Tài liệu CCNA chuẩn của Cisco

Tài liệu hữu ích cho những ai thích mảng Networking


Contents at a Glance
Introduction xvii
PART I: Networking Fundamentals 3
Chapter 1 Introduction to Computer Networking Concepts 5
Chapter 2 The TCP/IP and OSI Networking Models 15
Chapter 3 Data Link Layer Fundamentals: Ethernet LANs 43
Chapter 4 Fundamentals of WANs 77
Chapter 5 Fundamentals of IP 109
Chapter 6 Fundamentals of TCP and UDP 145
PART II: Operating Cisco Devices 169
Chapter 7 Operating Cisco Routers 171
Chapter 8 Operating Cisco LAN Switches 209
PART III: LAN Switching 227
Chapter 9 Cisco LAN Switching Basics 229
Chapter 10 Virtual LANs and Trunking 259
Chapter 11 LAN Cabling, Standards, and Topologies 279
PART IV: TCP/IP 311
Chapter 12 IP Addressing and Subnetting 313
Chapter 13 Basic Router Configuration and Operation 363
Chapter 14 Introduction to Dynamic Routing Protocols 403
PART V: Wide-Area Networking 427
Chapter 15 Remote Access Technologies 429
PART VI: Final Preparation 477
Chapter 16 Final Preparation 479
PART VII: Appendixes 497
Appendix A Answers to the “Do I Know This Already?” Quizzes and Q&A Sections 499
Appendix B Binary/Decimal Conversion Chart 565
Appendix C Using the Simulation Software for Hands-on Exercises 571
Glossary 577
Index 593
vii
Contents
Introduction xvii
Part I Networking Fundamentals 3
Chapter 1 Introduction to Computer Networking Concepts 5
Perspectives on Networking 5
The Flintstones Network: The First Computer Network? 7
Chapter 2 The TCP/IP and OSI Networking Models 15
“Do I Know This Already?” Quiz 16
Foundation Topics 20
The TCP/IP Protocol Architecture 21
The TCP/IP Application Layer 22
The TCP/IP Transport Layer 24
The TCP/IP Internetwork Layer 26
The TCP/IP Network Interface Layer 27
Data Encapsulation 29
OSI Reference Model 31
OSI Layers 31
OSI Layering Concepts and Benefits 34
OSI Terminology 35
OSI Summary 37
Foundation Summary 38
Q&A 41
Chapter 3 Data Link Layer Fundamentals: Ethernet LANs 43
“Do I Know This Already?” Quiz 43
Foundation Topics 47
OSI Perspectives on Local-Area Networks 47
Typical LAN Features for OSI Layer 1 47
Typical LAN Features for OSI Layer 2 50
Data Link Function 1: Arbitration 50
Data Link Function 2: Addressing 51
Data Link Function 3: Error Detection 51
Data Link Function 4: Identifying the Encapsulated Data 52
Early Ethernet Standards 52
Standards Overview 53
The Original Ethernet Standards: 10BASE2 and 10BASE5 53
Repeaters 55
10BASE-T Ethernet 56
Ethernet 10BASE-T Cabling 57
10BASE-T Hubs 59
Performance Issues: Collisions and Duplex Settings 60
Reducing Collisions Through LAN Switching 60
Eliminating Collisions to Allow Full-Duplex Ethernet 62
viii
Ethernet Data-Link Protocols 63
Ethernet Addressing 64
Ethernet Framing 65
Identifying the Data Inside an Ethernet Frame 66
Layer 2 Ethernet Summary 68
Recent Ethernet Standards 68
Fast Ethernet 68
Gigabit Ethernet 69
Foundation Summary 70
Q&A 74
Chapter 4 Fundamentals of WANs 77
“Do I Know This Already?” Quiz 77
Foundation Topics 81
OSI Layer 1 for Point-to-Point WANs 81
WAN Connections from the Customer Viewpoint 84
WAN Cabling Standards 85
Clock Rates, DCE, and DTE 88
Link Speeds Offered by Telcos 89
OSI Layer 2 for Point-to-Point WANs 91
HDLC 91
Point-to-Point Protocol 92
Other Point-to-Point WAN Data-Link Protocols 94
Synchronization 94
Point-to-Point WAN Summary 95
Packet-Switching Services 95
Frame Relay 96
Frame Relay Basics 97
ATM and SONET 100
SONET 100
ATM 101
WAN Terminology Related to Packet Switching 102
Foundation Summary 104
Q&A 106
Chapter 5 Fundamentals of IP 109
“Do I Know This Already?” Quiz 109
Foundation Topics 114
Typical Features of OSI Layer 3 114
Routing (Path Selection) 114
PC1’s Logic: Sending Data to a Nearby Router 114
R1 and R2’s Logic: Routing Data Across the Network 115
R3’s Logic: Delivering Data to the End Destination 116
