When existing class and attribute definitions in the Active Directory schema do not meet the needs of your organization, you can use schema-based administrative tools to modify or add schema objects. You can modify an existing attribute or add a new class or attribute to the schema to store a new type of information in the directory. The process of modifying or updating the schema is often referred to as “extending the schema.” In addition to using schema tools to extend the schema, you can perform most schema extensions by using customized applications or Active Directory Service Interfaces (ADSI) scripts.
The following tools are associated with the Active Directory schema.
Adsiedit.exe: ADSI Edit
ADSI Edit is included when you install Support Tools for Windows Server 2003 and later.
ADSI Edit is a Microsoft Management Console (MMC) snap-in that uses ADSI, which uses the Lightweight Directory Access Protocol (LDAP). You can use ADSI Edit to view and modify directory objects in the Active Directory database. You can also use it to view schema directory partition objects and properties. When you open ADSI Edit, the Schema container is displayed by default. You can expand the container to view schema classes and attributes.
Csvde.exe: Csvde
Csvde is a command-line tool that ships with Windows Server 2003.
You can use Csvde.exe to export directory information to an Excel spreadsheet or to import data from a spreadsheet into Active Directory. You can use this format only for additions to the directory. Csvde.exe cannot be used to modify or delete objects.
Ldifde.exe: Ldifde
Ldifde is a command-line tool that ships with Windows Server 2003.
Active Directory supports the use of files that are formatted with the LDAP Data Interchange Format (LDIF) for importing and exporting information in the directory. This includes information that is stored in the schema, such as schema modifications. After an LDIF file is created, a tool such as Ldifde.exe performs the import operation by using the LDIF file for input. You can also use Ldifde.exe to add, modify, and delete directory objects; export Active Directory user and group information to other applications or services; and populate Active Directory with data from other directory services.
Schmmgmt.msc: The Active Directory Schema snap-in
The Active Directory Schema snap-in is an MMC snap-in in Administrative Tools that is installed automatically on all domain controllers running Windows Server 2003. However, you must register it manually before you use it for the first time. To register the Active Directory Schema snap-in, run Regsvr32 Schmmgmt.dll from the command prompt or from the Run command on the Start menu. Open MMC and add Active directory schema snap in.
ADSI and Visual Basic Scripts
Active Directory provides a set of interfaces that you can use programmatically to gain access to directory objects, including schema objects. ADSI conforms to the Component Object Model (COM), and it supports standard COM features. ADSI defines a directory service model and a set of COM interfaces that you can easily use with a variety of programming languages. With Microsoft Visual Basic, Scripting Edition and ADSI, you can write scripts to modify the directory in various ways, including extending the schema.
