Requiring the Privilege Level Attribute for Authentication
You can require that the privilege level attribute (priv-lvl) must be specified for TACACS authentication to occur. Setting the privilege level attribute as required does not change any behavior associated with values received in the priv-lvl attribute, only the presence/absence of the attribute.
To require that the priv-lvl is set to allow authentication, use the following command:
configure tacacs priv-lvl [required | optional]