CIT Cisco Internetwork Troubleshooting Version 5.2 Student Guide Text Part Number: ILSG Production Services: 03.25.05 Copyright 2005, Cisco Systems, Inc. All rights reserved. Cisco Systems has more than 200 offices in the following countries and regions. Addresses, phone numbers, and fax numbers are listed on the Cisco Website at www.cisco.com/go/offices. Argentina Australia Austria Belgium Brazil Bulgaria Canada Chile China PRC Colombia Costa Rica Croatia Cyprus Czech Republic Denmark Dubai, UAE Finland France Germany Greece Hong Kong SAR Hungary India Indonesia Ireland Israel Italy Japan Korea Luxembourg Malaysia Mexico The Netherlands New Zealand Norway Peru Philippines Poland Portugal Puerto Rico Romania Russia Saudi Arabia Scotland Singapore Slovakia Slovenia South Africa Spain Sweden Switzerland Taiwan Thailand Turkey Ukraine United Kingdom United States Venezuela Vietnam Zimbabwe Copyright 2005 Cisco Systems, Inc. All rights reserved. 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Table of Contents Course Introduction 1 Overview 1 Learner Skills and Knowledge 1 Course Goals and Objectives 2 Course Flow 3 Additional References 4 Cisco Glossary of Terms 4 Your Training Curriculum 5 Establishing a Baseline 1-1 Overview 1-1 Module Objectives 1-1 Creating Network Configuration Documentation 1-3 Overview 1-3 Objectives 1-3 Identifying the Components of a Network Configuration Table 1-4 Example: Network Configuration Table (Router) 1-6 Example: Network Configuration Table (Switch) 1-7 What Are the Components of a Topology Diagram? 1-8 Example: Network Topology Diagram No. 1 1-10 Example: Network Topology Diagram No. 2 1-11 Discovering Network Configuration Information 1-12 Example: Discovering Network Configuration of a Router 1-12 Example: Discovering Network Configuration of a Standard Switch 1-14 Creating Network Documentation 1-16 Identifying the Guidelines for Creating Network Documentation 1-18 Example: Creating Successful Network Documentation 1-19 Summary 1-20 Creating End-System Network Configuration Documentation 1-21 Overview 1-21 Objectives 1-21 What Are the Components of an End-System Network Configuration Table? 1-22 Example: End-System Network Configuration Table 1-24 What Are the Components of an End-System Network Topology Diagram? 1-25 Example: Topology Diagram with Both Network Devices and End Systems 1-27 What Are the Commands and Applications Used to Gather Information About End-System Network Configurations? 1-28 What Is the Process of Discovering End-System Network Configuration Information? 1-32 Example: Discovering End-System Network Configurations 1-32 Identifying the Guidelines for Creating End-System Network Configuration Documentation 1-34 Example: Creating Successful End-System Network Configuration Documentation 1-35 Summary 1-36 Module Summary 1-37 References 1-37 Module Self-Check 1-38 Module Self-Check Answer Key 1-40 Determining an Effective Troubleshooting Strategy 2-1 Overview 2-1 Module Objectives 2-1 Applying a Layered Model to a Network 2-3 Overview 2-3 Objectives 2-3 What Are the Differences Between Layered Networking Models? 2-4 Example: Comparing the OSI Model with the TCP/IP Model 2-4 Identifying the Encapsulated Data Flow Process 2-6 ii Cisco Internetwork Troubleshooting (CIT) v5.2 Copyright © 2005, Cisco Systems, Inc. Where Do Network Devices Map in a Logical Model? 2-7 Summary 2-8 Describing the General Troubleshooting Process 2-9 Overview 2-9 Objectives 2-9 What Are the Stages of the General Troubleshooting Process? 2-10 What Is the Gathering Symptoms Stage? 2-11 What Is the Isolate the Problem Stage? 2-12 What Is the Correct the Problem Stage? 2-13 Summary 2-14 Gathering Symptoms 2-15 Overview 2-15 Objectives 2-15 Gathering Network Symptoms 2-16 Gathering User Symptoms 2-19 Example: Gathering Network Symptoms from the End User 2-20 Gathering End-System Symptoms 2-21 Summary 2-24 Selecting a Troubleshooting Approach 2-25 Overview 2-25 Objectives 2-25 What Is the Bottom-Up Troubleshooting Approach? 2-26 What Is the Top-Down Troubleshooting Approach? 2-27 What Is the Divide-and-Conquer Troubleshooting Approach? 2-28 Selecting a Troubleshooting Approach 2-29 Example: Selecting a Troubleshooting Approach 2-30 Summary 2-31 Module Summary 2-32 References 2-32 Module Self-Check 2-33 Module Self-Check Answer Key 2-38 Resolving Problems at the Physical and Data Link Layers 3-1 Overview 3-1 Module Objectives 3-1 Isolating the Problem at the Physical and Data Link Layers 3-3 Overview 3-3 Objectives 3-3 What Are the Symptoms of Problems at the Physical Layer? 