'Trivial' AAA is used only after trying all the server groups and 'Local'
AAA (if configured). Trivial AAA corresponds to one of the following
based on the value of corresponding instance of AAAFunction.
- User name based authentication, if 'AAAFunction' value is
'authentication'
- No Authorization check, if 'AAAFunction' value is 'authorization'
- No accounting, if 'AAAFunction' value is 'accounting'.