I remember when I started working as Windows Admin several years ago, FSMO (Flexible Single Master Operations) was one kind of nightmare for me. I Googled hundred times to find out what exactly it is, but found too theoretical/non-practical information. Now when I actually came to know what exactly it is, I find it simple. So I will try to explain it in a absolute layman language. Hope it will help many engineers like me. Also instead of explaining it in one shot, we will discuss one role at a time for better understanding.
So I hope everyone is aware of Forest and Domain concept in Windows. Domain is just a logical boundary which represents it's reach and limitation. For example, wipro.com is a domain which represents reach and limitation of all employee within the organization. We can't go beyond wipro.com and no one from outside can come inside it. If we have group of domains which belong to a single organization or infrastructure, it's called a forest and it's identified as the root domain. For example, wipro.com, mywipro.wipro.com, newmywipro.wipro.com, careers.wipro.com, itms.wipro.com etc, all are different domains but belong to a single organization Wipro Ltd., hence this group of domain is called as Forest which will be represent by the root domain, wipro.com. If we have only one domain in our infrastructure, by default that will also be the forest for that organization.
This is all for this post. In next post, we will discuss why we need FSMO roles, how many are they and how they can actually placed within the organization. In the meanwhile, your feedback and questions are welcome.