Copyright Implementing Cisco IP Switched Networks (SWITCH) Foundation Learning Guide Richard Froom, CCIE No. 5102 Balaji Sivasubramanian Erum Frahim, CCIE No. 7549 Copyright© 2010 Cisco Systems, Inc. Published by: Cisco Press 800 East 96th Street Indianapolis, IN 46240 USA All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission from the publisher, except for the inclusion of brief quotations in a review. Printed in the United States of America First Printing June 2010 Library of Congress Cataloging-in-Publication data is on file. ISBN-13: 978-1-58705-884-4 Warning and Disclaimer This book is designed to provide information about the Implementing Cisco IP Switched Networks (SWITCH) course in preparation for taking the SWITCH 642-813 exam. Every effort has been made to make this book as complete and as accurate as possible, but no warranty or fitness is implied. The information is provided on an “as is” basis. The authors, Cisco Press, and Cisco Systems, Inc. shall have neither liability nor responsibility to any person or entity with respect to any loss or damages arising from the information contained in this book or from the use of the discs or programs that may accompany it. The opinions expressed in this book belong to the author and are not necessarily those of Cisco Systems, Inc. Trademark Acknowledgments All terms mentioned in this book that are known to be trademarks or service marks have been appropriately capitalized. Cisco Press or Cisco Systems, Inc., cannot attest to the accuracy of this information. Use of a term in this book should not be regarded as affecting the validity of any trademark or service mark. 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All other trademarks mentioned in this document or website are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (0812R) Dedications This book is dedicated to my wife Beth and my son Nathan. I appreciate their support for the extra time that went into completing this book. —Richard This book is dedicated to my wife Swapna, who has been very supportive and encouraging in me writing this book. —Balaji This book is dedicated to my husband Faraz and my dearest daughter Alisha, who were very supportive as I wrote this book. I would like to say extra thanks to my mom and grandmother for remembering me in their prayers. I would also like to dedicate this book to my niece and nephew Shayan and Shiza and a very new member Zayan, who are the love of my life, and finally, my siblings, sister-in-law, and father, who are always there to help me out in any situation. —Erum About the Authors Richard E. Froom, CCIE No. 5102, attended Clemson University where he majored in computer engineering. While attending Clemson, Richard held positions at different times for the university network team, IBM, and Scientific Research Corporation. After graduation, Richard joined Cisco. Richard’s first role within Cisco was as a TAC engineer supporting Cisco Catalyst switches. After several years in the TAC, Richard moved into a testing role supporting Cisco MDS and SAN technologies. In 2009, Richard moved into the Enhanced Customer Aligned Testing Services (ECATS) organization within Cisco as a test manager of a team focused on testing customer deployments of UCS and Nexus. Balaji Sivasubramanian is a product line manager in the Cloud Services and Switching Technology Group focusing on upcoming products in the cloud services and Data Center virtualization area. Before this role, Balaji was a senior product manager for the Catalyst 6500 switches product line, where he successfully launched the Virtual Switching System (VSS) technology worldwide. He started his Cisco career in Cisco Technical Assistant Center working in the LAN switching products and technologies. Balaji has been a speaker at various industry events such as Cisco Live and VMworld. Balaji has a Master of Science degree in computer engineering from the University of Arizona and a Bachelor of Engineering degree in electrical and electronics from the College of Engineering, Guindy, Anna University (India). Erum Frahim, CCIE No. 7549, is a technical leader working for Enhanced Customer Aligned Testing Services (ECATS) at Cisco. In her current role, Erum is leading efforts to test Datacenter solutions for several Cisco high-profile customers. Prior to this, Erum managed the Nexus platform escalation group and served as a team lead for Datacenter SAN Test lab under the Cisco Datacenter Business Unit. Erum joined Cisco in 2000 as a technical support engineer. Erum has a Master of Science degree in electrical engineering from Illinois Institute of Technology and also holds a Bachelor of Engineering degree from NED University, Karachi Pakistan. Erum also authors articles in Certification Magazine and Cisco.com. About the Technical Reviewers Geoff Tagg runs a small U.K. networking company and has worked in the networking