Dell Configuration Guide for the S4048–ON System 9.14.2.4

Configuring Role-based Only AAA Authorization

You can configure authorization so that access to commands is determined only by the user’s role. If the user has no user role, access to the system is denied as the user is not able to login successfully. When you enable role-based only AAA authorization using the aaa authorization role-only command in Configuration mode, the Dell EMC Networking OS checks to ensure that you do not lock yourself out and that the user authentication is available for all terminal lines.

Pre-requisites

Before you enable role-based only AAA authorization:

1. Locally define a system administrator user role. This gives you access to login with full permissions even if network connectivity to remote authentication servers is not available.
2. Configure login authentication on the console. This ensures that all users are properly identified through authentication no matter the access point.

   If you do not configure login authentication on the console, the system displays an error when you attempt to enable role-based only AAA authorization.

3. Specify an authentication method list—RADIUS, TACACS+, or Local. 

   You must specify at least local authentication. For consistency, the best practice is to define the same authentication method list across all lines, in the same order of comparison; for example VTY and console port.

   You could also use the default authentication method to apply to all the LINES; for example, console port and VTY.

   NOTE The authentication method list must be in the same order as the authorization method list. For example, if you configure the authentication method list in the following order—TACACS+, local—Dell EMC Networking recommends configuring the authorization method list in the same order—TACACS+, local.
4. Specify the authorization method list—RADIUS, TACACS+, or Local. At a minimum, you must specify local authorization.

   For consistency, the best practice is to define the same authorization method list across all lines, in the same order of comparison; for example, VTY and console port.

   You could also use the default authorization method list to apply to all the LINES—console port, VTY.

   If you do not, the following error displays when you attempt to enable role-based only AAA authorization:

   % Error: Exec authorization must be applied to more than one line to be useful, e.g. console and vty lines. Could use default authorization method list as alternative.

5. Verify the configuration is applied to the console or VTY line.

   DellEMC(conf)#do show running-config line 
   !
   line console 0
   login authentication test
   authorization exec test 
   exec-timeout 0 0
   line vty 0
   login authentication test
   authorization exec test
   line vty 1
   login authentication test
   authorization exec test
   

To enable role-based only AAA authorization, enter the following command in Configuration mode:

DellEMC(conf)#aaa authorization role-only