Active Directory's logical and physical topology

If it's a single forest-single domain environment, it is not wrong to keep all the FSMO roles in one domain controller. According to the best practices, the infrastructure operations master role should not be held by a global catalog server. But, this is only if the environment has multiple domains. In a single forest-single domain environment, on most occasions, all servers are global catalog servers as well.

In the following example, in the rebeladmin.com single forest-single domain environment, there are three domain controllers in the infrastructure:

Figure 5.3: FSMO role placement example 1

PDC01 is recognized as the most powerful (capacity) and most reliable domain controller. Therefore, PDC01 holds all five FSMO roles. SDC01 and SDC02 are also two global catalog servers. In this case, just moving the infrastructure operations master role to one of the domain controllers will not have a significant impact...