Network Layer Interaction with the Data Link Layer 116
ix
Network Layer (Layer 3) Addressing 118
Example Layer 3 Address Structures 119
Routing Protocols 119
IP Addressing Fundamentals 120
IP Addressing Definitions 120
How IP Addresses Are Grouped Together 121
Classes of Networks 122
The Actual Class A, B, and C Network Numbers 124
IP Subnetting 124
Network Layer Utilities 127
Address Resolution Protocol and the Domain Name System 127
ICMP Echo and the ping Command 130
RARP, BOOTP, and DHCP 130
IP Routing and Routing Protocols 133
IP Routing Protocols 135
Foundation Summary 138
Q&A 142
Chapter 6 Fundamentals of TCP and UDP 145
“Do I Know This Already?” Quiz 145
Foundation Topics 149
Typical Features of OSI Layer 4 149
The Transmission Control Protocol 150
Multiplexing Using TCP Port Numbers 151
Popular TCP/IP Applications 154
Error Recovery (Reliability) 155
Flow Control Using Windowing 156
Connection Establishment and Termination 158
Connectionless and Connection-Oriented Protocols 159
Data Segmentation and Ordered Data Transfer 160
TCP Function Summary 161
The User Datagram Protocol 161
Foundation Summary 164
Q&A 167
Part II Operating Cisco Devices 169
Chapter 7 Operating Cisco Routers 171
“Do I Know This Already?” Quiz 171
Foundation Topics 176
The Cisco IOS Software Command-Line Interface 176
Access to the CLI 176
CLI Help Features 179
The
debug
and
show
Commands 181
x
Configuring Cisco IOS Software 181
Example Configuration Process 183
Router Memory, Processors, and Interfaces 187
Managing Configuration Files 188
Viewing the Configuration and Old-Style Configuration Commands 190
Initial Configuration (Setup Mode) 190
Upgrading Cisco IOS Software and the Cisco IOS Software Boot Process 194
Upgrading a Cisco IOS Software Image into Flash Memory 194
The Cisco IOS Software Boot Sequence 197
Foundation Summary 200
Q&A 204
Chapter 8 Operating Cisco LAN Switches 209
“Do I Know This Already?” Quiz 209
Foundation Topics 213
Navigating Through a Cisco 2950 Switch 213
2950 Series Features and Functions 213
2950 Switch Operating System 214
Accessing the Cisco 2950 Switch CLI 215
Switch Initialization 216
Switch LEDs During POST 216
Initial Configuration Mode 218
Configuring 2950 IOS Software 220
Foundation Summary 221
Q&A 223
Part III LAN Switching 227
Chapter 9 Cisco LAN Switching Basics 229
“Do I Know This Already?” Quiz 229
Foundation Topics 234
The Case for Bridging and Switching 234
Transparent Bridging 236
The Forward Versus Filter Decision 237
How Bridges Learn MAC Addresses 239
Forwarding Unknown Unicasts and Broadcasts 240
LAN Switching 240
Full-Duplex Ethernet 242
Internal Processing on Cisco Switches 242
Speed and Autonegotiation 244
Summary: Bridges and Switches 244
LAN Segmentation 245
The Need for Spanning Tree 248
How Spanning Tree Works 249
Foundation Summary 252
Q&A 255
xi
Chapter 10 Virtual LANs and Trunking 259
“Do I Know This Already?” Quiz 259
Foundation Topics 263
Virtual LAN Concepts 263
VLAN Basics 263
Creating VLANs 264
Trunking with ISL and 802.1q 265
Cisco ISL 266
IEEE 802.1q 266
ISL and 802.1q Compared 267
Passing Traffic Between VLANs 268
Layer 2 Switching 268
Layer 3 Forwarding Using a Router 268
Layer 3 Forwarding Using a Layer 3 Switch 270
Layer 4 Switching 271
Layer 5–7 Switching 272
Multilayer Switching 272
Foundation Summary 274
Q&A 276
Chapter 11 LAN Cabling, Standards, and Topologies 279
“Do I Know This Already?” Quiz 279
Foundation Topics 283
Network Topologies 283
Cabling and Connectors 287
General Features of Metallic Cabling 287
Unshielded Twisted-Pair and Shielded Twisted-Pair Cabling and Connectors 289
UTP Standards 290
UTP Connectors 290
Coaxial Cabling 291
Fiber-Optic Cabling and Connectors for Ethernet 293
Optical Connectors for Ethernet 295
Summary: Ethernet Cabling 297
Ethernet Standards 297
Ethernet Framing 298
