CCENT. Certification 4BOOKS. Making Everything Easier! Networking Basics Cisco Device Basics Routing and Switching Advanced Topics

Transcription

1 Making Everything Easier! CCENT Certification A L L - I N - O N E 4BOOKS IN 1 Networking Basics Cisco Device Basics Routing and Switching Advanced Topics Bonus CD includes Test Engine, demonstration videos, and Lab Manual Glen E. Clarke Coauthor of CompTIA A+ Certification All-in-One For Dummies

2 Get More and Do More at Dummies.com Start with FREE Cheat Sheets Cheat Sheets include Checklists Charts Common Instructions And Other Good Stuff! To access the Cheat Sheet created specifically for this book, go to dummies.com/cheatsheet/ccentcertificationaio Get Smart at Dummies.com Dummies.com makes your life easier with 1,000s of answers on everything from removing wallpaper to using the latest version of Windows. Check out our Videos Illustrated Articles Step-by-Step Instructions Plus, each month you can win valuable prizes by entering our Dummies.com sweepstakes. * Want a weekly dose of Dummies? Sign up for Newsletters on Digital Photography Microsoft Windows & Office Personal Finance & Investing Health & Wellness Computing, ipods & Cell Phones ebay Internet Food, Home & Garden Find out HOW at Dummies.com *Sweepstakes not currently available in all countries; visit Dummies.com for official rules.

3 CCENT Certification ALL-IN-ONE FOR DUMmIES

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5 CCENT Certification ALL-IN-ONE FOR DUMmIES by Glen E. Clarke

6 CCENT Certification All-In-One For Dummies Published by Wiley Publishing, Inc. 111 River Street Hoboken, NJ Copyright 2011 by Wiley Publishing, Inc., Indianapolis, Indiana Published by Wiley Publishing, Inc., Indianapolis, Indiana Published simultaneously in Canada No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) , fax (978) Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) , fax (201) , or online at Trademarks: Wiley, the Wiley Publishing logo, For Dummies, the Dummies Man logo, A Reference for the Rest of Us!, The Dummies Way, Dummies Daily, The Fun and Easy Way, Dummies.com, Making Everything Easier, and related trade dress are trademarks or registered trademarks of John Wiley & Sons, Inc. and/ or its affiliates in the United States and other countries, and may not be used without written permission. CCENT is a registered trademark of Cisco Technology, Inc. All other trademarks are the property of their respective owners. Wiley Publishing, Inc., is not associated with any product or vendor mentioned in this book. LIMIT OF LIABILITY/DISCLAIMER OF WARRANTY: THE PUBLISHER AND THE AUTHOR MAKE NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY OR COMPLETENESS OF THE CONTENTS OF THIS WORK AND SPECIFICALLY DISCLAIM ALL WARRANTIES, INCLUDING WITH- OUT LIMITATION WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE. NO WARRANTY MAY BE CREATED OR EXTENDED BY SALES OR PROMOTIONAL MATERIALS. THE ADVICE AND STRATEGIES CONTAINED HEREIN MAY NOT BE SUITABLE FOR EVERY SITUATION. THIS WORK IS SOLD WITH THE UNDERSTANDING THAT THE PUBLISHER IS NOT ENGAGED IN RENDERING LEGAL, ACCOUNTING, OR OTHER PROFESSIONAL SERVICES. IF PROFESSIONAL ASSISTANCE IS REQUIRED, THE SERVICES OF A COMPETENT PROFESSIONAL PERSON SHOULD BE SOUGHT. NEITHER THE PUBLISHER NOR THE AUTHOR SHALL BE LIABLE FOR DAMAGES ARISING HEREFROM. THE FACT THAT AN ORGANIZA- TION OR WEBSITE IS REFERRED TO IN THIS WORK AS A CITATION AND/OR A POTENTIAL SOURCE OF FURTHER INFORMATION DOES NOT MEAN THAT THE AUTHOR OR THE PUBLISHER ENDORSES THE INFORMATION THE ORGANIZATION OR WEBSITE MAY PROVIDE OR RECOMMENDATIONS IT MAY MAKE. FURTHER, READERS SHOULD BE AWARE THAT INTERNET WEBSITES LISTED IN THIS WORK MAY HAVE CHANGED OR DISAPPEARED BETWEEN WHEN THIS WORK WAS WRITTEN AND WHEN IT IS READ.. For general information on our other products and services, please contact our Customer Care Department within the U.S. at , outside the U.S. at , or fax For technical support, please visit Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. Library of Congress Control Number: ISBN: Manufactured in the United States of America

