Select No limit to avoid limiting the bandwidth used for discovery.

Select An average of to limit the bandwidth used for discovery, then select the average (1-9999 Mbps) to set as the limit.

Select Only on policy update to perform full discovery only when a discovery policy changes.

Select On policy update or fingerprinting version update to perform full discovery when a discovery policy or a fingerprinting version changes.

Select Always to perform full discovery at the scheduled time, no matter what has changed. (Forcepoint does not recommend choosing "always," because this slows the discovery process and taxes the system and SharePoint servers.)