Chapter 6 -- Coexistence with Previous Microsoft Exchange Server Versions

Chapter 6

About This Chapter

Because of significant differences in the system architecture, migrating from previous versions of Microsoft Exchange Server to Microsoft Exchange 2000 Server is a complex undertaking. Unlike earlier versions, Exchange 2000 Server does not use its own directory service, but relies on the Active Directory directory service. You therefore need to integrate Exchange Server 5.5 with Active Directory if you wish to bring both Exchange versions together. In fact, Active Directory integration of Exchange Server 5.5 is a very important task during any upgrade project.

It is possible to split the migration process into three general phases: preparation, upgrade, and cleanup. During the preparation phase, you need to integrate Exchange Server 5.5 with Active Directory. This may include updating the operating system to Microsoft Windows 2000 Server Service Pack 1 and the server installation to Exchange Server 5.5 Service Pack 3 first. After that, during the upgrade phase, you need to install Exchange 2000 Server. The upgrade may require a long period of coexistence until you have thoroughly deployed Exchange 2000 Server. The cleanup phase involves deleting Exchange objects from Active Directory, switching the organization into native mode, and removing duplicate user accounts that might have been created during the migration.

This chapter covers, in detail, the important tasks you face when upgrading or migrating an existing Exchange Server 5.5 organization to Exchange 2000 Server. The first lesson illustrates how to integrate Exchange Server 5.5 with Active Directory, an essential prerequisite. The second lesson deals with the actual upgrade procedures and concludes with a discussion of postupgrade tasks.

Before You Begin

To complete this chapter:

• Have a general understanding of Exchange Server administration and the concepts related to synchronizing Active Directory with the Exchange directory service.
• Be familiar with the concepts of upgrading Microsoft Windows NT Server 4.0 to Windows 2000 Server.
• The exercises in this chapter assume that you have installed Windows NT Server 4.0 on two computers operating in a single domain environment. Both computers need to run an installation of Exchange Server 5.5 Service Pack 3, as described in the "Getting Started" section of "About This Book."