Set-ADForestMode

Module:

ActiveDirectory

Sets the forest mode for an Active Directory forest.

Syntax

Set-ADForestMode
   [-WhatIf]
   [-Confirm]
   [-AuthType <ADAuthType>]
   [-Credential <PSCredential>]
   [-ForestMode] <ADForestMode>
   [-Identity] <ADForest>
   [-PassThru]
   [-Server <String>]
   [<CommonParameters>]

Description

The Set-ADForestMode cmdlet sets the forest mode for an Active Directory forest. You specify the forest mode by setting the ForestMode parameter.

The Identity parameter specifies the Active Directory forest to modify. You can identify a forest by its fully qualified domain name (FQDN), GUID, DNS host name, or NetBIOS name. You can also specify the forest by passing a forest object through the pipeline. For example, you can use the Get-ADForest cmdlet to retrieve a forest object and then pass the object through the pipeline to the Set-ADForestMode cmdlet.

Set-ADForestMode prompts for confirmation by default.

Examples

Example 1: Set the forest mode for a forest

Set-ADForestMode -Identity fabrikam.com -ForestMode Windows2003Forest

This command sets the ForestMode to Windows2003Forest in the forest fabrikam.com.

Example 2: Set the forest mode for the current user

$params = @{
    Identity = (Get-ADForest)
    Server = $params.Identity.SchemaMaster
    ForestMode = 'Windows2008R2Forest'
}
Set-ADForestMode @params

This example sets the forest mode of the current user's forest. The set operation targets the schema master flexible single master operation (FSMO) role to apply the update.

Parameters

-AuthType

Specifies the authentication method to use. The acceptable values for this parameter are:

• Negotiate or 0
• Basic or 1

The default authentication method is Negotiate.

A Secure Sockets Layer (SSL) connection is required for the Basic authentication method.

Type:	ADAuthType
Accepted values:	Negotiate, Basic
Position:	Named
Default value:	None
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False

-Confirm

Prompts you for confirmation before running the cmdlet.

Type:	SwitchParameter
Aliases:	cf
Position:	Named
Default value:	False
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False

-Credential

Specifies the user account credentials to use to perform this task. The default credentials are the credentials of the currently logged on user unless the cmdlet is run from an Active Directory module for Windows PowerShell provider drive. If the cmdlet is run from such a provider drive, the account associated with the drive is the default.

To specify this parameter, you can type a user name, such as User1 or Domain01\User01 or you can specify a PSCredential object. If you specify a user name for this parameter, the cmdlet prompts for a password.

You can also create a PSCredential object by using a script or by using the Get-Credential cmdlet. You can then set the Credential parameter to the PSCredential object.

If the acting credentials do not have directory-level permission to perform the task, Active Directory module for Windows PowerShell returns a terminating error.

Type:	PSCredential
Position:	Named
Default value:	None
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False

-ForestMode

Specifies the forest mode for an Active Directory forest. The acceptable values for this parameter are:

• Windows2000Forest or 0
• Windows2003InterimForest or 1
• Windows2003Forest or 2
• Windows2008Forest or 3
• Windows2008R2Forest or 4
• Windows2012Forest or 5
• Windows2012R2Forest or 6
• Windows2016Forest or 7
• Windows2025Forest or 10

The values are listed in order of functionality from least to most.

Type:	ADForestMode
Accepted values:	Windows2000Forest, Windows2003InterimForest, Windows2003Forest, Windows2008Forest, Windows2008R2Forest, Windows2012Forest, Windows2012R2Forest, Windows2016Forest, Windows2025Forest, UnknownForest
Position:	2
Default value:	None
Required:	True
Accept pipeline input:	False
Accept wildcard characters:	False

-Identity

Specifies an Active Directory forest object by providing one of the following attribute values. The identifier in parentheses is the Lightweight Directory Access Protocol (LDAP) display name for the attribute. The acceptable values for this parameter are:

• A fully qualified domain name
• A GUID (objectGUID)
• A DNS host name
• A NetBIOS name

The cmdlet searches the default naming context or partition to find the object. If two or more objects are found, the cmdlet returns a non-terminating error.

This parameter can also get this object through the pipeline or you can set this parameter to a forest object instance.

Type:	ADForest
Position:	0
Default value:	None
Required:	True
Accept pipeline input:	True
Accept wildcard characters:	False

-PassThru

Returns an object representing the item with which you are working. By default, this cmdlet does not generate any output.

Type:	SwitchParameter
Position:	Named
Default value:	None
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False

-Server

Specifies the Active Directory Domain Services (AD DS) instance to connect to, by providing one of the following values for a corresponding domain name or directory server. The service may be any of the following:

• Active Directory Lightweight Directory Services (AD LDS)
• AD DS
• Active Directory snapshot instance.

Specify the AD DS instance in one of the following ways:

Domain name values:

• Fully qualified domain name
• NetBIOS name

Directory server values:

• Fully qualified directory server name
• NetBIOS name
• Fully qualified directory server name and port

The default value for this parameter is determined by one of the following methods in the order that they are listed:

• By using the Server value from objects passed through the pipeline
• By using the server information associated with the AD DS Windows PowerShell provider drive, when the cmdlet runs in that drive
• By using the domain of the computer running Windows PowerShell

Type:	String
Position:	Named
Default value:	None
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False

-WhatIf

Shows what would happen if the cmdlet runs. The cmdlet is not run.

Type:	SwitchParameter
Aliases:	wi
Position:	Named
Default value:	False
Required:	False
Accept pipeline input:	False
Accept wildcard characters:	False

Inputs

None or Microsoft.ActiveDirectory.Management.ADForest

You can pipe a forest object to the Identity parameter.

Outputs

None or Microsoft.ActiveDirectory.Management.ADForest

This cmdlet returns the modified forest object when the PassThru parameter is specified. By default, this cmdlet does not generate any output.

Notes

• This cmdlet does not work with AD LDS.
• This cmdlet does not work with an Active Directory snapshot.
• This cmdlet does not work with a read-only domain controller.

Related Links

• Get-ADForest