7 About the Author Glen E. Clarke (CCENT/MCSE/MCSD/MCDBA/MCT/MCTS/CEH/CHFI/ Security+) is an independent trainer and consultant, focusing on network security and security auditing services. Glen spends most of his time delivering certified courses on A+, Network+, Windows Server, SQL Server, Exchange Server, Visual Basic.NET, and ASP.NET. Glen also teaches a number of security related courses covering topics such as ethical hacking and countermeasures, vulnerability testing, firewall design, and packet analysis. Glen is an experienced author and technical editor who has worked on eighteen certification books. Glen designed and coauthored the award nominated A+ Certification Bible and has worked on certification titles involving topics such as Windows certification, CIW certification, Network+ certification, and Security+ certification. Glen is also author of The Network+ Certification Study Guide, 4th Edition, and coauthor of CompTIA A+ Certification All-One For Dummies, 2nd Edition. When he s not working, Glen loves to spend quality time with his wife, Tanya, and their four children, Sara, Brendon, Ashlyn, and Rebecca. You can visit Glen online at or contact him at glenclarke@accesswave.ca.

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9 Dedication To Tanya, my beautiful wife and partner in life. Author s Acknowledgments I want to thank the people at Wiley for their hard work and continued support. A special thank you to acquisitions editor, Katie Feltman, for her support with this project and her patience as I worked through the chapters. I also want to thank project editor Blair Pottenger for his patience and quick responses to any questions I fired his way! Katie and Blair, you are both great people to work for and I always look forward to our next project together! Much appreciation goes to copy editor Heidi Unger for an outstanding job on the editing of the chapters thank you! I also want to thank Dan Lachance and Ed Tetz for their feedback as technical editors and a job well done! Thanks guys love working with you both! I also want to thank the folks at Tim Horton s for not kicking me out when I occupy a table for hours at a time and for keeping the coffee always fresh! I would also like to thank Bob Canning and Dan Tooke for their interest in technology and taking the time to give me a tour of their work environment it was great, thank you! A special thank you goes to my four children, Sara, Brendon, Ashlyn, and Rebecca, for giving me the time to sit down and participate in kids play with them it makes me realize what is important in life. A needed thank you goes to my wife, Tanya, for all her support you have made great sacrifices with this project as well. Thank you for all that you do!

10 Publisher s Acknowledgments We re proud of this book; please send us your comments at For other comments, please contact our Customer Care Department within the U.S. at , outside the U.S. at , or fax Some of the people who helped bring this book to market include the following: Acquisitions, Editorial, and Media Development Project Editor: Blair J. Pottenger Acquisitions Editor: Katie Feltman Copy Editor: Heidi Unger Technical Editor: Dan Lachance, Ed Tetz Editorial Manager: Kevin Kirschner Media Development Project Manager: Laura Moss-Hollister Media Development Assistant Project Manager: Jenny Swisher Media Development Associate Producer: Marilyn Hummel Editorial Assistant: Amanda Graham Sr. Editorial Assistant: Cherie Case Cartoons: Rich Tennant ( Composition Services Project Coordinators: Katie Crocker, Patrick Redmond Layout and Graphics: Nikki Gately, Joyce Haughey, Christin Swinford Special Art: Rashell Smith Proofreaders: Melissa D. Buddendeck, Melanie Hoffman Indexer: BIM Indexing & Proofreading Services Publishing and Editorial for Technology Dummies Richard Swadley, Vice President and Executive Group Publisher Andy Cummings, Vice President and Publisher Mary Bednarek, Executive Acquisitions Director Mary C. Corder, Editorial Director Publishing for Consumer Dummies Diane Graves Steele, Vice President and Publisher Composition Services Debbie Stailey, Director of Composition Services

