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Analyzing Business Requirements

This exam is based on the concepts found in exam 70-217. Make sure that you are familiar with all of the concepts covered in that exam before you begin learning the design concepts. 

ANALYSIS OF THE BUSINESS MODEL
To analyze the business model, you must perform an analysis of the company model and its corresponding geographical scope. Models can include branch office, subsidiaries, regional, national, and sometimes international offices. The process of analyzing the business model begins with understanding the dynamic decision-making processes, business information flow, communication flow, and service and product life cycles.

To accomplish a thorough analysis of the existing and planned organizational structures, you should take into consideration the management model; the company’s organizational structure; relationships with third-party vendors and partners, and customer relationships.

Both the existing model and any planned changes must be taken into consideration. This includes future planned acquisitions. Business models refer to the ways in which a company conducts its business. You must understand both information and communication flow, and the mechanism these flows rely on (e.g. e-mail, Web sites, printed or verbal communication).

ANALYSIS OF THE COMPANY MODEL AND THE GEOGRAPHICAL SCOPE
In your analysis, you must determine where the company’s resources are located and how are they distributed among the locations. The scope of operations may include international, national, regional, subsidiary, and branch offices. You must take into account where remote offices are located, and the relationship of those offices to each other and to the company headquarters.

International operations occur when a company has a global presence in the business community.

Business is conducted in more than one country, and often, remote offices are located in different countries. International regulations and laws play an important factor in international operations.

National operations occur when the company does business within a country, and rarely conducts business outside the national boundaries. In most cases, you do not need to worry about things such as international translations, and currency.

Regional operations occur when the company operates within a state or a specific region of the country.

Subsidiary operations will require the approval for any propositions or solutions of the parent company.

Many organizations are relatively local, in which all or most business comes from members of the community, or within a city.

ANALYSIS OF COMPANY PROCESSES
Information Flow
Information flow normally follows the company’s organizational chart. Geographic separation can interrupt or disrupt information flow.

Communication Flow
Communication flow often lacks formal structure. It generally results from daily contact with peers, third-party vendors, customers, etc.

Service and Product Life Cycles
The life span must be considered for each product or service the company produces. The cycle a product endures from conception to delivery may be very dynamic. Similar products or services may remain constant for years. Technological advancements often necessitate the redesign of a portion, or all of the product’s life cycle.

Decision-Making Process
The decision-making process can be very formal, or decentralized, according to the strengths of the company’s employees, and the delegation power of management. Analysis of the decision- making process is critical.

ANALYSIS OF THE ORGANIZATIONAL STRUCTURE
Consideration of the organizational structure should include the management model, the company organization, vendor, partner, and customer relationships, and potential acquisition plans. This analysis must include both the current existing, and future planned structure.

Management Model
You must determine the chain-of-command within the company. As different risk models are associated with different management models, you must determine the dynamics of the management model. The management style may be based on the organizational structure, or on the management style. Management can dictate rules and regulations, or it can adopt a teamoriented approach. Companies can include family-owned enterprises, privately held businesses, or large public entities. The management model will often determine the scope and planning structure that is put into place.

Company Organization
Organizations are divided in many different ways. Some organizations divide their operations by products, geographic location, or services. Remote offices may or may not include each division of the company’s organization.

Vendor, Partner and Customer Relationships
You must know contractual agreements, third-party partnerships, liability limits, and the dynamics of the company’s relationship with their customers. Key contact points should be indicated in the analysis. Many companies offer more advanced methods of doing business such as offering a web presence on an Internet, Intranet, or Extranet basis.

Acquisition Plans
Planning for the future is critical in analyzing the organizational structure. The company may be either seeking an acquisition, or conversely, they may be the potential target of an acquisition.

FACTORS INFLUENCING COMPANY STRATEGIES
A great many factors influence company strategies. These are identified during the information gathering and analysis stages of the planning process. Some common factors include: Company Priorities
Priorities change with management philosophy, employee dynamics, technology advancements, and even market shifts of product sales. Priorities should be outlined based on current, and projected growth, organizational structure, and corporate philosophy.

Projected Growth and Growth Strategy
You need to analyze how is expansion for your company is accomplished. This can be accomplished by many different avenues; acquisition, divestiture, franchises, etc.

Relevant Laws and Regulations
Laws and regulations are subject to change not only by country, but also over time. Many companies dedicate a portion of their staff to keeping an eye out on changing regulations, and how it will impact their products and services. The geographic scope will affect the necessity to review local laws, state laws, regional laws and even international laws. When designing your Active Directory structure, you may have to create multiple domains to apply differing sets of rules for sites.

Identifying Tolerance for Risk
Risk to an implementation can take many forms, not all of them technical or commercial.

The possibility of suffering loss in the form of having a lower quality system than anticipated, exceeding budgetary constraints, or the failure to have satisfied the business requirements are consequences of inadequate analysis and planning. Risk management involves continuous assessment of potential risks and critical decisions to define and implement strategies to counter them.

