MCSA/MCSE Self-Paced Training Kit (Exam 70-270): Installing ...

Replication Within an Active Directory Site
F14us05
Lesson 1 Overview of Active Directory
14-11
Active Directory also includes a replication feature. Replication ensures that changes
to a domain controller are reflected in all domain controllers within a domain. To
understand replication, you must understand domain controllers. A domain controller
stores a replica of the domain directory. Each domain can contain one or more domain
controllers.
Within a site, Active Directory automatically generates a ring topology for replication
among domain controllers in the same domain. The topology defines the path for
directory updates to flow from one domain controller to another until all receive the
directory updates (see Figure 14-5).
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Replication topology links
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Figure 14-5 Within a site, replication between domain controllers happens automatically.
The ring structure ensures that there are at least two replication paths from one domain
controller to another. Therefore, if one domain controller is down temporarily, replication
still continues to all other domain controllers.
Active Directory periodically analyzes the replication topology within a site to ensure
that it is still efficient. If you add or remove a domain controller from the network or a
site, Active Directory reconfigures the topology to reflect the change.
On the CD At this point, please view the multimedia presentation “Replication Within
Sites,” which is included in the Multimedia folder on the CD accompanying this book.