Troubleshooting andMaintaining Cisco IPNetworks (TSHOOT)Foundation Learning GuideAmir Ranjbar,CCIE No. 8669Cisco Press800 East 96th StreetIndianapolis, IN 46240

iiTroubleshooting and Maintaining Cisco IP Networks (TSHOOT) Foundation Learning GuideTroubleshooting and Maintaining Cisco IP Networks(TSHOOT) Foundation Learning GuideAmir RanjbarCopyright 2015 Pearson Education, Inc.Published by:Cisco Press800 East 96th StreetIndianapolis, IN 46240 USAAll rights reserved. No part of this book may be reproduced or transmitted in any form or by anymeans, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without written permission from the publisher, except for the inclusion ofbrief quotations in a review.Printed in the United States of AmericaFirst Printing December 2014Library of Congress Control Number: 2014955936ISBN-13: 978-1-58720-455-5ISBN-10: 1-58720-455-XWarning and DisclaimerThis book is designed to provide information about the Troubleshooting and Maintaining Cisco IPNetworks (TSHOOT) course, which is an element of the CCNP Routing and Switching certificationcurriculum. 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 author, 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 programsthat may accompany it.The opinions expressed in this book belong to the author and are not necessarily those of CiscoSystems, Inc.Trademark AcknowledgmentsAll terms mentioned in this book that are known to be trademarks or service marks have beenappropriately capitalized. Cisco Press or Cisco Systems, Inc., cannot attest to the accuracy of thisinformation. Use of a term in this book should not be regarded as affecting the validity of anytrademark or service mark.Special SalesFor information about buying this title in bulk quantities, or for special sales opportunities (whichmay include electronic versions; custom cover designs; and content particular to your business,training goals, marketing focus, or branding interests), please contact our corporate sales department at [email protected] or (800) 382-3419.For government sales inquiries, please contact [email protected] questions about sales outside the U.S., please contact [email protected].

iiiFeedback InformationAt Cisco Press, our goal is to create in-depth technical books of the highest quality and value. Eachbook is crafted with care and precision, undergoing rigorous development that involves the uniqueexpertise of members from the professional technical community.Readers’ feedback is a natural continuation of this process. If you have any comments regardinghow we could improve the quality of this book, or otherwise alter it to better suit your needs, youcan contact us through email at [email protected]. Please make sure to include the booktitle and ISBN in your message.We greatly appreciate your assistance.Publisher: Paul BogerAssociate Publisher: Dave DusthimerBusiness Operation Manager,Cisco Press: Jan CornelssenAcquisitions Editor: Mary Beth RayManaging Editor: Sandra SchroederDevelopment Editor: Ellie BruSenior Project Editor: Tonya SimpsonCopy Editor: Keith ClineTechnical Editor: Ted KimTeam Coordinator: Vanessa EvansCover Designer: Mark ShirarComposition: Trina WurstIndexer: Lisa StumpfProofreader: Debbie Williams

ivTroubleshooting and Maintaining Cisco IP Networks (TSHOOT) Foundation Learning GuideAbout the AuthorAmir Ranjbar, CCIE No. 8669, is a Certified Cisco Systems Instructor and a seniornetwork consultant. Operating under his own corporation, AMIRACAN Inc., Amiroffers his training services to Global Knowledge Network, his consulting expertise toa variety of clients (mainly Internet service providers), and his technical writing skillsto Cisco Press (Pearson Education, Inc.). Born in Tehran, Iran, Amir immigrated toCanada in 1983 at the age of 16 and completed his Master’s degree in knowledge-basedsystems (a branch in artificial intelligence [AI]) in 1991. He has been involved in training,consulting, and technical writing for the greater part of his career. Amir Ranjbar can becontacted through his email address [email protected] the Technical ReviewerTed Kim, CCIE No. 22769 (Routing and Switching and Service Provider), has 10 yearsof experience in the IT industry, with a focus on data center technologies during the pastseveral years. He has experience with designing, implementing, and troubleshooting largeenterprise environments. Ted’s networking career began at Johns Hopkins as a networkengineer, and he has been with Cisco since 2013 as a network consulting engineer.

