Exchange 2000 and Active Directory can't be treated as separate islands in a system, according to AD expert Ratmir...
Timashev. While AD must be in place before Exchange 2000 can be deployed, Exchange's characteristics must be factored into the actual AD design.
In a recent SearchWindowsManageability interview, Timashev -- president and CEO of Aelita Software -- discussed the implications for single forest and multi-forest AD designs. In this SWM interview, Timashev explains the issues and challenges administrators might face with a multi forest AD design in Exchange 2000. In part two, he details setting up multi forest environments and the messaging systems within them.
|SWM:||Why is Exchange deployment an issue for AD design?|
It's an issue because Exchange 2000 integrates with Active Directory. Exchange 2000 uses AD for all directory-related operations, such as information storage and look-ups, replication and synchronization, but even the end-user e-mail experience relies on AD. For example, e-mail relies on AD for information about users, and AD is used to populate the Global Catalog, which is used as the Exchange 2000 address book.
|SWM:||What are some of the issues involved in setting up Exchange in a multi-forest AD design?|
With a multi-forest AD design, in which each forest has a separate AD service, you have to decide whether each forest should have its own Exchange organization or whether each forest will share a single Exchange organization. Each option will affect collaboration level, replication and other options you have. So at a high level, the main issues are collaboration, replication, and synchronization of data. Together, these issues affect the designs that can be implemented when setting up Exchange.
|SWM:||What are the main AD/Exchange designs that are possible?|
When deploying AD and Exchange, there are three main designs: single forest/single org, multi-forest/single org, and multi-forest/multi-org. Most companies select a single forest/single org (SF/SO) configuration during the early AD deployments. It is the simplest AD/Exchange structure. The whole AD consists of a single forest and that forest has a single Exchange 2000 organization installed in it as the messaging system.
|SWM:||How does each design increase/decrease collaboration capabilities?|
Native Microsoft tools support the single forest/single organization model. Having a single forest and Exchange 2000 organization means that all users have mailboxes within a single Exchange organization and access the same Public Folders, address book, and calendar information. In addition, all the replication tasks are handled by the native AD/Exchange mechanisms.
|SWM:||How does each design increase/decrease administrative cost?|
The single forest/single organization model offers the lowest administrative cost because it is the simplest design and because native Microsoft tools support this model. Having a single forest and Exchange 2000 organization also means that all the replication tasks are handled by the native AD/Exchange mechanisms.
FOR MORE INFORMATION
Continue on to part two.
Read SWM's first interview with Timashev, "Single forest vs. multi-forest Active Directory design"