Q. Are there any tools provided with Windows Server 2008 and above to compare schemas?

A. If you install the Active Directory Lightweight Directory Services (AD LDS) role in Server 2008, the AD Schema Analyzer (ADSchemaAnalyzer.exe) is also installed. You can run Schema Analyzer using a link in the Advanced Tools section of Server Manager, or you can run it directly as C:WindowsADAMADSchemaAnalyzer.exe. You don't have to create any AD LDS instances—you just need to install the role to get access to the tools.

Once you've executed the tool, you have the option to load a target schema and a base schema. For both the target and base, you can load either an LDIF file, as shown here, or the schema from a live AD (by passing a DC and credentials). This means you can compare a live AD to an LDIF file, compare two LDIF files, or compare two live ADs.

Once both schemas are loaded, the utility compares them. You can select the "Hide present elements" option to show only differences between the schemas. You can select each element you want to export individually, or include every element using the "Mark all non-present elements as included" option from the Schema menu.

To create a file containing the differences between the schemas, select "Create LDIF file" from the File menu. You can load this file into another forest to close any differences. If you open the difference file, you'll see text similar to the following:

# Attribute: accountExpiresdn: cn=Account-Expires,cn=Schema,cn=Configuration,dc=Xchangetype: addobjectClass: attributeSchemaattributeId: 1.2.840.113556.1.4.159

Note that for the domain, it only has dc=X. To load the differencing file you need a valid domain, but you don't have to edit the difference file—you can tell the ldifde utility to make the change.

To import, use the command below. Note the switch -c, which tells the command to replace dc=X with the DC=Savilltech,DC=Net and the -i says to import.

ldifde -i -f difference.ldf -c dc=X DC=Savilltech,DC=Net

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