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

CLSC Exam Certification Guide

Kevin Downes, CCIE #1987, and Tim Boyles, CCNP

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1
The Cisco LAN Switch
Configuration (CLSC) Exam
Overview
The CLSC exam evaluates the internetworking knowledge of network administrators,
network specialists, and technicians who configure and support multiprotocol
internetworks. The candidates attempting the CLSC exam must possess the skills to
perform the following tasks:

individual objective, is open to interpretation. This book generally follows the CLSC course
to determine the depth of coverage for various objectives.
A full definition of exactly what topics are on the exam will probably never be stated by
Cisco. Cisco does want candidates to succeed at passing the CLSC exam, but not at the
expense of making the Cisco career certification an easily attained paper diploma. Cisco’s
goal is that passing the CLSC exam should reflect the fact that you have internalized and
mastered the concepts, not that you can read a book and memorize well. To protect against
the CCDP and CCNP losing credibility due to people just reading a book and passing the
test, Cisco will probably always avoid an exact definition of the topics on the exam. Giving
a general definition only will reward those who understand networks; those who prefer to
memorize will be less likely to pass the test.
Table 1-1 Training Paths for Becoming a CCNP
Training Path What Is Involved
1
CCNP Path As defined by Cisco Systems, this involves taking these courses:
Advanced Cisco Router Configuration (ACRC)
Cisco LAN Switch Configuration (CLSC)
Configuring, Monitoring, and Troubleshooting Dialup Services (CMTD)
Cisco Internetworking Troubleshooting (CIT)
The candidate then would take a test for each class attended. (Note that
the ACRC, CLSC, and CMTD exams can be taken all together as the
Foundation Routing and Switching [FRS] exam.)
2
On-the-job
training
The courses are not required to take the exams, but the exams require a
large amount of specific knowledge. Candidates who have not taken the
courses should use this book to make sure they are familiar with all the
objectives.
When the candidate is familiar with the exam objectives, he or she would

CLSC Exam Preparation
This book contains many solid tools to help you prepare for the CLSC exam. Some of the
key features to help you are outlined in the next few sections.
Chapters Follow the Objectives
Each chapter clearly follows the CLSC exam objectives so that you can stay on track with
the material that will be covered in the exam. You’ll know clearly what objective each
section is covering.
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6 Chapter 1: The Cisco LAN Switch Configuration (CLSC) Exam Overview
Determining Your Strengths and Weaknesses
You may feel confident about one topic and less confident about another. However, that may
be a confidence problem, not a knowledge problem! One key to using your time well is to
determine whether you truly need more study or not—and if so, how much?
The chapters are designed to guide you through the process of determining what you need
to study. Suggestions are made as to how to study a topic based on your personal strengths.
Each chapter begins with a quiz that helps you decide how well you recall the topics in that
chapter. From there, you can choose to fully read the entire chapter, to ignore that chapter
because you know it already, or something in between. Much of the factual information is
summarized into lists and charts in the Foundations Summaries sections, so a review of the
chapter is easy. Also, exercises at the end of the chapter provide an excellent tool for
practice and for quick review.
Questions and Exercises That Are Harder Than the Actual Exam
The exercises in this book are intended to make you stretch beyond what the exam requires.
Do not be discouraged as you take the quizzes and exercises in the book; they are intended
to be harder than the exam. If, by the end of your study time, you are getting 70 or 80
percent of these harder non-multiple choice questions correct, you should find the CLSC
exam easier to handle. You will probably want to validate your readiness by using the
testing engine included on the CD-ROM with this book.
The main purpose for making this book’s exams harder than the CLSC exam is not by
asking for facts or concepts you will never see on the CLSC exam; it is by asking for

The Catalyst 5000 series switch hardware
•
Configuring the Supervisor module and Fast Ethernet
•
The Catalyst 5000 switch series software
•
Managing the Catalyst 5000 series switch
•
Troubleshooting the Catalyst 5000 series switch
•
The Catalyst 5000 FDDI module
•
ATM LAN Emulation concepts
•
The Catalyst 5000 series ATM LANE module
•
Configuring the Catalyst 5000 series ATM LANE modules
•
Catalyst 2820 and Catalyst 1900 features
•
Configuring Catalyst 2820 and Catalyst 1900 switches
•
Catalyst 3000 series switches
•
Configuring the Catalyst 3000 series switch
List of the CLSC Exam Objectives
Table 1-2 lists all the CLSC exam objectives. These are the objectives this book will help
you master to pass the CLSC exam. Each chapter also begins with a list of which objectives
are covered in that chapter.
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The CLSC Exam Objectives 9
26 Describe local resources and remote resources.
27 Describe configuration rules for local resources and remote resources.
28 Name five applications for Catalyst 5000 series switches.
29 Describe Catalyst 5000 series switch product evolution.
30 Describe Catalyst 5000 product features.
31 Describe Catalyst 5002 product features.
32 Describe Catalyst 5500 product features.
33 Describe the architecture and function of major components of the Catalyst 5000 series
switch:
• Processors: NMP, MCP, and LCP
• Logic Units: LTL, CBL, Arbiter, and EARL
• ASICs: SAINT, SAGE, SAMBA, and Phoenix
34 Trace a frame’s progress through a Catalyst 5000 series switch.
35 Describe the hardware features, functions, and benefits of Catalyst 5000 series switches.
36 Describe the hardware features and functions of the Supervisor engine.
37 Describe the hardware features and functions of the modules in the Catalyst 5000 series
switches.
38 Prepare network connections.
39 Establish a serial connection.
40 Use the Catalyst 5000 switch CLI to:
• Enter privileged mode.
• Set system information.
• Configure interface types.
41 Upon completion of this module, you will be able to describe the different ways of
managing the Catalyst 5000 series switch, including:
• Out-of-band management (console port)
• In-band management (network connection using SNMP)
• RMON
•SPAN