Ethernet Cabling Standards 298
10-Gigabit Ethernet 299
Wireless Communications 300
IEEE 802.11 Wireless LANs 301
Foundation Summary 303
Q&A 308
xii
Part IV TCP/IP 311
Chapter 12 IP Addressing and Subnetting 313
“Do I Know This Already?” Quiz 313
Foundation Topics 319
IP Addressing Review 319
IP Subnetting 321
Analyzing and Interpreting IP Addresses and Subnets 323
Math Operations Used to Answer Subnetting Questions 324
Converting IP Addresses from Decimal to Binary, and Back Again 324
The Boolean AND Operation 326
Prefix Notation 328
How Many Hosts, and How Many Subnets? 329
What Is the Subnet Number, and What Are the IP Addresses in the Subnet? 333
Finding the Subnet Number 333
Finding the Subnet Broadcast Address 335
Finding the Range of Valid IP Addresses in a Subnet 336
Finding the Answers Without Using Binary 338
What Subnet Masks Meet the Stated Design Requirements? 344
What Are the Other Subnet Numbers? 347
Scaling the IP Address Space for the Internet 351
CIDR 351
Private Addressing 353
Network Address Translation 354
IP Version 6 Addressing 355
Foundation Summary 356
Q&A 358
Chapter 13 Basic Router Configuration and Operation 363
“Do I Know This Already?” Quiz 363
Foundation Topics 368
Configuring IP Addresses 368
Basic Administrative Configuration 370
Configuring IP Addresses 372
Prefix Notation 375
Seeding the Routing Table with Connected IP Routes 375
Bandwidth, Clock Rate, and Serial Lines in the Lab 380
IP Troubleshooting Features 381
Internet Control Message Protocol 381
ICMP Echo Request and Echo Reply 382
Destination Unreachable ICMP Message 385
IP Naming Commands 387
Telnet and Suspend 389
Cisco Discovery Protocol 392
Foundation Summary 397
Q&A 400
xiii
Chapter 14 Introduction to Dynamic Routing Protocols 403
“Do I Know This Already?“ Quiz 403
Foundation Topics 407
Routing Protocol Overview 407
Comparing and Contrasting IP Routing Protocols 408
Routing Through the Internet with the Border Gateway Protocol 410
Distance Vector Protocols: RIP and IGRP 411
Routing Information Protocol Version 1 413
RIP Version 2 414
Interior Gateway Routing Protocol 414
Link-State Protocols: OSPF and Integrated IS-IS 416
Open Shortest Path First 417
Integrated IS-IS 418
Balanced Hybrid Protocols: Enhanced IGRP 419
Summary of Interior Routing Protocols 420
Foundation Summary 422
Q&A 425
Part V Wide-Area Networking 427
Chapter 15 Remote Access Technologies 429
“Do I Know This Already?” Quiz 429
Foundation Topics 435
Perspectives on the PSTN 435
Converting Analog Voice to Digital Voice 438
Analog Modems 441
Modulation and Demodulation 442
Point-to-Point Protocol Features with Modems 444
Modem Installation and Cabling 445
Modem Standards 446
Analog Modem Summary 447
Integrated Services Digital Network 447
ISDN Channels 449
ISDN Call Setup and Data Link Protocols 449
Typical Uses of ISDN 451
ISDN Installation and Cabling 453
ISDN Summary 453
Digital Subscriber Line 454
DSL Standards 456
DSL Protocols 458
DSL Summary 459
Cable Modems 460
Layer 1 and Layer 2 between the Home and the Head End 462
Upstream Data 463
Cable Modem Summary 464
xiv
Comparison of Remote Access Technologies 464
Foundation Summary 467
Q&A 474
Part VI Final Preparation 477
Chapter 16 Final Preparation 479
Suggestions for Final Preparation 479
Preparing for the Actual Exam Experience 480
A Final Lab Scenario 482
Scenario, Part A: Planning 482
Solutions to Part A: Planning 485
Scenario Part B: Configuration 486
Solutions to Part B: Configuration 486
Scenario Part C: Verification and Questions 488
Solutions to Part C: Verification and Questions 493
Part VII Appendixes 497
Appendix A Answers to the “Do I Know This Already?” Quizzes and Q&A Sections 499
Appendix B Decimal to Binary Conversion Table 565
Appendix C Using the Simulation Software for the Hands-on Exercises 571
Glossary 577
Index 593