LAN Switching and Wireless: CCNA Exploration Companion Guide Book

Chapter 1 LAN Design 1

Objectives 1

Key Terms 1

Switched LAN Architecture 2

The Hierarchical Network Model 2

Access Layer 2

Distribution Layer 3

Core Layer 3

A Hierarchical Network in a Medium-Sized Business 4

Benefits of a Hierarchical Network 4

Principles of Hierarchical Network Design 6

Network Diameter 7

Bandwidth Aggregation 8

Redundancy 9

What Is a Converged Network? 10

Legacy Equipment 10

Advanced Technology 11

New Options 12

Separate Voice, Video, and Data Networks 13

Matching Switches to Specific LAN Functions 15

Considerations for Hierarchical Network Switches 15

Traffic Flow Analysis 15

User Community Analysis 17

Data Stores and Data Servers Analysis 19

Topology Diagrams 20

Switch Features 22

Switch Form Factors 22

Switch Performance 24

Power over Ethernet and Layer 3 Functionality 26

Switch Features in a Hierarchical Network 28

Access Layer Switch Features 28

Distribution Layer Switch Features 30

Core Layer Switch Features 31

Switches for Small and Medium Sized Business (SMB) 33

Catalyst Express 500 33

Catalyst 2960 34

Catalyst 3560 35

Catalyst 3750 36

Catalyst 4500 36

Catalyst 4900 37

Catalyst 6500 38

Comparing Switches 39

Summary 40

Labs 40

Check Your Understanding 41

Challenge Questions and Activities 44

Chapter 2 Basic Switch Concepts and Configuration 45

Objectives 45

Key Terms 45

Introduction to Ethernet/802.3 LANs 46

Key Elements of Ethernet/802.3 Networks 46

CSMA/CD 46

Ethernet Communications 47

Duplex Settings 49

Switch Port Settings 50

Switch MAC Address Table 51

Design Considerations for Ethernet/802.3 Networks 52

Bandwidth and Throughput 52

Collision Domains 53

Broadcast Domains 54

Network Latency 54

Network Congestion 55

LAN Segmentation 55

LAN Design Considerations 56

Forwarding Frames Using a Switch 58

Switch Forwarding Methods 59

Symmetric and Asymmetric Switching 60

Memory Buffering 60

Layer 2 and Layer 3 Switching 62

Switch Management Configuration 63

Navigating Command-Line Interface Modes 63

GUI-Based Alternatives to the CLI 65

Using the Help Facility 68

Accessing the Command History 70

Switch Boot Sequence 71

Prepare to Configure the Switch 72

Basic Switch Configuration 72

Management Interface 73

Default Gateway 74

Duplex and Speed 75

HTTP Access 76

MAC Address Table Management 77

Verifying Switch Configuration 78

Basic Switch Management 80

Backing Up and Restoring Switch Configuration Files 80

Using a TFTP Server with Switch Configuration Files 82

Clearing Switch Configuration Information 84

Configuring Switch Security 85

Configuring Password Options 85

Securing Console Access 85

Securing Virtual Terminal Access 87

Securing Privileged EXEC Access 88

Encrypting Switch Passwords 89

Password Recovery 90

Login Banners 92

Configure Telnet and SSH 93

Configuring Telnet 93

Configuring SSH 94

Common Security Attacks 96

MAC Address Flooding 96

Spoofing Attacks 100

CDP Attacks 101

Telnet Attacks 102

Security Tools 103

Configuring Port Security 105

Securing Unused Ports 110

Summary 111

Labs 111

Check Your Understanding 112

Challenge Questions and Activities 117

Chapter 3 VLANs 121

Objectives 121

Key Terms 121

Introducing VLANs 122

Defining VLANs 122

Benefits of VLANs 124

VLAN ID Ranges 126

Types of VLANs 126

Voice VLANs 131

Network Application Traffic Types 133

Switch Port Membership Modes 136

Controlling Broadcast Domains with VLANs 138

VLAN Trunking 143

VLAN Trunks 144

IEEE 802.1Q Frame Tagging 145

Native VLANs 147

Trunking Operation 148

Trunking Modes 149

Configure VLANs and Trunks 151

Configure a VLAN 152

Managing VLANs 155

Managing VLAN Memberships 158

Configure a Trunk 160

Troubleshooting VLANs and Trunks 164

Common Problems with Trunks 165

A Common Problem with VLAN Configurations 171

Summary 173

Labs 173

Check Your Understanding 174

Challenge Questions and Activities 178

Chapter 4 VTP 181

Objectives 181

Key Terms 181

VTP Concepts 182

What Is VTP? 182

Benefits of VTP 184

VTP Components 184

VTP Operation 186

Default VTP Configuration 186

VTP Domains 188

VTP Advertising 190

VTP Configuration Revision Number 192

VTP Advertisement Types 193

VTP Modes 197

VTP Server-to-Client Behavior 198

VTP Server-to-Transparent-to-Client Behavior 199

VTP Pruning 201

VTP Pruning in Action 202

Configure VTP 204

Configuring VTP 204

