Active Directory Group Policy

Group Policy Overview

Successor to NT policies Much more flexible

Only applies to 2000 workstations Use old style policies for NT

Used to manage desktop environment Integrated into Active Directory

What Can Group Policy Manage?

Administrative Templates — registry-based settings Security settings Software installation Scripts

Login, logout, startup, shutdown Folder redirection Remote Installation Services Internet Explorer maintenance

Registry-based Settings

Control over desktop, control panel access, Start Menu and Taskbar, some Windows components, and more…

Generally three settings — Not configured, Enabled, Disabled Implemented via Administrative Templates

Text file with .adm extension Extensible Can create your own Some programs ship with their own (Office)

Security Policy Settings

Account Policies — password, account, Kerberos Local Policies — auditing, user rights, security options Event Log — e.g. maximum size Restricted Group — group membership System Services — security and startup settings Registry — registry key security File System — file system security Public Key Policies — encryped data, certificate authorities IP Security Policies — IP security

Software Installation

Use to install software Use to upgrade software Three methods

Assign applications to users Assign applications to computers Publish applications to users

Available to users, but not installed unless requested

Script Settings

Assign scripts (login, logout etc.) Set processing order

Folder Redirection

Redirect special folders Start Menu, Desktop My Pictures, My Documents, Application Data

Choices No redirection Direct to same location Different locations based on security groups

Parts of Group Policy Objects

Each GPO has two sections Computer Configuration User Configuration

Each part may be disabled Properties of GPO/General

Recommended — if a section is unused, disable it E.g. On GPO to configure user desktop, disable

Computer Configuration section

Creating Group Policy Objects

AD Users and Computers Properties of Domain/OU Creates new GPO linked to that domain/OU

AD Sites and Services To create site GPO

Also via MMC Group Policy Snap-in To create a GPO not linked to a site, domain or OU

How are Group Policy Objects Applied

GPOs may be linked to AD containers Sites, Domains and Organizational Units (OUs) Apply to users and computers within container

Objects in child OUs inherit GPO settings from parent OUs, domain and site unless explicitly blocked

No inheritance across domain boundaries One GPO may be linked to multiple containers Multiple GPOs may be linked to a container GPOs are not linked to groups

Modifying GPO Inheritance

Block Inheritance If enabled on a container, objects in container do not

receive any GPO settings from parent containers No Override

If enabled on a GPO link, inheritance of GPO settings cannot be stopped via block inheritance

NB Applied to link, not the GPO itself

Filtering Group Policy Settings

GPO settings applied to all objects in container Filter using security groups

Change default GPO permissions Need Read and Apply GP ACEs to be able to apply a GPO Need Read and Write GP ACEs to be able to read and

modify a GPO

Deleting and Disabling Group Policy Objects

Disabling a GPO Disable Computer or User sections Disable both to disable GPO entirely Also disable using Options button in AD Users and

Computers/Container Properties Deleting a GPO

AD Users and Computers Will be offered two options

Remove the link from the list — deletes link but not GPO Remove the link and delete the GPO permanently — deletes GPO

Disabling and Inheriting:— What do the Properties Belong to?

Properties of a given GPO Disable Computer Configuration Settings Disable User Configuration Settings

Properties of a given container Block policy inheritance

Properties of a given link No override Disabled: the GPO is not applied to this container

Storage of Group Policy Objects

Group Policy Container (GPC) Active Directory object storing version, status etc. View by enabling Advanced Features in AD Users and Computers,

then System/Policies Named by GUID

Group Policy Template (GPT) Sysvol\Policies folder Contains all GP) settings Named by GUID

GPC and GPT replicated separately Policies only apply if both GPC and GPT are in sync

Storage of Group Policy Settings

Stored in client registry HKEY_LOCAL_MACHINE (Computer settings) HKEY_CURRENT_USER (User settings)

Special registry keys used \Software\Policies (preferred) \Software\Microsoft\Windows\CurrentVersion\Policies

Removed when GPO no longer applies

Order of GPO Application

Order of application is Site, Domain OU (SDOU) Multiple OUs — order of application is according to

domain hierarchy (start at top of tree and work down) Multiple GPOs for same OU — processed in reverse

order of list of GPOs shown for that OU I.e. GPO at top of list takes precedence Order can be changed

When are GP Settings Applied?

