Diagnostics for VMware Cloud Foundation helps you monitor the operational status and reachability issues of vCenter instances based on analyses of logs and events.
Diagnostics tracks network reachability and service health enabling administrators to proactively identify and address potential problem before they impact operations. The card is linked to a dashboard that reports the reachability of each vCenter and any issues with its services. You can either look at Overall Findings or log in to vCenter instances with reported issues to identify an underlying problem.
For more information, see the vCenter Appliance Availability Dashboard topic in Configuring VMware Aria Operations guide.