Red Hat DIRECTORY SERVER 7.1 - DEPLOYMENT Deployment Manual page 145

Additionally, Windows Sync must be configured on a primary domain
controller (PDC) for Windows NT4 servers. Synchronization will not function
properly on a non-PDC machine.
• Determine the type of connection you will use.
Although it is not required, it is strongly recommended that you use an SSL or
other secure connection for synchronization. If you want to synchronize
passwords from the Windows server (by installing the Password Sync Service),
then you must have SSL enabled on both servers and have the synchronization
proceed over a secure port.
• Decide whether your Directory Server will be in a replicated environment.
You should only create one sync agreement to any given Windows domain. To
propagate the changes and information synched from the Windows server
throughout the Directory Server, create the sync agreement with a
multi-master supplier, preferrably a data master for the replication
deployment.
• Identify a data master.
A data master contains the primary source for directory data. Windows and
Directory Server services are kept continously in sync through the sync
agreement, which will minimize potential conflicts between the two services.
However, if your Directory Server if part of a replication deployment, then
conflicts could arise between changes made within the Directory Server
replication scenario and the Windows domain depending on your replication
schedule.
Choose one area (Windows domain or Directory Server) to master the data.
Alternatively, choose a single Directory Server as a data master and
synchronize it with each Windows domain. If your Directory Server is
involved in replication, design the replication structure to avoid conflicts,
losing data, or overwriting data.
NOTE
Deletions on an NT4 Server are not synchronized by the NT4 LDAP
Server, so the corresponding entry is not deleted automatically from
the Directory Server. Issues like these can help determine which
platform should be the data master for your directory information.
See chapter 18, "Windows Sync," in the Red Hat Directory Server
Administrator' s Guide for more information on the uses and
limitations of synchronization.
• Develop a strategy for both total and incremental updates.
Designing Windows Sync
Chapter 7 Designing Synchronization 145