Risk to an Active Directory program can take two forms: Risk to the implementation project or its schedule, and Risk to its efficient running after implementation. Risk management solution involves five steps: Risk Identification, Risk Analysis, Risk Action Planning, Risk Tracking, and Risk Control. Risk management involves evaluating both the risks and the opportunities.

Risk Identification
The first step in risk management must be to identify the risk, both the originating condition and the projected consequence.

Risk Analysis
The next step is to analyze the risk to outline proposals for countering action. This involves identifying the risk probability, risk impact, and risk exposure.

Risk Action Planning
The risk action planning stage is comprised of formulating strategies for risk management and contingency planning. There are four areas of risk action planning: Research, Acceptance, Manage, and Avoidance.

Risk Tracking
Tracking involves the continuous monitoring of known risks and the continuing effects of any countering actions taken.

Risk Control
This step involves setting up procedures for monitoring and controlling risk action plans, documenting and compensating for variations, and responding to warnings.

Identifying Total Cost of Operations
This must take into account all the factors related to any factor that will end up costing money. There may be obvious costs, such as software and licensing, and there may be less obvious costs. These additional costs may include the need for new hardware, administrator and end-user training, resources and implementation costs. By establishing a baseline, you can acquire reliable data regarding how costs are being incurred, conduct research into budget figures against actual figures, and identify unbudgeted expenses. You then need to develop a plan of how costs can be brought under closer control, and how they can be reduced.

Common recommendations include: • Introducing a system of checks, such as firewalls, that do not allow access to unknown and untrusted web sites.

• Imposing policies to reduce the control that users have over their own desktops.

• Changing IT management structures to reduce local autonomy.

ANALYSIS OF IT MANAGEMENT STRUCTURE
It is important to consider the network administrative structure. You must identify if the structure is centralized in one IT department or is administrative authority distributed throughout the organization based on geographic location, department, or other divisions of responsibility. You need to consider the type of administration, the funding model, outsourcing requirements, the decision-making process, and the change-management process.

Administration Type
Administration types can be either centralized or decentralized. An example of a centralized administration type is the U.S. postal system. Administrators are centrally located in one city, where the main post office branch is located, while branch offices exist throughout the United States. With a decentralized model, an administrator is stationed at each branch office to handle the needs at that office.

Funding Model
You should build a cost into each stage of any planned implementation. From that, you will be able to identify all of the stages where capital or other costs are going to occur. You can then plan for costs and have them approved in principle before you incur them. Funding will not run out before completion. Occasionally, there will be a funding model that divides responsibility for funding between several departments or divisions. You may have to deal with more than one executive sponsor. You should also, if possible, agree on a backup funding source as a fallback for your worst case scenario taking place.

Outsourcing
Outsourcing occurs when a company employs another company, usually a specialist in one area, to run certain aspects of a corporation’s affairs. This frees up resources allowing the company to concentrate on their core business. Outsourcing can include anything from accounting to IT functions. Any service that cannot be performed internally without great cost should be outsourced. When outsourcing, you must consider: • Any or all personnel within a division or department may actually be working for another company.

• You may have to adjust your OU structure to reflect the outsourcing. It may seem logical for members of a team to report to a particular manager, but if the manager is employed by an outsourcing company, it may be practical to remove that manager from the hierarchy.

• Security considerations are heightened. You may have to rethink your views on security, and on rights and permissions in Active Directory.

Decision-making process
In most instances, decisions come from the top in a pyramid-shaped hierarchy. This may not always be the case, so you must know exactly where they are made, versus where they seem to be made. You must determine whether all decisions are made in the same place, or whether certain types of decisions are delegated to specialists. You need to establish the decision- making hierarchy, and any deviations from it, to allow you to decide where organizational and reporting boundaries can be drawn. You should create a minimum number of OUs to support the organizational structure. The fewer OUs you have, the more flexible the structure will be.

Change Management
Change management is a process intended to provide a level of corporate fault tolerance by allowing you to backtrack after a mistake, or after an erroneous decision. Change control should encompass all aspects of the Active Directory implementation, including creating, renaming, moving, or deleting objects, adding new hardware to the network, and revising the Active Directory organizational structure. You should designate one source as a permissiongranting authority, and require permission to be granted before a change. This will ensure that changes by people, who are not aware of the big picture, will not be made. The permission- granting authority allows you to schedule changes to be made at the most appropriate times. All appropriate personnel need to be told of the change to limit the risk of applying a crucial change at a moment when it will conflict with another process. This will allow you to coordinate changes and schedule them at a specific time to limit downtime.

All changes should be documented, and should include recording the time and date of any changes, the people informed, and identifying the person making the change.

Analyzing Technical Requirements

You must assess how directory services will impact the technical aspects of the network infrastructure.

