Designing for Cisco Internetwork Solutions (DESGN) Foundation Learning Guide: (CCDA DESGN 640-864) / Edition 3

by Sean Wilkins

Overview

Designing for Cisco Internetwork Solutions (DESGN)

Foundation Learning Guide

Third Edition

Sean Wilkins

Foundation learning for the CCDA DESGN 640-864 exam

Designing for Cisco Internetwork Solutions (DESGN) Foundation Learning Guide, Third Edition, is a Cisco^®-authorized, self-paced learning tool for CCDA^® foundation learning. This book provides you with the knowledge needed to design enterprise networks. By reading this book, you will gain a thorough understanding of designing routed and switched network infrastructures and services involving LAN, WAN, and broadband access for businesses and organizations.

Designing for Cisco Internetwork Solutions (DESGN) Foundation Learning Guide, Third Edition teaches you how to gather internetworking requirements, identify solutions, and design the network infrastructure and services to ensure basic functionality using the principles of hierarchical network design to structure and modularize a converged enterprise network design. Specific topics include understanding the design methodology; structuring and modularizing the network design; designing the Enterprise Campus, Enterprise Data Center, Enterprise Edge, and remote modules as needed; designing an addressing plan and selecting suitable routing protocols; designing basic voice transport across the network; designing a basic wireless solution; and evaluating security solutions. Chapter-ending review questions illustrate and help solidify the concepts presented in the book.

Whether you are preparing for CCDA certification or simply want to gain a better understanding of network design principles, you will benefit from the foundation information presented in this book.

Designing for Cisco Internetwork Solutions (DESGN) Foundation Learning Guide, Third Edition, is part of a recommended learning path from Cisco that includes simulation and hands-on training from authorized Cisco Learning Partners and self-study products from Cisco Press. To find out more about instructor-led training, e-learning, and hands-on instruction offered by authorized Cisco Learning Partners worldwide, please visit www.cisco.com/go/authorizedtraining.

· Understand network design methodologies and the lifecycle of a network

· Learn how to structure and modularize network designs within the Cisco Network Architectures for the Enterprise

· Design basic campus and data center networks

· Build designs for remote connectivity with WAN technologies

· Examine IPv4 and IPv6 addressing schemes

· Select the appropriate routing protocols for various modules in the enterprise architecture

· Evaluate security solutions for the network

· Identify voice and video networking considerations

· Understand design technologies and considerations when implementing a controller-based wireless network

This book is in the Foundation Learning Guide Series. These guides are developed together with Cisco^® as the only authorized, self-paced learning tools that help networking professionals build their understanding of networking concepts and prepare for Cisco certification exams.

Product Details

ISBN-13:	9781587204241
Publisher:	Cisco Press
Publication date:	08/14/2011
Series:	Foundation Learning Guides Series
Edition description:	Revised
Pages:	550
Product dimensions:	7.40(w) x 9.10(h) x 1.40(d)

About the Author

Sean Wilkins is an accomplished networking consultant for SR-W Consulting (www.srwconsulting.com) and has been in the field of IT since the mid-1990s working with companies such as Cisco, Lucent, Verizon, and AT&T, as well as several other private companies. Sean currently holds certifications with Cisco (CCNP/CCDP), Microsoft (MCSE), and CompTIA (A+ and Network+). He also retains a Master of Science degree in information technology with a focus in network architecture and design, a Master of Science in organizational management, a Master’s Certificate in network security, a Bachelor of Science degree in computer networking, and an Associate of Applied Science degree in computer information systems. In addition to working as a consultant, Sean is a technical writer and editor for various companies.

