Introduction to Networks Course Booklet (CCNAv7)

Introduction to Networks Companion Guide is the official supplemental textbook for the Introduction to Networks course in the Cisco Networking Academy CCNA curriculum. The course introduces the architecture, protocols, functions, components, and models of the internet and computer networks. The principles of IP addressing and fundamentals of Ethernet concepts, media, and operations are introduced to provide a foundation for the curriculum. By the end of the course, you will be able to build simple LANs, perform basic configurations for routers and switches, understand the fundamentals of network security, and implement IP addressing schemes. The Companion Guide is designed as a portable desk reference to use anytime, anywhere to reinforce the material from the course and organize your time. The book's features help you focus on important concepts to succeed in this course: * Chapter objectives: Review core concepts by answering the focus questions listed at the beginning of each chapter. * Key terms: Refer to the lists of networking vocabulary introduced and highlighted in context in each chapter. * Glossary: Consult the comprehensive Glossary with more than 300 terms. * Summary of Activities and Labs: Maximize your study time with this complete list of all associated practice exercises at the end of each chapter. * Check Your Understanding: Evaluate your readiness with the end-of-chapter questions that match the style of questions you see in the online course quizzes. The answer key explains each answer. * How To: Look for this icon to study the steps you need to learn to perform certain tasks. * Interactive Activities: Reinforce your understanding of topics with dozens of exercises from the online course identified throughout the book with this icon. * Videos: Watch the videos embedded within the online course. * Packet Tracer Activities: Explore and visualize networking concepts using Packet Tracer. There are multiple exercises interspersed throughout the chapters and provided in the accompanying Labs & Study Guide book. * Hands-on Labs: Work through all the labs and other activities that are included in the course and published in the separate Labs & Study Guide.

Cisco Networking Academy teaches hundreds of thousands of students annually the skills needed to build, design, and maintain networks, improving their career prospects while filling the global demand for networking professionals. With 10,000 academies in 165 countries, it helps individuals prepare for industry-recognized certifications and entry-level information and communication technology careers in virtually every industry-developing foundational technical skills while acquiring vital 21st-century career skills in problem solving, collaboration, and critical thinking. Cisco Networking Academy uses a public-private partnership model to create the "world's largest classroom."

