ldap { fail=1}

Hi, i'm using freeradius 1.0.1 from Red Hat entreprise 4. my radius server is connected to a ldap directory to store users and to a mysql database to store NAS I want the radius server to authenticate users thanks to the "users" file even if the ldap directory is not reachable and the radius server to start even if the DB is not reachable I tried with ldap { fail =1} in the authorize section and sql { fail = 1 } in the instantiate section without any success. "fail" doen't seem to be know. Thank you for your help Thomas