MCSE: Windows® 2000Directory Services

Design Exam Notes™

Robert KingGary Govanus

SYBEX®

MCSE:

Windows 2000 Directory Services Design

Exam Notes

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San Francisco

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Paris

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MCSE:

Windows

®

2000 Directory Services Design

Exam Notes

™

Robert KingGary Govanus

Associate Publisher: Neil EddeContracts and Licensing Manager: Kristine O’CallaghanAcquisitions and Developmental Editor: Jeff Kellum Editor: Dale Good Production Editor: Elizabeth CampbellTechnical Editor: Mark KovachBook Designer: Bill GibsonGraphic Illustrator: Tony JonickElectronic Publishing Specialist: Maureen Forys, Happenstance Type-O-RamaProofreaders: Laurie O’Connell, Nancy RiddioughIndexer: Ted LauxCover Designer: Archer Design

Cover Illustrator/Photographer: Natural Selection

Copyright © 2001 SYBEX Inc., 1151 Marina Village Parkway, Alameda, CA 94501. World rights reserved. No part of this publication may be stored in a retrieval system, transmitted, or reproduced in any way, including but not limited to photocopy, photograph, magnetic, or

other record, without the prior agreement and written permission of the publisher.

Library of Congress Card Number: 00-107344

ISBN: 0-7821-2765-7

SYBEX and the SYBEX logo are trademarks of SYBEX Inc. in the USA and other countries.Exam Notes is a trademark of SYBEX Inc.

Screen reproductions produced with FullShot 99. FullShot 99 © 1991–1999 Inbit Incorporated. All rights reserved.FullShot is a trademark of Inbit Incorporated.

Microsoft, the Microsoft Internet Explorer logo, Windows, Windows NT, and the Windows logo are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries.

SYBEX is an independent entity from Microsoft Corporation, and not affiliated with Microsoft Corporation in any manner. This publication may be used in assisting students to prepare for a Microsoft Certified Professional Exam. Neither Microsoft Corporation, its designated review company, nor SYBEX warrants that use of this publication will ensure passing the relevant exam. Microsoft is either a registered trademark or trademark of

Microsoft Corporation in the United States and/or other countries.

TRADEMARKS: SYBEX has attempted throughout this book to distinguish proprietary trade-marks from descriptive terms by following the capitalization style used by the manufacturer.The author and publisher have made their best efforts to prepare this book, and the content is based upon final release software whenever possible. Portions of the manuscript may be based upon pre-release versions supplied by software manufacturer(s). The author and the publisher make no representation or warranties of any kind with regard to the completeness or accuracy of the contents herein and accept no liability of any kind including but not lim-ited to performance, merchantability, fitness for any particular purpose, or any losses or damages of any kind caused or alleged to be caused directly or indirectly from this book.

Manufactured in the United States of America

10 9 8 7 6 5 4 3 2 1

To my wife and best friend, Suze.

—Robert King

To Bobbi, my very best friend

in the whole world.

—Gary Govanus

Acknowledgments

I

t’s funny how life throws you curveballs from time to time. When I accepted this project, I was living just north of Tampa, was self-employed, and planned to use the traditional slow period at the beginning of the year to write. By the time we started working, I was moving to Grand Rapids, had a new job, and ended up using all of my free-time trying to keep up! Special thanks go to my little girls, Katie and Carrie, with whom I missed a lot of bedtime stories and Disney videos! My wife, Susan, who (because of the business I’m in) has experienced single parenting for the last few months (I’ll take some time off now—I promise!)

I’d also like to thank the guys at Ingram Micro who donated a couple of killer Everest computers to my home lab so I could test my theories before I committed them to print! Ingram Micro doesn’t sell to the public, but if you’re a reseller I give them two thumbs up for service! (You can visit them at

www.ingrammicro.com

.)

—Bob King

I think Bob will agree that whenever we take on these projects, they sure sound good. It should be really easy to knock these books out. It usually takes about two weeks before the enormity of the task hits and we start looking at the page count and thinking we may never finish. And then, someone is asking us for our dedications and acknowledgements. My how time does fly.