Introduction xxx Chapter 1 Networking Today 1 Objectives 1 Key Terms 1 Introduction (1.0) 3 Networks Affect Our Lives (1.1) 3 Networks Connect Us (1.1.1) 3 No Boundaries (1.1.3) 3 Network Components (1.2) 4 Host Roles (1.2.1) 4 Peer-to-Peer (1.2.2) 5 End Devices (1.2.3) 6 Intermediary Devices (1.2.4) 6 Network Media (1.2.5) 7 Network Representations and Topologies (1.3) 8 Network Representations (1.3.1) 8 Topology Diagrams (1.3.2) 10 Physical Topology Diagrams 10 Logical Topology Diagrams 10 Common Types of Networks (1.4) 11 Networks of Many Sizes (1.4.1) 11 LANs and WANs (1.4.2) 12 LANs 13 WANs 14 The Internet (1.4.3) 15 Intranets and Extranets (1.4.4) 16 Internet Connections (1.5) 17 Internet Access Technologies (1.5.1) 17 Home and Small Office Internet Connections (1.5.2) 18 Businesses Internet Connections (1.5.3) 19 The Converging Network (1.5.4) 20 Reliable Networks (1.6) 23 Network Architecture (1.6.1) 23 Fault Tolerance (1.6.2) 24 Scalability (1.6.3) 24 Quality of Service (1.6.4) 25 Network Security (1.6.5) 26 Network Trends (1.7) 27 Recent Trends (1.7.1) 28 Bring Your Own Device (BYOD) (1.7.2) 28 Online Collaboration (1.7.3) 28 Video Communications (1.7.4) 29 Cloud Computing (1.7.6) 29 Technology Trends in the Home (1.7.7) 31 Powerline Networking (1.7.8) 31 Wireless Broadband (1.7.9) 32 Wireless Internet Service Providers 32 Wireless Broadband Service 32 Network Security (1.8) 33 Security Threats (1.8.1) 33 Security Solutions (1.8.2) 34 The IT Professional (1.9) 35 CCNA (1.9.1) 35 Networking Jobs (1.9.2) 36 Summary (1.10) 37 Networks Affect Our Lives 37 Network Components 37 Network Representations and Topologies 37 Common Types of Networks 37 Internet Connections 38 Reliable Networks 38 Network Trends 38 Network Security 39 The IT Professional 40 Practice 40 Check Your Understanding Questions 40 Chapter 2 Basic Switch and End Device Configuration 45 Objectives 45 Key Terms 45 Introduction (2.0) 46 Cisco IOS Access (2.1) 46 Operating Systems (2.1.1) 46 GUI (2.1.2) 47 Purpose of an OS (2.1.3) 48 Access Methods (2.1.4) 49 Terminal Emulation Programs (2.1.5) 50 IOS Navigation (2.2) 52 Primary Command Modes (2.2.1) 52 Configuration Mode and Subconfiguration Modes (2.2.2) 53 Navigate Between IOS Modes (2.2.4) 54 A Note About Syntax Checker Activities (2.2.6) 55 The Command Structure (2.3) 56 Basic IOS Command Structure (2.3.1) 56 IOS Command Syntax Check (2.3.2) 57 IOS Help Features (2.3.3) 58 Hot Keys and Shortcuts (2.3.5) 58 Basic Device Configuration (2.4) 61 Device Names (2.4.1) 61 Password Guidelines (2.4.2) 62 Configure Passwords (2.4.3) 63 Encrypt Passwords (2.4.4) 64 Banner Messages (2.4.5) 65 Save Configurations (2.5) 66 Configuration Files (2.5.1) 67 Alter the Running Configuration (2.5.2) 68 Capture Configuration to a Text File (2.5.4) 68 Ports and Addresses (2.6) 71 IP Addresses (2.6.1) 71 Interfaces and Ports (2.6.2) 73 Configure IP Addressing (2.7) 74 Manual IP Address Configuration for End Devices (2.7.1) 75 Automatic IP Address Configuration for End Devices (2.7.2) 76 Switch Virtual Interface Configuration (2.7.4) 77 Verify Connectivity (2.8) 78 Summary (2.9) 79 Cisco IOS Access 79 IOS Navigation 79 The Command Structure 79 Basic Device Configuration 79 Save Configurations 80 Ports and Addresses 80 Configure IP Addressing 80 Verify Connectivity 80 Practice 81 Check Your Understanding Questions 81 Chapter 3 Protocols and Models 85 Objectives 85 Key Terms 85 Introduction (3.0) 86 The Rules (3.1) 86 Communications Fundamentals (3.1.2) 86 Communication Protocols (3.1.3) 87 Rule Establishment (3.1.4) 88 Network Protocol Requirements (3.1.5) 88 Message Encoding (3.1.6) 89 Message Formatting and Encapsulation (3.1.7) 90 Message Size (3.1.8) 91 Message Timing (3.1.9) 92 Message Delivery Options (3.1.10) 92 A Note About the Node Icon (3.1.11) 94 Protocols 94 Network Protocol Overview (3.2.1) 94 Network Protocol Functions (3.2.2) 95 Protocol Interaction (3.2.3) 96 Protocol Suites (3.3) 97 Network Protocol Suites (3.3.1) 97 Evolution of Protocol Suites (3.3.2) 98 TCP/IP Protocol Example (3.3.3) 99 TCP/IP Protocol Suite (3.3.4) 99 Application Layer 101 Transport Layer 102 Internet Layer 102 Network Access Layer 103 TCP/IP Communication Process (3.3.5) 103 Standards Organizations (3.4) 108 Open Standards (3.4.1) 108 Internet Standards (3.4.2) 108 Electronic and Communications Standards (3.4.3) 111 Reference Models (3.5) 111 The Benefits of Using a Layered Model (3.5.1) 112 The OSI Reference Model (3.5.2) 112 The TCP/IP Protocol Model (3.5.3) 114 OSI and TCP/IP Model Comparison (3.5.4) 115 Data Encapsulation (3.6) 116 Segmenting Messages (3.6.1) 116 Sequencing (3.6.2) 118 Protocol Data Units (3.6.3) 118 Encapsulation Example (3.6.4) 120 De-encapsulation Example (3.6.5) 120 Data Access (3.7) 121 Addresses (3.7.1) 121 Layer 3 Logical Address (3.7.2) 122 Devices on the Same Network (3.7.3) 123 Role of the Data Link Layer Addresses: Same IP Network (3.7.4) 124 Devices on a Remote Network (3.7.5) 125 Role of the Network Layer Addresses (3.7.6) 125 Role of the Data Link Layer Addresses: Different IP Networks (3.7.7) 126 Data Link Addresses (3.7.8) 127 Summary (3.8) 130 The Rules 130 Protocols 130 Protocol Suites 130 Standards Organizations 131 Reference Models 131 Data Encapsulation 132 Data Access 132 Practice 133 Check Your Understanding Questions 133 Chapter 4 Physical Layer 137 Objectives 137 Key Terms 137 Introduction (4.0) 138 Purpose of the Physical Layer (4.1) 138 The Physical Connection (4.1.1) 138 The Physical Layer (4.1.2) 139 Physical Layer Characteristics (4.2) 141 Physical Layer Standards (4.2.1) 141 Physical Components (4.2.2) 142 Encoding (4.2.3) 142 Signaling (4.2.4) 143 Bandwidth (4.2.5) 145 Bandwidth Terminology (4.2.6) 145 Latency 146 Throughput 146 Goodput 146 Copper Cabling (4.3) 146 Characteristics of Copper Cabling (4.3.1) 147 Types of Copper Cabling (4.3.2) 148 Unshielded Twisted-Pair (UTP) (4.3.3) 148 Shielded Twisted-Pair (STP) (4.3.4) 150 Coaxial Cable (4.3.5) 151 UTP Cabling (4.4) 152 Properties of UTP Cabling (4.4.1) 152 UTP Cabling Standards and Connectors (4.4.2) 153 Straight-Through and Crossover UTP Cables (4.4.3) 157 Fiber-Optic Cabling (4.5) 158 Properties of Fiber-Optic Cabling (4.5.1) 158 Types of Fiber Media (4.5.2) 159 Single-Mode Fiber 159 Multimode Fiber 160 Fiber-Optic Cabling Usage (4.5.3) 160 Fiber-Optic Connectors (4.5.4) 161 Fiber Patch Cords (4.5.5) 162 Fiber Versus Copper (4.5.6) 163 Wireless Media (4.6) 164 Properties of Wireless Media (4.6.1) 164 Types of Wireless Media (4.6.2) 165 Wireless LAN (4.6.3) 166 Summary (4.7) 168 Purpose of the Physical Layer 168 Physical Layer Characteristics 168 Copper Cabling 168 UTP Cabling 169 Fiber-Optic Cabling 169 Wireless Media 169 Practice 170 Check Your Understanding Questions 170 Chapter 5 Number Systems 175 Objectives 175 Key Terms 175 Introduction (5.0) 176 Binary Number System (5.1) 176 Binary and IPv4 Addresses (5.1.1) 176 Binary Positional Notation (5.1.3) 178 Convert Binary