Connecting Networks Companion Guide / Edition 1

by Cisco Networking Academy

Overview

Connecting Networks Companion Guide is the official supplemental textbook for the Connecting Networks course in the Cisco® Networking Academy® CCNA® Routing and Switching curriculum.

This course discusses the WAN technologies and network services required by converged applications in a complex network. The course allows you to understand the selection criteria of network devices and WAN technologies to meet network requirements. You will learn how to configure and troubleshoot network devices and resolve common issues with data link protocols. You will also develop the knowledge and skills needed to implement IPSec and virtual private network (VPN) operations in a complex network.

The Companion Guide is designed as a portable desk reference to use anytime, anywhere to reinforce the material from the course and organize your time.

The book’s features help you focus on important concepts to 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 lists of networking vocabulary introduced and highlighted in context in each chapter.
• Glossary–Consult the comprehensive Glossary with 195 terms.
• Summary of Activities and Labs–Maximize your study time with this complete list of all associated practice exercises at the end of each chapter.
• Check Your Understanding–Evaluate your readiness with the end-of-chapter questions that match the style of questions you see in the online course quizzes. The answer key explains each answer.
• How To–Look for this icon to study the steps you need to learn to perform certain tasks.
• Interactive Activities–Reinforce your understanding of topics with all the different exercises from the online course identified throughout the book with this icon.
• Videos–Watch the videos embedded within the online course.
• Packet Tracer Activities–Explore and visualize networking concepts using Packet Tracer exercises interspersed throughout the chapters.
• Hands-on Labs–Work through all the course labs and Class Activities that are included in the course and published in the separate Lab Manual.

Product Details

ISBN-13:	9781587133329
Publisher:	Cisco Press
Publication date:	05/16/2014
Series:	Companion Guide Series
Edition description:	New Edition
Pages:	576
Product dimensions:	8.20(w) x 9.30(h) x 1.30(d)

About the Author

Rick Graziani teaches computer science and computer networking courses at Cabrillo College in Aptos, California. Prior to teaching, Rick worked in the informationtechnology field for 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. Rick is also a member of the Curriculum Development team for the Cisco Networking Academy since 1999.

Rick has authored multiple books for Cisco Press and multiple online courses for the Cisco Networking Academy. Rick is the author of the Cisco Press book IPv6 Fundamentals and has presented on IPv6 at several Cisco Academy conferences. He is the coauthor of the Cisco Press book Routing Protocols Companion Guide.

When Rick is not working, he is most likely surfing at one of his favorite Santa Cruz surf breaks.

Bob Vachon is a professor in the Computer Systems Technology program at Cambrian College in Sudbury, Ontario, Canada, where he teaches networking infrastructure courses. He has over 30 years of work and teaching experience in the computer networking and information technology field.

Since 2001, Bob has collaborated as team lead, lead author, and subject matter expert on various CCNA, CCNA-S, and CCNP projects for Cisco and the Cisco Networking Academy. He also authored the CCNA Accessing the WAN Companion Guide and the CCNA Security (640-554) Portable Command Guide. He is the coauthor of the Cisco Press book Routing Protocols Companion Guide.

In his downtime, Bob enjoys playing the guitar, shooting darts or pool, and either working in his gardens or white-water canoe tripping.