61 Describe the architecture.
Table 1-2 List of CLSC Exam Objectives (Continued)
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The CLSC Exam Objectives 11
62 Describe the following key features and applications of the Catalyst 1900 and 2820
switches:
• Switching modes
• Virtual LANs
• Multicast packet filtering and registration
• Broadcast storm control
• Management support, CDP, and CGMP
63 Trace a frame’s progress through a Catalyst 1900 or Catalyst 2820 switch.
64 Use the Catalyst 1900 and Catalyst 2820 switch menus for configuration.
65 Configure IP addresses and ports on the Catalyst 1900 and Catalyst 2820 switches.
66 Configure VLANs on the Catalyst 1900 and Catalyst 2820 switches.
67 View the Catalyst 1900 and Catalyst 2820 switch reports and summaries.
68 Configure the ATM LANE module on the Catalyst 2820 switch.
69 Describe Catalyst 3000 series LAN switch products.
70 Describe Catalyst 3000 series LAN switch product differences.
71 Describe the Catalyst Stack System.
72 Perform initial setup of a Catalyst 3000 series switch.
73 Configure the switch for management.
74 Configure port parameters.
75 Configure VLANs and trunk links.
76 Configure the ATM LANE module.
77 Perform basic router module configuration.
78 Describe the POST and diagnostic messages on the Catalyst 1900 and Catalyst 2820
switches.
79 Describe the cabling guidelines for the Catalyst 1900 and Catalyst 2820 switches.
80 Use the statistics and reports to maintain the Catalyst 1900 and Catalyst 2820 switches.

7 Configuring the Catalyst 5000 Series Switch 5
8 Catalyst 5000 Series Switch Software 4
9 Managing the Catalyst 5000 Series Switches 4
10 Troubleshooting the Catalyst 5000 Series Switches 2
11 Catalyst 5000 Series Switch FDDI Module 4
12 ATM LANE Concepts 3
13 Catalyst 5000 Series Switch ATM LANE Module 4
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Cross-Reference to Objectives Covered in Each Chapter of the Book 13
Cross-Reference to Objectives Covered in Each
Chapter of the Book
Table 1-4 provides a breakdown of where the test objectives fall in each chapter.
(For convenience, the objectives also are listed at the beginning of each chapter.)
Section Number Section Title
Number of
Questions
14 Configuring the Catalyst 5000 Series Switch ATM
LANE Module
6
15 Catalyst 2820 and Catalyst 1900 Hardware 3
16 Catalyst 2820 and Catalyst 1900 Features 4
17 Configuring Catalyst 2820 and Catalyst 1900 Switches 3
18 Catalyst 3000 Series Switches 3
19 Configuring the Catalyst 3000 Series Switches 4
Table 1-4 CLSC Exam Objectives Cross-Reference List
Chapter Objectives Covered
2 7–13
3 14–23
4 3, 24–28
5 2, 33, 34

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2
Introduction to Switching
Concepts
In the past, network designers had only a limited number of hardware options when
purchasing a technology for their campus networks. Hubs were for wiring closets, and
routers were for the data center or main telecommunications operations. The increasing
power of desktop processors and the requirements of client-server and multimedia
applications, however, have driven the need for greater bandwidth in traditional shared-
media environments. These requirements are prompting network designers to replace hubs
in their wiring closets with switches.
Switching is a technology that alleviates congestion in Ethernet, Token Ring, and Fiber
Distributed Data Interface (FDDI) LANs by reducing traffic and increasing bandwidth.
Such switches, known as LAN switches, are designed to work with existing cable
infrastructures so that they can be installed with minimal disruption of existing networks.
How to Best Use This Chapter
By taking the following steps, you can make better use of your study time:
•
Keep your notes and the answers for all your work with this book in one place, for

Low/Medium
Score
Take the End of
Chapter Quiz
Proceed to the
Next Chapter
Take the End of
Chapter Review Quiz
Review Answers to
Quiz in Appendix A
Review Answers to
Quiz in Appendix A
Review Answers to
Quiz in Appendix A
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Do I Know This Already? Quiz 19
b.
It provides more bandwidth per user.
c.
It reduces WAN costs.
d.
It increases the number of dumb terminals on the network.
2
Segmenting LANs with bridges:
a.
Occurs at OSI Layer 3.
b.
Reduces the propagation of multicast and broadcast frames.
c.
Provides fewer users per segment.