These aspects include performance and stability. You should evaluate the company’s existing and planned technical environment. After you assess the existing systems and applications and identify existing and planned software and hardware upgrades and rollouts, you should attempt to predict the impact of the Active Directory design on the existing and planned technical environment. The following factors are critical: 

• Available connectivity between the geographic locations of sites 
• Available network bandwidth and latency 
• Company size 
• Existing and planned network and systems management 
• Existing methods for accessing data and systems 
• Network roles and responsibilities 
• Performance requirements 
• Technical support structure 
• User and resource distribution 

EVALUATING THE EXISTING AND PLANNED TECHNICAL ENVIRONMENT
Areas you will want to consider in assessing the existing technical environment and developing a plan for the transition to Windows 2000 include: 

 • Proactive training of users before the rollout of the new operating system.

• Training of all technical personnel on the new operating system and how to use the directory services.

• Written documentation to aid in assisting users with common problems, and documenting reported problems.

Analyzing Company Size and User and Resource Distribution
The geographic scope plays an important part of designing your Directory Services. You must take into account the size and geographic location of all parts of the company. Analysis should also include the size and distribution of users, both internal and external. Resource allocation for peripherals and server access must be determined. Connectivity issues across geographic locations and within sites must also be documented. Identify if users are connecting for authentication only or for the entire session as with a Terminal Server.

Assessing Available Connectivity and Bandwidth
You must work closely with the network operations team to assess network connectivity and performance based on reliability, capacity, and latency. Reliability is how dependable the network link is. Capacity is the ability of the connection to transfer data packets. Bandwidth is the theoretical capacity of the network connection. Throughput, or actual capacity, is the capacity of the link, minus overhead caused by administrative data needing to flow over the link. Latency, or delay, is the delay of how long it takes to get data from one point to another.

Performance Requirements
To obtain peak performance, you must assess performance requirements, and create a baseline from which to judge future modifications. You must determine peak utilization, the type of circuits used, application requirements, and resource conflicts. During this analysis, identify any bottlenecks or potential performance hazards.

Analyzing Data and System Access Patterns
In your analysis, you need to determine if all resources are centralized or remotely disbursed.

Frequently used resources should be across a highly reliable connection. You must determine if users should go through a firewall, or if they need to use encryption. If encryption is used, you need to clarify if the password, data, or both should be encrypted.

Authentication can be accomplished through the use of the following: CHAP Challenge Handshake Authentication Protocol. Does not use cleartext passwords.

EAP Extensible Authentication Protocol. The client and the server negotiate the protocol that will be used. Protocols include one-time passwords, username / password combinations, or access tokens.

MS-CHAP Microsoft Challenge Handshake Authentication Protocol. Requires the client to be using a Microsoft Operating System (Version 2), or other compatible OSs (Version 1).

PAP Password Authentication Protocol. Uses a plain-text password authentication method and should only be used if clients cannot handle encryption.

SPAP Shiva Password Authentication Protocol. For backwardcompatibility and is not favored for new installations.

Analyzing Network Roles and Responsibilities
Administrative roles are predefined by the operating system with additional responsibilities above the normal user. Administrative type roles include Backup Operator, Server Operator, Print Operator, and Account Operator. Service roles run as services, without user interaction, in the operating system. User roles include the right to logon and use network resources.

Other roles include being an application, a group, or owner.

Analyzing Security Considerations
The most effective means of implementing security with Windows 2000 clients is through the use of Group Policies. You must analyze security considerations and provide information about access to data and resources, password policies, security protocols (IPSec), disaster recover, and authentication. You must analyze what are the needs of the organization, and what operating systems does the organization support. Determine the optimum protocol, and assess the security features that are compatible with that protocol. Determine if the existing technical structure will allow the user of Kerberos, RADIUS, or Encrypting File System. In the analysis, ensure that all potential solutions will not conflict with existing third-party tools and applications.

ANALYZING THE IMPACT OF ACTIVE DIRECTORY
Assessing Existing Systems and Applications
To understand the impact Windows 2000, and Active Directory will have on your existing network, you must analyze how the current network operates. You must identify abilities and limitations. Compatibility and testing play an important role in the design and implementation of Active Directory. All existing applications must current, with the latest service pack installed. You must identify any network issues and problems including network connectivity and LAN and WAN media speeds. Protocols and addressing must be compatible with Windows 2000 and Active Directory’s dependence on TCP/IP. DNS is the choice for resolution because of the foundational use of TCP/IP and the mirroring of Internet processes by Windows 2000.

Identifying Upgrades and Rollouts
You must identify planned upgrades and rollouts of new applications, and assess the impact Active Directory will have on them. Consider all compatibility issues with Active Directory, and plan accordingly.