Table of Contents

Introduction xix

Chapter 1: Hierarchical Network Designs 1

Objectives 1

Key Terms 1

Introduction (1.0.1.1) 2

Hierarchical Network Design Overview (1.1) 2

Enterprise Network Campus Design (1.1.1) 2

Network Requirements (1.1.1.1) 3

Structured Engineering Principles (1.1.1.2) 4

Hierarchical Network Design (1.1.2) 4

Network Hierarchy (1.1.2.1) 4

The Access Layer (1.1.2.2) 6

The Distribution Layer (1.1.2.3) 7

The Core Layer (1.1.2.4) 9

Two-Tier Collapsed Core Design (1.1.2.5) 10

Cisco Enterprise Architecture (1.2) 10

Modular Design (1.2.1.1) 11

Modules in the Enterprise Architecture (1.2.1.2) 12

Cisco Enterprise Architecture Model (1.2.2) 14

Cisco Enterprise Architecture Model (1.2.2.1) 14

Cisco Enterprise Campus (1.2.2.2) 15

Cisco Enterprise Edge (1.2.2.3) 17

Service Provider Edge (1.2.2.4) 18

Remote Functional Area (1.2.2.5) 21

Enterprise Branch 21

Enterprise Teleworker 22

Enterprise Data Center 22

Evolving Network Architectures (1.3) 22

IT Challenges (1.3.1.1) 22

Emerging Enterprise Architectures (1.3.1.2) 23

Emerging Network Architectures (1.3.2) 24

Cisco Borderless Networks (1.3.2.1) 24

Collaboration Architecture (1.3.2.2) 25

Data Center and Virtualization (1.3.2.3) 26

Expanding the Network (1.3.2.4) 27

Summary (1.4) 29

Practice 30

Class Activities 30

Packet Tracer Activities 30

Check Your Understanding Questions 31

Chapter 2: Connecting the WAN 35

Objectives 35

Key Terms 35

Introduction (2.0.1.1) 37

WAN Technologies Overview (2.1) 37

Why a WAN? (2.1.1.1) 37

Are WANs Necessary? (2.1.1.2) 38

Evolving Networks (2.1.1.3) 39

Small Office (2.1.1.4) 39

Campus Network (2.1.1.5) 40

Branch Networks (2.1.1.6) 42

Distributed Network (2.1.1.7) 43

WAN Operations (2.1.2) 44

WANs in the OSI Model (2.1.2.1) 44

Common WAN Terminology (2.1.2.2) 45

WAN Devices (2.1.2.3) 47

Circuit-Switched Networks (2.1.2.4) 48

Packet-Switched Networks (2.1.2.5) 50

Selecting a WAN Technology (2.2) 51

WAN Link Connection Options (2.2.1.1) 51

Service Provider Network Infrastructure (2.2.1.2) 52

Private WAN Infrastructures (2.2.2) 54

Leased Lines (2.2.2.1) 54

Dialup (2.2.2.2) 55

ISDN (2.2.2.3) 56

Frame Relay (2.2.2.4) 58

ATM (2.2.2.5) 59

Ethernet WAN (2.2.2.6) 60

MPLS (2.2.2.7) 62

VSAT (2.2.2.8) 63

Public WAN Infrastructure (2.2.3) 64

DSL (2.2.3.1) 64

Cable (2.2.3.2) 65

Wireless (2.2.3.3) 66

3G/4G Cellular (2.2.3.4) 67

VPN Technology (2.2.3.5) 68

Selecting WAN Services (2.2.4) 70

Choosing a WAN Link Connection (2.2.4.1, 2.2.4.2) 70

What Is the Purpose of the WAN? 70

What Is the Geographic Scope? 70

What Are the Traffic Requirements? 71

Summary (2.3) 73

Practice 74

Class Activities 74

Labs 74

Check Your Understanding Questions 74

Chapter 3: Point-to-Point Connections 79

Objectives 79

Key Terms 79

Introduction (3.0.1.1) 80

Serial Point-to-Point Overview (3.1) 80

Serial Communications (3.1.1) 81

Serial and Parallel Ports (3.1.1.1) 81

Serial Communication (3.1.1.2) 82

Point-to-Point Communication Links (3.1.1.3) 84

