《CCNP学习指南 Cisco网络互连故障排除 英文版》

1 Troubleshooting Methodology1

Foreword3

Symptoms, Causes, and Actions3

Slow Response Time4

Performance Alerts and Notifications5

About the Contributors7

Generic Problem-Solving Model7

Steps to Solving a Problem8

Acknowledgments10

Pointers for Problem Solving11

Recommended Troubleshooting Procedures12

Documentation Methods14

Protocol Characteristics Review16

Connection-Oriented vs. Connectionless16

Preface21

Introduction25

Certification Summary29

Two-Minute Drill30

SelfTest33

2 LAN Troubleshooting Problem Areas37

PHysical Layer Responsibilities38

Data Link Layer Responsibilities39

MAC Layer41

Logical Link Layer42

Ethernet/IEEE 802.345

CSMA/CD Protocol45

Ethernet Statistics for Troubleshooting49

Token Ring/IEEE 802.552

Understanding MAC Communications53

Troubleshooting Token Ring Networks57

FDDI59

ATM LAN Emulation(LANE)61

Encapsulation Methods66

Certification Summary69

Two-Minute Drill70

SelfTest72

3 WAN Troubleshooting Problem Areas75

Point-to-Point Protocols76

PPP Frame76

LCP/NCP77

Encapsulation78

Authentication79

Link States80

SHOW INTERFACE and DEBUG Commands80

HDLC82

SDLC84

PPP85

Switched Protocols87

Frame Relay87

X.2594

SMDS96

ATM99

ISDN104

Layer 2 of ISDN106

Layer 3 of ISDN107

Certification Summary111

Two-Minute Drill111

SelfTest114

4 The Internet Protocol(IP)117

Technology Features Recap118

A Note About Terminology119

IP, UDP, TCP, ICMP, and Common Ports119

A Closer Look at TCP123

UDP136

IP Broadcast and Multicast140

ICMP143

ICMP Redirects145

ARP Caching148

DNS and DNS Caching154

Default Gateway157

IP Helper Addresses158

Obtaining an Address via DHCP160

Common User Tasks160

Web Page Download168

FTP Transfer171

Common Problems and Fixes173

Splitting the Problem in Half173

Ping Test173

Packet-Level Debugging174

Troubleshooting Lower Layers177

Transport and Above178

Certification Summary181

Two-Minute Drill184

SelfTest188

5 Novell s Internetwork Packet Exchange(IPX) Protocol191

IPX Protocol Suite192

IPX192

SPX199

NCP202

Packet Burst204

LIP204

IPX NetBIOS206

RIP209

SAP212

NLSP217

Common Packet Types and Port Numbers224

Common User Tasks226

Workstation Bootup(Bindery Mode)229

Workstation Bootup(NDS Mode)230

How SLIST Really Works232

How Printing Really Works233

Router Proxy GNS by Default233

Common Problems and Fixes235

Local Connectivity Problems235

Connectivity Problems Through a Cisco Router237

Intermittent Connectivity Problems241

IPX NetBIOS Problems242

Certification Summary243

Two-Minute Drill244

SelfTest247

6 Apple s AppleTalk Protocol249

The Evolution of Apple Talk250

LocalTalk251

Common Mac User Tasks252

Bootup and Address Assignment253

Zone Lists260

Chooser Lists266

Common AppleTalk Problems and Fixes269

Routing Problems270

Something Missing on the Network273

AppleTalk Interface Goes Down275

Certification Summary277

Two-Minute Drill278

SelfTest281

7 Common Routing Protocols285

Periodic Broadcast-Based Protocols286

Routing Information Protocol(RIP)287

Troubleshooting RIP290

Cisco s Interior Gateway Routing Protocol(IGRP)293

Troubleshooting IGRP295

IPX RIP and Service Advertising Protocol(SAP)296

Troubleshooting IPX RIP297

AppleTalk Routing Table Maintenance Protocol(RTMP)298

Troubleshooting AppleTalk Networks300

Event-Driven Protocols302

Open Shortest Path First(OSPF)303

Troubleshooting OSPF305

Cisco s Enhanced IGRP(EIGRP)307

Troubleshooting EIGRP309

Border Gateway Protocol (BGP)314

Troubleshooting BGP316

Certification Summary320

Two-Minute Drill321

SelfTest324

8 Troubleshooting Tools327

Using Router Diagnostic Tools329

Telnet330

Ping331

Traceroute333

Accounting334