Because Bob and I live so far apart (I live in Minnesota and at last check, he lived in Michigan), I can’t tell you what he is like during the book writing process. I do know that I am not the most fun person in the world to live with. I am never the most fun person in the world to live with, but while writing a book, I can be an absolute bear. So, I really have to thank all those people closest to me.

Thanks to my wife Bobbi; the best daughters a guy can have, Dawn and Denise; and my three grandchildren, Brandice, CJ, and Courtney; and finally to my dear and loving parents, Dolly and Jack Govanus. Thanks all for sticking by me.

—Gary Govanus

We’d both like to thank everyone at Sybex who helped us put this book together: Special thanks to Associate Publisher Neil Edde and Developmental Editor Jeff Kellum. Thanks to Technical Editor Mark Kovach, Production Editor Elizabeth Campbell, Editor Dale Good, Electronic Publishing Specialist Maureen Forys, Graphic Artist Tony Jonick, and to the proofreaders, Laurie O’Connell and Nancy Riddiough. Without your hard work and dedication, this project could never have happened.

Contents

Introduction xi

Chapter 1 Analyzing Business Requirements 1

�

Analyze the existing and planned business models.

3

�

Analyze the existing and planned organizational structures. Considerations include management model; company organization; vendor, partner, and customer relationships; and acquisition plans.

34

�

Analyze factors that influence company strategies.

50

�

Analyze the structure of IT management. Considerations include type of administration, such as centralized or decentralized; funding model; outsourcing; decision-making process; and change-management process.

58

Chapter 2 Analyzing Technical Requirements 75

�

Evaluate the company’s existing and planned technical environment.

77

�

Analyze the impact of Active Directory on the existing and planned technical environment.

105

�

Analyze the business requirements for client computer desktop management.

110

Chapter 3 Designing a Directory Service Architecture 141

�

Design an Active Directory forest and domain structure.

143

Contents

ix

�

Design an Active Directory naming strategy.

153

�

Design and plan the structure of organizational units (OU).

189

�

Plan for the coexistence of Active Directory and other directory services.

210

�

Design an Active Directory site topology.

237

�

Design a schema modification policy.

261

�

Design an Active Directory implementation plan.

288

Chapter 4 Designing Services Locations 325

�

Design the placement of operations Masters.

326

�

Design the placement of global catalog servers.

333

�

Design the placement of domain controllers.

337

�

Design the placement of DNS servers.

343

Index 349

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Introduction

M

icrosoft’s new Microsoft Certified Systems Engineer (MCSE) track for Windows 2000 is the premier certification for computer industry professionals. Covering the core technologies around which Microsoft’s future will be built, the new MCSE certification is a pow-erful credential for career advancement.

This book has been developed, in cooperation with Microsoft Corpo-ration, to give you the critical skills and knowledge you need to prepare for one of the new MCSE certification programs; Directory Services Infrastructure Design. You will find the information you need to acquire a solid understanding of Windows 2000 Directory Services Design, to prepare for Exam 70-219: Designing a Directory Services Infrastructure, and to progress toward MCSE certification.

Is This Book for You?

The MCSE Exam Notes books were designed to be succinct, portable exam review guides that can be used either in conjunction with a more complete study program (book, CBT courseware, classroom/lab environment) or as an exam review for those who don’t feel the need for more extensive test preparation. It isn’t our goal to give the answers away, but rather to identify those topics on which you can expect to be tested and to provide sufficient coverage of these topics.

Perhaps you’re already familiar with the features and functionality of Windows 2000. The thought of paying lots of money for a specialized MCSE exam preparation course probably doesn’t sound too appealing. What can they teach you that you don’t already know, right? Be careful, though. Many experienced network administrators have walked confi-dently into test centers only to walk sheepishly out of them after failing an MCSE exam. As they discovered, there’s the Microsoft of the real world and the Microsoft of the MCSE exams. It’s our goal with these Exam Notes books to show you where the two converge and where they diverge. After you’ve finished reading through this book, you should have a clear idea of how your understanding of the technologies involved matches up with the expectations of the MCSE test makers in Redmond.

