Introduction xxxiv Your Study Plan 2 Part I Networking Fundamentals 13 Chapter 1 Introduction to TCP/IP Networking 14 "Do I Know This Already?" Quiz 14 Foundation Topics 17 Perspectives on Networking 17 TCP/IP Networking Model 18 History Leading to TCP/IP 19 Overview of the TCP/IP Networking Model 20 TCP/IP Application Layer 22 TCP/IP Transport Layer 23 TCP/IP Network Layer 25 TCP/IP Link Layer (Data Link Plus Physical) 28 TCP/IP Model and Terminology 30 OSI Networking Model 32 Comparing OSI and TCP/IP 32 Describing Protocols by Referencing the OSI Layers 33 OSI Layers and Their Functions 33 OSI Layering Concepts and Benefits 35 OSI Encapsulation Terminology 35 Chapter 2 Fundamentals of Ethernet LANs 38 "Do I Know This Already?" Quiz 38 Foundation Topics 40 An Overview of LANs 40 Typical SOHO LANs 41 Typical Enterprise LANs 42 The Variety of Ethernet Physical Layer Standards 43 Consistent Behavior over All Links Using the Ethernet Data Link Layer 44 Building Physical Ethernet Networks with UTP 45 Transmitting Data Using Twisted Pairs 45 Breaking Down a UTP Ethernet Link 46 UTP Cabling Pinouts for 10BASE-T and 100BASE-T 48 UTP Cabling Pinouts for 1000BASE-T 51 Sending Data in Ethernet Networks 51 Ethernet Data-Link Protocols 51 Sending Ethernet Frames with Switches and Hubs 55 Chapter 3 Fundamentals of WANs 60 "Do I Know This Already?" Quiz 60 Foundation Topics 62 Leased-Line WANs 62 Positioning Leased Lines with LANs and Routers 62 Physical Details of Leased Lines 63 Data-Link Details of Leased Lines 66 Ethernet as a WAN Technology 69 Ethernet WANs that Create a Layer 2 Service 70 How Routers Route IP Packets Using Ethernet Emulation 71 Accessing the Internet 72 The Internet as a Large WAN 72 Internet Access (WAN) Links 73 Digital Subscriber Line 74 Cable Internet 76 Chapter 4 Fundamentals of IPv4 Addressing and Routing 78 "Do I Know This Already?" Quiz 78 Foundation Topics 81 Overview of Network Layer Functions 81 Network Layer Routing (Forwarding) Logic 81 How Network Layer Routing Uses LANs and WANs 83 IP Addressing and How Addressing Helps IP Routing 84 Routing Protocols 85 IPv4 Addressing 86 Rules for IP Addresses 86 Rules for Grouping IP Addresses 87 IP Subnetting 91 IPv4 Routing 93 IPv4 Host Routing 93 Router Forwarding Decisions and the IP Routing Table 94 IPv4 Routing Protocols 96 Other Network Layer Features 98 Using Names and the Domain Name System 98 The Address Resolution Protocol 99 ICMP Echo and the ping Command 100 Chapter 5 Fundamentals of TCP/IP Transport and Applications 102 "Do I Know This Already?" Quiz 102 Foundation Topics 104 TCP/IP Layer 4 Protocols: TCP and UDP 104 Transmission Control Protocol 105 User Datagram Protocol 113 TCP/IP Applications 114 Uniform Resource Identifiers 114 Finding the Web Server Using DNS 115 Transferring Files with HTTP 117 How the Receiving Host Identifies the Correct Receiving Application 118 Part I Review 120 Part II Implementing Basic Ethernet LANs 125 Chapter 6 Using the Command-Line Interface 126 "Do I Know This Already?" Quiz 126 Foundation Topics 128 Accessing the Cisco Catalyst Switch CLI 128 Cisco Catalyst Switches 128 Accessing the Cisco IOS CLI 129 CLI Help Features 136 The debug and show Commands 137 Configuring Cisco IOS Software 138 Configuration Submodes and Contexts 139 Storing Switch Configuration Files 141 Copying and Erasing Configuration Files 143 Chapter 7 Analyzing Ethernet LAN Switching 146 "Do I Know This Already?" Quiz 146 Foundation Topics 148 LAN Switching Concepts 148 Overview of Switching Logic 149 Forwarding Known Unicast Frames 150 Learning MAC Addresses 153 Flooding Unknown Unicast and Broadcast Frames 154 Avoiding Loops Using Spanning Tree Protocol 154 LAN Switching Summary 155 Verifying and Analyzing Ethernet Switching 156 Demonstrating MAC Learning 156 Switch Interfaces 158 Finding Entries in the MAC Address Table 159 Managing the MAC Address Table (Aging, Clearing) 161 MAC Address Tables with Multiple Switches 162 Chapter 8 Configuring Basic Switch Management 166 "Do I Know This Already?" Quiz 166 Foundation Topics 168 Securing the Switch CLI 168 Securing User Mode and Privileged Mode with Simple Passwords 