Which command can be used to dump the FortiGuard web filtering cache?

The command used to dump the FortiGuard web filtering cache is "diagnose webfilter fortiguard cache dump." This command is specifically designed to display the contents of the web filter cache, allowing administrators to see cached entries and their corresponding statuses in relation to the FortiGuard service. By executing this command, one can analyze how web categorization is being handled by the FortiGate device and troubleshoot any potential issues with web filtering.

In contrast, the other options do not perform the cache dumping function. For instance, getting webfilter categories is a command that retrieves the current web filtering categories but does not access or display the cache. Configuring the system for FortiGuard involves changing settings relevant to FortiGuard services but doesn't involve examination of the cache itself. Finally, the command relevant to OSPF routing has no relation to web filtering or cache management. Thus, the correct choice effectively addresses the task of viewing the FortiGuard web filtering cache.