Ccent Study Guide

Todd Lammle is the Authority on Cisco Certification and Internetworking and is Cisco certified in all Cisco certification categories. He is a world-renowned author, speaker, trainer, and consultant. Todd has three decades of experience working with LANs, WANs, and large enterprise licensed and unlicensed wireless networks, including the implementation of large Cisco Data Centers world-wide. His books draw on his practical experience working on the largest networks in the world at companies such as Xerox, Hughes Aircraft, Texaco, AAA, Cisco and Toshiba. He has published over 60 books, including the very popular CCNA: Cisco Certified Network Associate Study Guide, CCNA Wireless Study Guide, and CCNA Data Center Study Guide, all from Sybex. He runs an international consulting and training company based in Colorado, Texas, and San Francisco. You can reach Todd through his forum and blog at www.lammle.com.

Introduction xxi CCENT Exam Objectives xxxii Assessment Test xxxviii Chapter 1 Internetworking 1 Internetworking Basics 2 Internetworking Models 10 The Layered Approach 11 Advantages of Reference Models 12 The OSI Reference Model 12 The Application Layer 14 The Presentation Layer 15 The Session Layer 15 The Transport Layer 16 The Network Layer 21 The Data Link Layer 23 The Physical Layer 26 Summary 27 Exam Essentials 28 Written Labs 29 Written Lab 1.1: OSI Questions 29 Written Lab 1.2: Defining the OSI Layers and Devices 30 Written Lab 1.3: Identifying Collision and Broadcast Domains 31 Review Questions 32 Chapter 2 Ethernet Networking and Data Encapsulation 39 Ethernet Networks in Review 40 Collision Domain 41 Broadcast Domain 42 CSMA/CD 43 Half- and Full-Duplex Ethernet 45 Ethernet at the Data Link Layer 47 Ethernet at the Physical Layer 53 Ethernet Cabling 57 Straight-Through Cable 58 Crossover Cable 58 Rolled Cable 60 Fiber Optic 62 Data Encapsulation 64 The Cisco Three-Layer Hierarchical Model 68 The Core Layer 68 The Distribution Layer 70 The Access Layer 70 Summary 71 Exam Essentials 71 Written Labs 72 Written Lab 2.1: Binary/Decimal/Hexadecimal Conversion 73 Written Lab 2.2: CSMA/CD Operations 77 Written Lab 2.3: Cabling 77 Written Lab 2.4: Encapsulation 78 Review Questions 79 Chapter 3 Introduction to TCP/IP 85 Introducing TCP/IP 86 A Brief History of TCP/IP 87 TCP/IP and the DoD Model 87 The Process/Application Layer Protocols 89 The Host-to-Host Layer Protocols 99 The Internet Layer Protocols 108 IP Addressing 116 IP Terminology 116 The Hierarchical IP Addressing Scheme 117 Private IP Addresses (RFC 1918) 122 IPv4 Address Types 124 Layer 2 Broadcasts 124 Layer 3 Broadcasts 124 Unicast Address 125 Multicast Address 126 Summary 127 Exam Essentials 128 Written Labs 130 Written Lab 3.1: TCP/IP 130 Written Lab 3.2: Mapping Applications to the DoD Model 130 Review Questions 132 Chapter 4 Easy Subnetting 137 Subnetting Basics 138 How to Create Subnets 140 Subnet Masks 140 Classless Inter-Domain Routing (CIDR) 142 IP Subnet-Zero 144 Subnetting Class C Addresses 144 Subnetting Class B Addresses 156 Subnetting Class A Addresses 165 Summary 168 Exam Essentials 168 Written Labs 169 Written Lab 4.1: Written Subnet Practice #1 169 Written Lab 4.2: Written Subnet Practice #2 170 Written Lab 4.3: Written Subnet Practice #3 171 Review Questions 172 