vDedicationI dedicate this book to my father, Mr. Kavos Ranjbar, whom I lost on January 2, 2013. Iwish we could all be so loving, helpful, and generous, yet humble, peaceful, and gentle,just like my dad.AcknowledgmentsThis book is the result of work done by many individuals. I would like to offer mysincere gratitude to all of them, whether we worked together directly or otherwise.Mary Beth Ray, Ellie Bru, Tonya Simpson, Keith Cline, Vanessa Evans, Mark Shirar,Trina Wurst, and Lisa Stumpf, please accept my most sincere gratitude for the time andeffort you put into this project. I wish I could attend the next Pearson Education socialgathering and thank you all in person! Ted Kim, thank you for your technical review andfeedback; I hope to meet you someday and thank you in person, too.

viTroubleshooting and Maintaining Cisco IP Networks (TSHOOT) Foundation Learning GuideContents at a GlanceIntroduction xxiChapter 1:Troubleshooting Methods 1Chapter 2:Structured Troubleshooting 15Chapter 3:Network Maintenance Tasks and Best Practices 29Chapter 4:Basic Switching and Routing Process and Effective IOS TroubleshootingCommands 61Chapter 5:Using Specialized Maintenance and Troubleshooting Tools 99Chapter 6:Troubleshooting Case Study: SECHNIK Networking 117Chapter 7:Troubleshooting Case Study: TINC Garbage Disposal 173Chapter 8:Troubleshooting Case Study: PILE Forensic Accounting 257Chapter 9:Troubleshooting Case Study: Bank of POLONA 333Chapter 10:Troubleshooting Case Study: RADULKO Transport 397Appendix A: Answers to Review Questions 451Index453

viiContentsIntroduction xxiChapter 1Troubleshooting Methods1Troubleshooting Principles 1Structured Troubleshooting Approaches 4The Top-Down Troubleshooting Approach6The Bottom-Up Troubleshooting Approach7The Divide-and-Conquer Troubleshooting ApproachThe Follow-the-Path Troubleshooting Approach89The Compare-Configurations Troubleshooting ApproachThe Swap-Components Troubleshooting Approach11Troubleshooting Example Using Six Different ApproachesSummary101213Review Questions 14Chapter 2Structured Troubleshooting 15Troubleshooting Method and Procedure 16Defining the Problem 17Gathering Information 18Analyzing the Information 20Eliminating Potential Causes 21Proposing a Hypothesis (Likely Cause of the Problem)21Testing and Verifying Validity of the Proposed HypothesisSolving the Problem and Documenting the Work2324Troubleshooting Example Based on the Structured Method andProcedures 25Summary26Review Questions 27Chapter 3Network Maintenance Tasks and Best Practices 29Structured Network Maintenance 29Network Maintenance Processes and Procedures 31Common Maintenance Tasks 32Network Maintenance Planning 33Scheduling Maintenance33Formalizing Change-Control Procedures34Establishing Network Documentation Procedures34Establishing Effective Communication 35Defining Templates/Procedures/Conventions (Standardization)Planning for Disaster Recovery3636

viiiTroubleshooting and Maintaining Cisco IP Networks (TSHOOT) Foundation Learning GuideNetwork Maintenance Services and Tools 37Network Time Services 39Logging Services 40Performing Backup and Restore 42Integrating Troubleshooting into the Network Maintenance Process 47Network Documentation and Baseline 48Communication50Change Control53Summary54Review Questions 57Chapter 4Basic Switching and Routing Process and Effective IOSTroubleshooting Commands 61Basic Layer 2 Switching Process 61Ethernet Frame Forwarding (Layer 2 Data Plane) 62Layer 2 Switching Verification 67Basic Layer 3 Routing Process 69IP Packet Forwarding (Layer 3 Data Plane) 70Using IOS Commands to Verify IP Packet Forwarding 73Selective Information Gathering Using IOS show Commands, debugCommands, Ping, and Telnet 76Filtering and Redirecting show Command’s Output 76Testing Network Connectivity Using Ping and Telnet 81Collecting Real-Time Information Using Cisco IOS debug Commands 85Diagnosing Hardware Issues Using Cisco IOS Commands 86Checking CPU Utilization87Checking Memory UtilizationChecking InterfacesSummary888992Review Questions 94Chapter 5Using Specialized Maintenance and Troubleshooting Tools 99Categories of Troubleshooting Tools 100Traffic-Capturing Features and Tools 101SPANRSPAN102103Information Gathering with SNMP 105Information Gathering with NetFlow 107Network Event Notification 109