Table of Contents

Introduction xxiii

Chapter 1 Network Fundamentals Review 1

Introduction to Networks 2

Protocols and the OSI Model 2

OSI Model 3

Protocols 3

OSI Layers 4

Physical Layer: Layer 1 4

Data Link Layer: Layer 2 4

Network Layer: Layer 3 5

Transport Layer: Layer 4 5

Upper Layers: Layers 5 Through 7 6

Communication Among OSI Layers 6

LANs and WANs 8

Network Devices 10

Terminology: Domains, Bandwidth, Unicast, Broadcast, and Multicast 10

Hubs 11

Physical Interfaces and Ports 11

Switches 11

Switches Versus Bridges 12

Routers 12

Introduction to the TCP/IP Suite 13

TCP/IP Transport Layer Protocols 15

Port Numbers 17

TCP Sequencing, Acknowledgment, and Windowing 18

TCP/IP Internet Layer Protocols 22

Protocols 22

IPv4 Datagrams 22

IPv6 Datagrams 24

Routing 25

Routers Work at the Lower Three OSI Layers 26

Routing Tables 27

Routing Protocols 28

Addressing 29

Physical Addresses 29

Logical Addresses 30

Routing and Network Layer Addresses 31

IPv4 Addresses 31

IPv4 Address Classes 31

Private and Public IPv4 Addresses 32

IPv4 Subnets 33

IPv6 Addresses 34

IPv6 Address Types 36

Switching Types 36

Layer 2 Switching 37

Layer 3 Switching 39

Spanning Tree Protocol 40

Redundancy in Layer 2 Switched Networks 40

STP Terminology and Operation 41

STP Terminology 41

STP States 43

Rapid STP 44

Virtual LANs 45

VLAN Membership 45

Trunks 46

STP and VLANs 46

Inter-VLAN Routing 47

Comprehensive Example 49

Summary 52

Review Questions 52

Chapter 2 Network Design Methodology 53

Understanding the Network Architectures for the Enterprise 53

Business Drivers for a New Network Framework 54

Business Forces 54

Technology-Related Forces 54

IT Challenges 55

Cisco Network Architectures for the Enterprise 55

Borderless Networks Architecture 56

Borderless Networks Architecture Approach 57

Collaboration Architecture Approach 58

Data Center/Virtualization Architecture Approach 59

Identifying Design Requirements 61

Using the PPDIOO Approach for Networks 61

Benefits of the Lifecycle Approach 63

Design Methodology 64

Identifying Customer Design Requirements 65

Identifying Network Applications and Network Services 65

Defining Organizational Goals 67

Identifying Organizational Constraints 69

Identifying Technical Goals 71

Assessing Technical Constraints 73

Characterizing the Existing Network and Sites 74

Identifying Major Features of the Network 74

Sample Site Contact Information 75

Sample High-Level Network Diagram 76

Auditing the Existing Network 77

Using Tools for Auditing the Network 79

RSPAN with VACLs for Granular Traffic Analysis 81

Analyzing Network Traffic and Applications 83

Using Tools for Analyzing Network Traffic 84

Reviewing Network Traffic Information 85

Analyzing Network Health 85

Creating a Draft Design Document 86

Time Estimates for Performing Network Characterization 88

Using the Top-Down Approach to Network Design 89

Top-Down Approach to Network Design 90

Top-Down Design Example 91

Decision Tables in Network Design 91

Assessing the Scope of the Network Design Project 93

Using Structured Design Principles 93

Logical Structure 94

Physical Structure 95

Network Design Tools 95

Testing the Design 96

Planning an Implementation 97

Documenting the Design 98

Summary 100

References 100

Review Questions 101

Chapter 3 Structuring and Modularizing the Network 103

Designing the Network Hierarchy 103

Introducing the Hierarchical Network Model 104

Describing Access Layer Functionality 106

Campus Access Layer Connectivity 107

Describing Distribution Layer Functionality 108

Virtual Switches 110

Describing Core Layer Functionality 111

Using a Modular Approach in Network Design 114

Describing the Enterprise Campus Functional Area 117

Enterprise Campus Infrastructure Module 117

Data Center Module 117

Describing the Enterprise Edge Area 119

E-Commerce Module 121

Internet Connectivity Module 121

WAN and MAN and Site-to-Site VPN Module 122

Remote Access and VPN Module 122

Describing the Service Provider Area 122

ISP Module 123

Public Switched Telephone Network Module 123

Frame Relay and ATM Module 123

Describing the Remote Area 124

Enterprise Branch Module 124

Enterprise Data Center Module 125

Enterprise Teleworker Module 125

Supporting Services on Borderless Networks 126

Explaining the Role of Borderless Network Services 126

Mobility Considerations 128

Security Infrastructure Services 129

Designing Security to Protect Against External Threats 132

Application Performance Considerations 134

Resolving Application Issues with Cisco Application Network Services 135