Analyzing the Technical Support Structure
Currently, most technical support is comprised of third-party products for logging user calls, generating trouble tickets, and remote access of systems for problem resolution. Windows 2000 and Active Directory provide many auditing, and security log features which will enhance troubleshooting efforts. These features include Microsoft Management Console (MMC), Group Policy Objects (GPOs), and Terminal Services.

Analyzing Network and Systems Management
There are a number of ways to proactively analyze network and systems management. Tools available to determine the health of individual systems, WANs, and LANs include network monitoring software, server management and monitoring software, and software distribution methods such as Systems Management Server (SMS). Windows Management Instrumentation (WMI) allows you to control and monitor the hardware on your local workstations. It allows you to provide information and notification to Windows 2000 Server.

ANALYZING REQUIREMENTS FOR CLIENT COMPUTER DESKTOP MANAGEMENT
Analyzing End-User Needs
Analysis of business and technical requirements for client computer desktop management involves analyzing user work needs in addition to technical support needs. The baseline developed will allow you to establish the most productive use of network and directory services in the client computer environment. In planning the deployment of Windows 2000 and designing your network infrastructure in the most effective way, you must determine the needs of those who use the network. This information can be obtain through personal interview to determine features and functionality to increase productivity, surveys to determine increased usability, personal observation, and time studies. Software distribution methods can be assigned to a user, or to a computer. The three stages of software deployment are: Testing and Development, Pilot Deployment, and Production Deployment. You must identify whether a roaming user profile is needed for individuals who use more than one desktop. Users can be limited in their scope through the use of lockdowns using Group Policy Objects and disk quotas.

Identifying Technical Support Needs
Users must be properly trained on any new application or operating system installed. Properly trained end-users have a higher productivity rate, and log fewer trouble calls. The use of WMI allows client computers to communicate with Windows 2000 Server. Remote access to resolve issues can be implemented, power-management settings can be centralized, and WMI can restart failed services, run a specific program, or reboot a system.

Establishing the Required Client Computer Environment
The life an application can be broken down into four stages: Preparation, Deployment, Maintenance and Removal. These stages can be managed through the use of Group Policies.

Users should be instructed on how to access needed applications, and problem resolution methods.

Designing a Directory Service Architecture

Active Directory’s naming scheme follows the path of Forest, Tree(s), and Domains. A forest can consist of a single domain, or multiple domains. A tree is a contiguous namespace, meaning the child has the parent as part of its name (e.g. acme.com and support.acme.com). Each tree has its own identity within the forest. Active Directory names are equivalent to DNS names and use the SRV records of DNS to store information about services. The first division of DNS is into domains. The InterNIC (Internet Network Information Center) controls top-level domains (e.g. .com is commercial organizations, .gov is non-military government organizations).

AD Database Overview
Forest and Trees
The AD database contains all information about objects in all the domains from logon authentication to objects in the directory. A hierarchical structure made up of multiple domains that trust each other is called a tree. A set of object definitions and their associated attributes is called a schema. All domains in a tree will share the same schema and will have a contiguous namespace. A namespace is a collection of domains that share a common root name. An example of this is support.acme.com, marketing.acme.com, and acme.com. A disjointed namespace contains domains that are interrelated, but don’t share common root name. This might occur when a company merges with another company. An example of this is acme.com, and abc.com. A forest is one or more domain trees that have separate contiguous namespaces. All the trees in a forest share a common schema and trust one another because of transitive trusts. If you have multiple forests, you must set up an explicit trust between them.

Sites
Use the Active Directory Sites And Services Microsoft Management Console (MMC) snapin to configure sites. To create a site, add the subnets the domain controllers are in to the site object. A site object is a collection of subnet addresses that usually share a geographic location.

Sites can span domains, and domains can span sites. If the subnet address of a client or domain controller has not been included in any site, it is assigned to the initial site container created by AD, named Default-First-Site. If a subnet requires fast access to the directory, it should be configured as a site. In every site, at least one global catalog server should be installed for fast directory access, and at least one domain controller should be installed.

Dynamic Domain Name System (DDNS)
AD requires Dynamic Domain Name System (DDNS) for name resolution of objects. The records in the DNS database are automatically updated instead of the normal DNS manual methods.

Organizational Units (OUs)
An Organizational Unit is a container object that can hold users, groups, printers, and other objects, as long as these objects are members of the same domain as the OU. You can organize the domain into logical administrative groups using OUs. OUs allow you to delegate the management of the objects in the OU to other users. You can assign separate sets of permissions over the objects in the OU, other than the permissions in your domain. The Active Directory Users And Computers MMC snap-in is used to create and manage OUs. To delegate the control of an OU, use the Delegation of Control Wizard.

Global Catalog
A global catalog contains all the objects in the AD, with only a subset of their attributes.