11 Contents at a Glance Introduction... 1 Book I: Networking Basics... 7 Chapter 1: About the CCENT Exam...9 Chapter 2: Introduction to Network Technologies...17 Chapter 3: Network Devices and Services...51 Chapter 4: Introduction to TCP/IP...77 Chapter 5: Subnetting and VLSM Book II: Cisco Device Basics Chapter 1: Introduction to the Cisco IOS Chapter 2: Basic Router Configuration Chapter 3: Managing Cisco Devices Chapter 4: Advanced Router Topics Book III: Routing and Switching Chapter 1: Static Routing Chapter 2: Dynamic Routing Protocols Chapter 3: Introduction to Switching Chapter 4: Basic Switch Configuration Chapter 5: Troubleshooting Network Communication Book IV: Advanced Topics Chapter 1: Network Security Terminology Chapter 2: Cisco Device Security Best Practices Chapter 3: Wireless Networking Chapter 4: Introduction to WANs Appendix A: About the CD Appendix B: CCENT Certification Exam Reference Matrix Index

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13 Table of Contents Introduction... 1 About This Book...1 Conventions Used in This Book...1 Foolish Assumptions...3 How This Book Is Organized...3 Book I: Networking Basics...4 Book II: Cisco Device Basics...4 Book III: Routing and Switching...4 Book IV: Advanced Topics...4 Appendixes...5 Online Cheatsheet...5 Icons Used in This Book...5 Where to Go from Here...6 Book I: Networking Basics... 7 Chapter 1: About the CCENT Exam The Value of CCENT Certification...9 CCENT Exam Details...10 What to Expect on the CCENT Exam...11 Types of questions...11 Exam objectives...13 Using This Book to Prepare for the Exam...14 On Your Test Day...14 Arriving at the test site...15 Getting lots of rest...15 Answering questions...15 Chapter 2: Introduction to Network Technologies Understanding Network Types...20 Local area network...20 Wide area network...21 Identifying Network Topologies...22 Bus topology...22 Ring topology...23 Star topology...24 Hybrid topology...24

14 xii CCENT Certification All-In-One For Dummies Looking at Cable Types...25 Coaxial cable...26 Twisted-pair cabling...27 Fiber-optic cabling...29 Connecting devices to one another...31 Accessing the Network with Access Methods...34 CSMA/CD...35 Token passing...36 CSMA/CA...36 Understanding Network Architectures...36 Ethernet architectures...37 Token Ring...40 Looking at the OSI Model...41 Chapter Summary...44 Lab Exercises...44 Lab 2-1: Identifying network architectures...45 Lab 2-2: Remembering cable specifications...45 Lab 2-3: OSI model terminology...46 Chapter 3: Network Devices and Services Building Networks with Network Devices...54 Hubs and repeaters...54 Network interface card...55 Bridges...57 Switches...58 Routers...60 Identifying Network Services...61 Web servers servers...62 DNS servers...62 Authentication servers...64 DHCP servers...64 Network Address Translation...65 Traffic Management Concepts...67 To duplex or not to duplex...67 Types of communication...67 Broadcast domains versus collision domains...68 Managing traffic...70 Chapter Summary...71 Lab Exercises...71 Lab 3-1: Network devices...72 Lab 3-2: Remembering network services...72

15 Table of Contents xiii Chapter 4: Introduction to TCP/IP The Basics of TCP/IP...80 IP addressing...80 Converting decimal to binary...83 IP Address Classes...85 Class A...85 Class B...87 Class C...88 Classes D and E...88 Looking at Special Addresses...89 Public versus private addresses...89 Automatic Private IP Addressing (APIPA)...89 Assigning IP Addresses...90 Identifying invalid addresses...90 Static addressing versus dynamic addressing...91 Configuring TCP/IP on a client...91 The TCP/IP Internet Model...93 The four layers...93 Data encapsulation...95 Application layer protocols...96 Transport layer protocols...97 Internet layer protocols Chapter Summary Lab Exercises Lab 4-1: Identifying address classes Lab 4-2: Converting decimal to binary Lab 4-3: Converting binary to decimal Lab 4-4: Identifying invalid addresses Lab 4-5: Match the protocol Chapter 5: Subnetting and VLSM Identifying Reasons to Subnet Subnetting a Network Subnetting a class A network Subnetting a class B network Subnetting a class C network Subnetting the quick way IP Subnet Zero Understanding Variable-Length Subnet Masks Chapter Summary Lab Exercises Lab 5-1: Subnetting class A Lab 5-2: Subnetting class B Lab 5-3: Subnetting class C Lab 5-4: Subnetting class B using the shortcut...153

