Learning Windows Server 2003, Second Edition

This is the Title of the Book, eMatter Edition

Copyright © 2008 O’Reilly & Associates, Inc. All rights reserved.

Understanding Directory Replication

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Time zones also play a role. Windows operates internally at Greenwich Mean Time,

and although each server can be set to a different time zone depending on either its

physical location or the location of the administrator who manages the box, within

Windows itself the current time is translated to GMT. Be wary of this, and ensure

that time zones are set correctly on all your servers. The object is to get Windows’

internal clocks to synchronize—even though the time might seem right to the naked

eye, if the time zone is set incorrectly, Windows is unforgiving when it comes to

Active Directory operations in that state.

Replication Topologies

Loops and meshes are just two examples of what Microsoft terms replication topolo-

gies—essentially, maps of the ways domain controllers replicate to each other. And

to confuse things, almost always, more than one replication topology exists simulta-

neously within any particular forest. Let’s take a closer look at that.

Four types of data need to be replicated among domain controllers:

• Updates that stay within a particular domain—username and password changes,

and other user account information

• Updates to the schema naming context and configuration naming context,

which are specific to all domains with a forest, as you saw previously in this

chapter

• Updates to the GC, which replicate to all domain controllers that function as GC

servers

• Updates to DNS partitions and custom application partitions

With many domain controllers in a forest, you can see where one replication topol-

ogy might either not suffice or not be the most efficient way to transmit information

between these selected subgroups of domain controllers. Figure 5-46 shows this sce-

nario graphically.

Figure 5-46. Creating a new site link

DC

B

DC

C

DC

D

DC

A

1

2

DC

E

3

4

7

6

8

9

5

“Two loops” result in many

inefficient transactions