Port 371

IBM Rational ClearCase uses the Atria Location Broker Daemon (ALBD) on port 371 to manage service discovery and communication between distributed components. The ALBD acts as an intermediary that accepts requests from ClearCase clients, then redirects them to specific service daemons that handle versioning, checkouts, metadata queries, and more. This architecture simplifies client configuration because clients initially connect only to a well-known port (371), and the ALBD coordinates further communication.

Under the hood, the ALBD server registers and tracks ClearCase services across multiple hosts, ensuring efficient mapping of user requests to the appropriate service endpoints. It supports both TCP and UDP communication, depending on the nature of the request. The reliance on ALBD allows organizations to deploy ClearCase in a scalable manner, supporting numerous projects and concurrent users without manual service management.

ClearCase ALBD is part of a broader ClearCase deployment that oversees versioned object bases (VOBs) and view management. It provides a central role in the communication fabric, ensuring that user operations, including code checkout and check-in, metadata operations, and administrative commands, flow seamlessly across a distributed environment.