This allows you to find object quickly even in a large multi-domain environment. The global catalog serves as an index to the entire structure of all domains and trees in a forest. It is also used for user authentication, so a user can log on at any location without having to perform a lookup back to the user’s home domain. The first server installed in a tree is called the global catalog server. Additional global catalog servers will improve the response time of queries for AD objects. Use the Active Directory Sites And Services MMC snap-in to create additional global catalog servers.

Domain Controllers
All domain controllers in a Windows 2000 domain have a writeable copy of the AD database.

All changes performed on any domain controller are replicated to all the other domain controllers within the domain via multimaster replication. Multimaster replication occurs when there is no master domain controllers, and all domain controls are considered equal.

Domain controllers are not required to replicate directly with each other. Domain controllers that are in close proximity to each other can replicate with each other, and then one of them can send all the changes to a remote domain controller.

Replication
A connection object is a connection that AD uses for replication. Connection objects are fault tolerant. When a communication fails, AD will automatically reconfigure itself to use another route to continue replication. The process that creates connection objects is called Knowledge Consistency Checker (KCC). It runs on all domain controllers every 15 minutes by default. It creates connection objects that provide the most favorable route for replication at the time of replication. KCC uses the network model that has been defined to determine connectivity between sites, but it will configure the links between domain controllers in the same site without assistance. Changes that need to be replicated are based on the update sequence number (USN). Each domain controller maintains a table of its own USNs, which is updated whenever it makes a change to an AD object. The USN is written to the AD database with the attribute that has changed. Other domain controllers use this USN to determine whether a change has occurred on a replication partner. To reduce network traffic, only the changed attribute will be transferred. After a domain controller fails, it attempts to replicate with all of the domain controllers when brought back online. It only requests updates with USNs greater than the last USN that was applied.

Sites
AD uses sites to control replication traffic over a WAN. A site is a group of domain controllers joined by a fast connection. Intrasite replication traffic can consume a large amount of bandwidth. Intersite traffic is compressed at a rate of 10:1.

Site Links
Site links are created using either Remote Procedure Call (RPC), or Simple Mail Transfer Protocol (SMTP) after sites are created. These links facilitate the replication between sites.

If not created, domain controllers will not be able to send or receive directory updates. Replication availability, cost, and replication frequency can be configured for greater efficiency.

The KCC uses settings from the site links to determine which connection objects to create to replicate directory data. SMTP transport is generally used for connections that are intermittent, such as dial-up links. Replication can be set up for a specific schedule by specifying when replication over that site link cannot take place, or by default, which allows replication to occur at any time. The default replication time is every three hours. Cost value determines which link to use when there are multiple links between sites. AD always uses the lowest cost path available. You can designate a domain controller as a bridgehead server to act as a replication gateway. It accepts all replication data from other sites via slow links and distributes it to other domain controllers in the site via fast links. Bridgehead servers are commonly used when sites are separated by firewalls, proxy servers, or Virtual Private Networks (VPNs).

Site Link Bridge
A site link bridge specifies a preferred route for replication traffic. It is the process of building a connection between two links. It is not needed in a fully routed IP network. If you set up site link bridges, you must turn off the default option to bridge all site links automatically.

DESIGNING AN ACTIVE DIRECTORY FOREST AND DOMAIN STRUCTURE
Designing a Forest and Schema Structure
Within the forest, you need to design a domain structure. The domain structure should include a domain tree consisting of a root domain and (optional) child domains, all of which share a contiguous namespace. You must analyze and optimize the trust relationships between domains, when you have devised the domain structure.

Designing a Domain Structure
As administrative privileges do not extend past domain boundaries, a domain is an administrative as well as security boundary. A simple network consists of a single domain. Creating additional domains allows you to retain existing NT domain structures, manage replication traffic, support and manage decentralized administration, support international boundaries, and support more than one domain policy.

DESIGNING AN ACTIVE DIRECTORY NAMING STRATEGY
Establishing the Scope of AD
You need to clearly outline the specific use of components. AD can be used as a central employee database to manage user accounts, mailboxes, and other databases. AD can be used in conjunction with other applications to eliminate administrative overhead in managing personnel.

AD is able to synchronize changes with multiple databases though replication.

Designing the Namespace
The hierarchy of the forest must be decided upon before designing the AD namespace. You must designate which domain will be the root domain, and assign its Domain Name System (DNS) name. Each additional domain should be designated as a child or subdomain of the root, or a new tree root. Use trees sparingly to avoid confusion. Use unique domain names even if those domains are not physically connected. Use names that are descriptive and distinct, but short enough to remember.

Planning DNS Strategy
DNS is a distributed database that provides host IP address resolution to client machines.

DNS is comprised of three parts: domains, zones, and DNS servers. Domains are top level DNS names like acme.com. These domains can contain child domains which are split into zones, support.acme.com, and shipping.acme.com. If your organization does not have existing DNS servers, or if you use them only to browse the Internet, you can use Windows 2000 DNS. But if you have UNIX DNS servers, you may have to forward all non-local requests to the corporate UNIX DNS server for resolution, create an A record for the Windows 2000 server that will host the Windows 2000 DNS server, or create an NS record on you UNIX DNS database.