Cisco ANS Components 135

IP Communications 136

Voice Transport 137

High-Availability Network Services 141

Full-Mesh Versus Partial-Mesh Redundancy 142

Identifying Network Management Protocols and Features 145

Network Management Overview 145

SNMP 146

SNMP Message Types 147

SNMP Version 2 148

SNMP Version 3 149

MIB Characteristics 150

MIB Variable Retrieval 152

Using RMON 153

NetFlow Characteristics 155

NetFlow Versus RMON Information Gathering 157

Applications Using NetFlow 158

Cisco Discovery Protocol Features 159

Syslog Features 160

Summary 164

References 164

Review Questions 164

Chapter 4 Designing Basic Campus and Data Center Networks 167

Describing Campus Design Considerations 167

Campus Design Factors 168

Network Application Characteristics and Considerations 168

Peer-Peer Applications 169

Client—Local Server Applications 170

Client—Data Center Applications 170

Client—Enterprise Edge Applications 172

Application Requirements 173

Environmental Characteristics and Considerations 174

Intrabuilding Structure 174

Interbuilding Structure 175

Distant Remote Building Structure 175

Transmission Media Considerations 176

Copper 176

Optical Fiber 177

Wireless 177

Campus Transmission Media Comparison 178

Transmission Media Cabling Example 179

Infrastructure Device Characteristics and Considerations 179

Quality of Service (QoS) 180

Designing the Campus Infrastructure Module 181

Design Considerations for the Campus Network 181

Design Considerations for the Building Access Layer 182

Managing VLANs and STP 183

Managing Trunks Between Switches 186

Managing Default PAgP Settings 186

Consider Implementing Routing in the Building Access Layer 186

Design Considerations for the Building Distribution Layer 187

Best Practices in the Distribution Layer 187

Using First-Hop Redundancy Protocols 188

Deploying Layer 3 Routing Protocols 189

Using the Virtual Switching System at the Distribution Layer 191

Campus Core Design Considerations 192

Small and Medium Campus Design Options 195

Edge Distribution at the Campus Core 196

Describing Enterprise Data Center Considerations 197

Describing the Enterprise Data Center Architectures 197

Cisco Enterprise Data Center Architecture Framework 198

Server Challenges 200

Data Center Facility Aspects 200

Enterprise Data Center Infrastructure 205

Data Center Access Layer 206

Data Center Aggregation Layer 207

Data Center Core Layer 207

Describing Enterprise Network Virtualization Tools 208

Virtualization Challenges 208

What Is Virtualization? 209

Types of Virtualization 209

Virtualization Technologies 210

Network Virtualization Design Considerations 211

Summary 212

References 212

Review Questions 213

Chapter 5 Designing Remote Connectivity 215

Identifying WAN Technology Considerations 215

Review of WAN Features 216

Comparison of WAN Transport Technologies 217

Time-Division Multiplexing 218

ISDN Connectivity 218

Frame Relay 219

Multiprotocol Label Switching 219

Metro Ethernet 219

DSL Technology 220

Cable Technology 221

Wireless Technology 221

SONET and SDH Technology 222

DWDM Technology 223

Dark Fiber 224

WAN Link Categories 224

WAN Transport Technology Pricing and Contract Considerations 225

WAN Design Requirements 226

Response Time 227

Throughput 227

Packet Loss 228

Reliability 228

QoS Considerations for Bandwidth Constraints 228

Classification 229

Congestion Management 230

Traffic Shaping and Policing 231

Link Efficiency 232

Window Size 233

Designing the Enterprise WAN 233

Traditional WAN Designs 234

Star Topology 234

Fully Meshed Topology 235

Partially Meshed Topology 235

Remote-Access Network Design 235

VPN Design 236

Enterprise Versus Service Provider—Managed VPNs 237

Enterprise Managed VPN: IPsec 237

Service Provider—Managed VPNs: MPLS 242

Service Provider—Managed VPNs: Metro Ethernet 242

Service Provider—Managed VPNs: VPLS 243

WAN Backup Strategy Design 244

Using the Internet as a WAN Backup 245

Selecting the Enterprise WAN Architecture 246

Cisco Enterprise MAN and WAN Architecture 247

Selecting Enterprise WAN Components 249

Hardware Selection 249

Designing the Enterprise Branch 251

Enterprise Branch Architecture 251

Enterprise Branch Design 252

New Features on the ISR G2 Routers 253

Small Branch Office Design 254

Medium Branch Office Design 255

Large Branch Office Design 256

Enterprise Teleworker (Cisco Virtual Office Solution) Design 256

New ISRs for Small Offices and Teleworkers 257

Summary 259

References 259

Review Questions 260

Chapter 6 Designing IP Addressing 261

