11 Standards Comparison 213
Wi-Fi Certification 214
Summary of Exploring Wireless Networking 215
Understanding WLAN Security 215
Wireless LAN Security Threats 215
Mitigating Security Threats 216
Evolution of Wireless LAN Security 217
Wireless Client Association 218
How 802.1x Works on WLANs 219
WPA and WPA2 Modes 220
Enterprise Mode 220
Personal Mode 221
Summary of Understanding WLAN Security 221
Implementing a WLAN 221
802.11 Topology Building Blocks 222
BSA Wireless Topology 223
Wireless Topology Data Rates 224
Access Point Configuration 226
Steps to Implement a Wireless Network 227
Wireless Clients 227
Wireless Troubleshooting 228
Summary of Implementing a WLAN 229
Chapter Summary 230
Review Questions 230
Chapter 4 LAN Connections 237
Chapter Objectives 237
Exploring the Functions of Routing 238
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Routers 238
Path Determination 239
Routing Tables 240
Routing Table Information 241
Routing Update Messages 241
Static, Dynamic, Directly Connected, and Default Routes 242
Dynamic Routing Protocols 242
Routing Metrics 243
Routing Methods 244
Summary of Exploring the Functions of Routing 246
Understanding Binary Numbering 246
Decimal and Binary Systems 247
Least Significant Bit and Most Significant Bit 248
Base 2 Conversion System 249
Powers of 2 249
Decimal-to-Binary Conversion 250
Binary-to-Decimal Conversion 251
Summary of Understanding Binary Numbering 252
Constructing a Network Addressing Scheme 252
Subnetworks 252
Two-Level and Three-Level Addresses 254
Subnet Creation 254
Computing Usable Subnetworks and Hosts 255
Computing Hosts for a Class C Subnetwork 255
Computing Hosts for a Class B Subnetwork 256
Computing Hosts for a Class A Subnetwork 257
How End Systems Use Subnet Masks 258
How Routers Use Subnet Masks 259
Mechanics of Subnet Mask Operation 261
Applying Subnet Mask Operation 263
Determining the Network Addressing Scheme 264
Class C Example 265
Class B Example 267
Class A Example 268
Summary of Constructing a Network Addressing Scheme 270
Starting a Cisco Router 271
Initial Startup of a Cisco Router 271
Initial Setup of a Cisco Router 272
Logging In to the Cisco Router 279
Showing the Router Initial Startup Status 282
Summary of Starting a Cisco Router 283
Configuring a Cisco Router 283
Cisco Router Configuration Modes 283
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Configuring a Cisco Router from the CLI 285
Configuring Cisco Router Interfaces 287
Configuring the Cisco Router IP Address 288
Verifying the Interface Configuration 289
Summary of Configuring a Cisco Router 294
Exploring the Packet Delivery Process 295
Layer 2 Addressing 295
Layer 3 Addressing 295
Host-to-Host Packet Delivery 295
Using the show ip arp Command 302
Using Common Cisco IOS Tools 304
Summary of Exploring the Packet Delivery Process 305
Understanding Cisco Router Security 305
Physical and Environmental Threats 306
Configuring Password Security 306
Configuring the Login Banner 307
Telnet and SSH Access 307
Summary of Understanding Cisco Router Security 308
Using the Cisco SDM 309
Cisco SDM Overview 309
Configuring Your Router to Support Cisco SDM 311
Start Cisco SDM 312
More Link 314
Configuration Overview 314
Cisco SDM Wizards 316
Summary of Using the Cisco SDM 317
Using a Cisco Router as a DHCP Server 317
Understanding DHCP 318
DHCPDISCOVER 318
DHCPOFFER 318
DHCPREQUEST 318
DHCPACK 319
Using a Cisco Router as a DHCP Server 319
Using Cisco SDM to Enable the DHCP Server Function 319
Monitoring DHCP Server Functions 321
Summary Using a Cisco Router as a DHCP Server 323
Accessing Remote Devices 323
Establishing a Telnet or SSH Connection 323
Telnet 323
SSH 324
Suspending and Resuming a Telnet Session 325
Closing a Telnet Session 326
Alternate Connectivity Tests 327
Summary of Accessing Remote Devices 329
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Chapter Summary 329
Review Questions 330
Chapter 5 WAN Connections 345
Chapter Objectives 345
Understanding WAN Technologies 346