ixSummary113Review Questions 114Chapter 6Troubleshooting Case Study: SECHNIK Networking 117SECHNIK Networking Trouble Ticket 1 118Troubleshooting PC1’s Connectivity Problem 118Gathering Information119Analyzing Information, Eliminating Causes, and Gathering FurtherInformation 119Proposing Hypotheses121Testing the Hypotheses and Solving the ProblemTroubleshooting Ethernet TrunksTroubleshooting PC2’s Connectivity ProblemGathering Information121122123124Proposing a Hypothesis, Testing the Hypothesis, and Solving theProblem 126Troubleshooting NAT127Troubleshooting PC3’s Connectivity ProblemGathering Information128129Eliminating Possibilities, Proposing a Hypothesis, and Testing theHypothesis 129Troubleshooting Network Device Interfaces130Troubleshooting PC4’s IPv6 Connectivity ProblemGathering Information131131Eliminating Possibilities, Proposing a Hypothesis, and Testing theHypothesis 132Troubleshooting IPv6 Address Assignment on Clients133SECHNIK Networking Trouble Ticket 2 134Troubleshooting PC1’s Internet Connectivity Problem 134Gathering Information135Proposing a Hypothesis, Testing the Hypothesis, and Solving theProblem 137Troubleshooting Network Layer ConnectivityTroubleshooting PC2’s SSH Connectivity ProblemVerifying and Defining the ProblemGathering Information138141141142Proposing a Hypothesis and Testing the HypothesisTCP Three-Way Handshake145143

xTroubleshooting and Maintaining Cisco IP Networks (TSHOOT) Foundation Learning GuideTroubleshooting PC4’s DHCP Address ProblemVerifying and Defining the ProblemGathering Information146146147Proposing a Hypothesis, Testing a Hypothesis, and Solving theProblem 148Troubleshooting Error-Disabled Ports151SECHNIK Networking Trouble Ticket 3 152Troubleshooting PC1 and PC2’s Internet Connectivity Issues 153Verifying and Defining the ProblemGathering Information153153Proposing a Hypothesis and Testing the HypothesisSolving the Problem159Troubleshooting DHCP160The passive-interface Command161Troubleshooting PC3’s Internet Connectivity IssuesVerifying and Defining the ProblemGathering Information162162162Proposing a Hypothesis and Testing the HypothesisSolving the Problem157164165IPv6 Review 166Summary166Review Questions 169Chapter 7Troubleshooting Case Study: TINC Garbage Disposal 173TINC Garbage Disposal Trouble Ticket 1 174Troubleshooting Lack of Backup Internet Connectivity ThroughGW2 174Information Gathering176Analyzing Information, Eliminating Possibilities, and Proposing aHypothesis 178Proposing a Hypothesis, Testing the Hypothesis, and Solving theProblem 178Troubleshooting BGP Neighbor RelationshipsTroubleshooting PC1’s Connectivity ProblemGathering Information181182182Analyzing Information and Gathering Further Information183Proposing a Hypothesis, Testing the Hypothesis, and Solving theProblem 184Troubleshooting Port Security186