Introduction

xii

Or perhaps you’re relatively new to the world of Microsoft network-ing, drawn to it by the promise of challenging work and higher sala-ries. You’ve just waded through an 800-page MCSE Windows 2000 study guide or taken a class at a local training center. Lots of infor-mation to keep track of, isn’t it? Well, by organizing the Exam Notes books according to the Microsoft exam objectives, and by breaking up the information into concise manageable pieces, we’ve created what we think is the handiest exam review guide available. Throw it in your briefcase and carry it to work with you. As you read through the book, you’ll be able to identify quickly those areas you know best and those that require more in-depth review.

NOTE

The goal of the Exam Notes series is to help MCSE candidates familiarize themselves with the subjects on which they can expect to be tested in the MCSE exams. For complete, in-depth coverage of the technologies and topics involved, we recommend the MCSE Win-

dows 2000 Study Guide series from Sybex.

How Is This Book Organized?

As mentioned above, this book is organized according to the official exam objectives list prepared by Microsoft for Exam 70-219. The chapters coincide to the broad objectives groupings, such as Analyz-ing Business Requirements, Analyzing Technical Requirements, and Designing a Directory Service Architechture. These groupings are also reflected in the organization of the MCSE exams themselves.

Within each chapter, the individual exam objectives are addressed in turn. Each objective’s coverage is further divided into the following sections of information:

Critical Information

This section presents the greatest level of detail on information for the objective. This is the place to start if you’re unfamiliar with or uncer-tain about the objective’s technical issues.

Introduction

xiii

Exam Essentials

In this section, we’ve put together a concise list of the most crucial topics that you’ll need to comprehend fully prior to taking the MCSE exam. These summaries can help you identify subject areas that might require more study on your part.

Key Terms and Concepts

Here you’ll find a mini-glossary of the most important terms and con-cepts related to the specific objective. This list will help you under-stand what the technical words mean within the context of the related subject matter.

Sample Questions

For each objective, we’ve included a selection of questions similar to those you’ll encounter on the actual MCSE exam. Answers and expla-nations are provided so you can gain some insight into the test-taking process.

How Do You Become an MCSE?

Attaining MCSE certification has always been a challenge. In the past, people could acquire detailed exam information—even most of the exam questions—from online “brain dumps” and third-party “cram” books or software products. For the new MCSE exams, how-ever, this simply will not be the case.

To avoid the “paper-MCSE syndrome” (a devaluation of the MCSE certification because unqualified individuals manage to pass the exams), Microsoft has taken strong steps to protect the security and integrity of the new MCSE track. Prospective MSCEs will need to complete a course of study that provides not only detailed knowledge

Introduction

xiv

of a wide range of topics, but true skills derived from working with Windows 2000 and related software products.

In the new MCSE program, Microsoft is heavily emphasizing hands-on skills. Microsoft has stated that “nearly half of the core required exams’ content demands that the candidate have troubleshooting skills acquired through hands-on experience and working knowledge.”

Fortunately, if you are willing to dedicate time and effort with Win-dows 2000, you can prepare for the exams by using the proper tools. If you work through this book and the other books in this series, you should successfully meet the exam requirements.

TIP

This book is part of a series of MCSE Study Guides and Exam Notes published by Sybex that covers the five core requirements as

well as the electives you need to complete your MCSE track.

Exam Requirements

Successful candidates must pass a minimum set of exams that mea-sure technical proficiency and expertise.

�

Candidates for MCSE certification must pass seven exams, includ-ing four core operating system exams, one design exam, and two electives.

�

Candidates who have already passed three Windows NT 4 exams (70-067, 70-068, and 70-073) may opt to take an “accelerated” exam plus one core design exam and two electives.

NOTE

If you do not pass the accelerated exam after one attempt,

you must pass the five core requirements and two electives.

Introduction

xv

The following tables show the exams that a new certification candi-date must pass.