169 Securing User Mode Access with Local Usernames and Passwords 173 Securing User Mode Access with External Authentication Servers 175 Securing Remote Access with Secure Shell 176 Enabling IPv4 for Remote Access 179 Host and Switch IP Settings 179 Configuring IPv4 on a Switch 181 Configuring a Switch to Learn Its IP Address with DHCP 182 Verifying IPv4 on a Switch 183 Miscellaneous Settings Useful in Lab 184 History Buffer Commands 184 The logging synchronous, exec-timeout, and no ip domain-lookup Commands 184 Chapter 9 Configuring Switch Interfaces 190 "Do I Know This Already?" Quiz 190 Foundation Topics 192 Configuring Switch Interfaces 192 Configuring Speed, Duplex, and Description 193 Configuring Multiple Interfaces with the interface range Command 195 Administratively Controlling Interface State with shutdown 195 Removing Configuration with the no Command 197 Autonegotiation 198 Port Security 202 Configuring Port Security 203 Verifying Port Security 205 Port Security Violation Actions 207 Port Security MAC Addresses as Static and Secure but Not Dynamic 207 Part II Review 212 Part III Ethernet LANs: Design, VLANs, and Troubleshooting 217 Chapter 10 Analyzing Ethernet LAN Designs 218 "Do I Know This Already?" Quiz 218 Foundation Topics 220 Analyzing Collision Domains and Broadcast Domains 220 Ethernet Collision Domains 220 Ethernet Broadcast Domains 224 Analyzing Campus LAN Topologies 227 Two-Tier Campus Design (Collapsed Core) 227 Three-Tier Campus Design (Core) 230 Topology Design Terminology 232 Analyzing LAN Physical Standard Choices 233 Ethernet Standards 234 Choosing the Right Ethernet Standard for Each Link 235 Wireless LANs Combined with Wired Ethernet 236 Chapter 11 Implementing Ethernet Virtual LANs 242 "Do I Know This Already?" Quiz 242 Foundation Topics 244 Virtual LAN Concepts 244 Creating Multiswitch VLANs Using Trunking 246 Forwarding Data Between VLANs 249 VLAN and VLAN Trunking Configuration and Verification 252 Creating VLANs and Assigning Access VLANs to an Interface 252 VLAN Trunking Protocol 257 VLAN Trunking Configuration 258 Implementing Interfaces Connected to Phones 262 Chapter 12 Troubleshooting Ethernet LANs 270 "Do I Know This Already?" Quiz 271 Foundation Topics 274 Perspectives on Applying Troubleshooting Methodologies 274 Troubleshooting on the Exams 275 A Deeper Look at Problem Isolation 275 Troubleshooting as Covered in This Book 277 Analyzing Switch Interface Status and Statistics 278 Interface Status Codes and Reasons for Nonworking States 278 Interface Speed and Duplex Issues 279 Common Layer 1 Problems on Working Interfaces 282 Predicting Where Switches Will Forward Frames 284 Predicting the Contents of the MAC Address Table 284 Analyzing the Forwarding Path 286 Analyzing Port Security Operations on an Interface 287 Troubleshooting Shutdown Mode and Err-disabled Recovery 288 Troubleshooting Restrict and Protect Modes 289 Analyzing VLANs and VLAN Trunks 292 Ensuring That the Right Access Interfaces Are in the Right VLANs 292 Access VLANs Not Being Defined 293 Access VLANs Being Disabled 294 Mismatched Trunking Operational States 294 Part III Review 298 Part IV IP Version 4 Addressing and Subnetting 301 Chapter 13 Perspectives on IPv4 Subnetting 302 "Do I Know This Already?" Quiz 302 Foundation Topics 304 Introduction to Subnetting 304 Subnetting Defined Through a Simple Example 305 Operational View Versus Design View of Subnetting 306 Analyze Subnetting and Addressing Needs 306 Rules About Which Hosts Are in Which Subnet 306 Determining the Number of Subnets 308 Determining the Number of Hosts per Subnet 309 One Size Subnet Fits All-Or Not 310 Make Design Choices 313 Choose a Classful Network 313 Choose the Mask 316 Build a List of All Subnets 320 Plan the Implementation 321 Assigning Subnets to Different Locations 322 Choose Static and Dynamic Ranges per Subnet 323 Chapter 14 Analyzing Classful IPv4 Networks 326 "Do I Know This Already?" Quiz 326 Foundation Topics 328 Classful Network Concepts 328 IPv4 Network Classes and Related Facts 328 Number of Hosts per Network 331 Deriving the Network ID and Related Numbers 332 Unusual Network IDs and Network.