Russ White has more than 20 years of experience in designing, deploying, breaking, and troubleshooting large-scale networks. Across that time, he has coauthored 48 software patents, has spoken at venues throughout the world, has participated in the development of several Internet standards, has helped develop the CCDE and the CCAr, and has worked in Internet governance with the ISOC. Russ is currently a senior architect at Akamai Technologies, where he works on next-generation data center designs, complexity, security, and privacy. His most recent books are The Art of Network Architecture, Navigating Network Complexity, and Problems and Solutions in Network Engineering.

Introduction xxvi Part I Foundations 3 Chapter 1 Shipping Things 6 Do I Know This Already? Quiz 6 Foundation Topics 8 The Purpose of Packaging 8 The Physical World 8 Computer Networks 9 Addressing 11 The Physical World 11 Computer Networks 12 Hosts and Devices 14 Packaging Data 15 What Is a Protocol? 16 What Is Metadata? 17 Tunnels 17 Review All the Key Topics 19 Key Terms You Should Know 20 Concepts and Actions 20 Chapter 2 Addresses 22 Do I Know This Already? Quiz 22 Foundation Topics 24 Address Scope 24 Receiver Set 24 Topological Reach 25 Physical Addresses 28 Internet Protocol Version 4 30 Why Two Addresses? 32 What an IP Address Represents 34 Calculating Prefixes and Subnets Using Subnet Masks 34 Calculating Prefixes and Subnets Using a Skip Chart 35 Calculating Prefixes Using Skips 36 Internet Protocol Version 6 37 Aggregation 39 Network Prefixes 41 Private Address Space 41 Publicly Routable Address Space 42 Reserved Addresses 43 Ports and Sockets 44 Network Address Translation 45 Review All the Key Topics 47 Key Terms You Should Know 48 Concepts and Actions 48 Chapter 3 Routing and Switching 52 Do I Know This Already? Quiz 52 Foundation Topics 54 Assigning IP Addresses to Hosts 54 Manual Configuration 54 Calculate an IP Address 54 Computing a Link Local Address 55 Computing a Global Address 56 Physical Addresses and Privacy 56 Assign an Address Through a Protocol 57 IPv4 DHCP 57 IPv6 DHCP and Router Advertisements 58 Host-to-Host Communication and Address Resolution on a Single Wire 59 IPv4 Address Resolution 60 IPv6 Address Resolution 60 Switching Packets 61 Multiple Hops and Switching 63 Routing Packets 66 Using the Routing Table to Forward Packets 68 Building the Routing Table 70 Metrics 73 What Happens Inside a Router? 74 Routers versus Switches 75 Routing Loops 76 Asymmetric Paths 76 Redirects and Relays 77 Review All the Key Topics 79 Key Terms You Should Know 79 Concepts and Actions 79 Chapter 4 Wired Host Networking Configuration 82 Do I Know This Already? Quiz 83 Foundation Topics 85 Windows 85 The Settings App 85 The Control Panel 86 The Command Line 88 macOS 91 System Preferences 91 The Terminal Command Line 93 System Information 94 Linux 95 Verifying Connectivity 97 Ping 97 Traceroute 99 Finding Your Public IP Address 101 Review All the Key Topics 103 Key Terms You Should Know 103 Concepts and Actions 103 Chapter 5 What's in a Network? 106 Do I Know This Already? Quiz 106 Foundation Topics 108 Hosts and Virtual Hosts 108 Mobile Devices 111 Things 113 Middleboxes 115 The Firewall 115 The Intrusion Detection System 116 The Proxy or Gateway 116 The Load Balancer 117 The Global Internet 118 Internet Assigned Numbers Authority 119 Internet Corporation for Assigned Names and Numbers 119 Regional Internet Registries 119 Top-Level Domain Owners 120 Transit Providers 120 Access Providers 120 Content Providers 120 Content Distribution Networks 121 Internet Exchange Providers 121 Review All the Key Topics 122 Key Terms You Should Know 123 Concepts and Actions 123 Chapter 6 Network Models 126 Do I Know This Already? Quiz 126 Foundation Topics 128 Why Are Models Important? 