Configuring the User and Computer Environment Using Group Policy Lesson 8

Computer Configuration Security Settings

User Configuration Security Settings

Account Policies Account policies influence how a user interacts with a computer or a domain. By default, they are linked to the Default Domain Policy. This account policy is applied to all accounts throughout the domain by default, unless you create one or more Fine-Grained Password Policies (FGPP) that override the domain-wide policy. These Fine-Grained Password Policies can be applied.

Password Policies

Fine-Grained Password Policy Prior to Windows Server 2008, an Active Directory administrator was only able to configure a single Password Policy and Account Lockout Policy for any Active Directory domain. If you were faced with a subset of users whose password policy requirements were different, you were left with the choice of configuring a separate domain or forcing all users within the domain to conform to a single password policy. Beginning in Windows Server 2008, you can configure Fine-Grained Password Policies, which allow you to define multiple password policies within a single domain.

Lockout Policy

Kerberos Policy Kerberos is the default mechanism for authenticating domain users in Windows Server 2008, Windows Server 2003, and Microsoft Windows Kerberos is a ticket- based system that allows domain access by using a Key Distribution Center (KDC), which is used to issue Kerberos tickets to users, computers, or network services. – These tickets have a finite lifetime and are based in part on system time clocks. Note that Kerberos has a 5-minute clock skew tolerance between the client and the domain controller. – If the clocks are off by more than 5 minutes, the client will not be able to log on.

Kerberos Policy

Enforce User Logon Restrictions tells Windows Server 2008 to validate each request for a session ticket against the rights associated with the user account. Although this process can slow the response time for user access to resources, it is an important security feature that should not be overlooked or disabled. Enforce User Logon Restrictions is enabled by default.

Local Policies Allow administrators to set user privileges on the local computer that govern what users can do on the computer and determine if these actions are tracked within an event log (auditing): – User Rights Assignment. – Security Options. – Audit Policy.

User Rights

Audit Policy

System events — Events that trigger a log entry in this category include system startups and shutdowns; system time changes; system event resources exhaustion, such as when an event log is filled and can no longer append entries; security log cleaning; or any event that affects system security or the security log. – In the Default Domain Controllers GPO, this setting is set to log successes by default.

Audit Policy Policy change events — By default, this policy is set to audit successes in the Default Domain Controllers GPO. – Policy change audit log entries are triggered by events such as user rights assignment changes, establishment or removal of trust relationships, IPSec policy agent changes, and grants or removals of system access privileges.

Audit Policy Account management events — This policy setting is set to audit successes in the Default Domain Controllers GPO. This setting triggers an event that is written based on changes to account properties and group properties. – Log entries written due to this policy setting reflect events related to user or group account creation, deletion, renaming, enabling, or disabling.

Audit Policy Logon events — This setting logs events related to successful user log-ons on a computer. – The event is logged to the Event Viewer Security Log on the computer that processes the request. The default setting is to log successes in the Default Domain Controllers GPO.

Audit Policy Account logon events — This setting logs events related to successful user log-ons to a domain. – The event is logged to the domain controller that processes the request. The default setting is to log successes in the Default Domain Controllers GPO.

Audit Policy Audit Directory Service Access — This event category logs user access to Active Directory objects, such as other user objects or OUs. Audit Object Access — This event category logs user access to files, folders, registry keys, and printers. – After you enable Audit Object Access, you need to then specify what you are going to audit via Windows Explorer, Registry, Printers and Faxes or Active Directory Users and Computers.

Audit Policy Events produced by auditing can be viewed by looking at the Security logs in the Event Viewer.

Configuring Files and Folders for Auditing In Windows Explorer, right-click the file or folder you want to audit. Select Properties. On the Security tab in the Properties dialog box for the selected file or folder, click Advanced. In the Advanced Security Settings dialog box for the file or folder, select the Auditing tab.

Restricted Groups Policy Allows an administrator to specify group membership lists. – You can control membership in important groups, such as the local Administrators and Backup Operators groups.

Folder Redirection Policy Folder redirection provides administrators with the ability to redirect the contents of certain folders to a network location or to another location on the user’s local computer. Contents of folders on a local computer located in the Documents and Settings folder, including the Documents, Application Data, Desktop, and Start Menu folders, can be redirected.

Configuring Folder Redirection If you choose Basic–Redirect Everyone's Folder To The Same Location, you must specify the Target folder location in the Settings dialog box. If you choose Advanced–Specify Locations For Various User Groups, you must specify the target folder location for each group that you add in the Settings dialog box.

Folder Redirection Policy

Offline Files Policy A separate Group Policy category that can allow files to be available to users, even when the users are disconnected from the network. – The Offline Files feature works well with Folder Redirection: When Offline Files is enabled, users can access necessary files as if they were connected to the network. – When the network connection is restored, changes made to any documents are updated to the server. – Folders can be configured so that either all files or only selected files within the folder are available for offline use. When it is combined with Folder Redirection, users have the benefits of being able to redirect files to a network location and still have access to the files when the network connection is not present.

Offline Folder Policy

Disk Quotas Limit the amount of space available on the server for user data.

Disk Quotas

Group Policy Refresh Computer configuration group policies are refreshed every 90 minutes (+/- 30 minutes) by default. Domain controller group policies are refreshed every 2 minutes. You can force group policies by using the gpupdate command: gpupdate /force

Summary Most security-related settings are found within the Windows Settings node of the Computer Configuration node of a GPO. Policy settings that you wish to apply to all computers or users within a domain should be made within the Default Domain Policy GPO. – Generally, domain-wide account policies, such as Password Policies, Account Lockout, and Kerberos settings, are modified here.

Summary Windows Server 2008 provides the ability to configure Fine-Grained Password Policies, which allow multiple password and account lockout policies within a single domain. Local Policy settings govern the actions users can perform on a specific computer and determine whether the actions are recorded in an event log. Create Audit Policies here.

Summary Auditing can be configured to audit successes, failures, or both. Plan auditing carefully before implementation. Events that are not important to your documentation and information needs can cause unnecessary overhead when audited. Auditing can be a very important security tool when used prudently.

Summary Because audited events are recorded in the appropriate event log, it is necessary to understand the Event Log Policy setting area. This area allows control over maximum log sizes, log retention, and access rights to each log.

Summary Restrictions on group memberships can be accomplished using the Group Restriction Policy setting. – Implementing this policy removes group members who are not part of the configured group membership list or adds group members according to a preconfigured list.

Summary Folder Redirection can be configured for folders located on a local computer within the Documents And Settings folder. The Offline Files settings allow redirected folders to be available when a network connection is not present. These two setting areas complement each other.

Summary Disk quotas can be used to control storage space on a network drive. Implementing disk quotas allows administrators to have tighter control over drive usage, which can affect tape backup and restore functionality.

Summary Computer configuration group policies are refreshed every 90 minutes by default. Domain controller group policies are refreshed every 2 minutes. These settings can be altered based on the frequency in which policy changes occur. Disabling unused portions of a GPO decreases the time it takes to complete policy processing.