the

content should be the most comprehensive coverage of BSCI exam-related topics available,

without too much coverage of topics not on the exam The third and ultimate goal is to get you

from where you are today to the point that you can confidently pass the BSCI exam Therefore,

all this book’s features, which are outlined in this chapter, are geared toward helping you

discover the IP routing topics that are on the BSCI exam, where you have a knowledge

deficiency in these topics, and what you need to know to master these topics

Trang 31

Prerequisites to Reading the Book 5

This Book’s Intended Audience

Although the only official prerequisite for CCNP and CCIP certificaion is CCNA status, and the only prerequisite for CCDP certification is CCDA status, Cisco does not expect you to be able to pass the professional-level exams (such as the BSCI exam) without additional training and experience This is why Cisco’s recommended training for CCNP/CCDP/CCIP involves an official Cisco course For the routing knowledge required of a CCNP/CCDP/CCIP, Cisco recommends a course called Building Scalable Cisco Internetworks (BSCI)

As stated on the Cisco web site, the BSCI course is targeted toward enterprise network engineers (including systems engineers [SEs], customers, and resellers) who are responsible for network administration and implementation The targeted audience performs one or more of the following tasks:

• Install and configure network devices

• Design and implement large enterprise networks

• Add services/applications to an existing network, and determine what router configurations are required to support the new services/applications

• Improve traffic flow, reliability, redundancy, and performance through the network

NOTE BSCI replaces the old Building Scalable Networks (BSCN) course, much as the new BSCI

exam (#640-901) replaces the old CCNP Routing exam (#640-503)

This book is a final stage preparation tool Therefore, this book will be most effective as a study resource after you have taken the BSCI course or have acquired an equivalent level of on-the-job experience and training

Prerequisites to Reading the Book

The following are the prerequisites for the BSCI course, and, for all practical purposes, should

be considered prerequsites for using this book effectively:

• Working knowledge of the OSI reference model and the hierarchical model

• Understanding of internetworking fundamentals

• Ability to operate and configure a Cisco IOS device

• Working knowledge of the TCP/IP stack and how to configure a routed protocol such as IP

• Understanding of distance vector routing protocols, such as Routing Information Protocol (RIP) and Interior Gateway Routing Protocol (IGRP)—and their operation and

configuration

Trang 32

• Ability to determine when to use static and default routes, and how to enable them on a Cisco router

• Ability to display and interpret routing table from a Cisco router

• Ability to enable a WAN serial connection

• Ability to configure Frame Relay permanent virtual circuits (PVCs) on interfaces and subinterfaces

• Ability to configure an IP standard and extended access list

• Ability to verify router configurations with available tools such as show and debug

commandsThe ideal audience for this book is someone who has attended the Interconnecting Cisco Networking Devices (ICND) course (or the retired Introduction to Cisco Router Configuration [ICRC] course), has acheived CCNA status, and has attended the BSCI course, or who has an equivalent level of on-the-job training and experience with Cisco switches and routers Cisco highly recommends that you take courses to support each certification level, but it also recognizes that attending courses might not be an option for everyone Therefore, if you find yourself struggling with CCNA-level knowledge as you work through this book, you might

want to review a copy of the Interconnecting Cisco Networking Devices Self-Study Guide

(ISBN 1-57870-111-2) from Cisco Press Similarly, if you want course details at the CCNP/

CCDP/CCIP level about routing, review the CCNP Self-Study: Building Scalable Cisco

Internetworks (BSCI) book (ISBN 1-58705-084-6), also from Cisco Press.

Overview of Cisco Certifications

Cisco’s main motivation behind the current certification program is to provide a means of measuring the skills of people working for Cisco resellers and certified partners Cisco fulfills only a small portion of its orders via direct sale from Cisco; normally, a Cisco reseller is involved Also, Cisco has not attempted to become the primary source for consulting and implementation services for network deployment using Cisco products, preferring instead to use partners as much as possible With that business model, there is a great need to distinguish, ensure, and certify the skill levels of the partner companies employees

The CCIE program was Cisco’s first foray into certifications Introduced in 1994, the CCIE was designed to be one of the most respected, difficult-to-achieve certifications To certify, a written test (also given at Sylvan Prometric) must be passed, and then a one-day hands-on lab test is administered by Cisco Cisco does not publish numbers on pass/fail rates for CCIE or the other certifications, but rumors have the failure rate on all lab test takers at over 50 percent, with failure rate for first-time lab takers at around 80 percent

