2.1 Introduction

Migrating from Exchange 4.0 to Exchange 5.0, or from Exchange 5.0 to Exchange 5.5, was a relatively simplistic challenge and fairly straightforward. Then along came Exchange 2000, and we endured a steep learning curve as we all struggled to come to grips with the complexities of migration to Exchange 2000 from Exchange 5.5. You might be forgiven for thinking that migration from Exchange 5.5 to Exchange 2003 would be even more complex, but the reality is that it is no more difficult and, if anything, is slightly more straightforward because there are fewer options to confuse us. Those technologies and techniques that we learned for Exchange 2000 migration are just as relevant today for Exchange 2003, and as before the fundamentals are key so directory synchronization interoperability is critical.

The Active Directory Connector is one of the most powerful tools available to the messaging consultant. We know that Exchange 2003 doesn't have its own built-in directory service. Instead, it uses the AD. During a migration exercise from a legacy Exchange 5.5 environment to Exchange 2003, one of the most important aspects of coexistence is that of synchronizing directory information between the Exchange 5.5 Directory Service and the Windows 2003 AD. The Active Directory Connector does just that: it maps the Exchange 5.5 Directory Service object types to the AD and vice versa. The Active Directory Connector available with Exchange 2003 is not that much different from the Active Directory Connector that was available with Exchange 2000. The core...