industry for nearly 30 years. Before that, he had 15 years of experience with systems programming and management on a wide variety of installations. Geoff has clients ranging from small local businesses to large multinationals and has combined implementation with training for most of his working life. Geoff’s main specialties are routing, switching, and networked storage. He lives in Oxford, England, with his wife, Christine, and family and is a visiting professor at nearby Oxford Brookes University. Sonya Coker has worked in the Cisco Networking Academy program since 1999 when she started a local academy. She has taught student and instructor classes locally and internationally in topics ranging from IT Essentials to CCNP. As a member of the Cisco Networking Academy development team she has provided subject matter expertise on new courses and course revisions. Jeremy Creech is a learning and development manager for Cisco with more than 13 years experience in researching, implementing, and managing data and voice networks. Currently, he is a curriculum development manager for the Cisco Networking Academy Program leveraging his experience as the content development manager for CCNP Certification exams. He has recently completed curriculum development initiatives for ROUTE, SWITCH, TSHOOT, and CCNA Security. Rick Graziani teaches computer science and computer networking courses at Cabrillo College in Aptos, California. Rick has worked and taught in the computer networking and information technology field for almost 30 years. Prior to teaching Rick worked in IT for various companies including Santa Cruz Operation, Tandem Computers, and Lockheed Missiles and Space Corporation. He holds a Master of Arts degree in computer science and systems theory from California State University Monterey Bay. Rick also does consulting work for Cisco and other companies. When Rick is not working, he is most likely surfing. Rick is an avid surfer who enjoys surfing at his favorite Santa Cruz breaks. David Kotfila, CCNA, CCDA, CCNP, CCDP, CCSP, CCVP, CCAI, teaches in the computer science department at Rensselaer Polytechnic Institute, Troy, New York. More than 550 of his students have received their CCNA, 200 have received their CCNP, and 14 have received their CCIE. David likes to spend time with his wife Kate, his daughter Charis, and his son Chris. David enjoys hiking, kayaking, and reading. Dr. Wayne Lewis has been a faculty member at Honolulu Community College since receiving a Ph.D. in math from the University of Hawaii at Manoa in 1992, specializing in finite rank torsion-free modules over a Dedekind domain. Since 1992, he served as a math instructor, as the state school-to-work coordinator, and as the legal main contact for the Cisco Academy Training Center (CATC). Dr. Lewis manages the CATC for CCNA, CCNP, and Security, based at Honolulu Community College, which serves Cisco Academies at universities, colleges, and high schools in Hawaii, Guam, and American Samoa. Since 1998, he has taught routing, multilayer switching, remote access, troubleshooting, network security, and wireless networking to instructors from universities, colleges, and high schools in Australia, Britain, Canada, Central America, China, Germany, Hong Kong, Hungary, Indonesia, Italy, Japan, Korea, Mexico, Poland, Singapore, Sweden, Taiwan, and South America both onsite and at Honolulu Community College. Jim Lorenz is an instructor and curriculum developer for the Cisco Networking Academy Program. Jim has co-authored Lab Companions for the CCNA courses and the textbooks for the Fundamentals of UNIX course. He has more than 25 years of experience in information systems, ranging from programming and database administration to network design and project management. Jim has developed and taught computer and networking courses for both public and private institutions. As the Cisco Academy Manager at Chandler-Gilbert College in Arizona, he was instrumental in starting the Information Technology Institute (ITI) and developed a number of certificates and degree programs. Jim co-authored the CCNA Discovery online academy courses, Networking for Home and Small Businesses and Introducing Routing and Switching in the Enterprise, with Allan Reid. Most recently, he developed the hands-on labs for the CCNA Security course and the CCNPv6 Troubleshooting course. Snezhy Neshkova, CCIE No. 11931, has been a Cisco Certified Internetwork Expert since 2003. She has more than 20 years of networking experience, including IT field services and support, management of information systems, and all aspects of networking education. Snezhy has developed and taught CCNA and CCNP networking courses to instructors from universities, colleges, and high schools in Canada, the United States, and Europe. Snezhy’s passion is to empower students to become successful and compassionate lifelong learners. Snezhy