Creating Multiple Forests
Because Windows Server 2003 domains in a forest share a single schema, configuration container, and global catalog, and are linked by two-way transitive trusts, you should strive to have only for your organization. Ideally, the use of multiple forests should be temporary and reserved for situations such as a merger, acquisition, or partnership where two or more organizations must be joined. By defining multiple forests, you add substantial administrative and usability costs to your organization.
Reasons to Create Multiple Forests
Although you should strive to define only one forest for your organization, there are some situations that might warrant the creation of multiple forests. You might need to consider creating multiple forests if you need to:
Secure data Sensitive data can be protected so that only users within that forest
can access it, such as a situation where business units must be separately maintained or when there is a need to isolate the schema, configuration container, orglobal catalog.
Isolate directory replication Schema changes, configuration changes, and the addition of new domains to a forest affect only that forest. Accommodate development/lab environments New or test environments that may not yet be ready for production can be isolated from the rest of the organization.
