D-PDD-DY-01: Dell PowerProtect Data Domain Deploy

A failed connection test when adding a Data Domain system to PowerProtect Data Manager is typically caused by one of three underlying issues: the DD Boost service not being enabled/running on the Data Domain (PPDM relies on DD Boost/REST connectivity to manage the system), network connectivity problems between the PPDM appliance and the Data Domain (blocked ports, DNS/name resolution issues, firewall rules), or incorrect/expired/locked credentials being used for the DD system user account. Checking and correcting these three areas — DD Boost service status, network connectivity, and credentials — resolves the vast majority of connection test failures documented in Dell's PowerProtect Data Manager troubleshooting knowledge base articles.