holds a Master of Science degree in computer science from Technical University, Sofia. Allan Reid, CCNA, CCNA-W, CCDA, CCNP, CCDP, CCAI, MLS, is a professor in information and communications engineering technology and the lead instructor at the Centennial College CATC in Toronto, Canada. He has developed and taught networking courses for both private and public organizations and has been instrumental in the development and implementation of numerous certificate, diploma, and degree programs in networking. Outside his academic responsibilities, Allan has been active in the computer and networking fields for more than 25 years and is currently a principal in a company specializing in the design, management, and security of network solutions for small and medium-sized companies. Allan is a curriculum and assessment developer for the Cisco Networking Academy Program and has authored several Cisco Press titles. Bob Vachon, CCNP, CCNA-S, CCAI, is a professor in the computer systems technology program at Cambrian College and has more than 20 years of experience in the networking field. In 2001 he began collaborating with the Cisco Networking Academy on various curriculum development projects including CCNA, CCNA Security, and CCNP courses. For 3 years Bob was also part of an elite team authoring CCNP certification exam questions. In 2007, Bob co-authored the Cisco Press book CCNA Exploration: Accessing the WAN. Acknowledgments Richard: I’d like to give special recognition to the entire Cisco Press team for the patience and support in producing this title. Balaji: I would like to acknowledge Mary Beth and Andrew from the Cisco Press team for their patience and support during the development of the book. Erum: I would like to give my thanks to Cisco Press— especially to Mary Beth for being understanding during the development of the book. In addition, I would like to acknowledge all the reviewers who helped make the book more valuable. Command Syntax Conventions The conventions used to present command syntax in this book are the same conventions used in the IOS Command Reference. The Command Reference describes these conventions as follows: • Boldface indicates commands and keywords that are entered literally as shown. In actual configuration examples and output (not general command syntax), boldface indicates commands that are manually input by the user (such as a show command). • Italic indicates arguments for which you supply actual values. • Vertical bars (|) separate alternative, mutually exclusive elements. • Square brackets ([ ]) indicate an optional element. • Braces ({ }) indicate a required choice. • Braces within brackets ([{ }]) indicate a required choice within an optional element. Introduction Over the past several years, switching has evolved from simple Layer 3 switches to switches supporting Layer 4 through Layer 7 features, such as server load balancing, URL inspection, firewalls, VPNs, access- based control, and so on, with large port densities. The multilayer switch has become an all-in-one component of the network infrastructure. As a result of this evolution, enterprise and service providers are deploying multilayer switches in place of multiple network components, such as routers and network appliances. Switching is no longer a part of the network infrastructure; it is now the network infrastructure, with wireless as the latest evolution. As enterprises, service providers, and even consumers deploy multilayer switching, the need for experienced and knowledgeable professionals to design, configure, and support the multilayer switched networks has grown significantly. CCNP and CCDP certifications offer the ability for network professionals to prove their competency. CCNP and CCDP are more than résumé keywords. Individuals who complete the CCNP and CCDP certifications truly prove their experience, knowledge, and competency in networking technologies. A CCNP certification demonstrates an individual’s ability to install, configure, and operate LAN, WAN, and dial access services for midsize to large networks deploying multiple protocols. A CCDP certification demonstrates an individual’s ability to design high-performance, scalable, and highly available routed and switched networks involving LAN, WAN, wireless, and dial access services. Both the CCNP and CCDP certification tracks require you to pass the SWITCH 642-813 exam. For the most up-to-date information about Cisco certifications, visit the following website: www.cisco.com/web/learning/le3/learning_career_certifications_and_learning_paths_home.html . Objectives and Methods This book’s content is based on the Cisco SWITCH course that has recently been introduced as part of the CCNP curriculum; it provides knowledge and examples in the area of implementing Cisco switched networks. It is assumed that the reader possesses as much Cisco background as is covered