All

of these exams are required:

One

of these exams is required:

Exam # Title Requirement Met

70-216 Implementing and Administering a Microsoft Windows 2000 Network Infrastructure

Core (Operating System)

70-210 Installing, Configuring, and Administering Microsoft Windows 2000 Professional

Core (Operating System)

70-215 Installing, Configuring, and Administering Microsoft Windows 2000 Server

Core (Operating System)

70-217 Implementing and Administering a Microsoft Windows 2000 Directory Services Infrastructure

Core (Operating System)

Exam # Title Requirement Met

70-219 Designing a Microsoft Windows 2000 Directory Services Infrastructure

Core (Design)

70-220 Designing Security for a Microsoft Windows 2000 Network

Core (Design)

70-221 Designing a Microsoft Windows 2000 Network Infrastructure

Core (Design)

Introduction

xvi

Two

of these exams are required:

NOTE

For a more detailed description of the Microsoft certification programs, including a list of current MCSE electives, check Micro-soft’s Training and Certification Web site at

www.microsoft.com/

trainingandservices

.

Exam Registration

You may take the exams at any of more than 1,000 Authorized Pro-metric Testing Centers (APTCs) and VUE Testing Centers around the world. For the location of a testing center near you, call Sylvan Promet-ric at (800) 755-EXAM (755-3926), or call VUE at (888) 837-8616. Outside the United States and Canada, contact your local Sylvan Prometric or VUE registration center.

Exam # Title Requirement Met

70-219 Designing a Microsoft Windows 2000 Directory Services Infrastructure

Elective

70-220 Designing Security for a Microsoft Windows 2000 Network

Elective

70-221 Designing a Microsoft Windows 2000 Network Infrastructure

Elective

Any current MCSE elective

Exams cover topics such as Exchange Server, SQL Server, Systems Management Server, Internet Explorer Administra-tors Kit, and Proxy Server (new exams are added regularly)

Elective

Introduction

xvii

You should determine the number of the exam you want to take, and then register with the Sylvan Prometric or VUE registration center nearest to you. At this point, you’ll be asked for advance payment for the exam. The exams are $100 each. Exams must be taken within one year of payment. You can schedule exams up to six weeks in advance or as late as one working day prior to the date of the exam. You can cancel or reschedule your exam if you contact the center at least two working days prior to the exam. Same-day registration is available in some locations, subject to space availability. Where same-day regis-tration is available, you must register a minimum of two hours before test time.

TIP

You may also register for your exams online at

www.sylvanprometric.com

or

www.vue.com

.

When you schedule the exam, you’ll be provided with instructions regarding appointment and cancellation procedures, ID require-ments, and information about the testing center location. In addition, you’ll receive a registration and payment confirmation letter from Sylvan Prometric or VUE.

Microsoft requires certification candidates to accept the terms of a nondisclosure agreement before taking certification exams.

What the Designing a Microsoft Windows 2000 Directory Services Infrastructure Exam Measures

The Designing a Microsoft Windows 2000 Directory Services Infra-structure exam covers concepts and skills required for the design of an Active Directory structure in an organization or business environ-ment. It emphasizes the following areas of Active Directory design:

�

Analysis of the business environment

�

Analysis of the physical environment

Introduction

xviii

�

Planning for the use of Active Directory and Windows 2000 features

�

Creating an optimized Active Directory environment

This exam differs from the core MCSE examinations in that there are no objectives that represent physical tasks. The test objectives guide you in analyzing given situations and suggesting solutions that meet the business needs of that environment. System analysis is not a skill that can be quantified into a series of facts or procedures to be memorized. Because of Microsoft’s emphasis on providing business solutions, much of this book (and most of the exam objectives) focus on enabling you to create an Active Directory structure that is stable, optimized, and designed in such a way that it fulfills true business needs.

Tips for Taking Your Exam

Here are some general tips for taking your exam successfully:

�

Arrive early at the exam center so you can relax and review your study materials, particularly tables and lists of exam-related information.

�

Read the questions carefully. Don’t be tempted to jump to an early conclusion. Make sure you know

exactly

what the question is asking.

�

When answering multiple-choice questions you’re not sure about, use a process of elimination to get rid of the obviously incorrect questions first. This will improve your odds if you need to make an educated guess.

�

This test has many exhibits (pictures). It can be difficult, if not impossible, to view both the questions and the exhibit simulation on the 14- and 15-inch screens usually found at the testing centers. Call around to each center and see if they have 17-inch monitors available. If they don’t, perhaps you can arrange to bring in your own. Failing this, some have found it useful to quickly draw the diagram on the scratch paper provided by the testing center and use the monitor to view just the question.