16 xiv CCENT Certification All-In-One For Dummies Book II: Cisco Device Basics Chapter 1: Introduction to the Cisco IOS Introducing the Cisco IOS Identifying Ports on the Cisco Device Cisco router ports Cisco switch ports Ways to Configure the Cisco Device Using the CLI Security Device Manager (SDM) Cisco Network Assistant Identifying Types of Memory ROM Flash memory Volatile RAM (VRAM) Nonvolatile RAM (NVRAM) Powering On Your Cisco Device The boot process Initial configuration dialog Understanding Cisco Configuration Modes User exec mode Priv exec mode Global configuration Cisco IOS Features Looking at IOS versions Using the help system Chapter Summary Lab Exercises Lab 1-1: Identifying ports Lab 1-2: Identifying terminology Lab 1-3: Identifying IOS configuration modes Lab 1-4: Identifying the boot process Lab 1-5: Using help Chapter 2: Basic Router Configuration Basic Configuration of a Cisco Router Connecting to your Cisco device Changing the hostname Configuring Ethernet Interfaces Configure IP settings for the Ethernet interface Configure a description for the Ethernet interface Configure other settings for the Ethernet interface Enabling and disabling the interface Configuring router R2 for the Ethernet interface...207

17 Table of Contents xv Configuring Serial Interfaces Configure IP settings for the serial interface Configure a description for the serial interface Configure other settings for the serial interface Configuring Passwords Console password Auxiliary port password Telnet password Creating Users Configuring Banners Types of banners Configuring a banner Other Useful Commands Saving configuration changes Deleting the configuration Looking at the most recently used commands Domain lookups and console timeout Verifying Your Configuration Viewing the configuration files Viewing interface configuration Chapter Summary Lab Exercises Lab 2-1: Configuring router interfaces Lab 2-2: Configuring passwords Lab 2-3: Viewing the configuration Chapter 3: Managing Cisco Devices Backing Up Your Configuration and IOS Installing TFTP software Backing up your configuration Restoring your configuration Backing up your IOS Upgrading the Cisco IOS Understanding CDP CDP overview Using CDP Disabling CDP Using Telnet for Remote Administration Telnet overview Using Telnet features Chapter Summary Lab Exercises Lab 3-1: Backing up and restoring your configuration Lab 3-2: Using CDP to discover the network Lab 3-3: Using Telnet for remote administration...263

18 xvi CCENT Certification All-In-One For Dummies Chapter 4: Advanced Router Topics Implementing Network Services Understanding hostname resolution Configuring DHCP services Implementing Network Address Translation Understanding Password Recovery Procedures Configuration registers Password recovery Using the Security Device Manager Configuring Security Device Manager Basic router configuration using SDM Configuring DHCP using SDM Configuring RIP using SDM Configuring NAT using SDM Chapter Summary Lab Exercises Lab 4-1: Configuring hostname resolution Lab 4-2: Configuring DHCP on a Cisco router Lab 4-3: Recovering passwords Book III: Routing and Switching Chapter 1: Static Routing Understanding Routing Concepts The Routing Process Configuring Routing Viewing the routing table Understanding static routes Adding a static route Deleting a static route Configuring the gateway of last resort Chapter Summary Lab Exercises Lab 1-1: Planning routes Lab 1-2: Configuring static routes Lab 1-3: Configuring the gateway of last resort Chapter 2: Dynamic Routing Protocols Introduction to Dynamic Routing Protocols Types of routing protocols Identifying popular routing protocols Configuring RIP Configuring RIPv Configuring RIPv Troubleshooting RIP...354