128 The OSI Seven-Layer Model 129 The TCP/IP Model 133 The Recursive Internet Architecture 134 Review All the Key Topics 136 Key Terms You Should Know 137 Concepts and Actions 137 Part II Infrastructure 139 Chapter 7 Wired Networks 140 Do I Know This Already? Quiz 141 Foundation Topics 142 Electrical Transmission and Interference 142 Measuring Interference 145 Other Cable Ratings 146 The Maximum Transmission Unit 146 Ethernet over Copper 147 Ethernet Bus Topologies 147 Ethernet Star Topologies 148 Ethernet Twisted Pair 150 Power Over Ethernet 152 Fiber 152 Fiber Cables 154 Fiber Networking Hardware 155 Fiber Connectors 156 Looking into a Fiber 157 Pluggable Interfaces 158 Review All the Key Topics 160 Key Terms You Should Know 161 Concepts and Actions 161 Chapter 8 Wireless Networks 162 Do I Know This Already? Quiz 162 Foundation Topics 164 Free Space Concepts 164 Wave Propagation and Beam Forming 164 Wireless Interference 167 Bandwidth and Signal Strength 168 The Electromagnetic Spectrum 169 Wi-Fi 170 Wi-Fi Components 171 Wi-Fi Mesh Systems 172 Advantages and Disadvantages of Wi-Fi 173 Sharing the Bandwidth 174 Channel Selection 174 Cellular 174 Radio Access Network (RAN) 175 Mobile Core 176 Advantages and Disadvantages of Cellular Networks 177 Satellite 177 Review All the Key Topics 179 Key Terms You Should Know 180 Concepts and Actions 180 Chapter 9 Bandwidth, Delay, and Jitter 182 Do I Know This Already? Quiz 182 Foundation Topics 184 Bandwidth and Throughput 184 Throughput versus Bandwidth 184 Bandwidth versus Goodput 185 The Bandwidth of a Link versus Bandwidth of a Path 186 Bandwidth and Delay 186 Clocking Packets onto the Wire 187 Queueing 188 Jitter 189 Measuring Network Performance 190 Speed Test Websites 190 iPerf 191 Mike's Traceroute (MTR) 193 Review All the Key Topics 194 Key Terms You Should Know 195 Concepts and Actions 195 Chapter 10 Basic Network Hardware 196 Do I Know This Already? Quiz 196 Foundation Topics 198 Hardware, Ports, and Lights 198 Network Diagrams 204 Network Wiring 207 Handling the Heat 209 Review All the Key Topics 211 Key Terms You Should Know 211 Concepts and Actions 212 Chapter 11 Local Area Networks 214 Do I Know This Already? Quiz 215 Foundation Topics 217 Building and Campus Networks 217 Equipment Closet (Building Distribution Frame) 218 Wiring Closet (Intermediate Distribution Frame) 218 Server Room 218 Riser 218 Wi-Fi Access Points 218 Zoned Access 218 The Home Network 219 Network Core 219 MODEM 220 Physical Connections to the Home 221 Cable Cutting 222 Combining the MODEM with Other Devices 223 Demarcation 223 The SSID and Wi-Fi Guest Network 224 Which Devices Should Be Wired? 225 Wi-Fi Limitations 225 Traffic Flows 226 Choosing Devices to Wire 226 Configuring the Home Network 227 Configuring the MODEM 227 Configuring the Router and Firewall 227 Main Configuration Screen 227 The More Settings Screen 229 Advanced Options 231 NAT Forwarding 232 Configuring the Wireless Access Point 234 SSID and Password 234 Security 235 Configuring a Windows Host for Wi-Fi Connectivity 236 Configuring Apple's macOS for Wi-Fi Connectivity 238 Configuring Mobile Devices for Wi-Fi Connectivity 240 Review All the Key Topics 241 Key Terms You Should Know 242 Concepts and Actions 242 Chapter 12 Wide Area Networks 244 Do I Know This Already? Quiz 244 Foundation Topics 246 Common Challenges to Building Wide Area Networks 246 Right-of-Way 246 Physical Plant 247 Metro and Last-Mile Network Design 249 Transit Provider Design 250 Ring and Hub-and-Spoke Topologies 251 Review All the Key Topics 253 Key Terms You Should Know 254 Concepts and Actions 254 Part III Services 257 Chapter 13 Data Centers and Fabrics 258 Do I Know This Already? Quiz 258 Foundation Topics 260 Web Applications 260 