⟩ How to place the FSMO roles?
★ Place the RID and PDC emulator roles on the same domain controller. Good communication from the PDC to the RID master is desirable as down-level clients and applications target the PDC, making it a large consumer of RIDs.
★ As a general rule, the infrastructure master should be located on a non-global catalog server that has a direct connection object to some global catalog in the forest, preferably in the same Active Directory site.