MS-GC
The Microsoft Global Catalog is a distributed data repository that contains a searchable, partial representation of every object in every domain in a multi-domain Active Directory Domain Services (ADDS) forest. The global catalog is stored on domain controllers that have been designated as global catalog servers and is distributed through multi-master replication.
Available to all SRX running 12.3X48+
Available to all MX running 20.2R1+
Available to all vSRX running 20.3R1+