to Decimal (5.1.5) 180 Decimal to Binary Conversion (5.1.7) 182 Decimal to Binary Conversion Example (5.1.8) 186 IPv4 Addresses (5.1.11) 193 Hexadecimal Number System (5.2) 194 Hexadecimal and IPv6 Addresses (5.2.1) 194 Decimal to Hexadecimal Conversions (5.2.3) 196 Hexadecimal to Decimal Conversion (5.2.4) 196 Summary (5.3) 198 Binary Number System 198 Hexadecimal Number System 198 Practice 198 Check Your Understanding Questions 198 Chapter 6 Data Link Layer 203 Objectives 203 Key Terms 203 Introduction (6.0) 204 Purpose of the Data Link Layer (6.1) 204 The Data Link Layer (6.1.1) 204 IEEE 802 LAN/MAN Data Link Sublayers (6.1.2) 206 Providing Access to Media (6.1.3) 207 Data Link Layer Standards (6.1.4) 209 Topologies (6.2) 209 Physical and Logical Topologies (6.2.1) 209 WAN Topologies (6.2.2) 211 Point-to-Point 211 Hub and Spoke 211 Mesh 212 Point-to-Point WAN Topology (6.2.3) 213 LAN Topologies (6.2.4) 213 Legacy LAN Topologies 214 Half-Duplex and Full-Duplex Communication (6.2.5) 215 Half-Duplex Communication 215 Full-Duplex Communication 215 Access Control Methods (6.2.6) 216 Contention-Based Access 216 Controlled Access 217 Contention-Based Access-CSMA/CD (6.2.7) 217 Contention-Based Access-CSMA/CA (6.2.8) 219 Data Link Frame (6.3) 221 The Frame (6.3.1) 221 Frame Fields (6.3.2) 222 Layer 2 Addresses (6.3.3) 223 LAN and WAN Frames (6.3.4) 225 Summary (6.4) 228 Purpose of the Data Link Layer 228 Topologies 228 Data Link Frame 229 Practice 229 Check Your Understanding Questions 229 Chapter 7 Ethernet Switching 233 Objectives 233 Key Terms 233 Introduction (7.0) 234 Ethernet Frames (7.1) 234 Ethernet Encapsulation (7.1.1) 234 Data Link Sublayers (7.1.2) 235 MAC Sublayer (7.1.3) 236 Data Encapsulation 236 Accessing the Media 237 Ethernet Frame Fields (7.1.4) 237 Ethernet MAC Address (7.2) 239 MAC Address and Hexadecimal (7.2.1) 240 Ethernet MAC Address (7.2.2) 241 Frame Processing (7.2.3) 243 Unicast MAC Address (7.2.4) 244 Broadcast MAC Address (7.2.5) 246 Multicast MAC Address (7.2.6) 247 The MAC Address Table (7.3) 248 Switch Fundamentals (7.3.1) 248 Switch Learning and Forwarding (7.3.2) 250 Examine the Source MAC Address 250 Find the Destination MAC Address 250 Filtering Frames (7.3.3) 252 Switch Speeds and Forwarding Methods (7.4) 254 Frame Forwarding Methods on Cisco Switches (7.4.1) 254 Cut-Through Switching (7.4.2) 255 Memory Buffering on Switches (7.4.3) 257 Duplex and Speed Settings (7.4.4) 257 Auto-MDIX (7.4.5) 259 Summary (7.5) 261 Ethernet Frame 261 Ethernet MAC Address 261 The MAC Address Table 261 Switch Speeds and Forwarding Methods 262 Practice 262 Check Your Understanding Questions 262 Chapter 8 Network Layer 267 Objectives 267 Key Terms 267 Introduction (8.0) 268 Network Layer Characteristics (8.1) 268 The Network Layer (8.1.1) 268 IP Encapsulation (8.1.2) 270 Characteristics of IP (8.1.3) 271 Connectionless (8.1.4) 271 Best Effort (8.1.5) 272 Media Independent (8.1.6) 273 IPv4 Packet (8.2) 274 IPv4 Packet Header (8.2.1) 274 IPv4 Packet Header Fields (8.2.2) 274 IPv6 Packet (8.3) 276 Limitations of IPv4 (8.3.1) 277 IPv6 Overview (8.3.2) 277 IPv4 Packet Header Fields in the IPv6 Packet Header (8.3.3) 278 IPv6 Packet Header (8.3.4) 280 How a Host Routes (8.4) 281 Host Forwarding Decision (8.4.1) 281 Default Gateway (8.4.2) 282 A Host