Port 3269 supports Active Directory Global Catalog over TLS and msft-gc-ssl (UDP reference coverage) across distinct transports. Review each protocol before writing firewall or monitoring policy.
TLS-protected Global Catalog directory queries across an Active Directory forest.
Encrypted forest-wide directory searches and application integrations that require the Global Catalog.
Client to server
Validate the domain controller certificate and hostname, maintain strong bind controls and restrict access to approved clients.
msft-gc-ssl (UDP reference coverage) is documented as a network service convention for port 3269 over UDP.
Use this reference entry when identifying or validating systems documented to use 3269/UDP.
Varies
Confirm the listening process and current vendor documentation before permitting traffic; a listed convention does not prove the active service or its security posture.