Certifying resellers and services partners, using the number of employed CCIEs as the gauge, worked well originally, partly because Cisco had far fewer partners than today Cisco uses the number of CCIEs on staff as part of the criteria in determining the level of partner status for the

Trang 33

Overview of Cisco Certifications 7

company, which in turn dictates the discount received by the reseller when buying from Cisco (For more insight into reseller certification, go to CCO, at www.cisco.com/en/us/partners/pr11/pr8/partners_pgm_category_page.html.) This practice continues to be a good way for Cisco to judge the commitment to having people with proven Cisco skills on staff, which in turn improves customer satisfaction—and customer satisfaction is tied to every Cisco executive’s goals

The CCIE certification became inadequate for helping certify resellers and other partners because, among other factors, the number of partners increased disproportionately to the difficulty of the CCIE exam For instance, there are more than 9000 CCIEs worldwide and not nearly as many resellers (and not all the CCIEs work for resellers, of course) Furthermore, many resellers that do not perform services do not require the extreme expertise of a CCIE on staff, other than to get a better discount What Cisco needed were certifications that were less rigorous than CCIE and that would allow Cisco more granularity in judging the skills on staff

at a partner company So, Cisco started an entire Cisco Career Certification program, of which CCNP, CCDP, and CCIP are a part

Cisco developed Routing and Switching career tracks, a security career track called Cisco Certified Security Professional (CCSP), and several specialization career tracks Thus far, the Routing and Switching career tracks, which begin with CCNA/CCDA certification, have proven to be the most popular and make up the heart of Cisco certification The BSCI exam required for CCNP/CCDP/CCIP certification is a central part of the Routing and Switching career tracks

Three categories of certifications exist—one to certify implementation skills, a second to certify design skills, and a third to certify communications and services skills Resellers working in a presales environment need more design skills, whereas services companies need more implementation or post-sales skills The CCNA and CCNP are implementation-oriented certifications, whereas CCDA and CCDP are design-oriented certifications, and the CCIP requires a knowledge of the communications and services technologies

Rather than requiring just one level of certification besides CCIE, Cisco created two additional levels—an associate level and a professional level The associate level (CCNA/CCDA) is the most basic, and the professional level (CCNP/CCDP/CCIP/CCSP) is the intermediate level between CCNA and CCIE

Several of the certifications require other certifications as a prerequisite For instance, CCNP, CCIP, and CCSP certification requires that you have CCNA certification Also, CCDP requires

a CCDA certification CCIE, however, does not require any other certification prior to the written and lab tests CCIE certification is extremely difficult, however, and it is unlikely that someone could acheive that level of certification without a level of experience and training equalled in attaining and practicing associate- and professional-level certification

Cisco certifications have taken on a much larger role and importance in the networking industry

in recent years From a career standpoint, Cisco certification can certainly be used to help you get a new job or a promotion Or, you can have certification added to your performance evaluation plan and then justify a raise based on passing an exam If you are looking for a new job, not only might passing an exam help you land the job, but it may actually help you make more money

Trang 34

Exams Required for Certification

In 2001, Cisco initiated an update, which was basically a question refresh, of the CCNP career certification exams The BSCI exam, originally required only for the CCIP certification, replaced the CCNP Routing exam #640-503

To certify for CCNP, you must pass multiple exams This book deals with the BSCI exam—Sylvan Promteric exam #640-901 The qualifying exams, the CCNA and the CCDA, require only a single exam The exams generally match the same topics that are covered in one of the official Cisco courses, but in most cases—and certainly on the BSCI exam—more topics are covered on the exam than are in the course Table 1-1 outlines the exams and the courses with which they are most closely matched

Table 1-1 Exams and Courses by Certification Level

#640-841* Foundation exam BSCI, BCMSN, and BCRAN

#640-606 Support exam Cisco Internetwork Troubleshooting (CIT)

#640-605 Remote Access exam BCRAN

#640-841* Foundation exam BSCI, BCMSN, and BCRAN

#640-025 CID exam Cisco Internetwork Design (CID)

** The CCIP certification requires an elective in addition to the two required exams See www.cisco.com/en/US/ learning/le3/le2/le37/le8/learning_certification_type_home.html for details.

