In Windows 2000 Server a forest is a forest is a forest. There are few additional features or benefits of a forest above and beyond that of a domain. Yes, forests allow multiple domains to be within the same master trust structure and to share the same master global catalog and schema. But is that really enough?
In Windows Server 2003 a forest offers many new features that expand and enhance the capabilities of Active Directory. Some of these improvements are transparent and more structural in nature, while others are features you can take advantage of (or at least use) as a domain administrator.
Those features which are core improvements to Active Directory forests with little or no configurable user interface include:
- Improvements to LVR (Linked Value Replication) to ensure that multiple near-simultaneous changes to AD objects, even across domains, within the same forest, replicate properly without causing object corruption.
- Improvements to the GC (Global Catalog) indexing process. The Windows 2000 Server indexing process re-indexed the entire GC whenever a new value was added. This often causes significant traffic among DCs. Now, adding new values only causes an index update change rather than a complete re-index, thus greatly reducing unnecessary network traffic.
- Improvements to ITG (Intersite Topology Generator) to allow more than ~250 AD sites without special assistance from Microsoft.
The improvements to the forest extend beyond the under-the-hood variety to include features a domain administrator can take direct advantage of. These include:
- The ability to rename domains. No more destruction and re-building of DCs just to change a domain name.
- The ability to create cross-forest trusts between Windows Server 2003 forests. This cuts out the need for multiple domain to domain trusts between forests.
- The ability to alter or fix additions to the schema. Never get stuck with a mistake or a legacy addition to the schema.
As you can see, just from a quick review of Windows Server 2003 AD forests, there is much to be desired. So, take some time to test Windows Server 2003 for yourself and see how well it meets your needs.
James Michael Stewart is a partner and researcher for ITinfopros, a technology-focused writing and training organization.