in the Cisco ROUTE and TSHOOT courses. The content of this book is enough to prepare the reader for the SWITCH exam, too. Note that the e-learning content of the Cisco SWITCH course has been integrated into this book. To accomplish these tasks, this text includes in-depth theoretical explanations of SWITCH topics and provides illustrative design and configuration examples. The theoretical explanations of SWITCH topics include background information, standards references, and document listings fromCisco.com. This book goes beyond just presenting the necessary information found on the certification exam and in the SWITCH course. This book attempts to present topics, theory, and examples in such a way that you truly understand the topics that are necessary to build multilayer switched networks in today’s demanding networks. The examples and questions found in the chapters of this book make you contemplate and apply concepts found in each chapter. The goal is to have you understand the topics and then apply your understanding when you attempt the certification exam or take the SWITCH course. Chapter review questions help readers evaluate how well they absorbed the chapter content. The questions are also an excellent supplement for exam preparation. Who Should Read This Book? Those individuals who want to learn about modern switching techniques and want to see several relevant examples will find this book very useful. This book is most suitable for those who have some prior routing and switching knowledge but would like to learn or enhance their switching skill set. Readers who want to pass the Cisco SWITCH exam can find all the content they need to successfully do so in this book. The Cisco Networking Academy CCNP SWITCH course students use this book as their official book. Cisco Certifications and Exams Cisco offers four levels of routing and switching certification, each with an increasing level of proficiency: Entry, Associate, Professional, and Expert. These are commonly known by their acronyms CCENT (Cisco Certified Entry Networking Technician), CCNA (Cisco Certified Network Associate), CCNP (Cisco Certified Network Professional), and CCIE (Cisco Certified Internetworking Expert). There are others, too, but this book focuses on the certifications for enterprise networks. For the CCNP certification, you must pass exams on a series of CCNP topics, including the SWITCH, ROUTE, and TSHOOT exams. For most exams, Cisco does not publish the scores needed for passing. You need to take the exam to find that out for yourself. To see the most current requirements for the CCNP certification, go to Cisco.com and click Training and Events. There you can find out other exam details such as exam topics and how to register for an exam. The strategy you use to prepare for the SWITCH exam might differ slightly from strategies used by other readers, mainly based on the skills, knowledge, and experience you have already obtained. For instance, if you have attended the SWITCH course, you might take a different approach than someone who learned switching through on-the-job training. Regardless of the strategy you use or the background you have, this book helps you get to the point where you can pass the exam with the least amount of time required. How This Book Is Organized This book is organized such that the fundamentals of multilayer switched network design are covered in the first chapters. Thereafter, the book continues with a discussion of implementation of the design features such as VLAN, Spanning Tree, and inter-VLAN routing in the multilayer switched environment. This book is organized as follows: • Chapter 1, “Analyzing the Cisco Enterprise Campus Architecture”—This chapter opens with a brief introdution to Cisco campus network architectures and designs. The chapter continues with a brief review of switching terminology for campus networks, followed by an introduction to Cisco switches. The chapter then continues with a of discussion of campus design fundamentals. Lastly, the chapter closes by introducting the PPDIOO Lifecycle Approach to Network Design and Implementation. • Chapter 2, “Implementing VLANs in Campus Networks”—This chapter covers implemenation of virtual LANs (VLAN) in a given campus network, including discussions on private VLANs, VTP, and 802.1Q trunking. In addition, this chapter covers implementation of EtherChannel in an enterpruse network. • Chapter 3, “Implementing Spanning Tree”—This chapter discusses the various Spanning Tree protocols, such as PVRST+ and MST, with overview and configuration samples. This chapter also continues the discussion with advanced Cisco STP enhancements and spanning-tree troubleshooting methodology. • Chapter 4, “Implementing Inter-VLAN Routing”—This chapter transitions into discussing Layer 3 switching by covering inter-VLAN routing. The chapter then continues with the discussion on