Introduction

xix

�

You are allowed to use the Windows calculator during your test. However, it may be better to memorize a table of the subnet addresses and to write it down on the scratch paper supplied by the testing center before you start the test.

Once you’ve completed an exam, you’ll be given immediate, online notification of your pass or fail status. You’ll also receive a printed Examination Score Report indicating your pass or fail status and your exam results by section. (The test administrator will give you the printed score report.) Test scores are automatically forwarded to Microsoft within five working days after you take the test. You don’t need to send your score to Microsoft. If you pass the exam, you’ll receive confirmation from Microsoft, typically within two to four weeks.

Contact Information

To find out more about Microsoft Education and Certification mate-rials and programs, to register with Sylvan Prometric, or to get other useful information, check the following resources. Outside the United States or Canada, contact your local Microsoft office or Sylvan Pro-metric testing center.

Microsoft Certified Professional Program—(800) 636-7544

Call the MCPP number for information about the Microsoft Certified Professional program and exams, and to order the latest Microsoft Roadmap to Education and Certification.

Sylvan Prometric testing centers—(800) 755-EXAM

Contact Sylvan to register to take a Microsoft Certified Professional exam at any of more than 800 Sylvan Prometric testing centers around the world.

Microsoft Certification Development Team—

www.microsoft.com/trainingandservices

Contact the Microsoft Certification Development Team through their Web site to volunteer for participation in one or more exam development phases or to report a problem with an exam. Address

Introduction

xx

written correspondence to the Certification Development Team, Microsoft Education and Certification, One Microsoft Way, Redmond, WA 98052.

Microsoft TechNet Technical Information Network—

(800) 344-2121

This is an excellent resource for support professionals and system administrators. Outside the United States and Canada, call your local Microsoft subsidiary for information.

How to Contact the Publisher

Sybex welcomes reader feedback on all of its titles. Visit the Sybex Web site at

www.sybex.com

for book updates and additional certification information. You’ll also find online forms to submit comments or suggestions regarding this or any other Sybex book.

Chapter

1

Analyzing Business Requirements

MICROSOFT EXAM OBJECTIVES COVERED IN THIS CHAPTER:

�

Analyze the existing and planned business

models.

(pages 3 – 33)�

Analyze the company model and the geographical scope. Models include regional, national, interna-tional, subsidiary, and branch offices.

�

Analyze company processes. Processes include information flow, communication flow, service and product life cycles, and decision-making.

�

Analyze the existing and planned organizational

structures. Considerations include management

model; company organization; vendor, partner,

and customer relationships; and acquisition

plans.

(pages 34 – 49)

�

Analyze factors that influence company

strategies.

(pages 50 – 57)�

Identify company priorities.�

Identify the projected growth and growth strategy.�

Identify relevant laws and regulations.�

Identify the company's tolerance for risk.�

Identify the total cost of operations.

�

Analyze the structure of IT management. Consid-

erations include type of administration, such as

centralized or decentralized; funding model; out-

sourcing; decision-making process; and change-

management process.

(pages 58 – 74)

F

or the MCSE Design exams, Microsoft has added content to test your ability to suggest, install, configure, and maintain its products in a real business environment. The end result for us, the MCSEs and potential MCSEs of the world, is that we need to have a broader sense of the business world. Therein lies the problem—many people have a background in technology, and many people have a background in business, but few people have experience in both are-nas. That’s where the Windows

®

2000 Directory Services Design comes in—this examination will test your ability to analyze a business environment and suggest a solution that will fill a business need.

This first group of exam objectives, “Analyze the Existing and Planned Business Models,” are designed to test your knowledge of basic business environments. How a business works has a great influ-ence on how technology should best be implemented. We’ll start by describing and defining basic business models that can act as guide-lines when designing an Active Directory (AD) structure. While no business will match a model exactly, most will match a model close enough to make some generic decisions.

