Active Directory

Global Catalog and Infrastructure Master

Infrastructure Master role in Global Catalog Server
The infrastructure master compares objects of the local domain against objects in other domains of the same forest. If the server holding the infrastructure master role is also a global catalog it won’t ever see any differences, since the global catalog holds a partitial copy of every object in the forest itself.
If every DC in the Domain is also global catalog server there’s no job for the IM since the GC already knows about the objects of other domains. So the following infrastructure is a valid configuration:So in short:

The Infrastructure Master is not supposed to configure on a Global Catalog Server if:
  • There are multiple domains
  • Domain Controllers in the same Domain are not Global Catalog Servers
The Infrastructure Master is allowed to run on a Global Catalog Server if:
  • There’s only one Domain in the Forest
  • Every Domain Controller in the Domain is Global Catalog Server