3-4 What Are the Symptoms of Problems at the Data Link Layer? 3-6 Analyzing Commands and Applications at the Physical and Data Link Layers 3-8 Example: Isolating Serial Interface Problems at the Physical Layer 3-13 Example: Isolating Frame Relay Problems at the Data Link Layer 3-17 Example: Isolating Ethernet Problems at the Physical and Data Link Layers 3-24 Example: Isolating Fast Ethernet Problems at the Physical and Data Link Layers 3-27 Example: Isolating a Problem at the Physical and Data Link Layers 3-29 Isolating Problems at the Physical and Data Link Layers 3-35 Example: Isolating Problems at the Physical and Data Link Layers 3-36 Summary 3-37 Correcting the Problem at the Physical and Data Link Layers 3-39 Overview 3-39 Objectives 3-39 What Are the Commands and Applications to Correct Problems at the Physical and Data Link Layers? 3-40 Example: Correcting a Serial Interface Problem at the Physical Layer 3-41 Example: Correcting a Frame Relay Problem at the Data Link Layer 3-44 Example: Correcting an Ethernet Problem at the Physical and Data Link Layers 3-48 Copyright 2005, Cisco Systems, Inc. Cisco Internetwork Troubleshooting (CIT) v5.2 iii Example: Correcting Fast Ethernet Problems at the Physical and Data Link Layers 3-51 Example: Correcting a Problem at the Physical and Data Link Layers 3-54 What Are Physical and Data Link Layer Support Resources? 3-58 Correcting Problems Occurring at the Physical and Data Link Layers 3-60 Summary 3-62 Module Summary 3-63 References 3-63 Module Self-Check 3-64 Module Self-Check Answer Key 3-66 Resolving Problems at the Network Layer 4-1 Overview 4-1 Module Objectives 4-1 Isolating the Problem at the Network Layer 4-3 Overview 4-3 Objectives 4-3 What Are the Symptoms of Problems at the Network Layer 4-4 Analyzing Cisco Command and Application Output at the Network Layer 4-6 Identifying End-System Commands and Applications at the Network Layer 4-15 Example: Isolating an Access List Problem at the Network Layer 4-17 Example: Isolating an IP Addressing Problem at the Network Layer 4-27 Example: Isolating Problems at the Network Layer 4-33 Isolating Problems at the Network Layer 4-39 Example: Isolating Problems Occurring at the Network Layer 4-40 Summary 4-41 Correcting the Problem at the Network Layer 4-43 Overview 4-43 Objectives 4-43 What Are the Cisco Commands Used at the Network Layer? 4-44 What Are the End-System Commands and Applications Used at the Network Layer? 4-50 Example: Correcting an Access List Problem at the Network Layer 4-51 Example: Correcting an IP Addressing Problem at the Network Layer 4-57 Example: Correcting Problems at the Network Layer 4-62 What Are the Network Layer Support Resources? 4-67 Correcting Problems at the Network Layer 4-68 Summary 4-70 Module Summary 4-71 References 4-71 Module Self-Check 4-72 Module Self-Check Answer Key 4-74 Resolving Problems at the Transport and Application Layers 5-1 Overview 5-1 Module Objectives 5-1 Isolating the Problem at the Transport and Application Layers 5-3 Overview 5-3 Objectives 5-3 What Are the Symptoms of Problems at the Transport Layer? 5-4 What Are the Symptoms of Problems at the Application Layer? 5-6 Analyzing Command and Application Output at the Transport Layer 5-8 Example: Isolating an Extended Access List Problem at the Transport Layer 5-12 Example: Isolating a Problem at the Transport Layer 5-21 Analyzing Command and Application Output at the Application Layer 5-31 Example: Isolating a TFTP Problem at the Application Layer 5-38 Example: Isolating a Problem at the Application Layer 5-44 Isolating Problems at the Transport and Application Layers 5-53 Example: Isolating a Problem Occurring at the Transport or Application Layer 5-54 Summary 5-55 iv Cisco Internetwork Troubleshooting (CIT) v5.2 Copyright © 2005, Cisco Systems, Inc. Correcting the Problem at the Transport and Application Layers 5-57 Overview 5-57 Objectives 5-57 What Are the Commands and Applications Used at the Transport Layer 5-58 Example: Correcting an Extended Access List Problem at the Transport Layer 5-59 Example: Correcting a Problem at the Transport Layer 5-61 What are the Commands and Applications Used at the Application Layer? 5-70 Example: Correcting a TFTP Problem at the Application Layer 5-73 Example: Correcting a Problem at the Application Layer 5-76 What Are Transport and Application Layer Support Resources? 