xiTroubleshooting PC2’s Connectivity ProblemGathering Information187188Eliminating Possibilities, Proposing a Hypothesis, and Testing theHypothesis 190Solving the Problem 191Troubleshooting VLANs 192TINC Garbage Disposal Trouble Ticket 2 193Troubleshooting GW1’s OSPF Neighbor Relation Problem with RouterR1 194Verifying the Problem194Gathering Information194Analyzing Information, Eliminating Possibilities, and Proposing aHypothesis 199Testing the Hypothesis and Solving the Problem199Troubleshooting OSPF Adjacency 201Troubleshooting Secure Shell Version 2 Access to Router R2 fromPC4 202Verifying the Problem202Gathering Information203Proposing a Hypothesis and Testing the HypothesisSolving the Problem204205Troubleshooting SSH and Telnet206Troubleshooting Duplicate Address Problem Discovered Through R1 andR2’s Log Messages 207Verifying the ProblemGathering Information207207Analyzing the Information and Proposing a HypothesisTesting the Hypothesis and Solving the ProblemTroubleshooting HSRP210210211TINC Garbage Disposal Trouble Ticket 3 212Troubleshooting Sporadic Internet Connectivity Problem Experienced byUsers of PC1 and PC2 212Verifying and Defining the ProblemGathering Information213213Analyzing Information and Proposing a HypothesisTesting the Hypothesis and Solving the ProblemTroubleshooting Erroneous Routing InformationTroubleshooting Multiple Masters within a VRRPVerifying and Defining the ProblemGathering Information221220215217218220

xiiTroubleshooting and Maintaining Cisco IP Networks (TSHOOT) Foundation Learning GuideAnalyzing the Information and Proposing a HypothesisTesting the Hypothesis, and Solving the ProblemTroubleshooting VRRP222224Troubleshooting EtherChannel Between ASW4 and ASW3Verifying the Problem224224Defining the Problem225Gathering Information225Proposing a Hypothesis and Testing the HypothesisSolving the Problem222227228Troubleshooting EtherChannel229TINC Garbage Disposal Trouble Ticket 4 231Troubleshooting Inconsistent and Sporadic Internet Connectivity ProblemExperienced By Users of PC1 and PC2 231Verifying and Defining the ProblemGathering Information232233Analyzing Information and Proposing a HypothesisTesting the HypothesesSolving the Problem235235239Troubleshooting FHRPs241Troubleshooting Sporadic Loss of Connectivity on PC4242Verifying the Problem and Making a Troubleshooting PlanGathering Information242242Analyzing the Information and Gathering Further InformationProposing a Hypothesis and Testing the HypothesisSolving the Problem245246The Cisco IOS DHCP Snooping FeatureCisco Technical Assistance Center248248Troubleshooting SSH Connection from PC4 to Router GW2Verifying the Problem and Making a Troubleshooting PlanGathering InformationSolving the Problem249249250Proposing a Hypothesis and Testing the HypothesisSummary244251252252Review Questions 255Chapter 8Troubleshooting Case Study: PILE Forensic Accounting 257PILE Forensic Accounting Trouble Ticket 1 258Troubleshooting PILE’s Branch Connectivity to HQ and the Internet 258Verifying and Defining the ProblemGathering Information260258

xiiiAnalyzing Information264Proposing a Hypothesis and Testing the HypothesisSolving the Problem264265Troubleshooting EIGRP Adjacency 266Troubleshooting PILE’s Secondary Internet Connection Through ISP2Verifying and Defining the ProblemGathering Information267268Analyzing Information and Proposing a HypothesisTesting the HypothesisSolving the Problem270271273PILE Forensic Accounting Trouble Ticket 2 274Troubleshooting Telnet Problem: From PC3 to BR 274Gathering Information275Troubleshooting PILE Network’s Internet Access ProblemVerifying and Defining the ProblemGathering Information275276276Analyzing Information, Eliminating Causes, and Gathering FurtherInformation 278Proposing and Testing a HypothesisSolving the Problem280281Troubleshooting BGP281Troubleshooting PILE Network’s NTP ProblemVerifying the Problem282283Gathering Information283Analyzing the Gathered Information and Gathering FurtherInformation 284Proposing a Hypothesis and Testing the HypothesisSolving the ProblemTroubleshooting NTP285286286PILE Forensic Accounting Trouble Ticket 3 287Troubleshooting PC3’s Lack of Internet Connectivity After the DisasterRecovery 287Verifying the Problem288Gathering Information (First Run)288Analyzing Information, Proposing, and Testing the FirstHypothesis 289Proposing and Testing the Second Hypothesis290Gathering Further Information (Second Run)292Proposing and Testing the Third Hypothesis293Solving the Problem294267