What Is a WAN? 346
Why Are WANs Necessary? 348
How Is a WAN Different from a LAN? 348
WAN Access and the OSI Reference Model 350
WAN Devices 350
WAN Cabling 351
The Role of Routers in WANs 353
WAN Data Link Layer Protocols 354
WAN Communication Link Options 355
Summary of Understanding WAN Technologies 356
Enabling the Internet Connection 356
Packet-Switched Communication Links 357
Digital Subscriber Line 358
DSL Types and Standards 359
Cable 360
Global Internet: The Largest WAN 361
Obtaining an Interface Address from a DHCP Server 362
Introducing NAT and PAT 363
Translating Inside Source Addresses 365
Example: Translating Inside Source Addresses 366
Example: Overloading an Inside Global Address 367
Configuring the DHCP Client and PAT 368
Verifying the DHCP Client Configuration 372
Verifying the NAT and PAT Configuration 373
Summary of Enabling the Internet Connection 373
Enabling Static Routing 374
Routing Overview 374
Static and Dynamic Route Comparison 376
Static Route Configuration 376
Example: Understanding Static Routes 376
Example: Configuring Static Routes 378
Default Route Forwarding Configuration 378
Static Route Configuration Verification 379
Summary of Enabling Static Routing 380
Configuring Serial Encapsulation 380
Circuit-Switched Communication Links 381
Public Switched Telephone Network 382
Point-to-Point Communication Links 383
xviii
Bandwidth 383
Point-to-Point Communication Considerations 385
High-Level Data Link Control Protocol 386
Configuring HDLC Encapsulation 386
Point-to-Point Protocol 387
PPP Layered Architecture 388
Example: PPP Configuration 389
Serial Encapsulation Configuration Verification 390
Frame Relay 391
ATM and Cell Switching 392
Summary of Configuring Serial Encapsulation 394
Enabling RIP 394
Dynamic Routing Protocol Overview 395
Features of Dynamic Routing Protocols 397
Example: Administrative Distance 397
Classful Routing Versus Classless Routing Protocols 398
Distance Vector Route Selection 399
Example: Distance Vector Routing Protocols 400
Example: Sources of Information and Discovering Routes 401
RIP Features 401
RIPv1 and RIPv2 Comparison 402
Dynamic Routing Configuration Tasks 403
RIP Configuration 403
RIP Configuration Verification 404
RIP Configuration Troubleshooting 407
Example: debug ip rip Command 407
Summary of Enabling RIP 407
Chapter Summary 408
Review Questions 409
Chapter 6 Network Environment Management 425
Chapter Objectives 425
Discovering Neighbors on the Network 425
Cisco Discovery Protocol 425
Information Obtained with CDP 426
Implementation of Cisco Discovery Protocol 428
Using the show cdp neighbors Command 428
Monitoring and Maintaining Cisco Discovery Protocol 430
Creating a Network Map of the Environment 432
Summary of Discovering Neighbors on the Network 433
Managing Cisco Router Startup and Configuration 433
Stages of the Router Power-On Boot Sequence 433
Internal Router Components 434
How a Device Locates and Loads Cisco IOS Image and
Configuration Files 437
xix
Configuration Register 439
Summary of Managing Cisco Router Startup and Configuration 442
Managing Cisco Devices 442
Cisco IOS File System and Devices 443
Managing Cisco IOS Images 445
Managing Device Configuration Files 448
Cisco IOS copy Command 449
Using show and debug Commands on Cisco Devices 452
Summary of Managing Cisco Devices 455
Chapter Summary 455
Review Questions 456
Appendix Answers to Chapter Review Questions 465
Chapter 1 465
Chapter 2 468
Chapter 3 471
Chapter 4 472
Chapter 5 475
Chapter 6 478
Index 480
xx
Icons Used in This Book
Home Office Branch Office Headquarters PC Printer Laptop
Router Switch IP Phone
IP
Bridge IP Telephony
Router
Network Cloud DSU/CSU uBR910
Cable DSU
Hub 100BaseT Hub Repeater
Server Database Host Access
Server
Access
Point
Modem
xxi
Command Syntax Conventions
The conventions used to present command syntax in this book are the same conventions
used in the IOS Command Reference.
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