Time-Division Multiplexing (3.1.1.4) 85

Statistical Time-Division Multiplexing (3.1.1.5) 86

TDM Examples — Sonet and SDM (3.1.1.6) 87

Demarcation Point (3.1.1.7) 88

DTE-DCE (3.1.1.8) 90

Serial Cables (3.1.1.9) 91

Serial Bandwidth (3.1.1.10) 94

HDLC Encapsulation (3.1.2) 96

WAN Encapsulation Protocols (3.1.2.1) 96

HDLC Encapsulation (3.1.2.2) 97

HDLC Frame Types (3.1.2.3) 98

Configuring HDLC Encapsulation (3.1.2.4) 100

Troubleshooting a Serial Interface (3.1.2.5) 100

PPP Operation (3.2) 104

Benefits of PPP (3.2.1) 104

Introducing PPP (3.2.1.1) 104

Advantages of PPP (3.2.1.2) 106

LCP and NCP (3.2.2) 106

PPP Layered Architecture (3.2.2.1) 106

PPP — Link Control Protocol (LCP) (3.2.2.2) 107

PPP — Network Control Protocol (NCP) (3.2.2.3) 108

PPP Frame Structure (3.2.2.4) 108

PPP Sessions (3.2.3) 109

Establishing a PPP Session (3.2.3.1) 110

LCP Operation (3.2.3.2) 111

LCP Packet (3.2.3.3) 113

PPP Configuration Options (3.2.3.4) 115

NCP Explained (3.2.3.5) 117

Configure PPP (3.3) 118

Configure PPP (3.3.1) 118

PPP Configuration Options (3.3.1.1) 119

PPP Basic Configuration Command (3.3.1.2) 120

PPP Compression Commands (3.3.1.3) 121

PPP Link Quality Monitoring Command (3.3.1.4) 122

PPP Multilink Commands (3.3.1.5) 123

Verifying PPP Configuration (3.3.1.6) 125

PPP Authentication (3.3.2) 126

PPP Authentication Protocols (3.3.2.1) 127

Password Authentication Protocol (PAP) (3.3.2.2) 127

Challenge Handshake Authentication Protocol (CHAP) (3.3.2.3) 129

PPP Encapsulation and Authentication Process (3.3.2.4) 131

Configuring PPP Authentication (3.3.2.5) 134

Configuring PPP with Authentication (3.3.2.6) 136

Troubleshoot WAN Connectivity (3.4) 138

Troubleshoot PPP (3.4.1) 138

Troubleshooting PPP Serial Encapsulation (3.4.1.1) 138

Debug PPP (3.4.1.2) 140

Troubleshooting a PPP Configuration with Authentication (3.4.1.3) 142

Summary (3.5) 145

Practice 146

Class Activities 146

Labs 146

Packet Tracer Activities 146

Check Your Understanding Questions 147

Chapter 4: Frame Relay 153

Objectives 153

Key Terms 153

Introduction (4.0.1.1) 154

Introduction to Frame Relay (4.1) 154

Benefits of Frame Relay (4.1.1) 155

Introducing Frame Relay (4.1.1.1) 155

Benefits of Frame Relay WAN Technology (4.1.1.2) 156

Dedicated Line Requirements (4.1.1.3) 157

Cost-Effectiveness and Flexibility of Frame Relay (4.1.1.4) 159

Frame Relay Operation (4.1.2) 160

Virtual Circuits (4.1.2.1) 160

Multiple Virtual Circuits (4.1.2.2) 163

Frame Relay Encapsulation (4.1.2.3) 165

Frame Relay Topologies (4.1.2.4, 4.1.2.5) 167

Frame Relay Address Mapping (4.1.2.6) 171

Local Management Interface (LMI) (4.1.2.7) 174

LMI Extensions (4.1.2.8) 175

Using LMI and Inverse ARP to Map Addresses (4.1.2.9) 178

Advanced Frame Relay Concepts (4.1.3) 180

Access Rate and Committed Information Rate (4.1.3.1) 180

Frame Relay Example (4.1.3.2) 181

Bursting (4.1.3.3) 183

Frame Relay Flow Control (4.1.3.4) 184

Configure Frame Relay (4.2) 187