Steps to Configuring VTP 206

Troubleshooting VTP Configurations 212

Incompatible VTP Versions 212

VTP Password Issues 212

Incorrect VTP Domain Name 213

All Switches Set to VTP Client Mode 214

VTP Troubleshooting Example 215

Managing VLANs on a VTP Server 217

Summary 219

Labs 219

Check Your Understanding 220

Challenge Questions and Activities 224

Chapter 5 STP 227

Objectives 227

Key Terms 227

Redundant Layer 2 Topologies 229

Redundancy 229

Issues with Redundancy 234

Broadcast Storms 238

Duplicate Unicast Frames 240

Real-World Redundancy Issues 241

Loops in the Wiring Closet 242

Loops in Cubicles 243

Introduction to STP 244

Spanning-Tree Algorithm (STA) 244

STP Topology 245

Port Types in the Spanning-Tree Algorithm 247

Root Bridge 248

Best Paths 249

STP BPDU 252

BPDU Process 253

Bridge ID 258

Configure and Verify the BID 261

Port Roles 263

Configure Port Priority 265

Port Role Decisions 266

STP Port States and BPDU Timers 268

Cisco PortFast 271

STP Convergence 273

Step 1. Elect a Root Bridge 273

Verify Root Bridge Election 274

Step 2. Elect Root Ports 276

Verify Root Port Election 278

Step 3. Elect Designated and Nondesignated Ports 279

Verify Designated and Nondesignated Port Election 283

STP Topology Change 285

PVST+, RSTP, and Rapid PVST+ 286

Cisco and IEEE STP Variants 287

Per-VLAN Spanning-Tree (PVST) Overview 287

Per-VLAN Spanning-Tree Plus (PVST+) Overview 287

Rapid Spanning-Tree Protocol (RSTP) Overview 288

Multiple Spanning-Tree Protocol (MSTP) Overview 288

PVST+ 288

Configure PVST+ 291

RSTP 294

RSTP BPDU 295

Edge Ports 296

Link Types 297

RSTP Port States and Port Roles 298

RSTP Proposal and Agreement Process 301

Configuring Rapid PVST+ 309

Design STP for Trouble Avoidance 312

Minimize the Number of Blocked Ports 313

Use Layer 3 Switching 314

Keep STP Even if It Is Unnecessary 316

Keep Traffic off of the Management VLAN 316

Troubleshoot STP Operation 316

PortFast Configuration Error 317

Network Diameter Issues 318

Summary 320

Labs 320

Check Your Understanding 321

Challenge Questions and Activities 327

Chapter 6 Inter-VLAN Routing 331

Objectives 331

Key Terms 331

Inter-VLAN Routing 332

Introducing Inter-VLAN Routing 332

One-Router-Interface-per-VLAN 332

Router-on-a-Stick 334

Layer 3 Switch 336

Interfaces and Subinterfaces 337

One-Router-Interface-per-VLAN 338

Router-on-a-Stick 341

Considerations for Inter-VLAN Routing Methods 345

Configuring Inter-VLAN Routing 347

Configure Inter-VLAN Routing 347

Configure Router-on-a-Stick Inter-VLAN Routing 351

Troubleshooting Inter-VLAN Routing 356

Switch Configuration Issues 356

Switch Cisco IOS Commands for Troubleshooting 359

Router Configuration Issues 360

Router Cisco IOS Commands for Troubleshooting 361

IP Addressing Issues 362

IP Addressing Cisco IOS Verification Commands 364

Summary 366

Labs 366

Check Your Understanding 367

Challenge Questions and Activities 373

Chapter 7 Basic Wireless Concepts and Configuration 377

Objectives 377

Key Terms 377

The Wireless LAN 379

Why Use Wireless? 379

Wireless LANs 380

Comparing a WLAN to a LAN 381

Wireless LAN Components 383

Wireless LAN Standards 383

Wi-Fi Certification 386

Wireless Infrastructure Components 387

Wireless NICs 387

Wireless Access Points 388

Wireless Routers 390

Wireless Operation 391

Configurable Wireless Parameters 391

Wireless Topologies 393

Wireless Association 396

Planning the Wireless LAN 399

Wireless LAN Security 402

Threats to Wireless Security 402

Rogue Access Points 402

Man-in-the-Middle Attacks 403

Denial of Service 404

Wireless Security Protocols 405

Authenticating the Wireless LAN 407

Wireless Encryption 408

Controlling Access to the WLAN 409

Configure Wireless LAN Access 410

Configuring the Wireless Access Point 410

Configuring Basic Wireless Settings 413

Configuring Wireless Security 415

Configuring a Wireless NIC 418

Scan for SSIDs 418

Select the Wireless Security Protocol 420

Verify Connectivity to the WLAN 423

Troubleshooting Simple WLAN Problems 424

A Systematic Approach to WLAN Troubleshooting 424

Solve Access Point Radio and Firmware Issues 426

Channel Settings 426

RF Interference 429

Access Point Placement 431

Authentication and Encryption 434

Summary 436

Labs 436

Check Your Understanding 437

Challenge Questions and Activities 441

Appendix Check Your Understanding and Challenge Questions

Answer Key 445

Glossary 461