xivTroubleshooting and Maintaining Cisco IP Networks (TSHOOT) Foundation Learning GuideDisaster Recovery Best Practices294Troubleshooting Inter-VLAN Routing296Troubleshooting PC4’s Problem Accessing Cisco.comVerify the Problem and Select an Approach297Gather Information and Analyze the InformationProposing and Testing a HypothesisSolve the Problem297298299299Troubleshooting DNS300Remote Device Management Notes301PILE Forensic Accounting Trouble Ticket 4 302Troubleshooting Branch Site Internet Connectivity Problem After EIGRPReconfiguration 302Verifying the Problem302Gathering Information303Gathering Further Information and Analyzing InformationProposing a Hypothesis and Testing the HypothesisSolving the Problem305307The EIGRP Stub Configuration308The New EIGRP Named Configuration309Troubleshooting Management Access to ASW2Verifying the Problem310310Gathering Information310Proposing a Hypothesis and Testing the HypothesisSolving the Problem303311312Providing a Default Route on Layer 2 And Multilayer Devices 313PILE Forensic Accounting Trouble Ticket 5 313Troubleshooting the Redundant Internet Access Path Through the NewHQ0 Edge Router 314Verifying and Defining the ProblemGathering Information314315Proposing a Hypothesis and Testing the HypothesisSolving the Problem318319Troubleshooting BGP Route Selection321Troubleshooting Unauthorized Telnet AccessVerifying the Problem322322Gathering Information322Gathering Further Information and Analysis InformationProposing a Hypothesis and Testing the HypothesisSolving the Problem325Securing the Management Plane325324323

xvSummary326Review Questions 329Chapter 9Troubleshooting Case Study: Bank of POLONA 333Bank of POLONA Trouble Ticket 1 334Troubleshooting PC3’s Lack of Connectivity to SRV2 335Verifying the Problem335Gathering Information336Analyzing Information and Proposing a Hypothesis, and Testing theHypothesis 338Solving the Problem 339Troubleshooting Redistribution 339Troubleshooting VRRP with Interface TrackingVerifying the ProblemGathering Information341Analyzing the Information342Proposing and Testing a HypothesisSolving the Problem342343FHRP Tracking Options344Troubleshooting IP SLA Test Not StartingVerifying the Problem345345Gathering Information346Proposing and Testing a HypothesisSolving the Problem340340347348Troubleshooting IP SLA349Bank of POLONA Trouble Ticket 2 349Troubleshooting Summarization Problem on BR3 350Verifying the Problem350Gathering Information350Analyzing Information351Proposing and Testing a HypothesisSolving the Problem351352Troubleshooting EIGRP Summarization353Troubleshooting PC0’s IPv6 Internet ConnectivityVerifying the Problem353Gathering Information354Analyzing Information356Proposing and Testing a HypothesisSolving the Problem357Troubleshooting RIPng357356353

xviTroubleshooting and Maintaining Cisco IP Networks (TSHOOT) Foundation Learning GuideTroubleshooting Branch 3’s IPv6 Internet ConnectivityVerifying the Problem358Gathering Information359Analyzing Information361Proposing and Testing a HypothesisSolving the Problem358361362Troubleshooting Access Control Lists362Bank of POLONA Trouble Ticket 3 364Troubleshooting Branch 1’s IP Connectivity to the Headquarters 364Verifying the Problem364Gathering Information365Proposing and Testing a HypothesisGathering Further Information366367Proposing and Testing Another HypothesisSolving the Problem367368Troubleshooting GRE Tunnels368Troubleshooting Branch 3’s Route Summarization369Verifying the Problem and Choosing an ApproachGathering Information369370Analyzing the Information and Proposing a HypothesisTesting the Hypothesis and Solving the ProblemOSPF Summarization Tips and Commands373373374Troubleshooting AAA Authentication on the Branch 1 RouterVerifying the Problem and Choosing an ApproachGathering Information375Proposing a Hypothesis376Testing the Hypothesis and Solving the ProblemTroubleshooting AAA375376377Bank of POLONA Trouble Ticket 4 378Troubleshooting PC0’s Connectivity to IPv6 Internet 378Verifying the Problem and Choosing an ApproachGathering Information378379Analyzing the Information and Proposing and Testing aHypothesis 381Gathering Further Information382Analyzing Information and Proposing and Testing AnotherHypothesis 383Solving the Problem 384Troubleshooting OSPF for IPv6 385375