Configure Basic Frame Relay (4.2.1) 187

Basic Frame Relay Configuration Commands (4.2.1.1) 187

Configuring a Static Frame Relay Map (4.2.1.2) 190

Verify a Static Frame Relay Map (4.2.1.3) 192

Configure Subinterfaces (4.2.2) 193

Reachability Issues (4.2.2.1) 193

Solving Reachability Issues (4.2.2.2) 196

Configuring Point-to-Point Subinterfaces (4.2.2.3) 199

Example: Configuring Point-to-Point Subinterfaces (4.2.2.4) 200

Troubleshoot Connectivity (4.3) 203

Troubleshoot Frame Relay (4.3.1) 203

Verifying Frame Relay Operation: Frame Relay Interface (4.3.1.1) 203

Verifying Frame Relay Operation: LMI Operations (4.3.1.2) 204

Verifying Frame Relay Operation: PVC Status (4.3.1.3) 205

Verifying Frame Relay Operation: Inverse ARP (4.3.1.4) 205

Troubleshooting Frame Relay Operation (4.3.1.5) 207

Summary (4.4) 209

Practice 210

Class Activities 210

Labs 210

Packet Tracer Activities 210

Check Your Understanding Questions 211

Chapter 5: Network Address Translation for IPv4 217

Objectives 217

Key Terms 217

Introduction (5.0.1.1) 218

NAT Operation (5.1) 219

NAT Characteristics (5.1.1) 219

IPv4 Private Address Space (5.1.1.1) 219

What Is NAT? (5.1.1.2) 220

NAT Terminology (5.1.1.3) 221

How NAT Works (5.1.1.5) 224

Types of NAT (5.1.2) 225

Static NAT (5.1.2.1) 225

Dynamic NAT (5.1.2.2) 226

Port Address Translation (PAT) (5.1.2.3) 227

Next Available Port (5.1.2.4) 228

Comparing NAT and PAT (5.1.2.5) 230

Benefits of NAT (5.1.3) 231

Benefits of NAT (5.1.3.1) 231

Disadvantages of NAT (5.1.3.2) 232

Configuring NAT (5.2) 233

Configuring Static NAT (5.2.1) 233

Configuring Static NAT (5.2.1.1) 233

Analyzing Static NAT (5.2.1.2) 235

Verifying Static NAT (5.2.1.3) 237

Configuring Dynamic NAT (5.2.2) 238

Dynamic NAT Operation (5.2.2.1) 238

Configuring Dynamic NAT (5.2.2.2) 239

Analyzing Dynamic NAT (5.2.2.3) 242

Verifying Dynamic NAT (5.2.2.4) 244

Configuring Port Address Translation (PAT) (5.2.3) 247

Configuring PAT: Address Pool (5.2.3.1) 247

Configuring PAT: Single Address (5.2.3.2) 249

Analyzing PAT (5.2.3.3) 251

Verifying PAT (5.2.3.4) 253

Port Forwarding (5.2.4) 255

Port Forwarding (5.2.4.1) 255

SOHO Example (5.2.4.2) 257

Configuring Port Forwarding with IOS (5.2.4.3) 258

Configuring NAT and IPv6 (5.2.5) 260

NAT for IPv6? (5.2.5.1) 260

IPv6 Unique Local Addresses (5.2.5.2) 262

NAT for IPv6 (5.2.5.3) 263

Troubleshooting NAT (5.3) 264

Troubleshooting NAT: show Commands (5.3.1.1) 264

Troubleshooting NAT: debug Command (5.3.1.2) 266

Case Study (5.3.1.3) 268

Summary (5.4) 271

Practice 272

Class Activities 272

Labs 272

Packet Tracer Activities 272

Check Your Understanding Questions 273

Chapter 6: Broadband Solutions 279

Objectives 279

Key Terms 279

Introduction (6.0.1.1) 280

Teleworking (6.1) 280

Benefits of Teleworking (6.1.1) 280

Introducing Teleworking (6.1.1.1) 281

Employer Benefits of Teleworking (6.1.1.2) 281

Community and Government Benefits (6.1.1.3) 282

Individual Benefits of Teleworking (6.1.1.4) 283

Detriments to Telework (6.1.1.5) 283