Chapter 5 VLSMs, Summarization, and Troubleshooting TCP/IP 179 Variable Length Subnet Masks (VLSMs) 180 VLSM Design 182 Implementing VLSM Networks 182 Summarization 191 Troubleshooting IP Addressing 194 Determining IP Address Problems 196 Summary 201 Exam Essentials 202 Written Lab 5 203 Review Questions 204 Chapter 6 Cisco s Internetworking Operating System (IOS) 211 The IOS User Interface 213 Cisco IOS 214 Connecting to a Cisco IOS Device 214 Bringing Up a Switch 216 Command-Line Interface (CLI) 217 Entering the CLI 217 Overview of Router Modes 217 CLI Prompts 218 Editing and Help Features 221 Administrative Configurations 226 Hostnames 226 Banners 227 Setting Passwords 229 Encrypting Your Passwords 235 Descriptions 237 Router and Switch Interfaces 239 Bringing Up an Interface 242 Viewing, Saving, and Erasing Configurations 248 Deleting the Configuration and Reloading the Device 250 Verifying Your Configuration 251 Summary 262 Exam Essentials 263 Written Lab 6 266 Hands-on Labs 266 Hands-on Lab 6.1: Erasing an Existing Configuration 267 Hands-on Lab 6.2: Exploring User, Privileged, and Configuration Modes 267 Hands-on Lab 6.3: Using the Help and Editing Features 268 Hands-on Lab 6.4: Saving a Configuration 269 Hands-on Lab 6.5: Setting Passwords 270 Hands-on Lab 6.6: Setting the Hostname, Descriptions, IP Address, and Clock Rate 272 Review Questions 275 Chapter 7 Managing a Cisco Internetwork 281 The Internal Components of a Cisco Router and Switch 282 The Router and Switch Boot Sequence 283 Backing Up and Restoring the Cisco Configuration 284 Backing Up the Cisco Configuration 284 Restoring the Cisco Configuration 286 Erasing the Configuration 287 Configuring DHCP 288 DHCP Relay 289 Verifying DHCP on Cisco IOS 290 Network Time Protocol (NTP) 291 Using Cisco Discovery Protocol (CDP) 293 Getting CDP Timers and Holdtime Information 293 Gathering Neighbor Information 294 Documenting a Network Topology Using CDP 298 Using Telnet 301 Telnetting into Multiple Devices Simultaneously 303 Checking Telnet Connections 304 Checking Telnet Users 304 Closing Telnet Sessions 304 Resolving Hostnames 305 Building a Host Table 305 Using DNS to Resolve Names 307 Checking Network Connectivity and Troubleshooting 309 Using the ping Command 310 Using the traceroute Command 310 Debugging 312 Using the show processes Command 314 Summary 315 Exam Essentials 315 Written Lab 7 317 Written Lab 7.1: IOS Management 317 Written Lab 7.2: Router Memory 317 Hands-on Labs 318 Hands-on Lab 7.1: Backing Up the Router Configuration 318 Hands-on Lab 7.2: Using the Cisco Discovery Protocol (CDP) 319 Hands-on Lab 7.3: Using Telnet 320 Hands-on Lab 7.4: Resolving Hostnames 321 Review Questions 323 Chapter 8 IP Routing 329 Routing Basics 331 The IP Routing Process 333 The Cisco Router Internal Process 339 Testing Your IP Routing Understanding 340 Configuring IP Routing 344 Configuring IP Routing in Our Network 354 Static Routing 355 Default Routing 360 Dynamic Routing 363 Routing Protocol Basics 363 Routing Information Protocol (RIP) 365 Configuring RIP Routing 365 Holding Down RIP Propagations 369 Summary 371 Exam Essentials 372 Written Lab 8 374 Hands-on Labs 374 Hands-on Lab 8.1: Creating Static Routes 375 Hands-on Lab 8.2: Configuring RIP Routing 376 Review Questions 378 Chapter 9 Open Shortest Path