xviiTroubleshooting the Dysfunctional Totally Stubby Branch AreasVerifying the Problem and Choosing an ApproachGathering Information387Analyzing Information389Proposing and Testing a HypothesisSolving the ProblemOSPF Stub AreasSummary389390391391Review QuestionsChapter 10386394Troubleshooting Case Study: RADULKO TransportRADULKO Transport Trouble Ticket 1397398Mitigating Unauthorized Switches Added by EmployeesGathering Information399Analyzing Information400Proposing a Hypothesis and Solving the ProblemTroubleshooting Spanning Tree ProtocolTroubleshooting Policy-Based RoutingVerifying and Defining the ProblemGathering Information403404405Proposing and Testing a Hypothesis405406Troubleshooting PBR407Troubleshooting Neighbor Discovery407Verifying and Defining the Problem408Gathering Information408Proposing and Testing a HypothesisSolving the Problem400401404Analyzing the InformationSolving the Problem398409409Troubleshooting CDP and LLDP410RADULKO Transport Trouble Ticket 2 411Troubleshooting VLANs and PCs Connectivity Problems 411Verifying the Problem412Gathering Information412Analyzing the Information413Proposing and Testing a HypothesisSolving the ProblemTroubleshooting VTP414415413386

xviii Troubleshooting and Maintaining Cisco IP Networks (TSHOOT) Foundation Learning GuideTroubleshooting Branch Router’s IPv6 ProblemsVerifying the Problem416Gathering Information417Proposing and Testing a HypothesisSolving the Problem416418418Troubleshooting EIGRP for IPv6419Troubleshooting MP-BGP Session ProblemVerifying the Problem420420Gathering Information420Analyzing the Information and Proposing a HypothesisSolving the Problem421422Troubleshooting MP-BGP423RADULKO Transport Trouble Ticket 3 424Troubleshooting PC1’s Problem Accessing the SRV Server at theDistribution Center 424Verifying and Defining the ProblemGathering Information425Analyzing Information428Proposing and Testing a HypothesisSolving the Problem424428429Troubleshooting the OSPFv3 Address Families FeatureTroubleshooting OSPFv3 AuthenticationVerifying the Problem430430Gathering Information431Analyzing Information432Proposing and Testing a HypothesisSolving the Problem429432433RADULKO Transport Trouble Ticket 4 433Troubleshooting Undesired External OSPF Routes in DST’s RoutingTable 434Verifying and Defining the ProblemGathering Information435Analyzing Information436Proposing and Testing a HypothesisSolving the Problem439434437

xixTroubleshooting PCs IPv6 Internet AccessVerifying the Problem440Gathering Information440Analyzing Information442Proposing and Testing a HypothesisSolving the ProblemSummary444444Review Questions 448Appendix AIndex453Answers to Review Questions 451443440

xxTroubleshooting and Maintaining Cisco IP Networks (TSHOOT) Foundation Learning GuideIcons Used in This BookRouterWorkgroupSwitchNetworkCloudPIX FirewallAccess PointLaptopFile/ApplicationServerTerminalSecure ServerUserMultilayer SwitchWLAN ControllerCommand Syntax ConventionsThe conventions used to present command syntax in this book are the same conventionsused in the IOS Command Reference. The Command Reference describes theseconventions as follows:QBoldface indicates commands and keywords that are entered literally as shown. Inactual configuration examples and output (not general command syntax), boldfaceindicates commands that are manually input by the user (such as a show command).QItalic indicates arguments for which you supply actual values.QVertical bars ( ) separate alternative, mutually exclusive elements.QSquare brackets ([ ]) indicate an optional element.QBraces ({ }) indicate a required choice.QBraces within brackets ([{ }]) indicate a required choice within an optional element.