Business Requirements for Teleworker Services (6.1.2) 284

Teleworker Solution (6.1.2.1) 284

Teleworker Connectivity Requirements (6.1.2.2) 286

Comparing Broadband Solutions (6.2) 287

Cable (6.2.1) 287

What is a Cable System? (6.2.1.1) 287

Cable and the Electromagnetic Spectrum (6.2.1.2) 289

DOCSIS (6.2.1.3) 290

Cable Components (6.2.1.4) 291

DSL (6.2.2) 293

What is DSL? (6.2.2.1) 293

DSL Connections (6.2.2.2) 294

Separating Voice and Data in ADSL (6.2.2.3) 295

Broadband Wireless (6.2.3) 298

Types of Broadband Wireless Technologies (6.2.3.1, 6.2.3.2) 298

Selecting Broadband Solutions (6.2.4) 303

Comparing Broadband Solutions (6.2.4.1) 303

Configuring xDSL Connectivity (6.3) 304

PPPoE Overview (6.3.1) 304

PPPoE Motivation (6.3.1.1) 304

PPPoE Concepts (6.3.1.2) 306

Configuring PPPoE (6.3.2) 306

PPPoE Configuration (6.3.2.1) 307

Summary (6.4) 309

Practice 310

Class Activities 310

Labs 310

Check Your Understanding Questions 310

Chapter 7: Securing Site-to-Site Connectivity 313

Objectives 313

Key Terms 313

Introduction (7.0.1.1) 314

VPNs (7.1) 314

Fundamentals of VPNs (7.1.1) 314

Introducing VPNs (7.1.1.1) 315

Benefits of VPNs (7.1.1.2) 316

Types of VPNs (7.1.2) 317

Remote-Access VPNs (7.1.2.2) 318

Site-to-Site GRE Tunnels (7.2) 319

Fundamentals of Generic Routing Encapsulation (7.2.1) 319

Introduction to GRE (7.2.1.1) 319

Characteristics of GRE (7.2.1.2) 320

Configuring GRE Tunnels (7.2.2) 321

GRE Tunnel Configuration (7.2.2.1) 322

GRE Tunnel Verification (7.2.2.2) 324

Introducing IPsec (7.3) 326

Internet Protocol Security (7.3.1) 326

IPsec (7.3.1.1) 326

IPsec Security Services (7.3.1.2) 327

IPsec Framework (7.3.2) 328

Confidentiality with Encryption (7.3.2.1) 328

Encryption Algorithms (7.3.2.2) 330

Diffie-Hellman Key Exchange (7.3.2.3) 332

Integrity with Hash Algorithms (7.3.2.4) 332

IPsec Authentication (7.3.2.5) 334

IPsec Protocol Framework (7.3.2.6) 335

Remote Access (7.4) 337

Remote-Access VPN Solutions (7.4.1) 337

Types of Remote-Access VPNs (7.4.1.1) 337

Cisco SSL VPN (7.4.1.2) 338

Cisco SSL VPN Solutions (7.4.1.3) 340

IPsec Remote-Access VPNs (7.4.2) 341

IPsec Remote Access (7.4.2.1) 341

Cisco Easy VPN Server and Remote (7.4.2.2) 342

Cisco Easy VPN Client (7.4.2.3) 343

Comparing IPsec and SSL (7.4.2.4) 345

Summary (7.5) 347

Practice 348

Class Activities 348

Labs 348

Packet Tracer Activities 348

Check Your Understanding Questions 348

Chapter 8: Monitoring the Network 351

Objectives 351

Key Terms 351

Introduction (8.0.1.1) 352

Syslog (8.1) 352

Syslog Operation (8.1.1) 352

Introduction to Syslog (8.1.1.1) 352

Syslog Operation (8.1.1.2) 354

Syslog Message Format (8.1.1.3) 355

Service Timestamp (8.1.1.4) 357

Configuring Syslog (8.1.2) 358

Syslog Server (8.1.2.1) 358

Default Logging (8.1.2.2) 359

Router and Switch Commands for Syslog Clients (8.1.2.3) 360

Verifying Syslog (8.1.2.4) 362

SNMP (8.2) 364

SNMP Operation (8.2.1) 364

Introduction to SNMP (8.2.1.1) 364