Internet Exchange Points 262 Spine-and-Leaf Fabrics 263 Clos Fabrics 264 Butterfly Fabrics 267 Review All the Key Topics 269 Key Terms You Should Know 269 Concepts and Actions 270 Chapter 14 Network Transport 272 Do I Know This Already? Quiz 273 Foundation Topics 275 Internet Protocol Version 4 275 Fragmentation 276 Time to Live 277 Internet Protocol Version 6 278 IPv6 Goals 279 Autoconfiguration 279 Eliminating NAT 280 IPv6 Packet Format 281 User Datagram Protocol 282 Connectionless versus Connection-Oriented Transport Protocols 282 The UDP Header 283 Checksums 283 Transmission Control Protocol 283 Building a TCP Connection 283 TCP Flow and Error Control 285 Quick UDP Internet Connections (QUIC) 288 Identifying Flows 289 Path MTU Discovery 289 Review All the Key Topics 291 Key Terms You Should Know 292 Concepts and Actions 292 Chapter 15 Application Transport 294 Do I Know This Already? Quiz 294 Foundation Topics 296 Marshaling Systems 296 Fixed-Length Fields 296 Type-Length Values 298 Secure Shell 300 Hypertext Transfer Protocol 303 File Transfer Protocol 305 Review All the Key Topics 307 Key Terms You Should Know 308 Concepts and Actions 308 Chapter 16 Names and Time 310 Do I Know This Already? Quiz 310 Foundation Topics 312 The Domain Name Space 312 Domain Names Can Represent an Organization 313 Domain Names Can Represent a Service 313 Domain Names Can Represent a Piece of Information 314 Domain Names and Addresses from a Computer Networking Perspective 314 The Life of a DNS Query 314 Negative DNS Responses 318 Common DNS Records 319 DNS Architecture and Operations 319 Recursive Servers 319 Root Servers 320 TLD Servers 322 Authoritative Servers 322 DNS Security and Privacy 323 Encrypted DNS Queries 323 Oblivious Encrypted DNS Queries 324 Encrypted DNS Records 325 Diagnosing DNS 326 Name Server Lookup 326 Domain Information Groper 329 Web-Based DNS Tools 330 The Network Time Protocol 332 Review All the Key Topics 334 Key Terms You Should Know 335 Concepts and Actions 335 Chapter 17 Cloud Computing 336 Do I Know This Already? Quiz 336 Foundation Topics 338 Cloud Computing 338 Who Owns the Resources 338 Cloud Computing Service Models 339 Typical Public Cloud Service Mix 340 Cloud Resilience 341 Connecting to the Cloud 342 Public versus Private Cloud 343 Insurance Estimation Application 344 Manufacturing IOT Deployment 346 Customer Analytics 348 Choosing Public or Private Cloud 348 The Impact of Cloud Computing on Network Engineering 349 Pets versus Cattle 349 Automation 349 Cloud-Based Network Management 350 Remote and Hybrid Work 350 Employment Shifts 350 Information Technology Cycles 350 Review All the Key Topics 351 Key Terms You Should Know 352 Concepts and Actions 352 Part IV Security 355 Chapter 18 Security and Privacy Concepts 358 Do I Know This Already? Quiz 358 Foundation Topics 360 A Security Taxonomy 360 Shift Left 362 Privacy Concepts 363 Personally Identifiable Information 363 Data Lifecycle 364 The Law and Privacy 365 Privacy Tools 366 Suppression 366 Noise Injection 367 Aggregation 368 Segmentation 368 Privacy and Network Operations 369 Forwarded Packets 369 Logged Information 369 Protecting Logged User Information 370 Authentication, Authorization, and Accounting 370 Identity Stores 372 Review All the Key Topics 373 Key Terms You Should Know 373 Concepts and Actions 374 Chapter 19 Attacks and Threats 376 Do I Know This Already? Quiz 377 Foundation Topics 378 Defining Attacks and Threats 378 Attack Surface 379 Vulnerability 379 Threat 380 Exploit 380 Risk 381 Gaining Access 381 Social Engineering 381 Malware 382 Supply Chain Attack 383 Poor Configuration 383 Man-in-the-Middle Attacks 383 Lateral Movement 384 Attack Actions 385 Command and Control 386 Data Exfiltration 386 Ransomware 386 Denial of Service 387 