xxiIntroductionThis book is based on the Cisco Systems TSHOOT course, which was recentlyintroduced as part of the CCNP curriculum. It provides troubleshooting andmaintenance information and examples that relate to Cisco routing and switching. Itis assumed that readers know and understand as much Cisco routing and switchingbackground as covered in the Cisco ROUTE and SWITCH courses. The book is enoughto prepare you for the TSHOOT exam, too.Teaching troubleshooting is not an easy task. This book introduces you to manytroubleshooting methodologies and identifies the benefits of different techniques.Technical routing and switching topics are briefly reviewed, but the emphasisis on troubleshooting commands, and most important, this book presents manytroubleshooting examples. Chapter review questions will help you evaluate how well youabsorbed material within each chapter. The questions are also an excellent supplementfor exam preparation.Who Should Read This Book?Those individuals who want to learn about modern troubleshooting methodologies andtechniques and want to see several relevant examples will find this book very useful. Thisbook is most suitable for those who have some prior routing and switching knowledgebut would like to learn more or otherwise enhance their troubleshooting skill set.Readers who want to pass the Cisco TSHOOT exam can find all the content they needto successfully do so in this book. The Cisco Networking Academy CCNP TSHOOTcourse students will use this book as their official textbook.Cisco Certifications and ExamsCisco offers four levels of routing and switching certification, each with an increasinglevel of proficiency: Entry, Associate, Professional, and Expert. These are commonlyknown by their acronyms CCENT (Cisco Certified Entry Networking Technician),CCNA (Cisco Certified Network Associate), CCNP (Cisco Certified NetworkProfessional), 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, includingthe SWITCH, ROUTE, and TSHOOT exams. For most exams, Cisco does not publishthe 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 andclick Training and Events. There you can find out other exam details such as examtopics and how to register for an exam.

xxiiTroubleshooting and Maintaining Cisco IP Networks (TSHOOT) Foundation Learning GuideThe strategy you use to prepare for the TSHOOT exam might differ slightly from strategiesused by other readers, mainly based on the skills, knowledge, and experience you havealready obtained. For instance, if you have attended the TSHOOT course, you might take adifferent approach than someone who learned troubleshooting through on-the-job training.Regardless of the strategy you use or the background you have, this book is designed to helpyou get to the point where you can pass the exam with the least amount of time required.How This Book Is OrganizedAlthough this book can be read cover to cover, it is designed to be flexible and allow youto easily move between chapters to cover only the material for which you might needadditional remediation. The chapters can be covered in any order, although some chaptersare related to and build upon each other. If you do intend to read them all, the order inthe book is an excellent sequence to follow.Each core chapter covers a subset of the topics on the CCNP TSHOOT exam. Thechapters cover the following topics:QChapter 1 introduces the troubleshooting principles and discusses the most commontroubleshooting approaches.QChapter 2 defines structured troubleshooting and analyzes all the subprocesses ofstructured troubleshooting.QChapter 3 introduces structured network maintenance and discusses network maintenance processes and procedures. Network maintenance services and tools, along withhow you can integrate troubleshooting into the network maintenance process, arealso presented in this chapter.QChapter 4 reviews the Layer 2 switching and Layer 3 routing processes and showshow to do selective information gathering using the IOS show command, debugcommand, ping, and Telnet.QChapter 5 discusses troubleshooting tools: traffic-capturing features and tools, information gathering with SNMP, information gathering with NetFlow, and networkevent notification with EEM.QChapters 6 through 10 are all troubleshooting cases. Each chapter is about a different network with many different problems. Each problem is dealt with in the formof a real-life trouble ticket, and it is fixed following the structured troubleshootingmethodology using the appropriate approach. All stages of troubleshooting, including fact gathering, are presented with output from Cisco IOS routers and switches.The network diagrams for Chapters 6 through 10 appear at the beginning and endof each chapter. For easier reference, a PDF of these network diagrams is available to download and print out or read on your e-device. Go to and click on the Downloads tab.There is also an appendix that has answers to the review questions found at the end of eachchapter.

Chapter 1Troubleshooting MethodsThis chapter cov

Collecting Real-Time Information Using Cisco IOS debug Commands 85 Diagnosing Hardware Issues Using Cisco IOS Commands 86 Checking CPU Utilization 87 Checking Memory Utilization 88 Checking Interfaces 89 Summary 92 Review Questions 94 Chapter 5 Using Specialized Maintenance and Trouble