Routes to the Default Gateway (8.4.3) 283 Host Routing Tables (8.4.4) 283 Introduction to Routing (8.5) 285 Router Packet Forwarding Decision (8.5.1) 285 IP Router Routing Table (8.5.2) 286 Static Routing (8.5.3) 287 Dynamic Routing (8.5.4) 288 Introduction to an IPv4 Routing Table (8.5.6) 290 Summary (8.6) 292 Network Layer Characteristics 292 IPv4 Packet 292 IPv6 Packet 292 How a Host Routes 293 Introduction to Routing 293 Practice 294 Check Your Understanding Questions 294 Chapter 9 Address Resolution 297 Objectives 297 Key Terms 297 Introduction (9.0) 298 MAC and IP (9.1) 298 Destination on Same Network (9.1.1) 298 Destination on Remote Network (9.1.2) 299 ARP (9.2) 301 ARP Overview (9.2.1) 301 ARP Functions (9.2.2) 302 Removing Entries from an ARP Table (9.2.6) 306 ARP Tables on Networking Devices (9.2.7) 306 ARP Issues-ARP Broadcasts and ARP Spoofing (9.2.8) 307 IPv6 Neighbor Discovery (9.3) 309 IPv6 Neighbor Discovery Messages (9.3.2) 309 IPv6 Neighbor Discovery-Address Resolution (9.3.3) 311 Summary (9.4) 313 MAC and IP 313 ARP 313 Neighbor Discovery 314 Practice 314 Check Your Understanding Questions 314 Chapter 10 Basic Router Configuration 319 Objectives 319 Introduction (10.0) 320 Configure Initial Router Settings (10.1) 320 Basic Router Configuration Steps (10.1.1) 320 Basic Router Configuration Example (10.1.2) 321 Configure Interfaces (10.2) 323 Configure Router Interfaces (10.2.1) 323 Configure Router Interfaces Example (10.2.2) 324 Verify Interface Configuration (10.2.3) 325 Configuration Verification Commands (10.2.4) 326 Configure the Default Gateway (10.3) 330 Default Gateway on a Host (10.3.1) 331 Default Gateway on a Switch (10.3.2) 332 Summary (10.4) 335 Configure Initial Router Settings 335 Configure Interfaces 335 Configure the Default Gateway 335 Practice 336 Check Your Understanding Questions 337 Chapter 11 IPv4 Addressing 341 Objectives 341 Key Terms 341 Introduction (11.0) 342 IPv4 Address Structure (11.1) 342 Network and Host Portions (11.1.1) 342 The Subnet Mask (11.1.2) 343 The Prefix Length (11.1.3) 344 Determining the Network: Logical AND (11.1.4) 345 Network, Host, and Broadcast Addresses (11.1.6) 347 Network Address 347 Host Addresses 348 Broadcast Address 349 IPv4 Unicast, Broadcast, and Multicast (11.2) 349 Unicast (11.2.1) 349 Broadcast (11.2.2) 350 IP Directed Broadcasts 351 Multicast (11.2.3) 352 Types of IPv4 Addresses (11.3) 353 Public and Private IPv4 Addresses (11.3.1) 353 Routing to the Internet (11.3.2) 354 Special Use IPv4 Addresses (11.3.4) 356 Loopback Addresses 356 Link-Local Addresses 357 Legacy Classful Addressing (11.3.5) 357 Assignment of IP Addresses (11.3.6) 358 Network Segmentation (11.4) 359 Broadcast Domains and Segmentation (11.4.1) 359 Problems with Large Broadcast Domains (11.4.2) 360 Reasons for Segmenting Networks (11.4.3) 362 Subnet an IPv4 Network (11.5) 364 Subnet on an Octet Boundary (11.5.1) 364 Subnet Within an Octet Boundary (11.5.2) 366 Subnet a Slash 16 and a Slash 8 Prefix (11.6) 367 Create Subnets with a Slash 16 Prefix (11.6.1) 367 Create 100 Subnets with a Slash 16 Prefix (11.6.2) 369 Create 1000 Subnets with a Slash 8 Prefix (11.6.3) 372 Subnet to Meet Requirements (11.7) 374 Subnet Private Versus Public IPv4 Address Space (11.7.1) 374 What About the DMZ? 377 Minimize Unused Host