Router Web Interface336

Router Logging337

Introduction to Cisco Works338

The Role of SNMP338

SNMP Traps341

Managing with Cisco Works342

The Cisco Works Applications345

Using Third-Party Tools346

CMU SNMP Library346

Packet Analyzers349

Hardware Tools350

Other Places to Find Troubleshooting Tools353

Certification Summary353

Two-Minute Drill355

SelfTest357

9 Cisco s Diagnostic Tools361

Interface-Specific Commands362

IP Interfaces366

IPX Interfaces368

Apple Talk Interfaces370

WAN Interfaces371

Memory and Process Commands377

Buffer and Message-Logging Commands380

Using Ping, Extended Ping, and Traceroute to Confirm Network Connectivity383

Certification Summary386

Two-Minute Drill387

SelfTest389

10 Advanced Diagnostic Tools391

Debug Mode392

Debug Mode Cautions394

Debugging at the Protocol Level396

Interface Debugging399

Fault-Tracking Commands406

Logging407

Interconnectivity Commands413

How to Perform a Core Dump416

Hardware Diagnostics418

Certification Summary430

Two-Minute Drill431

SelfTest433

11 Campus Switches and VLANs437

Interface Configuration438

Speed and Duplex Detection440

Security440

Virtual LANs(VLANs)441

VLAN Assignment442

Virtual Trunking Protocol(VTP)444

Inter-Switch Link(ISL)Trunks447

Spanning Tree Protocol449

BPDU Hello Packets451

PortFast453

UplinkFast454

Troubleshooting with the Span Port455

Spanning a Switch Port456

Spanning a VLAN457

Common Problems and Fixes457

The SHOW Commands(CAM DYNAMIC, VLAN, MODULE, and PORT)458

Deleted VLAN460

10/100 Autodetect Broken460

Missing VTP Domain460

Disabled Ports460

Wrong Speed461

Mismatched Duplex461

Code Rev Not Supporting New Module461

Certification Summary463

Two-Minute Drill464

SelfTest467

12 Hands-on Troubleshooting471

Troubleshooting LANs472

Ethernet473

Token Ring477

Fiber Distributed Data Interface(FDDI)479

Troubleshooting WANs482

Serial Line Connections482

ISDN484

Frame Relay486

Troubleshooting TCP/IP488

Troubleshooting IPX493

Troubleshooting AppleTalk496

Using Cisco Support Functions499

CCO Docs499

CCO Open Forum499

CD-ROM500

Cisco Technical Assistance Center (TAC)500

Certification Summary500

Two-Minute Drill501

SelfTest503

13 Troubleshooting the ISDN Basic Rate Interface (BRI)507

The ISDN Physical Layer508

The ISDN CO Switch509

The NT1 Device510

Verifying Layer 1 Activation511

The ISDN Data Link Layer (Q.921)513

Q.921 Startup Procedures513

Verifying LAPD Status515

Configuring SPIDs517

ISDN Layer 3: SPIDs517

SPID Verification518

Dial-on-Demand Routing(DDR)520

DefiningInteresting Traffic520

Defining Whom to Call521

Troubleshooting DDR522

ISDN Q.931 for Call Setup and Teardown524

Q.931 Call Establishment524

Q.931 Setup Messages525

Call Teardown527

PPP: The Point-to-Point Protocol529

The Link Control Protocol531

The Network Control Protocols534

Multilink PPP535

Certification Summary535

Two-Minute Drill536

SelfTest539

A SelfTest Answers543

Answers to Chapter 1 SelfTest544

Answers to Chapter 2 SelfTest548

Answers to Chapter 3 SelfTest551

Answers to Chapter 4 SelfTest554

Answers to Chapter 5 SelfTest558

Answers to Chapter 6 SelfTest561

Answers to Chapter 7 SelfTest564

Answers to Chapter 8 SelfTest567

Answers to Chapter 9 SelfTest570

Answers to Chapter 10 SelfTest574

Answers to Chapter 11 SelfTest577

Answers to Chapter 12 SelfTest580

Answers to Chapter 13 SelfTest583

B About the CD587

Personal Testing Center Test Type Choices588

Saving Scores as Cookies589

Using the Browser Buttons589

Managing Windows589

Live589

JavaScript Errors590

Practice590

Review590

Scoring591

C About the Web Site593

Access Global Knowledge594

What You ll Find There594

Glossary595

Index641