Trang 35

What’s on the BSCI Exam 9

Be cautioned that, although the exam coverage and course coverage are similar, there are no guarantees that if you know absolutely everything in the course, you will pass the test Cisco is moving more toward the certifications being tied to technology, not to specific courses A Cisco Press Exam Certification Guide can help you prepare for the certification exam, with the added guidance of stressing the most important exam items and coverage of other topics not taught in the prerequisite courses Cisco also maintains the right to change the exam content at will to ensure that the exam is current and fair

What’s on the BSCI Exam

Every one of us would like to know exactly what is on the BSCI exam, as well as the other Cisco certification exams Well, to be honest, exactly what is on the exam is a very closely guarded secret Only those who write the questions for Cisco and who have access to the entire question database truly know what is entirely on the exam

Cisco publicly only reveals general details about the contents and objectives of the BSCI exam You can find a list of Cisco exams and the general outline that accompanies each exam at www.cisco.com/en/US/learning/le3/learning_career_certifications_and_learning_paths_home.html.You will have to download the outline for each exam The following section contains excerpts from the BSCI exam outline

Cisco BSCI Exam Outline File Excerpts from Cisco.com

Given your experience, this outline and guide will help you with the best methods of preparation for the Cisco Career Certifications exam

The BSCI course is the recommended method of preparation for the BSCI exam

The topic areas listed in this outline are general guidelines for the type of content that is likely

to appear on the exam However, please be advised that other relevant or related topic areas may also appear This list was taken from the Cisco.com website

The BSCI (#640-901) exam will contain a combination of the following topics:

Routing principles

• List the key information routers need to route data

• Describe classful and classless routing protocols

• Compare distance vector and link-state routing protocol operation

• Describe the use of the fields in a routing table

• Analyze the routing table, and test connectivity using accepted troubleshooting techniques

Trang 36

Extending IP addresses

• Use VLSMs to extend the use of the IP addresses

• Explain if route summarization is or is not possible for a specific addressing scheme

• Configure an IP helper address to manage broadcasts

Configuring OSPF in a single area

• Explain why OSPF is better than RIP in a large internetwork

• Explain how OSPF discovers, chooses, and maintains routes

• Explain how OSPF operates in a single-area NBMA environment

• Configure OSPF for proper operation in a single area

• Verify OSPF operation in a single area

Interconnecting multiple OSPF areas

• Describe the issues with interconnecting multiple areas and how OSPF addresses each

• Explain the differences between the possible types of areas, routers, and LSAs

• Explain how OSPF supports the use of VLSM

• Explain how OSPF supports the use of route summarization in multiple areas

• Explain how OSPF operates in a multiple-area NBMA environment

• Configure a multiarea OSPF network

• Verify OSPF operation in multiple areas

Configuring IS-IS Protocol

• Explain basic OSI terminology and network layer protocols used in OSI

• Identify similarities and differences between Integrated IS-IS and OSPF

• Identify characteristics of an effective addressing plan for IS-IS deployment

• Explain how networks and interfaces are represented in IS-IS

• List the types of IS-IS routers and their role in IS-IS area design

• Describe the hierarchical structure of IS-IS areas

• Describe the concept of establishing adjacencies

• Describe the concepts of routing traffic transport and database synchronization

Trang 37

What’s on the BSCI Exam 11

• Explain the basic principles of area routing

• Explain IS-IS NBMA modeling solutions in switched WAN networks

• Given an addressing scheme and other laboratory parameters, identify the steps to configure Cisco routers for proper Integrated IS-IS operation

• Identify verification methods which ensure proper operation of Integrated IS-IS on Cisco routers

Configuring EIGRP

• Describe EIGRP features and operation

• Explain how EIGRP discovers, chooses, and maintains routes

• Explain how EIGRP supports the use of VLSM

• Explain how EIGRP operates in an NBMA environment

• Explain how EIGRP supports the use of route summarization

• Describe how EIGRP supports large networks

• Configure EIGRP

• Verify EIGRP operation

Configuring Basic BGP

• Describe BGP features and operation

• Describe how to connect to another autonomous system using an alternative to BGP, static routes

• Explain how BGP policy-based routing functions within an autonomous system

• Explain how BGP peering functions

• Describe BGP communities and peer groups

• Describe and configure external and internal BGP

• Describe BGP synchronization

• Configure a BGP environment and verify proper operation

Implementing BGP in scalable networks

• Describe the scalability problems associated with internal BGP

• Explain and configure BGP route reflectors

• Describe and configure policy control in BGP using prefix lists

• Describe methods to connect to multiple ISPs using BGP

Trang 38

• Explain the use of redistribution between BGP and Interior Gateway Protocols (IGPs).

