FSMO role ( First of three blog series)

Hi Friends

I hope this blog finds you in good health and spirit. Most of the time I am training people on AD and Windows Server technologies and FSMO role is most common topic which is discussed often. So. I thought to compile the information in a blog which will work during training session and also for post-session review. So lets start.

What do you mean by FSMO ?

So, first thing first. What is FSMO ? AD has multi-master replication model. You can write on any DC and the changes will replicate to all others. This concept holds true for all except few operations which are done by specific authorized DC. DCs which are responsible for performing these operations are called operation master or Flexible Single Master Operations (FSMO pronounced as fizmo).

You can think it in this way. Say, you have big party at your house where you have invited lot of people. You thought to take help of your friends for arrangements. So, you designated one friend to look after decoration, second for food arrangement, third for stay arrangement of guests and so on. These works are operations and your friends are operation master because they are responsible to perform those operations.

There are five operation master roles, two of them are forest wide and three are domain wide, listed as below:

Forest-wide

Schema master
Domain Naming Master

Domain Wide

RID master
Infrastructure master
PDC Emulator

When you configure first DC in forest, it holds all five role. When you configure first DC in domain, it holds all domain wide roles. You can check roles via GUI and command prompt. One easiest way is to use this command:

Netdom query fsmo

Netdom query fsmo /d:<domain name> for specified domain.