Cisco Press
201 W 103rd Street
Indianapolis, IN 46290 USA

CCNP Support Exam Certification
Guide

Amir S. Ranjbar, MSc.

ii

CCNP Support Exam Certification Guide

Amir S. Ranjbar, MSc.
Copyright© 2001 Cisco Systems, Inc.
Cisco Press logo is a trademark of Cisco Systems, Inc.
Published by:
Cisco Press
201 West 103rd Street
Indianapolis, IN 46290 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 1 2 3 4 5 6 7 8 9 0
First printing October 2000
Library of Congress Cataloging-in-Publication Number: 00-105174
ISBN: 0-7357-0995-5

Warning and Disclaimer


Cisco Systems Program Manager Bob Anstey
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Development Editors Andrew Cupp
Howard Jones
Technical Editors Elan Beer
Steve Kalman
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Indexer Tim Wright

Copyright © 1999 Cisco Systems, Inc. All rights reserved. Printed in the USA. Access Registrar, AccessPath, Any to Any, AtmDirector, CCDA, CCDE, CCDP, CCIE, CCNA,
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, CCIE #1837, is president and founder of Synaptic Solutions, Inc. For the past
14 years, Elan has held several key positions within the telecommunications industry,
including Senior Telecommunication Consultant, Project Manager, and
Telecommunications Instructor, as well as Canadian Training Manager with GeoTrain
Corporation, a multinational training and consulting organization. Through his global
consulting and training engagements, Elan is recognized internationally as a
telecommunications industry expert. Elan’s strong technical skills have enabled him to
attain several top-level industry certifications, including Cisco System’s top-level
certification, the Cisco Certified Internetwork Expert (CCIE). As one of the first product-
based public Certified Cisco Instructors in the world, Elan has utilized his expertise in
multiprotocol internetworking, LAN, WAN, and MAN technology, network management,
and software engineering to provide training and consulting services to many of Canada’s
top companies. As a senior trainer and course developer, Elan has designed and presented
intensive public and implementation-specific technical courses for clients in North
America, Europe, Australia, Africa, Asia, and Scandinavia.

Steve Kalman

is a data communications trainer. He is the author or technical editor of 12
CBT titles and has been the author, technical editor, or trainer for eight instructor-led
courses. Steve is also beginning a new distance-learning project as both author and
presenter. In addition to those responsibilities, he runs a consulting company, Esquire
Micro Consultants, that specializes in data network design.
v

Dedication


Support Resources for Troubleshooting 3

Chapter 2

Understanding Troubleshooting Methods 33

Chapter 3

Identifying Troubleshooting Targets 49

Chapter 4

Applying Cisco Troubleshooting Tools 101

Chapter 5

Diagnosing and Correcting Campus TCP/IP Problems 159

Chapter 6

Diagnosing and Correcting Novell Networking Problems 189

Chapter 7

Diagnosing and Correcting AppleTalk Problems 215

Chapter 8

Diagnosing and Correcting Catalyst Problems 241


“Do I Know This Already?” Quiz 3
Foundation Topics 6
Network Media Test Equipment 6
Network Monitors 7
Protocol Analyzers 8
Network Management Systems 10
CiscoWorks 11
CiscoWorks for Switched Internetworks Software 12
TrafficDirector Remote Monitoring Software 12
Simulation and Modeling Tools 13
Cisco Connection Online (CCO) 13
Using CCO to Prevent Problems 15
Cisco Documentation CD-ROM 15
Cisco MarketPlace 16
CCO Software Library 17
Using CCO to Correct Problems 18
CCO Bug Toolkit 18
CCO Troubleshooting Engine 20
CCO Stack Decoder 20
CCO Open Forum 20
Escalation to Cisco Service and Support 22
CCO Case Management Toolkit 23
Foundation Summary 24
Q&A 26

Chapter 2

Understanding Troubleshooting Methods 33


The show interfaces Command 54
The show interfaces ethernet

n

Command 55
The show interfaces tokenring

n

Command 62
The show controllers Command 64
The show controller token Command Section 1 65
The show controller token Command Section 2 66
The show controller token Command Section 3 66
Token Ring Soft Errors 67
The show interfaces fddi Command 68
The show interfaces atm Command 73
Cisco Discovery Protocol 75
Common Protocol Characteristics 76
Understanding Protocol Connection Troubleshooting Targets 78
TCP Connection Sequence 78

x

The show ip arp Command 79
Novell Connection Sequence 80
The show novell traffic Command 81
AppleTalk Connection Sequence 82
The show appletalk traffic Command 82

show buffers Command 132
xi

show memory Command 133
show processes Command 134
show controllers cxbus Command 136
show stacks Command 137
Core Dumps 138
Foundation Summary 140
Handling Cisco IOS Troubleshooting Tools 140
Routing and Switching Tasks and Route Caching 140
Route Caching Methods and Commands 141
Debug Notes 141
Logging Options 142
Information Needed by Technical Support 143
General Information 143
Crash Situations 144
Performance Degradation Situations 144
Loss of Functionality Situations 144
Output of the show tech-support Command 144
Terms and Concepts Related to Buffer and Queues 145
Reported Conditions 145
Q&A 147

