It is recommended that your Active Directory design be certified by Microsoft or a certified partner with vast experience with Active Directory. Active Directory design (logical structure and site topology) must be completed prior to any migration.
Before the migration, you should check Active Directory replication to ensure that any changes to Active Directory (such as object creations and deletions) will be properly replicated between domain controllers and Global Catalog servers in different locations.
When planning a migration to Active Directory, it is recommended that your delegation model be engineered ahead of the project in order to identify all business rules that must be enforced. Quest Active Roles is the most comprehensive delegation and provisioning product available. The best practice is to install and configure Active Roles soon after implementing Active Directory and prior to migrating any accounts to ensure a pristine Active Directory from the start. For more details on Active Roles, see https://quest.com/products/activeroles-server/.
It is recommended that the Exchange design be completed and certified by Microsoft or a certified partner with vast experience with Exchange.
We also recommend you fully complete the target Exchange deployment prior to starting the Exchange migration to avoid Exchange organization re-enumerations in Migration Manager when you make changes to the environment (such as create administrative groups or add new Exchange servers and information stores). Having all servers in place also lets you configure all synchronization jobs with the right target servers and avoid any mailbox moves in the future.
In an inter-org migration, running the target Exchange infrastructure in native mode from day one also allows you leverage Exchange features such as administrative groups and routing groups. Running Exchange in native mode from the very beginning allows you re-configure and optimize mail routing for your target organization according to Microsoft Exchange best practices before users start using the target Exchange servers.
Before the migration, you should check that the Domain Naming System (DNS) and the Windows Internet Naming Service (WINS) are functioning properly so that machine names can be successfully resolved into IP addresses.
You can use the DCDiag and NetDiag utilities from Windows Support Tools to test network connectivity and identify the host name resolution problems. To install Windows Support Tools, run Setup.exe from the \SUPPORT\TOOLS folder of Windows Server distribution CD. For more information about the utilities, refer to their online help and other documentation.
DNS Name Resolution
The DNS names of the source and target servers and of the servers on which ADAM or AD LDS project partition and SQL configuration database are located must be successfully resolved to IP addresses from the servers running the Directory Synchronization Agents as well as from the console.
Make sure that the DNS is configured and functioning properly in your environment.
NetBIOS Name Resolution
Since the agents installed on the source and target Exchange servers communicate with each other, Exchange source-target server pairs must be able to resolve each other’s NetBIOS names. In other words, each server must be able to “see” the other servers by NetBIOS.
Windows Internet Naming Service (WINS) is usually used to resolve servers’ NetBIOS names to IP addresses. If WINS is not configured in an environment, host files can be used instead.
You should check the host NetBIOS name resolution and make sure that the servers’ NetBIOS names can be resolved from the console as well.