IPv4 Addresses and Maximize Subnets (11.7.2) 377 Example: Efficient IPv4 Subnetting (11.7.3) 378 VLSM (11.8) 381 IPv4 Address Conservation (11.8.3) 381 VLSM (11.8.4) 383 VLSM Topology Address Assignment (11.8.5) 386 Structured Design (11.9) 387 IPv4 Network Address Planning (11.9.1) 388 Device Address Assignment (11.9.2) 389 Summary (11.10) 390 IPv4 Addressing Structure 390 IPv4 Unicast, Broadcast, and Multicast 390 Types of IPv4 Addresses 390 Network Segmentation 391 Subnet an IPv4 Network 391 Subnet a /16 and a /8 Prefix 391 Subnet to Meet Requirements 391 Variable-Length Subnet Masking 392 Structured Design 392 Practice 393 Check Your Understanding Questions 393 Chapter 12 IPv6 Addressing 397 Objectives 397 Key Terms 397 Introduction (12.0) 398 IPv4 Issues (12.1) 398 Need for IPv6 (12.1.1) 398 Internet of Things 399 IPv4 and IPv6 Coexistence (12.1.2) 399 Dual Stack 399 Tunneling 400 Translation 401 IPv6 Address Representation (12.2) 401 IPv6 Addressing Formats (12.2.1) 401 Preferred Format 402 Rule 1-Omit Leading Zeros (12.2.2) 403 Rule 2-Double Colon (12.2.3) 404 IPv6 Address Types (12.3) 406 Unicast, Multicast, Anycast (12.3.1) 406 IPv6 Prefix Length (12.3.2) 406 Types of IPv6 Unicast Addresses (12.3.3) 407 A Note About the Unique Local Address (12.3.4) 408 IPv6 GUA (12.3.5) 408 IPv6 GUA Structure (12.3.6) 409 Global Routing Prefix 410 Subnet ID 410 Interface ID 410 IPv6 LLA (12.3.7) 411 GUA and LLA Static Configuration (12.4) 413 Static GUA Configuration on a Router (12.4.1) 413 Static GUA Configuration on a Windows Host (12.4.2) 414 Static Configuration of a Link-Local Unicast Address (12.4.3) 415 Dynamic Addressing for IPv6 GUAs (12.5) 417 RS and RA Messages (12.5.1) 417 Method 1: SLAAC (12.5.2) 418 Method 2: SLAAC and Stateless DHCPv6 (12.5.3) 419 Method 3: Stateful DHCPv6 (12.5.4) 420 EUI-64 Process vs. Randomly Generated (12.5.5) 421 EUI-64 Process (12.5.6) 422 Randomly Generated Interface IDs (12.5.7) 424 Dynamic Addressing for IPv6 LLAs (12.6) 425 Dynamic LLAs (12.6.1) 425 Dynamic LLAs on Windows (12.6.2) 425 Dynamic LLAs on Cisco Routers (12.6.3) 426 Verify IPv6 Address Configuration (12.6.4) 427 IPv6 Multicast Addresses (12.7) 430 Assigned IPv6 Multicast Addresses (12.7.1) 430 Well-Known IPv6 Multicast Addresses (12.7.2) 430 Solicited-Node IPv6 Multicast Addresses (12.7.3) 432 Subnet an IPv6 Network (12.8) 432 Subnet Using the Subnet ID (12.8.1) 432 IPv6 Subnetting Example (12.8.2) 433 IPv6 Subnet Allocation (12.8.3) 434 Router Configured with IPv6 Subnets (12.8.4) 435 Summary (12.9) 436 IPv4 Issues 436 IPv6 Address Representation 436 IPv6 Address Types 436 GUA and LLA Static Configuration 437 Dynamic Addressing for IPv6 GUAs 437 Dynamic Addressing for IPv6 LLAs 437 IPv6 Multicast Addresses 438 Subnet an IPv6 Network 438 Practice 439 Check Your Understanding Questions 439 Chapter 13 ICMP 443 Objectives 443 Introduction (13.0) 444 ICMP Messages (13.1) 444 ICMPv4 and ICMPv6 Messages (13.1.1) 444 Host Reachability (13.1.2) 444 Destination or Service Unreachable (13.1.3) 445 Time Exceeded (13.1.4) 446 ICMPv6 Messages (13.1.5) 446 Ping and Traceroute Tests (13.2) 449 Ping-Test Connectivity (13.2.1) 449 Ping the Loopback (13.2.2) 450 Ping the Default Gateway (13.2.3) 450 Ping a Remote Host (13.2.4) 451 Traceroute-Test the Path (13.2.5) 452 Round-Trip