Designing IPv4 Addressing 261

IPv4 Addressing 261

Private and Public Addressing Guidelines 262

Recommended Practices for NAT 262

Developing an Addressing Plan 263

Planning the IP Addressing Hierarchy 266

Design Consideration: Route Summarization Groups 266

Address Blocks by Location 267

Hierarchical IP Addressing Plan 268

Recommended Practices for Name Resolution 270

Locating DHCP and DNS Servers in the Network 272

IP Address Space Planning Road Map 272

Designing IPv6 Addressing 272

IPv6 Addressing 273

Benefits of IPv6 Addressing 273

IPv6 Address Types 274

IPv6 Address Assignment Strategies 277

Identifying IPv6 Name Resolution 277

Making the Transition from IPv4 to IPv6 278

Strategies for IPv6 Deployment 279

Dual-Stack Model 280

Hybrid Model 281

Service Block Model 284

Summary 285

References 286

Review Questions 287

Chapter 7 Designing and Selecting Routing Protocols 289

Reviewing Enterprise Routing Protocols 289

Reviewing Routing Protocol Fundamentals 289

Differentiating Between Distance Vector and Link-State Routing Protocols 289

Differentiating Between Interior and Exterior Routing Protocols 292

Differentiating Between Hierarchical and Flat Routing Protocols 293

Routing Protocol Convergence 294

Routing Protocols for the Enterprise 295

EIGRP 295

Open Shortest Path First 296

Border Gateway Protocol 298

IPv6 Routing 300

Selecting an Enterprise Routing Protocol 301

When to Choose EIGRP 301

When to Choose OSPF 301

Designing a Routing Protocol Deployment 301

Applying Routing Protocols to a Hierarchical Network Structure 301

Routing in the Campus Core 302

Routing in the Building Distribution Layer 302

Routing in the Enterprise Edge Functional Area 302

Route Redistribution 303

Route Redistribution Planning 304

Remote-Access and VPN and Internet Connectivity Module Route Redistribution 305

Route Filtering 306

Route Filtering and Internet Connectivity 306

Route Summarization 306

Recommended Practice: Summarize at the Distribution Layer 307

Recommended Practice: Passive Interfaces for IGP at the Access Layer 308

IPv6 Route Summarization 308

Summary 309

Review Questions 310

Chapter 8 Evaluating Security Solutions for the Network 311

Defining Network Security 311

Network Security Background 312

Security Legislation 312

Threats and Risks 313

Reconnaissance Attacks 314

Vulnerability Assessment 315

Example Threat: Gaining Unauthorized Access to Systems 316

Example Risk: Loss of Availability 318

Everything Is a Potential Target 319

Understanding Network Security Policy and Processes 319

Definition of a Security Policy 319

Risk Assessment and Management 320

Example: Security Policy 322

Network Security Is a Continuous Process 323

Integrating Security Design and Network Design 324

Understanding the Cisco SAFE Approach 325

Cisco SAFE Architecture 325

The Network as a Platform for Security 326

Cisco Security Control Framework 327

Trust and Identity Management 328

Trust 329

Identity 330

Access Control 331

Trust and Identity Management Technologies 331

Example: Cisco IBNS 332

Example: Firewall Filtering Using ACLs 332

Example: Cisco NAC Appliance 333

Identity and Access Control Deployment Locations 333

Threat Defense 335

Incorporating Physical Security 335

Infrastructure Protection 336

Threat Detection and Mitigation 338

Threat Detection and Mitigation Solutions 339

Example: Cisco IronPort ESA 341

Example: Cisco IronPort WSA 341

Secure Connectivity 342

Encryption Fundamentals 343

VPN Protocols 344

Ensuring Privacy 345

Example: Providing Confidentiality over the Internet 347

Example: Protecting Communication over the Public Infrastructure 347

Example: Network Authentication over a VPN 347

Maintaining Data Integrity 347

Example: VPN Tunneling for Data Integrity 348

Example: Implementation of Digital Signatures 349

Security Management 349

Selecting Network Security Solutions 352

Security Integration in Network Devices 352

Cisco IOS Security 352

Security Appliances 354

Intrusion Prevention System 355

Cisco Catalyst Services Modules 356

Endpoint Security Solutions 357

Securing the Enterprise Network 358

Example: Deploying Identity and Access Control in the Enterprise Campus 358

Example: Deploying Threat Detection and Mitigation in the Enterprise Campus 359

Example: Deploying Infrastructure Protection in the Enterprise Campus 359

Example: Deploying Security in the Enterprise Campus 359

Example: Deploying Identity and Access Control in the Enterprise Data Center 361

Example: Deploying Threat Detection and Mitigation in the Enterprise Data Center 361