DESIGNING AND PLANNING THE STRUCTURE OF ORGANIZATIONAL UNITS
Developing an OU Delegation Plan
Organizational Units (OUs) allow administrators to delegate authority on a granular basis.

You must consider many factors in designing an OU plan, including the administrative policies, geographic distribution and company structure, as well as existing resource domains.

An Organizational Unit (OU) is a container for organizing objects within a domain into logical sub-groupings. Creating OUs allows you to create group policy objects, control access to resources, to delegate administration if needed, to group common objects, and to establish boundaries for application of Group Policy.

Planning Group Policy Object Management
Group policies are collections of computer and user configuration settings that are linked to domains, sites, computers, and organizational units. When applied, a Group Policy affects all users and computers within a container. Group Policy settings define what controls, freedoms, or restrictions are placed over an OU. Group Policy Objects can contain seven types of settings: 

  Setting Description
Administrative Templates Defines application and desktop configurations via Registry controls.

Security Controls access and security (account policies, lockout policies, audit policies, user rights, etc.) Software Installation Controls installation, update, and removal of software.

Scripts Controls when Windows 2000 will execute specific scripts.

Remote Installation Services Controls options when Client Installation Wizard is used by RIS.

Internet Explorer Maintenance Manages and customizes Internet Explorer.

Folder Redirection Defines folder redirection for user profile home directories and folders.

User configuration settings apply group policies to users, regardless of what computer they have logged on to. Settings are only applied at time of logon and removed when the user logs off. Computer configuration settings
apply group policies to computers, regardless of what user logs on to them. Settings are applied when Windows initializes.

Creating a Group Policy Object (GPO)
A GPO is stored in two locations; a Group Policy template (GPT), and a Group Policy container (GPC). Local GPOs are created using the Group Policy snap-in for the MMC. Site GPOs are created by Start | Programs | Administrative Tools | AD Sites And Services. Rightclick the Site folder, and choose Properties, Group Policy tab. Each Windows 2000 computer can have one local GPO. Local GPOs can have their settings overridden by non-local GPOs when used in conjunction with AD. In a peer-to-peer environment, local GPOs are not overwritten by non-local GPOs. Domain/OU GPOs are created by Start | Programs | Administrative Tools | AD Users And Computers. Right-click domain or OU, and choose Properties, Group Policy tab.

Linking an Existing GPO
GPOs are linked with a container. It’s through the container that GPOs are applied to individual users and computers. GPOs cannot be tied directly to users or computers. A single GPO can be linked to multiple OUs, or multiple GPOs can be linked to a single OU. Only Domain Admins and Enterprise Admins have the ability to link GPOs to domains, OUs, or sites. To link a GPO to an existing, domain or OU, use Administrative Tools | AD Users And Computers | Right-click domain or OU, and choose Properties, Group Policy tab. Click Add then choose the policy and click OK. To link a GPO to an existing, site use Administrative Tools | AD Sites And Services | Right-click domain or OU, and choose Properties, Group Policy tab. Click Add then choose the policy and click OK.

Delegating Administrative Control of Group Policy
Delegating a GPO to a user grants that user control over the GPO, not the container to which the GPO applies. GPO management delegation includes; GPO links to sites, domains and OUs, creating GPOs, and editing GPOs. The default permissions are: 

Security Group Default Settings
Authenticated users Read, Apply Group Policy, Special Permissions 
Creator Owner Special Permissions 
Domain Admins Read, Write, Create All Child Objects, Delete All Child Objects, Special Permissions 
Enterprise Admins Read, Write, Create All Child Objects, Delete All Child Objects, Special Permissions 
System Read, Write, Create All Child Objects, Delete All Child Objects, Special Permissions 

Modifying Group Policy Inheritance
When multiple Group Polices apply to an object, the inheritance rules (order in which applied) of Group Policy apply. The order is Local GPO, Site GPO, Domain GPO, and OU GPO. Each previous GPO is overwritten by the next in line. When several GPOs are linked to a single OU, they are processed synchronously, in the order specified by the administrator.

Exceptions to Inheritance Order
Any site, domain or OU can block inheritance of group policy from above, except when an administrator has set No Override to the GPO link. No override can be set so that none of its policies will be overridden by a child container it is linked to. Loopback setting is used to merge or replace modes.

Filtering Group Policy Settings by Associating Security Groups to GPOs
By default, a GPO is applied to all members of its linked container. Filtering grants or restricts Read access to the GPO. If a user/group has Read access, the GPO can be applied; if not, it has been filtered. To apply the GPO to specific uses, modify the GPO’s Access Control List (ACL). To prevent a GPO from applying to a listed group, remove the Allow setting for the Apply Group Policy setting from the Security tab. To prevent a GPO from applying to a specific user within a listed group, add the user to the list of names and then select the Deny setting for the Apply Group Policy setting.