Chapter 5

Diagnosing and Correcting Campus TCP/IP Problems 159

Foundation Summary 207
Q&A 210

Chapter 7

Diagnosing and Correcting AppleTalk Problems 215

“Do I Know This Already?” Quiz 215
Foundation Topics 217
AppleTalk Configuration and Troubleshooting Checklist 217
The ping appletalk and test appletalk Commands 217
AppleTalk show Commands 218
show appletalk interface 219
show appletalk route 220
show appletalk zone 220
show appletalk access-lists 221
show appletalk adjacent-routes 221
show appletalk arp 222
show appletalk globals 222
show appletalk name-cache 223
show appletalk neighbors 223
show appletalk traffic 223
debug apple Commands 224
debug apple arp 225
debug apple errors 225
debug apple events 226
debug apple nbp 226

The show mac Command 260
The show module Command 262
The show port Command 263
The show config Command 267
The show span and show flash Commands 269
The show trunk Command 269
The show spantree Command 270
The show vtp domain Command 272
Catalyst Symptoms, Problems, and Suggested Actions 273
Case 1: Users Report that the Connection to Their Designated Local Switch is Not
Working 273

xiv

Case 2: Trouble Regarding Communication of the Terminal or Modem with the
Switch 274
Case 3: Switch Cannot Be Accessed from Remote Devices 274
Foundation Summary 275
Q&A 276

Chapter 9

Troubleshooting VLANS on Routers and Switches 285

“Do I Know This Already?” Quiz 286
Foundation Topics 289
Troubleshooting Cisco IOS Configuration 289
VLAN Design Issues for Troubleshooting 291
Switch/Router Configuration Consistency 291
Router VLAN Diagnostic Tools: show Commands 293

n

313
Frame Relay Loopback Testing 317
show frame-relay lmi [

interface

] 319
show frame-relay map 320
show frame-relay pvc 321
xv

The Frame Relay Diagnostic Tools: debug 322
debug serial interface 323
debug frame-relay lmi 324
The debug frame-relay and the debug frame-relay events Commands 325
debug frame-relay packet 326
Frame Relay Problem Isolation 327
Foundation Summary 330
Q&A 334

Chapter 11

Diagnosing and Correcting ISDN BRI Problems 345

“Do I Know This Already?” Quiz 345

Troubleshooting [CIT] Exam). I am a Certified Cisco Systems Instructor, and CIT is one of
the courses that I teach. I started teaching this course in the first quarter of 1999. I have
passed both the old CIT 4.0 and the new Support exams, and I am fully familiar with the
structure, content, and objectives of each of those exams. My students often ask me how I
think the Support exam is different from the old CIT 4.0 exam. My answer is that I did not
notice much change; therefore, any training material that can enhance your knowledge of
the subjects covered in Cisco’s instructor-based CIT course is still very much valid and
useful.
The Support (640-506) exam is one of the four exams you will need to pass to achieve Cisco
Certified Network Professional (CCNP) certification in the Routing and Switching career
track. The other three exams are the Routing (640-503), Switching (640-504), and Remote
Access (640-505) exams. Optionally, you can take one exam that combines these three
exams, Foundation 2.0 (640-509), but you will still need to pass the Support exam
separately to attain CCNP status. Also note that Cisco Certified Network Associate
(CCNA) status is a prerequisite to becoming CCNP certified.
Cisco strongly recommends that you attend its CCNP training courses before taking the
CCNP exams. Table I-1 shows these courses and how they roughly map to the various
exams. Cisco Press publishes coursebooks and Exam Certification Guides like this one to
support your preparation for these exams.

Table I-1

Cisco Courses and Exams for CCNP Routing and Switching Certification

Course Exam

Building Scalable Cisco Networks (BSCN) Routing (640-503)
Building Cisco Multilayer Switched Networks
(BCMSN)
Switching (640-504)

also contains additional features designed specifically for test preparation, such as quick-
reference Foundation Summary sections and a testing engine on the CD-ROM.