5-81 Correcting Problems at the Transport and Application Layers 5-83 Summary 5-85 Module Summary 5-86 References 5-86 Module Self-Check 5-87 Module Self-Check Answer Key 5-89 CIT Course Introduction Overview Cisco Internetwork Troubleshooting (CIT) v5.2 is designed to provide learners with hands-on experience in troubleshooting suboptimal performance in a converged network and is an integral part of any approach to obtain the technical proficiency of Cisco CCNP ® . The course deepens the technical ability of the learner rather than introducing new baseline technology. Learner Skills and Knowledge This subtopic lists the skills and knowledge that learners must possess to benefit fully from the course. The subtopic also includes recommended Cisco learning offerings that learners should complete in order to benefit fully from this course. ©2005 Cisco Systems, Inc. All rights reserved. CIT v5.2 3 Learner Skills and Knowledge Interconnecting Cisco Network Devices (ICND) Building Cisco Multilayer Switched Networks (BCMSN) Building Cisco Remote Access Networks (BCRAN) Building Scalable Cisco Internetworks (BSCI) 2 Cisco Internetwork Troubleshooting (CIT) v5.2 Copyright © 2005, Cisco Systems, Inc. Course Goals and Objectives This topic describes the course goal and objectives. ©2005 Cisco Systems, Inc. All rights reserved. CIT v5.2 4 !To provide learners with hands-on experience in troubleshooting sub- optimal performance in a converged network" Cisco Internetwork Troubleshooting (CIT) v5.2 Course Goal Upon completing this course, you will be able to meet these objectives: Establish a baseline so that the network topology and configuration are diagrammed and tabulated Determine an effective troubleshooting strategy so that learners can detect, isolate, and correct network problems consistently Isolate and correct problems at the physical and data link layers so that framed data moves from one end of a data link to another at the expected data error rate determined in the network baseline Isolate and correct problems at the network layer so that connectivity at the network layer can be verified, the routing tables show reachability to all expected network devices specified in the baseline, and traffic is flowing over the correct path detailed in the network baseline Isolate and correct problems at the transport and application layers so that applications transmit data at an expected throughput, latency, and jitter based on the network baseline Copyright © 2005, Cisco Systems, Inc. Course Introduction 3 Course Flow This topic presents the suggested flow of the course materials. ©2005 Cisco Systems, Inc. All rights reserved. CIT v5.2 5 Course Flow Creating Network Configuration Documentation Course Introduction Creating End-System Network Configuration Documentation Correcting the Problem (Transport & Application) Lunch Describing a General Troubleshooting Process Isolating the Problem (Network Layer) Isolating the Problem (Transport & Application) A M P M Day 1Day 2Day 3Day 4Day 5 Applying a Layered Model to a Network Gathering Symptoms Selecting a Trouble- shooting Approach Isolating the Problem (Physical & Data Link) Correcting the Problem (Network Layer) Correcting the Problem (Cont.) (Transport & Application) Correcting the Problem (Cont.) (Physical & Data Link) Correcting the Problem (Physical & Data Link) Correcting the Problem (Cont.) (Network Layer) Correcting the Problem (Cont.) (Network Layer) Wrap-Up The schedule reflects the recommended structure for this course. This structure allows enough time for the instructor to present the course information and for you to work through the lab activities. The exact timing of the subject materials and labs depends on the pace of your specific class. 4 Cisco Internetwork Troubleshooting (CIT) v5.2 Copyright © 2005, Cisco Systems, Inc. Additional References This topic presents the Cisco icons and symbols used in this course, as well as information on where to find additional technical references. ©2005 Cisco Systems, Inc. All rights reserved. CIT v5.2 6 PC Cisco Icons and Symbols Router Workgroup Switch Network Cloud, Gray File Server Laptop Line: Serial Line: Ethernet Terminal Hub Network Cloud, White Token Ring Token Ring Cisco Glossary of Terms For additional information on Cisco terminology, refer to the Cisco Internetworking Terms and Acronyms glossary of terms at http://www.cisco.com/univercd/cc/td/doc/cisintwk/ita/index.htm. [...]