Removing and Deleting GPOs
Deleting a GPO removes it from any sites, domains or OUs it was linked to. When a GPO link is removed, it is no longer applied, but still exists.

Managing and Troubleshooting User Environments by Using Group Policy
Group policies can be used to control the abilities of a user to perform tasks or access portions of the operating system or network. System Policies are a collection of user environment settings that are enforced by the operating system and cannot be modified by the user.

User profiles refers to the environment settings that users can change. Environment control takes place via Administrative Templates. Administrative Templates control a system through editing or overwriting portions of the Registry.

PLANNING FOR THE COEXISTENCE OF ACTIVE DIRECTORY
The Active Directory can coexist and interact with other directory services, such as the DNS database and other LDAP compatible directory services that are in use on your network.

DESIGNING AN ACTIVE DIRECTORY SITE TOPOLOGY
Active Directory sites are IP subnets or groups of subnets that are connected by high performance links. Establish sites to control Active Directory replication between sites to optimize the use of network bandwidth. Bandwidth usage can be optimized by setting the interval period or by scheduling replication to occur during off-peak usage hours.

Designing a Replication Strategy
Replication takes place for domain controllers between sites (intersite replication) based upon a schedule, the amount of network traffic, and costs. The replication schedule, defined by site link and connection objects, is used to define the time that replication is allowed to occur. The replication interval is used to define how often replication should occur during a “window of opportunity” based on the schedule. Bridgehead servers are computers with additional hardware or network capacity that are specified as preferred recipients for intersite replication. The bridgehead server subsequently replicates its AD information to its replication partners. Using bridgehead servers improves replication performance between sites.

When using a firewall proxy server, you must establish it as a bridgehead server and allow it to replicate AD information to other domain controllers outside the firewall.

Managing Intrasite Replication
Replication takes place between domain controllers within a site (intrasite replication) as needed without regard to cost or schedules. Domain controllers in the same site replicate using notification. When one domain controller has changes, it notifies its partners. The partners then request the changes and the replication occurs.

Urgent replication triggers: 

Events replicated immediately in native-mode domains: 
• changing an LSA secret 
• newly locked-out account 
• RID manager state changes 

Events replicated immediately in mixed-mode domains: 
• changes to account lockout policy 
• changes to domain password policy 
• changing an LSA secret 
• changing the password on a machine account 
• inter-domain trust password changes 
• newly locked-out account 
• RID manager state changes 

Defining Site Boundaries
Prior to defining sites and site boundaries, you must know where all computers will be located, and how they connect to your network. Replication plans an important factor in site boundaries. Computers within a site should have a fast and reliable connection. When planning a site structure, consider load balance and fault tolerance. You must determine the need for a domain controller, the location of any domain controllers, and the location of global catalog servers. Windows 2000 will always look first for a domain controller within the same site boundary when a user tries to log in.

DESIGNING A SCHEMA MODIFICATION POLICY
An Active Directory schema is a description of the object classes and attributes stored in Active Directory. The schema defines the attributes an object class must have, the additional attributes it may have, and the object class that can be its parent for each object class. Authorized users can modify the Active Directory schema, or it can be updated dynamically. Any changes to the schema are global in nature and schema extensions are not reversible.

DESIGNING AN ACTIVE DIRECTORY IMPLEMENTATION PLAN
Your Active Directory implementation plan should be based on the existing Windows NT network and its domain structure. This plan should take into account the need to merge existing resource domains into one domain and using organizational units for the administrative delegation purposes formerly served by separate domains.

Designing Service Locations

Service locations are the placement of servers performing different functions throughout the network.

DESIGNING THE PLACEMENT OF OPERATIONS MASTERS
AD uses multimaster replication of the directory to make all domain controllers equal. Some operations are impractical to perform in a multimaster environment. In a single-master model, only one DC in the entire directory is allowed to process updates. The Windows 2000 Active Directory has the ability to transfer roles to any domain controller (DC) in the enterprise.

Because an Active Directory role is not bound to a single DC, it is referred to as operations masters roles. In designing the plan for assigning operations master roles, consider performance, fault tolerance, functionality, and manageability. Operations Master placement is crucial for load balancing and fault tolerance. There are five operations masters roles: 

 Role Description
Domain naming master Forest-level master that controls adding/deleting of domains to the forest. Responsible for domain name uniqueness.

Infrastructure daemon Domain-level master that maintains inter-domain consistency.

PDC emulator Domain-level master that provides support for non-AD compatible clients. Handles the replication of data to Windows NT BDCs.

Relative Identifier (RID) pool operations master Domain-level master that allocates relative IDs to domain controllers.

Schema master Forest-level master responsible for write updates and changes to the schema.