19 Table of Contents xvii Chapter Summary Lab Exercises Lab 2-1: Enabling RIP Chapter 3: Introduction to Switching Introduction to Cisco Switches System LED RPS LED Switch display modes Understanding Switch Functionality Switch overview Core switch services Switch operation modes Understanding Data Flow Local communication Remote communication Basic Switch Configuration Configuring the device name Configuring the IP address Remembering to configure the default gateway setting Chapter Summary Lab Exercises Lab 3-1: Configuring a switch Chapter 4: Basic Switch Configuration Configuring Switch Ports Adding a port description Choosing port speed Adjusting the duplex setting Disabling and enabling ports Viewing port configuration Port security Understanding VLANs VLAN concepts Basic VLAN configuration Chapter Summary Lab Exercises Lab 4-1: Configuring ports Lab 4-2: Configuring port security Lab 4-3: Configuring VLANs Chapter 5: Troubleshooting Network Communication Understanding Troubleshooting Utilities Using Cisco commands to troubleshoot Troubleshooting commands in Windows Troubleshooting Connectivity Issues Identifying physical issues Identifying logical issues...424

20 xviii CCENT Certification All-In-One For Dummies Using Show Commands to View Configuration Viewing configuration files Viewing router configuration Viewing network topology Using Debug Commands Knowing how to use debugging efficiently Looking at a debugging example Disabling debugging Chapter Summary Lab Exercises Lab 5-1: Identifying connectivity issues Lab 5-2: Using the show commands Lab 5-3: Troubleshooting configuration Lab 5-4: Enabling debugging Book IV: Advanced Topics Chapter 1: Network Security Terminology Introduction to Security Terminology Authentication Authorization Vulnerability Exploit What about CIA? Identifying Types of Attacks Social engineering attacks Network-based attacks Software-based attacks Looking at Security Devices Firewalls Intrusion detection system Switches Virtual Private Networks Mitigating Security Threats Workstations Servers Network Chapter Summary Lab Exercises Lab 1-1: Security terminology Lab 1-2: Types of attacks...469

21 Table of Contents xix Chapter 2: Cisco Device Security Best Practices The Importance of Physical Security Physical premises Windows and lighting Secure facility Workstations and servers Cisco Router Best Practices Configuring passwords Configuring user accounts Configuring banners Configuring SSH Cisco Switch Best Practices Configuring port security Disabling ports Chapter Summary Lab Exercises Lab 2-1: Configuring passwords Lab 2-2: Configuring banners Lab 2-3: Reviewing router configuration Lab 2-4: Configuring port security Chapter 3: Wireless Networking Looking at Wireless Terminology Wireless concepts Wireless equipment Types of wireless networks Introduction to Wireless Standards a b g n Wireless Configuration and Troubleshooting Basic configuration overview Designing a multi-access point WLAN Troubleshooting wireless networks Wireless Security Practices General security practices Encryption protocols Chapter Summary...513

22 xx CCENT Certification All-In-One For Dummies Chapter 4: Introduction to WANs Introduction to WAN Terminology Circuit switching Leased lines Packet switching Methods of Connecting to WANs Serial ports Integrated CSU/DSU port ISDN ports Configuring Serial Links Serial link protocols Setting the clock rate Chapter Summary Lab Exercises Lab 4-1: Configuring HDLC encapsulation Lab 4-2: Configuring PPP encapsulation Appendix A: About the CD System Requirements Using the CD What You Will Find on the CD Test Engine Videos Lab Manual PDF Files Adobe Reader Troubleshooting Appendix B: CCENT Certification Exam Reference Matrix Index

23 Introduction The CCENT certification is a new, fast-growing certification that tests your knowledge of basic Cisco device-management and networking concepts. It is a great stepping stone to the CCNA certification and other Cisco certification tracks. The CCENT exam tests your knowledge of real-world networking concepts and Cisco features found on most networks today! About This Book CCENT Certification All-In-One For Dummies is designed to be a hands-on, practical guide to help you pass the CCENT certification exam. This book is written in a way that helps you not only understand complex technical content, but also prepares you to apply that knowledge to real-world scenarios. I understand the value of a book that covers the points needed to pass the exam, but I also understand the value of ensuring that the information helps you perform IT-related tasks when you are on the job. That is what this book offers you key points to pass the exam combined with practical information to help you in the real world, which means that you can use this book in more than one way. An exam preparation tool: Because my goal is to help you pass the CCENT certification exam, this book is packed with exam-specific information and tips to help you with tricky exam questions. You should understand everything that is in this book before taking the exam, but to identify key points that you must know, look for icons named For the Exam. In those paragraphs, you will find helpful tips on topics you are certain to be tested on. A reference: Rely on my extensive experience in the IT industry not only to study for (and pass) the exam, but also to help you perform common network-related tasks on the job. I hope you find this book a useful tool that you can refer to time and time again in your career as you configure networks and Cisco devices. Conventions Used in This Book Each chapter in this book has different elements that help you prepare to pass your CCENT, including the following features:

24 2 Conventions Used in This Book Quick Assessments: Located at the beginning of each chapter is a Quick Assessment section that gives a number of questions related to the chapter content for you to assess whether you have the knowledge already in that chapter. It is highly recommended to read all chapters in the book, but if you find you are limited on study time you may want to focus on the topics you know the least about the Quick Assessments help you determine what topics you know and what you need more work on. Icons: Look for the icons used in each chapter to draw your attention to information needed for the exam or in the real world. For more details on the icons I use, check out the later section, Icons Used in This Book. Chapter Summary: Found at the end of each chapter, the Chapter Summary section covers key points you should remember for the exam. Labs: Lab exercises offer the opportunity to get your hands dirty with a particular topic with real-world experience performing specific tasks. In order to totally grasp the topics discussed in a chapter, be sure to perform the lab exercises. The CCENT certification has a number of simulators that will test your real-world knowledge so you really need to know how to perform the different tasks to pass the exam. Due to the fact that you may have different configurations when you do the labs, there are no lab answers within the Labs section. Prep Test: Following each Chapter Summary section, you can find questions to help review the chapter content and prepare you for the CCENT certification exam. Be sure to answer the review questions in each chapter! Then, after you finish reading the entire book and do the lab exercises, check out the practice exams on the companion CD-ROM, which is designed to function like the real exam, with the same level of difficulty. Monofont text: To help you distinguish commands you type or text you should see on the screen I apply the monofont style to the text. Examples where you see this style are on router commands, IP addresses, and names of devices. Boldface text: To help identify new commands that you are learning within a code listing the boldface text style is applied. Although you should read over all code in a code example, using the boldface text will help draw your attention to the new commands presented in a code listing.

25 How This Book Is Organized 3 Foolish Assumptions I make a few assumptions about you as a reader and have written this book with these assumptions in mind: You are interested in obtaining the CCENT Certification. Anyone who is looking to get a solid introduction to networking and how to manage a Cisco device can use this book, but the focus of this book is concentrated on the exam objectives needed to pass the CCENT certification exam. You have Cisco equipment to work on. To perform the labs in the book, you will need to have two Cisco switches and two Cisco routers. If you do not have access to the Cisco hardware, you can search online for a simulator to purchase. An example simulator you can purchase is the Network simulator for CCENT from You will study hard and do as much hands-on work as possible. There is a lot of content on the CCENT exam, and you will most likely need to read over the information contained in this book a few times to ensure that you understand it. You should also experiment as much as possible on the actual devices after you read a particular topic. For example, after you read about CDP on a router, be sure to spend some time trying the commands on your router to ensure you are comfortable with what the protocol can do and what it offers as a feature. You will read the chapters of this book in the order presented. Although you are not required to read the chapters in order, it is highly recommended as chapters that appear later in the book assume you have read, or have the knowledge, of the previous chapters. For example, during the routing discussion I assume you have already read the subnetting and variable-length subnet mask (VLSM) chapter and use those terms within the routing chapter. It is best to read the book from cover to cover at least once and then you can jump to the chapters you need more work on. How This Book Is Organized Like all All-In-One For Dummies books, chapters are organized into minibooks. The chapters in each minibook are related by a specific theme or topic. For example, Book I Networking Basics contains all the basic networking information, including explanations of terminology and devices.

