Here are the design considerations surrounding the FSMO Role: Infrastructure Master:
- This FSMO is responsible for tracking object changes in Active Directory
- Like to be with the RID (since you place the RID where most changes occur)
- Should not be on a GC Server, unless GC is installed on all DCs
Exam Alert: In general FSMO Roles should never be placed “anywhere”, they should always be placed somewhere intentionally; yet there are sometimes the “best answer” is “any other domain controller”.