Time (RTT) 453 IPv4 TTL and IPv6 Hop Limit 453 Summary (13.3) 454 ICMP Messages 454 Ping and Traceroute Testing 454 Practice 455 Check Your Understanding Questions 456 Chapter 14 Transport Layer 461 Objectives 461 Key Terms 461 Introduction (14.0) 462 Transportation of Data (14.1) 462 Role of the Transport Layer (14.1.1) 462 Transport Layer Responsibilities (14.1.2) 463 Transport Layer Protocols (14.1.3) 467 Transmission Control Protocol (TCP) (14.1.4) 467 User Datagram Protocol (UDP) (14.1.5) 468 The Right Transport Layer Protocol for the Right Application (14.1.6) 469 TCP Overview (14.2) 470 TCP Features (14.2.1) 470 TCP Header (14.2.2) 471 TCP Header Fields (14.2.3) 471 Applications That Use TCP (14.2.4) 472 UDP Overview (14.3) 473 UDP Features (14.3.1) 473 UDP Header (14.3.2) 474 UDP Header Fields (14.3.3) 474 Applications that use UDP (14.3.4) 475 Port Numbers (14.4) 476 Multiple Separate Communications (14.4.1) 476 Socket Pairs (14.4.2) 477 Port Number Groups (14.4.3) 478 The netstat Command (14.4.4) 479 TCP Communication Process (14.5) 480 TCP Server Processes (14.5.1) 480 TCP Connection Establishment (14.5.2) 483 Session Termination (14.5.3) 484 TCP Three-Way Handshake Analysis (14.5.4) 485 Reliability and Flow Control (14.6) 486 TCP Reliability-Guaranteed and Ordered Delivery (14.6.1) 486 TCP Reliability-Data Loss and Retransmission (14.6.3) 488 TCP Flow Control-Window Size and Acknowledgments (14.6.5) 490 TCP Flow Control-Maximum Segment Size (MSS) (14.6.6) 491 TCP Flow Control-Congestion Avoidance (14.6.7) 493 UDP Communication (14.7) 494 UDP Low Overhead Versus Reliability (14.7.1) 494 UDP Datagram Reassembly (14.7.2) 494 UDP Server Processes and Requests (14.7.3) 495 UDP Client Processes (14.7.4) 495 Summary (14.8) 499 Transportation of Data 499 TCP Overview 499 UDP Overview 499 Port Numbers 499 TCP Communications Process 500 Reliability and Flow Control 500 UDP Communication 501 Practice 501 Check Your Understanding Questions 502 Chapter 15 Application Layer 507 Objectives 507 Key Terms 507 Introduction (15.0) 508 Application, Presentation, and Session (15.1) 508 Application Layer (15.1.1) 508 Presentation and Session Layer (15.1.2) 508 TCP/IP Application Layer Protocols (15.1.3) 510 Peer-to-Peer (15.2) 511 Client-Server Model (15.2.1) 511 Peer-to-Peer Networks (15.2.2) 512 Peer-to-Peer Applications (15.2.3) 513 Common P2P Applications (15.2.4) 514 Web and Email Protocols (15.3) 515 Hypertext Transfer Protocol and Hypertext Markup Language (15.3.1) 515 HTTP and HTTPS (15.3.2) 516 Email Protocols (15.3.3) 518 SMTP, POP, and IMAP (15.3.4) 519 SMTP 519 POP 520 IMAP 521 IP Addressing Services (15.4) 521 Domain Name Service (15.4.1) 522 DNS Message Format (15.4.2) 524 DNS Hierarchy (15.4.3) 525 The nslookup Command (15.4.4) 526 Dynamic Host Configuration Protocol (15.4.6) 527 DHCP Operation (15.4.7) 528 File Sharing Services (15.5) 530 File Transfer Protocol (15.5.1) 530 Server Message Block (15.5.2) 531 Summary 534 Application, Presentation, and Session 534 Peer-to-Peer 534 Web and Email Protocols 534 IP Addressing Services 535 File Sharing Services 535 Practice 536 Check Your Understanding Questions 536 Chapter 16 Network Security Fundamentals 541 Objectives 541 Key Terms 541 Introduction (16.0) 542 Security Threats and Vulnerabilities (16.1) 