26 4 How This Book Is Organized This book is designed as a study tool that you can read from cover to cover; reading the chapters in the order they are presented. I recommend that you read through the book at least once in the order it is presented and then after that pick the chapters that you need to revisit. The reason I recommend reading the chapters in order is because each chapter is written assuming you have the knowledge of the previous chapters. The following sections outline what you can find in each minibook. Book I: Networking Basics In this minibook, you discover what the CCENT certification is all about and what you will be tested on when taking the exam. You also find out about the basics of networking, starting with network types, cables, and devices, and then move on to the basics of IP addressing and the very important exam topic of subnetting. Book II: Cisco Device Basics In Book II, you are introduced to Cisco devices and the basics of how they work. You first read about the physical aspects of the devices, such as the ports, and then move on to discover the Cisco operating system and the boot process. You then learn how to perform some basic configuration tasks, such as configuring interfaces and passwords before finding out how to back up your configuration, discover neighbors, and manage devices remotely with Telnet. This minibook finishes with a discussion on network services like name resolution, DHCP, and NAT. Book III: Routing and Switching Book III first focuses on the routing process and how data is routed from one network to another, and then discusses static routing and dynamic routing protocols and how to control the routing process with the routing table. The minibook then changes focus to switches and talks about basic features of the switch, and I tell you how to perform basic configuration tasks on switches. The final topic in this minibook is troubleshooting, which covers basic troubleshooting steps and commands you can use on Cisco devices. Book IV: Advanced Topics The final minibook starts with two chapters on network security and introduces the security best practices you need to know for the CCENT certification exam. The minibook then continues with chapters on wireless networks and introduces you to wide area networks (WANs).

27 Icons Used in This Book 5 Appendixes Appendix A gives you an overview of what you can find on the CD-ROM that accompanies the book. Please have a look at this section to get the scoop on valuable resources on the book s companion CD-ROM, such the Test Engine. Appendix B is an exam-objective mapping table that lets you know where in the book you can find details on each of the exam objectives. This is very useful when you are preparing for the exam; it can help you make sure that you know each point in the objectives. Online Cheatsheet To help you prepare for the CCENT certification exam, and to give you a quick listing of commands for the real world, I have created an online cheatsheet that is designed to give you some of the core facts to remember for the exam. Be sure to read and understand this book, but the online resource is there as a good refresher. The URL for the online cheatsheet is: Icons Used in This Book I use a number of icons in this book to draw your attention to pieces of useful information. This icon gives you a heads-up on information you should absolutely know for the certification exams. Information that would be helpful to you in the real world is indicated with a Tip icon. Expect to find shortcuts and timesavers here. This icon flags information that may be useful to remember on the job. Information that could cause problems to you or to the devices you are working with is indicated with a Warning icon. If you see a Warning icon, make sure you read it. The computer you save may be your own.

28 6 Where to Go from Here Detailed information that is not needed for the exams or that is a step above the knowledge you absolutely need to know for the exams is indicated with a Technical Stuff icon. This icon lets you know when you can find accompanying information or supporting documents on the CD-ROM. Where to Go from Here The CCENT certification is considered an entry-level certification for candidates interested in a certification career with Cisco products. It provides a great networking foundation for other certification paths, such as these: CCNA: The logical next step would be to take the ICND2 exam, which is exam number The exam combined with your CCENT certification earns you the Cisco Certified Network Associate (CCNA) certification. Other Vendors: After receiving your CCNA certification, you could look to other certifications, such as Microsoft Certified Technology Specialist (MCTS), or even look to security certifications such as SCP s Security Certified Network Professional (SCNP) or EC-Council s Certified Ethical Hacker (CEH) certification.

29 Book I Networking Basics

30 Contents at a Glance Chapter 1: About the CCENT Exam The Value of CCENT Certification...9 CCENT Exam Details...10 What to Expect on the CCENT Exam...11 Using This Book to Prepare for the Exam...14 On Your Test Day...14 Chapter 2: Introduction to Network Technologies Understanding Network Types...20 Identifying Network Topologies...22 Looking at Cable Types...25 Accessing the Network with Access Methods...34 Understanding Network Architectures...36 Looking at the OSI Model...41 Chapter Summary...44 Lab Exercises...44 Chapter 3: Network Devices and Services Building Networks with Network Devices...54 Identifying Network Services...61 Traffic Management Concepts...67 Chapter Summary...71 Lab Exercises...71 Chapter 4: Introduction to TCP/IP The Basics of TCP/IP...80 IP Address Classes...85 Looking at Special Addresses...89 Assigning IP Addresses...90 The TCP/IP Internet Model...93 Chapter Summary Lab Exercises Chapter 5: Subnetting and VLSM Identifying Reasons to Subnet Subnetting a Network Understanding Variable-Length Subnet Masks Chapter Summary Lab Exercises...151