Which domain controller stores extra information across the entire organization and enables cross-domain object lookup, using port 3268?

Which domain controller stores extra information across the entire organization and enables cross-domain object lookup, using port 3268?

• A. DHCP
• B. Global Catalog Service
• C. Active Directory Domain Services
• D. DNS

Answer: (B)

Global Catalog servers are domain controllers that hold a partial, forest-wide copy of every object. This enables searches that span multiple domains without querying each domain separately, which is exactly what cross-domain object lookup requires. The Global Catalog uses LDAP on port 3268 (3269 for LDAP over SSL) to provide these lookups across the forest. DHCP, DNS, and AD DS each serve other roles—DNS for name resolution, DHCP for IP assignment, and AD DS as the directory service for a single domain—whereas the cross-domain lookup across the forest is the function of the Global Catalog.

Global Catalog servers are domain controllers that hold a partial, forest-wide copy of every object. This enables searches that span multiple domains without querying each domain separately, which is exactly what cross-domain object lookup requires. The Global Catalog uses LDAP on port 3268 (3269 for LDAP over SSL) to provide these lookups across the forest. DHCP, DNS, and AD DS each serve other roles—DNS for name resolution, DHCP for IP assignment, and AD DS as the directory service for a single domain—whereas the cross-domain lookup across the forest is the function of the Global Catalog.