Dynamic Host Configuration Protocol (DHCP). In addition, it discusses Cisco Express Forwarding (CEF)–based multilayer switching. • Chapter 5, “Implementing High Availability and Redundancy in a Campus Network”— This chapter covers the introduction to high availability in campus networks, followed by methodology on how to build resilient networks. This chapter continues to describe the tools available to monitor high availability such as SNMP and IP Service Level Agreement (SLA). This chapter concludes with available high availability options for switch supervisor engine and gateway redundancy protocols such as Hot Standby Router Protocol (HSRP), Virtual Router Redundancy Protocol (VRRP), and Gateway Load Balancing Protocol (GLBP). • Chapter 6, “Securing the Campus Infrastructure”—This chapter covers the potential campus security risks and how to mitigate them through features such as DCHP snooping, Dynamic ARP Inspection (DAI), and IP Source Guard. The chapter then continues to cover how to secure the switch device, and troubleshooting tools and techniques such as Switched Port Analyzer (SPAN) and Remote SPAN. • Chapter 7, “Preparing the Campus Infrastructure for Advanced Services”—This chapter discusses the application of advanced services to Cisco switches. The three main services discussed in this chapter are IP telephony (voice), video, and wireless. Moreover, because these advanced services require additional switch features for implementation, topics such as QoS and IP multicast are also discussed. • Appendix A, “Answers to Chapter Review Questions”—This appendix provides answers for the review questions that appear at the end of each chapter. Chapter 1. Analyzing the Cisco Enterprise Campus Architecture This chapter covers the following topics: • Introduction to Enterprise Campus Network Design • Enterprise Campus Design • PPDIOO Lifecycle Approach to Network Design and Implementation Over the last half century, businesses have achieved improving levels of productivity and competitive advantages through the use of communication and computing technology. The enterprise campus network has evolved over the last 20 years to become a key element in this business computing and communication infrastructure. The interrelated evolution of business and communications technology is not slowing, and the environment is currently undergoing another stage of evolution. The complexity of business and network requirements creates an environment where a fixed model no longer completely describes the set of capabilities and services that comprise the enterprise campus network today. Nevertheless, designing an enterprise campus network is no different than designing any large, complex system—such as a piece of software or even something as sophisticated as the international space station. The use of a guiding set of fundamental engineering principles serves to ensure that the campus design provides for the balance of availability, security, flexibility, and manageability required to meet current and future business and technological needs. This chapter introduces you to the concepts of enterprise campus designs, along with an implementation process that can ensure a successful campus network deployment. Introduction to Enterprise Campus Network Design Cisco has several different design models to abstract and modularize the enterprise network. However, for the content in this book the enterprise network is broken down into the following sections: • Core Backbone • Campus • Data Center • Branch/WAN • Internet Edge Figure 1-1 illustrates at a high level a sample view of the enterprise network. Figure 1-1. High-Level View of the Enterprise Network [View full size image] The campus, as a part of the enterprise network, is generally understood as that portion of the computing infrastructure that provides access to network communication services and resources to end users and devices spread over a single geographic location. It might span a single floor, a building, or even a large group of buildings spread over an extended geographic area. Some networks have a single campus that also acts as the core or backbone of the network and provides interconnectivity between other portions of the overall network. The campus core can often interconnect the campus access, the data center, and WAN portions of the network. In the largest enterprises, there might be multiple campus sites distributed worldwide with each providing both end-user access and local backbone connectivity. Figure 1-1 depicts the campus and the campus core as separate functional areas. Physically, the campus core is generally self contained. The campus itself may be physically spread out through an enterprise to reduce the cost of cabling. For example, it might be less expensive to aggregate switches for end-user connectivity in wiring closets dispersed throughout the enterprise.