Example: Deploying Infrastructure Protection in the Enterprise Data Center 361

Example: Deploying Security in the Data Center 361

Example: Deploying Identity and Access Control in the Enterprise Edge 364

Example: Deploying Threat Detection and Mitigation in the Enterprise Edge 364

Example: Deploying Infrastructure Protection in the Enterprise Edge 364

Example: Deploying Security in the Enterprise Edge 366

Summary 367

References 368

Review Questions 369

Chapter 9 Identifying Voice and Video Networking Considerations 371

Integrating Voice and Video Architectures 371

Differentiating Between Analog and Digital Signaling 372

Introducing Voice and Video over IP 373

Voice and Video Standards 376

Terminals 376

Gateways 377

Gatekeepers 377

Multipoint Control Units 378

H.264 379

Introducing VoIP 379

IP Telephony Design Models 381

Introducing Video Considerations 385

Media Application Models 386

Delivery of Media Application 386

Architectural Framework for Media Services 387

Call Control and Transport Protocols 388

Call Control Functions with H.323 388

Voice Conversation with RTP 389

Call Control Functions with SSCP 389

Call Control Functions with SIP 390

Call Control Functions with MGCP 392

Identifying the Requirements of Voice and Video Technologies 393

Minimizing Delay, Jitter, and Loss 394

One-Way Network Delay Recommendations 394

Propagation Delay 394

Serialization Delay 395

Processing Delay 395

Queuing Delay 395

Dejitter Buffers 396

Packet Loss 397

Preventing Echo 398

Echo Canceller Example 399

Echo Cancellation Guidelines 399

Voice Coding and Compression 399

Codec Complexity, DSPs, and Voice Calls 402

Bandwidth Considerations 402

Reducing Voice Traffic with cRTP 403

Reducing Voice Traffic with VAD 403

Voice Bandwidth Calculation 404

Typical Video Resolution and Bandwidth 406

Using QoS for Voice and Video 407

QoS Considerations for Voice and Video in the WAN 413

Call Rerouting Alternatives 414

Call Admission Control Examples 414

Implementing CAC with RSVP 415

Voice Traffic Engineering Overview 416

Summary 418

References 419

Review Questions 420

Chapter 10 Identifying Design Considerations for Basic Wireless Networking 421

Cisco Unified Wireless Network Review 421

Cisco Unified Wireless Network Architecture 421

Cisco Unified Wireless Network Elements 422

CAPWAP and LWAPP Fundamentals 423

Split Media Access Control 425

Local Media Access Control 426

Access Point Modes 427

Wireless Infrastructure 428

Wireless Authentication 430

Overview of WLAN Controllers 432

Access Point Support and Scaling 435

Access Point Scalability Considerations 437

Multiple AP Manager Interface Example 437

Link Aggregation (LAG) with a Single AP Manager Interface Example 439

Wireless Network Controller Technology 440

Lightweight Access Point Connectivity to a WLC 440

WLC Selection 440

Lightweight Access Point Operations 442

Mobility in the Cisco Unified Wireless Network 442

Intracontroller Roaming 443

Intercontroller Roaming–Layer 2 444

Intercontroller Roaming–Layer 3 444

Mobility Groups 446

Mobility Group Requirement Example 447

Recommended Practices for Supporting Roaming 448

Controller Redundancy Design 449

Deterministic Controller Redundancy 449

Dynamic Controller Redundancy 451

N + 1 Redundancy Design 452

N + N Redundancy Design 453

N + N + 1 Redundancy Design 454

Radio Resource Management (RRM) and RF Groups 455

RF Grouping 456

Access Point Self-Healing 458

Designing Wireless Networks Using Controllers 458

RF Site Survey 458

RF Site Survey Process 459

Design Considerations for Campus Wireless Networks 466

CAPWAP Access Point Feature Summary 466

Controller Placement Design 467

Campus Cisco Wireless LAN Controller Options 469

Design Considerations for Branch Wireless Networks 470

Hybrid REAP 470

Branch Office Cisco Wireless LAN Controller Options 472

Design Considerations for Guest Services in Wireless Networks 474

Design Considerations for Outdoor Wireless Networks 474

Wireless Mesh Components 476

Mesh Design Recommendations 477

Summary 478

References 478

Review Questions 479

Appendix A Answers to Review Questions 481

Appendix B Acronyms and Abbreviations 489

9781587204241 TOC 6/29/2011