Target Audience

This book’s target audience is primarily those who want a condensed, exam-oriented book
to prepare them for the CCNP Support exam. On the other hand, very often a great portion
of my students who have thoroughly enjoyed the CIT course they have taken express their
desire to have my discussions and presentation in a written and organized format. This book
provides that, too. Indeed, the material adds explanations, output, configuration examples,
and exercises to those you might have seen in CIT training, to help you better understand
the topics being discussed.
I would like to share the following thought with the readers of this book. This book is not
a magic tool that somebody without the proper background can pick up, read, and use to
pass the Support exam. My assumption of the target audience’s background is a more-than-
basic familiarity with internetworking, routing, switching, and wide-area networking. You
should have at least a CCNA’s knowledge of these subjects. With reference to Cisco’s
training curriculum, this book’s prerequisite, if you will, is similar to the CIT course’s
prerequisite. In other words, I assume that the reader has a good grasp of the material
presented in the ICND (or CRLS/ICRC), BSCN (or ACRC), and BCMSN (or CLSC) Cisco
official training curriculum courses.

xviii

Support Exam Preparation Method

My personal opinion about preparing for any of the examinations is an orthodox one. I
believe that once somebody meets the prerequisites of a course, he or she should then take
the official training curriculum course. Next, he/she should practice the material learned in
the course through hands-on experimentation and/or using other reference material, such as

chapter ends with many review questions taken directly out of that chapter’s contents. Each
chapter’s review questions highlight the points that I want you to retain and to consider very
important.
This book is also accompanied by a CD-ROM that offers multiple-choice questions out of
the entire book’s content. Each question in the CD-ROM refers you to the chapter and
section it is drawn from. Being a quick and accurate reader, and having the knowledge and

Introduction

xix

skill to recognize the correct answer—or at least eliminate the incorrect answers—are the
skills that those who want to score well in multiple-choice exams must acquire.

Command Syntax Conventions

The conventions used to present command syntax in this book are the same conventions
used in the

Cisco IOS Command Reference

, as follows:

•

Boldface

indicates commands and keywords that are entered literally as shown. In
examples (not syntax), boldface indicates user input (for example, a


This final section of the introduction covers briefly the contents of each chapter in the book.

Chapter 1

Chapter 1 covers three main topics. First, it lists and introduces you to a number of
troubleshooting tools that are adequate for testing different aspects or components of an
internetworking model. You must learn when and why each tool is used, and what
information may be obtained from each. Next, Cisco Connection Online is introduced. You
should know who can access CCO and how. Familiarity with the content and structure of
CCO is required for the Support examination. Finally, Chapter 1 discusses the methodology
and the information required to escalate trouble scenarios to Cisco Service and Support.

Chapter 2

Chapter 2 discusses what systematic troubleshooting is and why it is absolutely essential
for every organization to have a formal methodology in place for this purpose. A generally
accepted troubleshooting methodology that is appropriate for internetwork support is
discussed element by element.
xx
Chapter 3
Chapter 3 covers identifying troubleshooting targets, and most of its attention is given to
the data-link layer. This chapter gives you a lot of information about the show interface
command’s output. In addition, the connection sequence in TCP/IP, IPX, and AppleTalk
environments are discussed.
Chapter 4
Chapter 4 has many topics and I consider it the core of CIT’s course material. Proper
handling of troubleshooting tools such as debug and logging, understanding router internal
operations (routing, switching, buffering), reachability testing, and troubleshooting
commands appropriate for performance degradation and crash cases are presented at
reasonable length.

3 Describe network media test equipment and their applications.
4 Explain network monitors, protocol analyzers, network management
systems, and network design/simulation tools.
5 Provide an overview of CiscoWorks and its components.
6 Describe CCO’s organization and the services, tools, and resources it
offers.
7 List the escalation steps to Cisco service and support.
C
H

A

P

T

E

R
1
Support Resources for
Troubleshooting
Today’s internetworks are large and complex. Furthermore, many businesses rely heavily
on steady and correct operation of their network infrastructure. Today’s networks are
mission critical resources, meaning that many companies stand to lose thousands,
sometimes millions, of dollars in a relatively short period, should their computing and
communications devices lose their local and remote connectivity. All of this makes the
network support task very essential. Should a component break down or be misconfigured,
the support group must be able to diagnose and fix the problem in a timely manner while
they allow for connectivity to be reinstated through alternate devices and paths during their

Name the tool that does multilayer analysis of network traffic.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
4
What are the five functional areas of network management?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
5
What is Cisco Systems’ flagship network management software called?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
6
List at least three members of the CWSI Campus Application.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
7
Name Cisco’s network simulation and modeling tool.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
8
What does the acronym CCO stand for, and what is the URL address for CCO?
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
“Do I Know This Already?” Quiz 5