About This Manual

This front matter section introduces the Troubleshooting Internetworking Systems audience and scope, organization, use, and conventions.

Audience and Scope

This publication addresses the network administrator or system administrator who will maintain a Cisco gateway, router, or bridge running Release 9.1 and earlier software. This release of the manual focuses on generic WAN/serial, TCP/IP, Novell IPX, IBM/SNA, and AppleTalk internets.

Readers should know how to configure a Cisco router and should be familiar with the protocols and media their routers have been configured to support. Awareness of their networking topology is also important.

Document Organization and Use

The Troubleshooting Internetworking Systems guide provides information about troubleshooting Cisco network servers.

Chapter 1, "Troubleshooting Overview," introduces a generic model of problem solving and provides basic information regarding troubleshooting Cisco internetworks. It is important that you read this chapter first before proceeding to other chapters of the manual.

Chapter 2, "Connectivity Problem Scenarios," presents problem-solving scenarios that focus on identifying, isolating, and solving internetworking connectivity problems. Scenarios for WAN/serial, TCP/IP, Novell/IPX, IBM/SNA, and Appletalk internets are included. Each of these describes the symptoms of the problem(s), the internetworking environment, problem cause alternatives, the process of isolating those causes, and a summary of the process.

Chapter 3, "Troubleshooting Apple Connectivity," presents protocol-related troubleshooting information for AppleTalk networks, including AppleTalk internetworking terminology, AppleTalk internetworking diagnostic tips, preventing AppleTalk configuration problems, and symptom modules. These symptom modules provide snapshots of common symptoms, possible causes, and suggested actions to resolve the problems.

Chapter 4, "Troubleshooting IBM Connectivity," presents protocol-related troubleshooting information for IBM networks, including diagnosing IBM network and Token Ring problems and symptom modules. These symptom modules provide snapshots of common symptoms, possible causes, and suggested actions to resolve the problems.

Chapter 5, "Troubleshooting Novell Connectivity," presents protocol-related troubleshooting information for Novell networks, including a Novell IPX Internet diagnostic overview and symptom modules. These symptom modules provide snapshots of common symptoms, possible causes, and suggested actions to resolve the problems.

Chapter 6, "Troubleshooting TCP/IP Connectivity," presents protocol-related troubleshooting information for TCP/IP networks, including a TCP/IP Internet diagnostic overview and symptom modules. These symptom modules provide snapshots of common symptoms, possible causes, and suggested actions to resolve the problems.

Chapter 7, "Troubleshooting WAN Connectivity," presents protocol-related troubleshooting information for IBM networks, including diagnosing WAN and serial line problems and symptom modules. These symptom modules provide snapshots of common symptoms, possible causes, and suggested actions to resolve the problems.

Chapter 8, "Performance Problem Scenarios," presents problem-solving scenarios that focus on identifying, isolating, and solving internetworking performance problems. Scenarios for WAN/serial, TCP/IP, Novell/IPX, IBM/SNA, and Appletalk internets are included. Each of these sections describes the symptoms of the problem(s), the internetworking environment, problem cause alternatives, the process of isolating those causes, and a summary of the process.

Chapter 9, "Troubleshooting Internet Performance," focuses on common symptoms associated with poor performance in internetworks, possible causes of those symptoms, and general suggestions for identifying, isolating, and resolving causes.

Chapter 10, "Debug Command Reference," presents reference information on over 40 commands that you can use as tools to debug your internetwork. Descriptions of the uses of these commands, sample output displays, and explanations of these displays are included.

Appendix A, "X.25 Cause and Diagnostics Codes," lists the codes that can appear in output from the Debug X.25, Debug X.25-Events, and Debug X.25-VC debugging commands.

Appendix B, "Technical Support Information List," lists the information you can provide your technical support representative in order to speed up and facilitate problem resolution.

Appendix C, "Problem Solving Checklist/Worksheet," includes a worksheet that you can use to structure your strategy for problem isolation and resolution.

Appendix D, "Creating Core Dumps," describes the various ways that you can capture core dump information following a router crash and transmit that information to your technical support representative for further analysis.

Appendix E, "References and Recommended Reading," lists commercially available publications that provide background information on troubleshooting internetworks and the protocols covered in this guide. It also includes a section listing other technical publications that you may find useful.

Document Conventions

The command descriptions use these conventions:

Commands and keywords are in boldface.
Filenames, directory names, and variables for which you supply values are in italics.
Elements in square brackets ([ ]) are optional.
Alternative but required keywords are grouped in braces ({ }) and are separated by a vertical bar (|).
A string is defined as a nonquoted set of characters. For example, when setting up a community string for SNMP to "public", do not use quotes around the string or the string will be set to "public".

The samples use these conventions:

Terminal sessions are printed in a screen font.
Information you enter is in a boldface screen font.
Nonprinting characters are shown in angle brackets (<>).
Information the system displays is in screen font, with default responses in square brackets ([ ]).

This publication also uses the following conventions:

Note is a special paragraph that means reader take note. It usually refers to helpful suggestions, the writer's assumptions, or reference to materials not contained in this manual.

Caution is a special paragraph that means reader be careful. It means that you are capable of doing something that might result in equipment damage, or worse, that you might have to take something apart and start over again.

Table of Contents