Active Directory and Replication ???


Abdul B.

Hello All:

I have a question regarding replication of Active Directory

My understanding of Active Directory Replication together with the
replication that occurs between Global Catalog Servers is that every
AD Domain Controller has got 3 full writable AD partition i.e.

1. Domain Directory Partition
2. Configuration Directory Partition and
3. Schema Directory Partition

in addition to that a Domain Controller that is also designated as a
Global Catalog Server has got a partial read-only partition of the
"Domain Directory Partition" of all other domain controllers in the
entire forest!!!!!!!!!!!!!!!!

I understand that Global Catalog Servers synchronize there partial
read-only partitions to each other I also understand that domain
controllers that are NOT Global Catalog Servers but are in the same
domain synchronize there 3 above mentioned partitions with each other
in addition to that they synchronize there 2. Configuration Partition
and 3. Schema Directory Partition to all other Domain Contollers in
the Forest

The question is am I taking it right that the 1. Domain Directory
Partition is only replicated and synchronized between Domain
Controllers of the same Domain??????? What I understand of the domain
directory partition is that it stores the user , computer , printer
objects etc... because if it would not be so than this whole global
catalogs would be unnecessary because every domain controller would
have all information ready anyway......

Your help is much appreciated.

Pashii B

Simon Geary

You are correct, the domain NC is replicated to every DC in the domain. This
is why in a single domain forest it is suggested to make all your DC's a GC.
The GC holds objects from every domain in the forest but only subset of
attributes so when you only have one domain making all DC's a GC will not
hurt performance.
If you have more than one domain in the forest, it becomes a very different
matter and you have to plan GC placement carefully.

Cary Shultz [A.D. MVP]


There are three partitions, or Naming Contexts: the Schema NC, the
Configuration NC and the Domain NC. Each and every Domain Controller in the
entire Forest replicates the first two NCs (
cn=schema,cn=configuration,dc=yourdomain,dc=com and
cn=configuration,dc=yourdomain,dc=com ) but only the Domain Controllers in
the same domain will replicate 'their' Domain NC.

So, if you have three domains and two Domain Controllers in each domain then
the two DCs from will be the only two replication partners
for that NC ( dc=yourdomain,dc=com ) and the two DCs from will be the only two replication partners for that NC
( dc=child1,dc=yourdomain,dc=com ) and the two DCs from will be the only replication partners for that NC (
dc=child2,dc=yourdomain,dc=com ).

A really good way to learn what is in the NCs - or partitions - is to
install the Support Tools and use adsiedit. You will see a lot of things
and things will become, hopefully, a lot more clear. For example, why can
you have only one Exchange Organization in your forest? Because it is
stored in the Configuration NC....


Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question