Get-ADForest

Gets an Active Directory forest.

Syntax

Get-ADForest
   [-AuthType <ADAuthType>]
   [-Credential <PSCredential>]
   [-Current <ADCurrentForestType>]
   [-Server <String>]
   [<CommonParameters>]
Get-ADForest
   [-AuthType <ADAuthType>]
   [-Credential <PSCredential>]
   [-Identity] <ADForest>
   [-Server <String>]
   [<CommonParameters>]

Description

The Get-ADForest cmdlet gets the specified Active Directory forest. You can specify the forest by setting the Identity or Current parameters.

The Identity parameter specifies the Active Directory forest to get. You can identify a forest by its fully qualified domain name (FQDN), DNS host name, or NetBIOS name. You can also set the parameter to a forest object variable, such as $<localForestObject>, or you can pass a forest object through the pipeline to the Identity parameter.

To get the forest of the local computer or current logged on user, set the Current parameter to LocalComputer or LoggedOnUser. When you set the Currentparameter, you do not need to set the Identity parameter.

When the Current parameter is set to LocalComputer or LoggedOnUser, the cmdlet uses the Server and Credential parameter values to determine the domain and the credentials to use to identify the domain of the forest according to the following rules:

  • If both the Server and Credential parameters are not specified:

The domain is set to the domain of the LocalComputer or LoggedOnUser and a server is located in this domain. The credentials of the current logged on user are used to get the domain.

  • If the Server parameter is specified and the Credential parameter is not specified:

The domain is set to the domain of the specified server and the cmdlet checks to make sure that the server is in the domain of the LocalComputer or LoggedOnUser. Then the credentials of the current logged on user are used to get the domain. An error is returned when the server is not in the domain of the LocalComputer or LoggedOnUser.

  • If the Server parameter is not specified and the Credential parameter is specified:

The domain is set to the domain of the LocalComputer or LoggedOnUser and a server is located in this domain. Then the credentials specified by the Credential parameter are used to get the domain.

  • If the Server and Credential parameters are specified:

The domain is set to the domain of the specified server and the cmdlet checks to make sure that the server is in the domain of the LocalComputer or LoggedOnUser. Then the credentials specified by the Credential parameter are used to get the domain. An error is returned when the server is not in the domain of the LocalComputer or LoggedOnUser.

Examples

Example 1: Get information for a domain forest

PS C:\> Get-ADForest -Identity Fabrikam.com

This command gets information for the Fabrikam.com forest.

Example 2: Get information for a local computer forest

PS C:\> Get-ADForest -Current LocalComputer

This command gets the information for the current local computer's forest.

Example 3: Get information for the current user's forest

PS C:\> Get-ADForest -Current LoggedOnUser

This command gets the forest information of the currently logged on user.

Example 4: Get information for the current user's forest

PS C:\> Get-ADForest
ApplicationPartitions  : {DC=ForestDnsZones,DC=Fabrikam,DC=com, DC=DomainDnsZones,DC=Fabrikam,DC=com}
CrossForestReferences  : {CN=northwind,CN=Partitions,CN=Configuration,DC=Fabrikam,DC=com}
DomainNamingMaster     : Fabrikam-DC1.Fabrikam.com
Domains                : {Fabrikam.com}
ForestMode             : Windows2003Forest
GlobalCatalogs         : {Fabrikam-DC1.Fabrikam.com, CSD2722780.Fabrikam.com}
Name                   : Fabrikam.com
PartitionsContainer    : CN=Partitions,CN=Configuration,DC=Fabrikam,DC=com
RootDomain             : Fabrikam.com
SchemaMaster           : Fabrikam-DC1.Fabrikam.com
Sites                  : {Default-First-Site-Name, UnitedKingdomHQ, BO3, RODC-Site-Name}
SPNSuffixes            : {}
UPNSuffixes            : {}

This command gets the forest information of the currently logged on user.

Example 5: Get all of the domain controllers for all domains in a forest

PS C:\> $AllDCs = (Get-ADForest).Domains | %{ Get-ADDomainController -Filter * -Server $_ }

This command gets all the domain controllers for all domains in a forest.

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

-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

-Current

Specifies whether to return the domain of the local computer or the current logged on user. The acceptable values for this parameter are:

  • LocalComputer or 0
  • LoggedOnUser or 1
Type:ADCurrentForestType
Accepted values:LocalComputer, LoggedOnUser
Position:Named
Default value:None
Required:False
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

-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, or 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

Inputs

None or Microsoft.ActiveDirectory.Management.ADForest

A forest object is received by the Identity parameter.

Outputs

ADForest

Returns one or more forest objects.

This cmdlet returns all of the properties of the forest. To view all of the properties for an ADForest object, use the following command and replace <forest> with a forest identifier such as a DNS host name.

Get-ADForest<forest>| Get-Member

Notes

  • This cmdlet does not work with AD LDS.
  • This cmdlet does not work when targeting a snapshot using the Server parameter.