Receive-and-send
d.
Store-and-forward
6
Using full-duplex Ethernet:
a.
Requires the attached node to be directly attached to a repeater hub.
b.
Requires the attached node to have an installed network interface card that supports
full-duplex Ethernet.
c.
Provides the same performance as half-duplex Ethernet.
d.
Increases contention on Ethernet point-to-point links.
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20 Chapter 2: Introduction to Switching Concepts
7
Full-duplex port connections can use which of the following media types to provide
point-to-point links between switches or end nodes:
a.
10BaseT
b.
10BaseFL
c.
100BaseTX
d.
100BaseFX
e.
ATM
f.

b.
2820
c.
3000
d.
5000
e.
5500
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Do I Know This Already? Quiz 21
Using the answer key in Appendix A, grade your answers.
•
5 or less correct—Read this chapter.
•
6, 7, or 8 correct—Review this chapter, looking at the charts and diagrams that
summarize most of the concepts and facts in this chapter.
•
9 or more correct—If you want more review on these topics, skip to the Q&A section
at the end of this chapter. If you do not want more review on these topics, skip this
chapter.
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22 Chapter 2: Introduction to Switching Concepts
Foundation Topics
Bridging and Switching Basics
The material presented here is intended to help the reader understand switch features;
however, it is not directly related to one of the objectives.
Bridges and switches are data communications devices that operate principally at Layer 2
of the OSI reference model. As such, they are widely referred to as data link layer devices.
Bridges became commercially available in the early 1980s. At the time of their introduction,
bridges connected and enabled packet forwarding between homogeneous networks. More

Token Ring). Finally, source-route transparent bridging combines the algorithms of
transparent bridging and source-route bridging to enable communication in mixed
Ethernet/Token Ring environments.
Today, switching technology has emerged as the evolutionary heir to bridging-based
internetworking solutions. Switching implementations now dominate applications in which
bridging technologies were implemented in prior network designs. Superior throughput
performance, higher port density, lower per-port cost, and greater flexibility have
contributed to the emergence of switches as replacement technology for bridges and as
complements to routing technology.
Internetworking Device Comparison
Internetworking devices offer communication between local-area network (LAN) segments.
Four primary types of internetworking devices exist: repeaters, bridges, routers, and
gateways. These devices can be differentiated very generally by the Open System
Interconnection (OSI) layer at which they establish the LAN-to-LAN connection. Repeaters
connect LANs at OSI Layer 1; bridges connect LANs at Layer 2; routers connect LANs at
Layer 3; and gateways connect LANs at Layers 4–7. Each device offers the functionality
found at its layer(s) of connection and uses the functionality of all lower layers.
OSI Layers
Now that the network equipment that services each layer of the OSI model has been
described, each individual OSI layer and its functions can be discussed. Each layer has a
predetermined set of functions it must perform for communication to occur.
Application Layer
The application layer is the OSI layer closest to the user. It differs from the other layers in
that it does not provide services to any other OSI layer, but rather to application processes
lying outside the scope of the OSI model. Examples of such application processes include
spreadsheet programs, word-processing programs, banking terminal programs, and so on.
The application layer identifies and establishes the availability of intended communication
partners, synchronizes cooperating applications, and establishes agreement on procedures
for error recovery and control of data integrity. Also, the application layer determines
whether sufficient resources for the intended communication exist.

Network Layer
The network layer is a complex layer that provides connectivity and path selection
between two end systems that may be located on geographically diverse subnetworks.
A subnetwork, in this instance, is essentially a single network cable (sometimes called a
segment).
Because a substantial geographic distance and many subnetworks can separate two end
systems desiring communication, the network layer is the domain of routing. Routing
protocols select optimal paths through the series of interconnected subnetworks.
Traditional network-layer protocols then move information along these paths.
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Broadcasts in Switched LAN Internetworks 25
Link Layer
The link layer (formally referred to as the data link layer) provides reliable transit of data
across a physical link. In so doing, the link layer is concerned with physical (as opposed to
network, or logical) addressing, network topology, line discipline (how end systems will
use the network link), error notification, ordered delivery of frames, and flow control.
Physical Layer
The physical layer defines the electrical, mechanical, procedural, and functional
specifications for activating, maintaining, and deactivating the physical link between end
systems. Such characteristics as voltage levels, timing of voltage changes, physical data
rates, maximum transmission distances, physical connectors, and other similar attributes
are defined by physical layer specifications.
Broadcasts in Switched LAN Internetworks
To communicate with all or part of the network, protocols use broadcast and multicast
datagrams at Layer 2 of the OSI model. When a node needs to communicate with the entire
network, it sends a datagram to MAC address 0xFFFFFFFF (a broadcast), an address to
which the network interface card (NIC) of every host must respond. When a host needs to
communicate with part of the network, it sends a datagram to address 0xFFFFFFFF, with
the leading bit of the vendor ID set to 1 (a multicast). Most NICs with that vendor ID
respond to a multicast by processing the multicast to its group address.