After analyzing the business models we’ll move to a discussion of company processes. Knowing how information is used, how the busi-ness deals with change, and how decisions are made can help to fine-tune an AD environment to match the needs of the company. We’ll also look at the existing Information Technology (IT) structure. The ways in which a company currently implements and manages tech-nology, how it makes decisions, and even how it acquires funding can also influence your decisions about which technologies you would recommend and how you would implement them.

Chapter 1 �

Analyzing Business Requirements

3

�

Analyze the existing and planned business models.

I

f you take a few courses in business management, you soon dis-cover that no matter how diverse the economy, and no matter how varied the products and services that are available, most successful businesses are organized along one of a few management philoso-phies. These philosophies, or

business models

, define the internal structures used to manage the complex interrelationships among the functions necessary to successfully conduct business. To put it more simply, a business model defines how work gets done. From a design perspective, knowing how work gets done allows you to design an Active Directory structure that matches (and maybe even enhances) the company’s management structure.

The bottom line for this section is that you must be able to look at a company, ask a few questions, and from that, be able to determine what technical solutions you would recommend for that environment. Microsoft expects you to understand the basics of business—the vari-ous types of management styles that exist, the difference technological needs based upon a company’s physical diversity, and how business processes affect technology. In this first section you are really reviewing “Business 101”—getting a background in the business of business.

Critical Information

If you approach these exam objectives as if you were really perform-ing an Active Directory design, one of the first things you would do is try to get a feel for the size and complexity of the project. This is

�

Analyze the company model and the geographical scope.

Models include regional, national, international, subsidiary,

and branch offices.

�

Analyze company processes. Processes include informa-

tion flow, communication flow, service and product life

cycles, and decision-making.

Windows 2000 Directory Services Design: Exam Notes

4

known as the

scope

of the project. The process involves gathering information about the physical and business aspects of the environ-ment. We will discuss these processes in the sections that follow.

Analyze the Company Model and

Geographical Scope

When you are determining the scope of a design project, there are cer-tain aspects of the environment that you can use to rate the network. For exam purposes, Microsoft has defined a set of standards that you can use as a yardstick to determine the scope of a design project. There are two sets of standards, or models, mentioned in the exami-nation objectives:

Geographic Scope

The

geographic scope

of a company is deter-mined by the number of physical locations that make up the network and the connectivity between them. There are three levels of geo-graphic models—regional, national, and international. The differ-ences between them will be examined a little later in this section.

Business Model

The

business model

refers to the business relation-ship between sites and services. In other words, you’ll look at each location and determine its relationship to the company. You might, for instance, have a research site that is technically part of your net-work but is in reality a completely separate entity, using none of the corporate resources and not requiring complete access to the com-pany infrastructure. On the other hand, you might have a location that is the central distribution point for all order processing for your company. Employees at this site might need to read data or use other resources at every location within the company. Each of these two examples would require a different level of access and would be handled differently in your final AD system design.

NOTE

For testing purposes Microsoft defines two business models—

the subsidiary and branch offices.

In the next sections, we discuss each of these two standards: the geo-graphic scope and the business model.

Chapter 1 �

Analyzing Business Requirements

5

Understanding the Geographic Scope

One of the most expensive components of any network consists of the connections between physical locations (hereafter known as

sites

). With this in mind, one of the first design goals for any network should be to reduce, or at least control, the network traffic that crosses any expensive wide area links. The bigger the network, or the larger the number of links in the network, the more important this first goal becomes! Microsoft defines three sizes of networks based upon the amount of wide area connectivity inherent in the geographic layout of facilities—regional (small), national (medium), and international (large). To this add one more class of network—the simple-network model, which often consists of just a single site. Microsoft doesn’t include this as a design model because a simple-network environment shouldn’t take a whole lot of planning. For testing purposes, though, you’ll need to know when to plan and when to go with the defaults.

SIMPLE-NETWORK MODEL

Remember, you’re not going to see this name on the exam, but you might see a case study or a question that revolves around a network that really doesn’t take much planning. The definition of a simple net-work is an environment in which all resources are connected over fast, reliable lines that have ample bandwidth available. In most cases, the simple network will be made up of a single site, and the company will have no need to create network relationships with outside ven-dors, customers, or other foreign systems. A simple network will not require any extensive planning—it will be a single domain, it will con-tain no special connectivity issues, and the existing network traffic will not push the limits of whatever topology (Ethernet, Token Ring, etc.) is currently in place. The simple network will be the most com-mon environment in the market—very few of us will be able to work on the design of large networks.

