FSMO Roles

Active Directory is like a database, a potentially huge database, sync’d across a potentially huge number of different Domain Controller servers in your environment. In an environment with lots of DCs spread across numerous sites, the potential for change conflict is huge. What if DC1 in Redmond receives a change and needs to sync it around the entire domain, and at the same time DC22 in London receives instruction to sync a change that is in conflict with the change of DC1. What now? Who wins? In the early days of Active Directory, there was one single master domain controller server, known as the Primary Domain Controller (PDC), that was responsible for making all changes like this. Technically, the PDC role no longer exists, but some of the same protections are still in place under the hood by the use of Flexible Single Master Operation (FSMO) roles. Every instance of Active Directory has FSMO roles, and FSMO role holders. In a lot of cases, the same Domain Controller...