Concept Guide

NOTE: When you enter a user role, you have already been authenticated and authorized. You do not need to enter an enable
password because you will be automatically placed in EXEC Priv mode.
For greater security, the ability to view event, audit, and security system log is associated with user roles. For information about these
topics, see Audit and Security Logs.
Privilege-or-Role Mode versus Role-only Mode
By default, the system provides access to commands determined by the user’s role or by the user’s privilege level. The user’s role takes
precedence over a user’s privilege level. If the system is in “privilege or role” mode, then all existing user IDs can continue to access the
switch even if they do not have a user role dened. To change to more secure mode, use role-based AAA authorization. When role-based
only AAA authorization is congured, access to commands is determined only by the user’s role. For more information, see Conguring
Role-based Only AAA Authorization.
Conguring Role-based Only AAA Authorization
You can congure 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 Conguration 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 dene 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 Congure login authentication on the console. This ensures that all users are properly identied through authentication no matter the
access point.
If you do not congure 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 dene 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
congure the authentication method list in the following order—TACACS+, local—Dell EMC Networking recommends
conguring 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 dene 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 conguration is applied to the console or VTY line.
DellEMC(conf)#do show running-config line
!
line console 0
login authentication test
authorization exec test
894
Security