We won’t go into great deal about the simple network, but you should be aware that systems so small that they do not fit into one of Microsoft’s defined environments are probably simple networks. It’s important to remember the following distinctions about a simple network:

�

No wide area links, unless those links are high speed, reliable, and have plenty of available bandwidth

Windows 2000 Directory Services Design: Exam Notes

6

�

No special relationships with outside systems

�

Single NT domain

REGIONAL MODEL

A

regional model

is one in which all sites are contained within a well-defined geographic area. Although this definition is vague, it works well in conjunction with the other two models defined by Microsoft. To make it a bit more specific, we would add that, in most cases, a regional network will be made up of connections that travel through a single vendor’s lines. If, for instance, all of a company’s lines are purchased through one of the regional Bells, then it follows that the network itself is regional in scope. The network in Figure 1.1 is a per-fect example of a regional environment.

F I G U R E 1 . 1 :

A regional network

Muskegon

Grand Rapids

Lansing

T1

T1

Chapter 1 �

Analyzing Business Requirements

7

In this example the network consists of two wide area links: one from Grand Rapids to Muskegon and another from Grand Rapids to Lan-sing. In this case, the region can be defined as western Michigan, and the same vendor probably provides both wide area lines.

Notice that no time zone is crossed, nor is any state boundary. You will not have to be concerned with the time differences on any sched-uled processes, and you will not have to know more than one set of legal issues. Unfortunately, there is no definitive description of a regional network. The network depicted in Figure 1.2 is considerably larger in area (but no more complex) than the first example, and it too qualifies as a regional environment.

F I G U R E 1 . 2 :

A larger regional network

GrandRapids

Boston

Washington D.C.

T1

T1

Windows 2000 Directory Services Design: Exam Notes

8

As you can see from Figure 1.2, geographic confinement is not the only criterion for ranking an environment as a regional network. You will also have to take into account the relative complexity of the envi-ronment. Take, for example, the network depicted in Figure 1.3. Outwardly, it appears almost identical to the network presented in Figure 1.2, but it has one additional site.

F I G U R E 1 . 3 :

A more complex network

This network is much more complex than the preceding example. In this network you will have to consider an unreliable dial-up connec-tion and a potential bottleneck on the 64K line. You also need to note that all traffic from both the Atlanta and the Washington sites must travel across a single T1 line to reach Grand Rapids. There is also a

GrandRapids

Boston

Washington D.C.

Atlanta

64K

T1

Dial-up

Chapter 1 �

Analyzing Business Requirements

9

straight-line path for data to travel from one end of the network to another. If either Grand Rapids or Boston becomes unavailable, the continuity of communication will be broken. Based upon the addi-tional complexity of the environment, this network would not be classified as regional. It would more likely fit into the next category—the national network model. The important distinctions to remember about a regional model are these:

�

Simple infrastructure design

�

Well defined geographic boundaries

�

No complex setup issues

NATIONAL MODEL

A

national model

environment is one that, as the name implies, covers all or parts of an entire country. The network infrastructure is com-plex, it crosses time zones, rules and regulations might differ from site to site, complex services are part of the mix, and/or in general, it ser-vices a larger number of users. If any one of these conditions is met, it

might

be a national network. Sound confusing? Welcome to the world of Microsoft testing. Let’s start our discussion by breaking down each of these points to get a clearer understanding of what each represents.

Complex Infrastructure

If the network in question is made up entirely of fast, reliable links that have plenty of available bandwidth, you don’t

really

have to take them into account for your design. You could assume that the Wide Area Network (WAN) links would not have an appreciable effect on network performance. Luckily for con-sultants, few networks match these specifications. A typical national network will be made up of the following components:

�

Different speed dedicated lines (T1, 256K, 64K, etc.)

�

Dial-up connections

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Different network topologies, such as Asynchronous Transfer Mode (ATM), Frame Relay, etc.

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Different connectivity vendors