[Cache authentication information] in [User information cash settings] sets whether to save LDAP authentication information into the cash on the machine.
Cache authentication information is a function which automatically switches to cash authentication when the machine cannot communicate with the LDAP server.
You can set an expiration date for the cache authentication information on a daily basis. The expiration date means length of time that elapses since the last successful online authentication. The elapsed time is watched on a per-user basis.