Specifies the lifetime (in hours) of the authentication data cache. The cache is used to speed up sign-in. It contains general data (workgroup name etc.) about affiliated realms, i.e. realms trusted by the machine realm. No user-specific data and no data for unaffiliated realms is cached. Rebooting the device clears the cache.
If the policy is unset, cached authentication data may be reused for up to 73 hours.
If the policy is set to 0, authentication data caching is turned off. This can significantly slow down sign-in of affiliated users since realm-specific data has to be fetched on every sign-in.
Note that realm data is cached even for ephemeral users. The cache should be turned off if tracing the realm of ephemeral users should be prevented.