... curriculum for this course Cisco Career Certifications Expand Your Professional Options and Advance Your Career Cisco Internetwork Troubleshooting (CIT) Professional-level recognition in CIT Expert CCIE Required Exam Recommended Training Through Cisco Learning Partners 642-831 Professional CCNP CCNP Associate CCNA CCNA CIT ©2005 Cisco Systems, Inc All rights reserved Cisco Internetwork Troubleshooting (CIT)... with current industry needs For more information on the Cisco Qualified Specialist focused certification, visit http://www .cisco. com/en/US/learning/le3/le11/learning_and_events _cisco_ certification_comm unity_tool_launch.html Copyright © 2005, Cisco Systems, Inc Course Introduction 5 6 Cisco Internetwork Troubleshooting (CIT) v5.2 Copyright © 2005, Cisco Systems, Inc Module 1 Establishing a Baseline Overview... EIGRP 10 s0/1 192.168.34.2/24 OSPF s1/0 Vesuvius, Cisco2 611XM fa0/0 fa0/1 Etna, Cisco1 760-V 172.18.2.1/16 EIGRP 10 ©2005 Cisco Systems, Inc All rights reserved CIT v5.21-4 A network configuration table can sometimes contain information that can be used to describe a router 1-6 Cisco Internetwork Troubleshooting (CIT) v5.2 Copyright © 2005, Cisco Systems, Inc Example: Network Configuration Table... documentation should be made by someone who has knowledge of the network being documented and has some previous experience troubleshooting that network 1-4 Cisco Internetwork Troubleshooting (CIT) v5.2 Copyright © 2005, Cisco Systems, Inc Network Configuration Table Components Related to Troubleshooting Physical Layer CPU Type Flash Memory DRAM Media Types Speed Duplex WAN Circuits Interface... consistent Keep the documents accessible Maintain the documentation ©2005 Cisco Systems, Inc All rights reserved 1-20 Cisco Internetwork Troubleshooting (CIT) v5.2 Copyright © 2005, Cisco Systems, Inc CIT v5.21-18 Lesson 2 Creating End-System Network Configuration Documentation Overview Network documentation can be a valuable tool for troubleshooting However, a network is not complete without end systems,... their existence is not particularly relevant to the diagram 1-8 Cisco Internetwork Troubleshooting (CIT) v5.2 Copyright © 2005, Cisco Systems, Inc Topology Diagram Components Physical Layer Device Name Media Type Interface Name Speed Data Link Layer MAC Address VLANs EtherChannel Trunk STP Route Encapsulation ©2005 Cisco Systems, Inc All rights reserved Network Layer IP Address... © 2005, Cisco Systems, Inc Establishing a Baseline 1-9 Example: Network Topology Diagram No 1 The figure illustrates a topology diagram that includes the following components: Device name Interface or port name IP address Routing protocol(s) Network Topology Diagram (Example No 1) ©2005 Cisco Systems, Inc All rights reserved A topology diagram can have many components 1-10 Cisco Internetwork Troubleshooting. .. interfaces to see a list of all interfaces at once 1-12 Cisco Internetwork Troubleshooting (CIT) v5.2 Copyright © 2005, Cisco Systems, Inc Discovering Network Configurations on Routers and Multilayer Switches (Cont.) View a summary of the IP routing protocols enabled for the device View details about the spanning-tree status on the device View a list of Cisco devices that are directly connected to the device... is complete 1-16 Cisco Internetwork Troubleshooting (CIT) v5.2 Copyright © 2005, Cisco Systems, Inc Note The process recommends that the network configuration table and topology diagram be created in concert However, it may benefit you to create one type of document first depending on your specific needs and the amount of documentation that is already available Copyright © 2005, Cisco Systems, Inc... objectives: Create network configuration documentation Create an end-system configuration table and end-to-end topology diagram 1-2 Cisco Internetwork Troubleshooting (CIT) v5.2 Copyright © 2005, Cisco Systems, Inc Lesson 1 Creating Network Configuration Documentation Overview When troubleshooting a network, a troubleshooter uses a baseline to efficiently diagnose and correct network problems The baseline . Certified Internetwork Expert logo, Cisco IOS, Cisco Press, Cisco Systems, Cisco Systems Capital, the Cisco Systems logo, Cisco Unity, Empowering the Internet. (BCRAN) Building Scalable Cisco Internetworks (BSCI) 2 Cisco Internetwork Troubleshooting (CIT) v5.2 Copyright © 2005, Cisco Systems, Inc. Course Goals