First (OSPF) 383 Open Shortest Path First (OSPF) Basics 384 OSPF Terminology 387 OSPF Operation 389 Configuring OSPF 391 Enabling OSPF 391 Configuring OSPF Areas 392 Configuring Our Network with OSPF 395 OSPF and Loopback Interfaces 400 Configuring Loopback Interfaces 401 Verifying OSPF Configuration 403 The show ip ospf Command 404 The show ip ospf database Command 405 The show ip ospf interface Command 406 The show ip ospf neighbor Command 407 The show ip protocols Command 409 Summary 409 Exam Essentials 410 Written Lab 9 411 Hands-on Labs 411 Hands-on Lab 9.1: Enabling the OSPF Process 412 Hands-on Lab 9.2: Configuring OSPF Interfaces 413 Hands-on Lab 9.3: Verifying OSPF Operation 414 Review Questions 415 Chapter 10 Layer 2 Switching 423 Switching Services 424 Three Switch Functions at Layer 2 425 Port Security 429 Configuring Catalyst Switches 434 Catalyst Switch Configuration 434 Verifying Cisco Catalyst Switches 442 Summary 445 Exam Essentials 445 Written Lab 10 446 Hands-on Labs 446 Lab 10.1: Configuring Layer 2 Switches 447 Lab 10.2: Verifying Layer 2 Switches 448 Lab 10.3: Configuring Port Security 448 Review Questions 450 Chapter 11 VLANs and Inter-VLAN Routing 457 VLAN Basics 458 Broadcast Control 461 Security 462 Flexibility and Scalability 462 Identifying VLANs 463 Frame Tagging 465 VLAN Identification Methods 466 Routing between VLANs 467 Configuring VLANs 470 Assigning Switch Ports to VLANs 473 Configuring Trunk Ports 474 Configuring Inter-VLAN Routing 478 Summary 485 Exam Essentials 486 Written Lab 11 487 Hands-on Labs 487 Hands-on Lab 11.1: Configuring and Verifying VLANs 488 Hands-on Lab 11.2: Configuring and Verifying Trunk Links 489 Hands-on Lab 11.3: Configuring Router on a Stick Routing 490 Hands-on Lab 11.4: Configuring IVR with a Layer 3 Switch 490 Review Questions 492 Chapter 12 Security 499 Perimeter, Firewall, and Internal Routers 500 Introduction to Access Lists 501 Mitigating Security Issues with ACLs 504 Standard Access Lists 505 Wildcard Masking 506 Standard Access List Example 508 Controlling VTY (Telnet/SSH) Access 512 Extended Access Lists 513 Extended Access List Example 1 517 Extended Access List Example 2 519 Extended Access List Example 3 520 Named ACLs 521 Remarks 523 Monitoring Access Lists 524 Summary 526 Exam Essentials 527 Written Lab 12 528 Hands-on Labs 528 Hands-on Lab 12.1: Standard IP Access Lists 529 Hands-on Lab 12.2: Extended IP Access Lists 530 Review Questions 533 Chapter 13 Network Address Translation (NAT) 539 When Do We Use NAT? 540 Types of Network Address Translation 542 NAT Names 542 How NAT Works 543 Static NAT Configuration 545 Dynamic NAT Configuration 546 PAT (Overloading) Configuration 546 Simple Verification of NAT 547 Testing and Troubleshooting NAT 548 Summary 553 Exam Essentials 554 Written Lab 13 555 Hands-on Labs 555 Lab 13.1: Preparing for NAT 556 Lab 13.2: Configuring Dynamic NAT 558 Lab 13.3: Configuring PAT 559 Review Questions 562 Chapter 14 Internet Protocol Version 6 (IPv6) 567 Why Do We Need IPv6? 