542 Types of Threats (16.1.1) 542 Types of Vulnerabilities (16.1.2) 543 Physical Security (16.1.3) 545 Network Attacks (16.2) 546 Types of Malware (16.2.1) 546 Viruses 546 Worms 547 Trojan Horses 547 Reconnaissance Attacks (16.2.2) 547 Access Attacks (16.2.3) 548 Password Attacks 548 Trust Exploitation 548 Port Redirection 549 Man-in-the-Middle 549 Denial of Service Attacks (16.2.4) 551 DoS Attack 551 DDoS Attack 551 Network Attack Mitigations (16.3) 552 The Defense-in-Depth Approach (16.3.1) 553 Keep Backups (16.3.2) 553 Upgrade, Update, and Patch (16.3.3) 554 Authentication, Authorization, and Accounting (16.3.4) 555 Firewalls (16.3.5) 555 Types of Firewalls (16.3.6) 557 Endpoint Security (16.3.7) 558 Device Security (16.4) 558 Cisco AutoSecure (16.4.1) 558 Passwords (16.4.2) 559 Additional Password Security (16.4.3) 560 Enable SSH (16.4.4) 561 Disable Unused Services (16.4.5) 563 Summary 565 Security Threats and Vulnerabilities 565 Network Attacks 565 Network Attack Mitigation 565 Device Security 566 Practice 567 Check Your Understanding Questions 567 Chapter 17 Build a Small Network 571 Objectives 571 Key Terms 571 Introduction (17.0) 572 Devices in a Small Network (17.1) 572 Small Network Topologies (17.1.1) 572 Device Selection for a Small Network (17.1.2) 573 Cost 573 Speed and Types of Ports/Interfaces 573 Expandability 573 Operating System Features and Services 574 IP Addressing for a Small Network (17.1.3) 574 Redundancy in a Small Network (17.1.4) 576 Traffic Management (17.1.5) 577 Small Network Applications and Protocols (17.2) 578 Common Applications (17.2.1) 578 Network Applications 578 Application Layer Services 579 Common Protocols (17.2.2) 579 Voice and Video Applications (17.2.3) 582 Scale to Larger Networks (17.3) 583 Small Network Growth (17.3.1) 583 Protocol Analysis (17.3.2) 583 Employee Network Utilization (17.3.3) 584 Verify Connectivity (17.4) 586 Verify Connectivity with Ping (17.4.1) 586 Extended Ping (17.4.2) 588 Verify Connectivity with Traceroute (17.4.3) 590 Extended Traceroute (17.4.4) 592 Network Baseline (17.4.5) 593 Host and IOS Commands (17.5) 596 IP Configuration on a Windows Host (17.5.1) 596 IP Configuration on a Linux Host (17.5.2) 599 IP Configuration on a macOS Host (17.5.3) 600 The arp Command (17.5.4) 601 Common show Commands Revisited (17.5.5) 602 The show cdp neighbors Command (17.5.6) 609 The show ip interface brief Command (17.5.7) 610 Verify Switch Interfaces 611 Troubleshooting Methodologies (17.6) 611 Basic Troubleshooting Approaches (17.6.1) 612 Resolve or Escalate? (17.6.2) 613 The debug Command (17.6.3) 613 The terminal monitor Command (17.6.4) 615 Troubleshooting Scenarios (17.7) 616 Duplex Operation and Mismatch Issues (17.7.1) 617 IP Addressing Issues on IOS Devices (17.7.2) 618 IP Addressing Issues on End Devices (17.7.3) 619 Default Gateway Issues (17.7.4) 619 Troubleshooting DNS Issues (17.7.5) 621 Summary (17.8) 624 Devices in a Small Network 624 Small Network Applications and Protocols 624 Scale to Larger Networks 624 Verify Connectivity 625 Host and IOS Commands 625 Troubleshooting Methodologies 626 Troubleshooting Scenarios 626 Practice 627 Check Your Understanding Questions 628 Appendix A Answers to "Check Your Understanding" Questions 631 Key Terms Glossary 645 9780136633662 TOC 6/3/2020