Computer settings On boot According to periodic refresh cycle

User settings On user logon According to periodic refresh cycle

If computer and user settings conflict, computer settings take precedence

Refreshing Group Policy

Default refresh intervals 2000 professional and member servers — very 90

minutes with randomized 30 minutes offset Domain controllers — every five minutes

Changed by altering administrative template settings for user or computers

Exception — software installation and folder redirection policies only applied on boot or user logon, not periodically

Conflicts

Where settings for GPO of parent container conflict with those for GPO of child, child container settings win

Where settings from different GPOs linked to same container conflict, settings of GPO highest in list are win Use Up/Down to change position

Exception — where computer and user settings conflict, computer settings win Except IP Security and User Rights settings

Managing Group Policy Objects

Creating or editing GPOs controlled by PDC emulator by default Minimise conflicts

To change Group Policy mmc snap-in/View/DC Options Or use Group Policy

Recommended that this is left unchanged NB By default, only Domain Admins, Enterprise Admins,

Group Policy Creator Owners and System account can create and edit GPOs

Loopback Processing

Computer settings part of GPO linked to OU apply only to computers within OU

Similarly, user settings apply only to users within OU Therefore, normally, user in OU A logging on to

computer in OU B gets combination of user settings from OU A GPOs and computer settings from OU B GPOs (and any inherited etc.)

Loopback Processing cont.

May want to apply same user settings to any user logging on to a given workstation, regardless of user OU E.g. classroom, public area workstations

Loopback processing does this Merge mode applies normal GPOs for user as well (but

those from computer take precedence) Replace mode does not apply normal GPOs for user

Local Group Policy

Computers also have a single Local Group Policy Object (LGPO)

Only supports Security Settings, Administrative Templates and Scripts

Processed before AD GPOs Block inheritance does not stop its application

Generally unused in an AD setup Most useful for configuring standalone computers

Delegation

It is possible to delegate responsibility for the following tasks Managing links Creating GPOs Editing GPOs

DomainExceptions for Domain Controllers

Some settings only from GPOs linked to domain Domain controllers share same account database so some settings

must be the same Not applied to Domain Controllers OU because DCs may be moved

out of this OU

NB Can change these settings in other GPOs but will have no effect on domain policy Will affect local logons (i.e. non-domain) if they apply to

workstations or member servers

Exceptions for Domain Controllers cont.

Domain-wide settings All account policies (Computer Configuration/Windows

Settings/Security Settings) I.e. Password, Account lockout and Kerberos policies)

Some settings from Computer Configuration/Windows Settings/Local Policies/Security Options

Automatically log off users when logon time expiresRename administrator accountRename guest account

Common Desktop Management Scenarios

Package containing GPOs developed for six different scenarios that can be loaded into AD Includes white paper describing scenarios Excel spreadsheet documenting all GPO settings

Scenarios are for the following Lightly Managed Desktop (e.g. power user) Mobile User Multi-User Desktop AppStation (Highly Managed Desktop) (e.g. admin user) TaskStation (e.g. single task) Kiosk (e.g. public workstation)

Common Desktop Management Scenarios

NB Loading GPOs into AD does not mean they take immediate effect Not linked to any container

Use as starting points Use Excel spreadsheet to document GPO changes

Common Desktop Management Scenarios

White paper http://www.microsoft.com/technet/treeview/default.asp?

url=/TechNet/prodtechnol/windows2000serv/deploy/grppolsc.asp

All files http://www.microsoft.com/windows2000/zipdocs/

grouppolscen.exe

OU Design Issues

Deep OU structure Easier to apply GPOs without filtering More likely to require inheritance modifications

Flat OU structure More likely to need filtering Easier to troubleshoot (less inheritance issues)

Number of GPOs Required

Few comprehensive GPOs Less to manage Shorter logon times

Many narrowly focussed GPOs More to manage Likely to need to more filtering Increased logon times

In theory, up to 20 GPOs applying to a user should not have major impact on logon times

Recommendations

Disable unused parts of GPO (computer, user settings)

Limit use of inheritance blocking, no override, loopback processing and filtering Simplifies troubleshooting

Limit total number of GPOs that apply to a user or computer Improves logon times

Recommendations cont.

Limit the number of admins who can edit GPOs Test thoroughly before applying to users/computers Document settings

Use spreadsheets from Common Desktop Management Scenarios package

References

Windows 2000 Group Policy http://www.microsoft.com/windows2000/docs/

grouppolwp.doc Loopback Processing of Group Policy

http://support.microsoft.com/support/kb/articles/Q231/2/87.ASP

How to Use Group Policy Objects to Deploy SP1 for Windows 2000 http://support.microsoft.com/support/kb/articles/

Q260/3/01.ASP

References

Group Policy Application Rules for Domain Controllers http://support.microsoft.com/support/kb/articles/

Q259/5/76.ASP Domain Security Policy in Windows 2000

http://support.microsoft.com/support/kb/articles/Q221/9/30.ASP

Configuring Account Policies in Active Directory http://support.microsoft.com/support/kb/articles/

Q255/5/50.ASP

Diagnosing Problems

Resource kit Gpotool.exe Gpresult.exe

FAZAM 2000 Help to see end results of applying a number of GPOs http://www.microsoft.com/windows2000/techinfo/reskit/tools/

existing/fazam2000-o.asp Reduced functionality version

http://www.fullarmor.com/solutions/group/ Full, commercial version