DESIGNING THE PLACEMENT OF GLOBAL CATALOG SERVERS
The Global Catalog Server is a domain controller that contains a partial replica of every domain in Active Directory. The global catalog holds a replica of every object in Active Directory.

Global Catalog Servers should be placed in locations to reduce traffic and help with load balancing and fault tolerance. Because the global catalog is needed to determine what groups the user belongs to, a user must have access to a global catalog server to successfully log on to the network.

The first Global Catalog Server is created automatically with the first domain controller within the forest. Network performance is increased if the domain controller at a site is also a global catalog server, so it can fulfill queries about all the objects in the entire forest. In areas where bandwidth is at a premium, a GCS can be configured to only receive updates after hours. If too many domain controllers are global catalog servers, replication traffic on your network will increase. For speed reasons, a GCS should be created at each site. Designing the proper placement of global catalog servers requires consideration of issues of fault tolerance, functionality, and manageability.

Creating Global Catalog Servers
There should be at least one global catalog server located in every site. If your network has multiple sites, you may wish to create additional global catalog servers to prevent queries from being performed across slow Wide Area Network (WAN) links. AD creates one global catalog server per forest by default. To create a global catalog server, go to Start | Programs | Administrative Tools | AD Sites And Services. Open the Site folder, and open the Servers folder, then expand the server object to get to the NTDS Settings. Right-click NTDS Settings, and choose Properties. Select the Global Catalog Server checkbox on the General tab.

DESIGNING THE PLACEMENT OF DOMAIN CONTROLLERS
Planning the placement of domain controllers will require that you first plan the domain structure. Domain controllers should be created for fault tolerance and functionality. As you can’t change a server’s name when it is a domain controller, you must carefully consider the names you will give to your domain controllers. Considerations in determining where to place domain controllers on the network include: performance (a domain controller at each Active Directory site will optimize logon traffic) and fault tolerance (multiple domain controllers provide for automatic backup of user accounts and other Active Directory information that is replicated from one DC to the others). The Infrastructure master should be placed on a domain controller that is not the global catalog server for load balancing and to separate the burden of each role.

DESIGNING THE PLACEMENT OF DNS SERVERS
You must determine how many DNS servers will be needed, and what role they will play in your Windows 2000 network. You must also consider whether the DNS server will also act as a domain controller or will be a member server. You will also have to decide which of the servers will host primary zone files and which will contain secondary copies. Consider replication traffic and fault tolerance in designing the DNS plan. If you have existing DNS servers, such as UNIX DNS servers on the network, you must plan for interoperability with them.

DNS servers can be running Windows 2000, or other operating systems, provided they accept SRV records. When you install Active Directory, you must identify a DNS server. If you cannot do so, the Active Directory Installation Wizard will prompt you to convert the existing machine into a DNS server as well.

Interoperability with Existing DNS
The Domain Name System (DNS) is the Active Directory locator in Windows 2000. Active Directory clients and client tools use DNS to locate domain controllers for administration and logon. You must have a DNS server installed and configured for Active Directory and the associated client software to function correctly. Non-Microsoft DNS servers can be used with AD if they support SRV records and dynamic updates. The DNS server in Windows NT Server 4.0 cannot be used with AD, but BIND versions 8.1.2 and later can. Active Directory Integrated DNS uses the directory for the storage and replication of DNS zone databases. If you use Active Directory Integrated DNS, DNS runs on one or more domain controllers and you do not need to set up a separate DNS replication topology.

Configuring Zones for Dynamic DNS (DDNS) Updates
Zones can be configured for dynamic updates. Resource records will then be updated by the DHCP clients and or server without administrator intervention. The Only Secure Updates option is only available in Active Directory integrated zones. To configure DDNS, from the DNS console, select the server you want to administer and then select Forward Lookup Zones. Right-click the domain name and choose Properties. Check the Allow Dynamic Updates box on the General tab. You must do the same for the Reverse Lookup Zones. Root or “.” zones cannot be configured for dynamic updates.

Managing Replication of DNS Data
Zone Transfer is the duplication of data between DNS servers that do not participate in AD.

Zone Replication is the replication of data between DNS servers (on domain controllers) that participate in AD. Zone Replication DNS servers poll AD every 15 minutes for updates.

Zone Transfer uses DNS Notification. There are two zone transfer types, full zone transfer (AXFR) and incremental zone transfer (IXFR): 

• AXFR:
When the refresh interval expires on a secondary server it queries its primary using an AXFR query. If serial numbers have changed since the last copy, a new copy of the entire zone database is transferred to the secondary.

• IXFR: Uses serial numbers, but transfers only information that has changed. The server will only transfer the full database if the sum of the changes is larger than the entire zone, the client serial number is lower than the serial number of the old version of the zone on the server or the server responding to the IXFR request doesn’t recognize that type of query.