Direct (or Burner) Attack 387 Reflection Attack 388 Resource Exhaustion 389 Review All the Key Topics 391 Key Terms You Should Know 392 Concepts and Actions 392 Chapter 20 Security Tools 394 Do I Know This Already? Quiz 394 Foundation Topics 397 Authentication Tools 397 Single Sign-On 397 Zero Trust 399 Strong Passwords 400 Two-Factor Authentication (2FA) 403 Passwordless Systems 404 Defensive Tools and Design 405 Stateful and Contextual Packet Filtering 405 Source Address Validation 408 Defense in Depth 409 Countering Spam and Phishing 410 System-Level Defenses 410 How to Detect a Phish 412 Encryption 413 Exchanging Private Keys 415 Cryptographic Signatures 416 Virtual Private Networks 418 Review All the Key Topics 421 Key Terms You Should Know 422 Concepts and Actions 422 Part V Managing Networks 425 Chapter 21 Managing Networks 426 Do I Know This Already? Quiz 427 Foundation Topics 428 Network Documentation 428 Descriptions 429 Baselines 430 Failure Reports 430 Hardware and Software 431 Network Processes and Lifecycle 431 Managing Change 433 Testing Techniques 433 Technical Debt 436 Management Challenges 436 The Observability Problem 436 Failure Rates in the Real World 437 Connecting to Manage 438 In-Band and Out-of-Band Management 438 Connecting Through a Terminal Emulator 439 Device Management Security Practices 439 Management Systems 440 NMS Dashboard 442 Work Process System 442 Modeling Language versus Configuration 442 Cloud-Managed Networks 443 Review All the Key Topics 445 Key Terms You Should Know 446 Concepts and Actions 446 Chapter 22 Troubleshooting 448 Do I Know This Already? Quiz 449 Foundation Topics 450 Failure Terminology 450 What Is a Failure? 450 Failure Frequency 451 Fragility and Resilience 452 Troubleshooting Tools and Techniques 454 The Half-Split Method 454 Fixes 456 The Post-Mortem 457 Applying the Process: An Example 457 Packet Captures 460 Advice to Troubleshooters 464 Review All the Key Topics 465 Key Terms You Should Know 465 Concepts and Actions 465 Chapter 23 Configuring a Network 468 Do I Know This Already? Quiz 468 Foundation Topics 471 Initial Access 471 Configuring IPv4 475 Configuring Routing 479 Configuring Remote Access and Security 485 Adding IPv6 487 Adding a Switch 490 Review All the Key Topics 494 Key Terms You Should Know 494 Concepts and Actions 495 Part VI Final Preparation 499 Chapter 24 Final Preparation 500 Advice to Future Engineers 500 Learning Consolidation Activities 501 Suggested Plan for Final Review and Study 503 Part VII Exam Updates 505 Chapter 25 Cisco Certified Support Technician CCST Networking 100-150 Official Cert Guide Exam Updates 506 The Purpose of This Chapter 506 About Possible Exam Updates 507 Impact on You and Your Study Plan 507 News About the Next Exam Release 508 Updated Technical Content 508 Part VIII Appendices 509 Appendix A Answers to the Do I Know This Already? Questions 510 Glossary of Key Terms 519 Online Elements Appendix B Concepts and Actions Memory Tables Appendix C Solutions to Concepts and Actions Memory Tables Appendix D Study Planner Glossary of Key Terms

Trust the best-selling Official Cert Guide series from Cisco Press to help you learn, prepare, and practice for the CCST Networking 100-150 exam. Well regarded for its level of detail, study plans, assessment features, and challenging review questions and exercises, Cisco Certified Support Technician CCST Networking 100-150 Official Cert Guide helps you master the concepts and techniques that ensure your exam success and is the only self-study resource approved by Cisco. Leading Cisco technology expert and best-selling author Russ White shares preparation hints and test-taking tips, helping you identify areas of weakness and improve both your conceptual knowledge and hands-on skills.