569 The Benefits and Uses of IPv6 569 IPv6 Addressing and Expressions 571 Shortened Expression 572 Address Types 573 Special Addresses 574 How IPv6 Works in an Internetwork 575 Manual Address Assignment 576 Stateless Autoconfiguration (EUI-64) 576 DHCPv6 (Stateful) 579 IPv6 Header 580 ICMPv6 581 IPv6 Routing Protocols 584 Static Routing with IPv6 584 OSPFv3 585 Configuring IPv6 on Our Internetwork 586 Configuring Routing on Our Internetwork 589 Verifying OSPFv3 592 Summary 597 Exam Essentials 597 Written Labs 599 Written Lab 14.1 599 Written Lab 14.2 599 Hands-on Labs 600 Hands-on Lab 14.1: Manual and Stateful Autoconfiguration 600 Hands-on Lab 14.2: Static and Default Routing 602 Hands-on Lab 14.3: OSPFv3 603 Review Questions 605 Appendix A Answers to Written Labs 611 Chapter 1: Internetworking 612 Written Lab 1.1: OSI Questions 612 Written Lab 1.2: Defining the OSI Layers and Devices 613 Written Lab 1.3: Identifying Collision and Broadcast Domains 614 Chapter 2: Ethernet Networking and Data Encapsulation 615 Written Lab 2.1: Binary/Decimal/Hexadecimal Conversion 615 Written Lab 2.2: CSMA/CD Operations 617 Written Lab 2.3: Cabling 617 Written Lab 2.4: Encapsulation 618 Chapter 3: Introduction to TCP/IP 618 Written Lab 3.1: TCP/IP 618 Written Lab 3.2: Mapping Applications to the DoD Model 618 Chapter 4: Easy Subnetting 619 Written Lab 4.1: Written Subnet Practice #1 619 Written Lab 4.2: Written Subnet Practice #2 620 Written Lab 4.3: Written Subnet Practice #3 621 Chapter 5: VLSMs, Summarization and Troubleshooting TCP/IP 621 Chapter 6: Cisco s Internetworking Operating System (IOS) 622 Written Lab 6 622 Chapter 7: Managing a Cisco Internetwork 622 Written Lab 7.1: IOS Management 622 Written Lab 7.2: Router Memory 623 Chapter 8: IP Routing 623 Chapter 9: Open Shortest Path First (OSPF) 624 Chapter 10: Layer 2 Switching 624 Chapter 11: VLANs and InterVLAN Routing 624 Chapter 12: Security 625 Chapter 13: Network Address Translation 625 Chapter 14: Internet Protocol Version 6 (IPv6) 626 Written Lab 14.1 626 Written Lab 14.2 626 Appendix B Answers to Review Questions 627 Chapter 1: Internetworking 628 Chapter 2: Ethernet Networking and Data Encapsulation 630 Chapter 3: Introduction to TCP/IP 631 Chapter 4: Easy Subnetting 633 Chapter 5: VLSMs, Summarization and Troubleshooting TCP/IP 635 Chapter 6: Cisco s Internetworking Operating System (IOS) 637 Chapter 7: Managing a Cisco Internetwork 639 Chapter 8: IP Routing 641 Chapter 9: Open Shortest Path First (OSPF) 642 Chapter 10: Layer 2 Switching 644 Chapter 11: VLANs and InterVLAN Routing 647 Chapter 12: Security 648 Chapter 13: Network Address Translation 651 Chapter 14: Internet Protocol Version 6 (IPv6) 652 Appendix C Disabling and Configuring Network Services 655 Blocking SNMP Packets 656 Disabling Echo 656 Turning off BootP and Auto-Config 657 Disabling the HTTP Interface 658 Disabling IP Source Routing 658 Disabling Proxy ARP 658 Disabling Redirect Messages 658 Disabling the Generation of ICMP Unreachable Messages 659 Disabling Multicast Route Caching 659 Disabling the Maintenance Operation Protocol (MOP) 659 Turning Off the X.25 PAD Service 660 Enabling the Nagle TCP Congestion Algorithm 660 Logging Every Event 660 Disabling Cisco Discovery Protocol 661 Disabling the Default Forwarded UDP Protocols 661 Cisco s Auto Secure 662 Appendix D About the Additional Study Tools 667 Additional Study Tools 668 Test Engine 668 Electronic Flashcards 668 Videos 668 Network Simulator 669 PDF of Glossary of Terms 669 System Requirements 669 Using the Study Tools 669 Troubleshooting 670 Customer Care 670 Index 671