SNMP Operation (8.2.1.2) 365

SNMP Agent Traps (8.2.1.3) 366

SNMP Versions (8.2.1.4) 368

Community Strings (8.2.1.5) 370

Management Information Base Object ID (8.2.1.6) 371

Configuring SNMP (8.2.2) 374

Steps for Configuring SNMP (8.2.2.1) 374

Verifying SNMP Configuration (8.2.2.2) 375

Security Best Practices (8.2.2.3) 378

NetFlow (8.3) 380

NetFlow Operation (8.3.1) 380

Introducing NetFlow (8.3.1.1) 380

Understanding NetFlow (8.3.1.2) 381

Network Flows (8.3.1.3) 383

Configuring NetFlow (8.3.2) 384

Verifying NetFlow (8.3.2.2) 386

Examining Traffic Patterns (8.3.3) 390

Identifying NetFlow Collector Functions (8.3.3.1) 390

NetFlow Analysis with a NetFlow Collector (8.3.3.2) 392

Summary (8.4) 397

Practice 397

Class Activities 398

Labs 398

Packet Tracer Activities 398

Check Your Understanding Questions 398

Chapter 9: Troubleshooting the Network 401

Objectives 401

Key Terms 401

Introduction (9.0.1.1) 402

Troubleshooting with a Systematic Approach (9.1) 402

Network Documentation (9.1.1) 402

Documenting the Network (9.1.1.1) 403

Network Topology Diagrams (9.1.1.2) 406

Network Baseline Performance Level (9.1.1.3) 408

Establishing a Network Baseline (9.1.1.4) 409

Measuring Data (9.1.1.5) 412

Troubleshooting Process (9.1.2) 415

General Troubleshooting Procedures (9.1.2.1) 415

Gathering Symptoms (9.1.2.2) 417

Questioning End Users (9.1.2.3) 418

Isolating the Issue Using Layered Models (9.1.3) 419

Using Layered Models for Troubleshooting (9.1.3.1) 419

Troubleshooting Methods (9.1.3.2, 9.1.3.3) 422

Guidelines for Selecting a Troubleshooting Method (9.1.3.4) 425

Network Troubleshooting (9.2) 426

Troubleshooting Tools (9.2.1) 426

Software Troubleshooting Tools (9.2.1.1, 9.2.1.2) 426

Hardware Troubleshooting Tools (9.2.1.3) 431

Using a Syslog Server for Troubleshooting (9.2.1.4) 435

Symptoms and Causes of Network Troubleshooting (9.2.2) 437

Physical Layer Troubleshooting (9.2.2.1) 437

Data Link Layer Troubleshooting (9.2.2.2) 439

Network Layer Troubleshooting (9.2.2.3) 441

Transport Layer Troubleshooting — ACLs (9.2.2.4) 443

Transport Layer Troubleshooting — NAT for IPv4 (9.2.2.5) 445

Application Layer Troubleshooting (9.2.2.6) 446

Troubleshooting IP Connectivity (9.2.3) 448

Components of Troubleshooting End-to-End Connectivity (9.2.3.1) 448

End-to-End Connectivity Problem Initiates Troubleshooting (9.2.3.2) 450

Step 1 - Verify the Physical Layer (9.2.3.3) 452

Step 2 - Check for Duplex Mismatches (9.2.3.4) 454

Step 3 - Verify Layer 2 and Layer 3 Addressing on the Local Network (9.2.3.5) 456

Step 4 - Verify Default Gateway (9.2.3.6) 461

Step 5 - Verify Correct Path (9.2.3.7) 464

Step 6 - Verify the Transport Layer (9.2.3.8) 468

Step 7 - Verify ACLs (9.2.3.9) 469

Step 8 - Verify DNS (9.2.3.10) 471

Summary (9.3) 474

Practice 475

Class Activities 475

Packet Tracer Activities 475

Check Your Understanding Questions 476

Appendix A: Answers to the “Check Your Understanding” Questions 479

Glossary 499

TOC, 9781587133329, 3/25/2014