• Configure a multihomed BGP environment and verify proper operation

Optimizing routing update operation

• Select and configure the different ways to control routing update traffic

• Configure route redistribution in a network that does not have redundant paths between dissimilar routing processes

• Configure route redistribution in a network that has redundant paths between dissimilar routing processes

• Resolve path selection problems that result in a redistributed network

• Verify route redistribution

• Configure policy-based routing using route maps

• Configure redistribution between different routing domains and verify proper operation

• Configure policy-based routing within your pod and verify proper operation

Author’s Note About Exam Content

As the Cisco authorized external publishing company, Cisco Press is the only publisher that is partnered with Cisco

Some points about the exam as it relates to this book are as follows:

• If we at Cisco Press believe that a topic is definitely on the exam, it is covered in Chapters

Trang 39

Topics in This Book 13

Topics in This Book

The list that follows outlines the topics that will be the focus of the exam The topics are listed corresponding to the chapters in which they are covered

• Chapter 2, “Managing Scalable Network Growth”

— The key requirements of a network

— The problem of network congestion

— The symptoms of network congestion

— Methods of controlling network traffic

— Access lists, how to restrict vty access, and uses of access lists

— Alternatives to access lists

• Chapter 3, “IP Addressing”

— Prefix routing

— The use of VLSM and its application

— The use, application, and configuration of summarization

— Key points in the design of an IP network

— How to connect to the outside world and use NAT and private addresses

• Chapter 4, “IP Routing Principles”

— The requirements of the routing process

— The routing table

— The differences between a classful and classless routing protocol

— The difference between distance vector and link-state routing protocol

— How routing tables are maintained

— Path selection

• Chapter 5, “Using OSPF in a Single Area”

— How a link-state routing protocol (such as OSPF) discovers, chooses, and

maintains links

— How OSPF operates in a single NBMA area WAN

— How to configure OSPF in a single area

— How to verify the operation of and troubleshoot an OSPF network

Trang 40

• Chapter 6, “Using OSPF Across Multiple Areas”

— The issues with interconnecting multiple OSPF areas

— The differences between the possible types of areas, routers, and LSAs

— How OSPF operates across multiple areas using NBMA

— How OSPF supports the use of VLSM and summarization

— The Cisco commands for implementing OSPF for multiple areas

• Chapter 7, “Configuring the Integrated IS-IS Protocol”

— Introduction to Integrated IS-IS

— ISO Addressing for Integrated IS-IS

— Integrated IS-IS Hierarchical Structure

— Basic Principles of Area Routing

— Integrated IS-IS Networks and Interfaces

— Network Layer Protocols Used in Integrated IS-IS

— Integrated IS-IS Operation

— Integrated IS-IS Design Considerations

— Configuring Integrated IS-IS

— Verifying the Integrated IS-IS Operation

— Troubleshooting the Integrated IS-IS Operation

• Chapter 8, “Using EIGRP in Enterprise Networks”

— The features and operation of EIGRP

— How EIGRP discovers, chooses, and maintains routes

— How EIGRP supports the use of VLSM and summarization

— How EIGRP functions in an NBMA environment

— How EIGRP supports large networks

— How to configure EIGRP, both in an enterprise network and in an NBMA

network

— How to verify an EIGRP configuration

• Chapter 9, “Connecting to Other Autonomous Systems—The Basics of BGP-4”

— The features and operation of BGP

— BGP terminology

— Design issues with BGP

Định dạng
Số trang	944
Dung lượng	12,69 MB

Tiêu đề	CCNP Self-Study CCNP BSCI Exam Certification Guide
Tác giả	Clare Gough
Trường học	Cisco Press
Chuyên ngành	Networking
Thể loại	Guide
Năm xuất bản	2003
Thành phố	Indianapolis