AD GC over SSL TLS (3269)
The port 3269 is used by the global catalog over Secure LDAP (LDAPS) in an AD environment.
The Global Catalog is a partial, read-only replica of all objects from all domains in the forest. Optimised for search and authentication. Unlike port 3268, which provides GC over regular LDAP, 3269 encrypts communication using SSL/TLS
Used for:
- Cross-domain authentication
- Forest-wide searches
- LDAP queries for GC-replicated attributes
- Secure lookup of user and group information