Concept Guide

Congure AAA Authentication for Roles
Authentication services verify the user ID and password combination. Users with dened roles and users with privileges are authenticated
with the same mechanism. There are six methods available for authentication: radius, tacacs+, local, enable, line, and none.
When role-based only AAA authorization is enabled, the enable, line, and none methods are not available. Each of these three methods
allows users to be veried with either a password that is not specic to their user ID or with no password at all. Because of the lack of
security these methods are not available for role only mode. When the system is in role-only mode, users that have only privilege levels are
denied access to the system because they do not have a role. For information about role only mode, see Conguring Role-based Only AAA
Authorization.
NOTE: Authentication services only validate the user ID and password combination. To determine which commands are
permitted for users, congure authorization. For information about how to congure authorization for roles, see Congure AAA
Authorization for Roles.
To congure AAA authentication, use the aaa authentication command in CONFIGURATION mode.
aaa authentication login {method-list-name | default} method [… method4]
Congure AAA Authorization for Roles
Authorization services determine if the user has permission to use a command in the CLI. Users with only privilege levels can use
commands in privilege-or-role mode (the default) provided their privilege level is the same or greater than the privilege level of those
commands. Users with dened roles can use commands provided their role is permitted to use those commands. Role inheritance is also
used to determine authorization.
Users with roles and privileges are authorized with the same mechanism. There are six methods available for authorization: radius,
tacacs+, local, enable, line, and none.
When role-based only AAA authorization is enabled, the enable, line, and none methods are not available. Each of these three
methods allows users to be authorized with either a password that is not specic to their userid or with no password at all. Because of the
lack of security, these methods are not available for role-based only mode.
To congure AAA authorization, use the aaa authorization exec command in CONFIGURATION mode. The aaa
authorization exec command determines which CLI mode the user will start in for their session; for example, Exec mode or Exec
Privilege mode. For information about how to congure authentication for roles, see
Congure AAA Authentication for Roles.
aaa authorization exec {method-list-name | default} method [… method4]
You can further restrict users’ permissions, using the aaa authorization command command in CONFIGURATION mode.
aaa authorization command {method-list-name | default} method [… method4]
Examples of Applying a Method List
The following conguration example applies a method list: TACACS+, RADIUS and local:
!
radius-server host 10.16.150.203 key <clear-text>
!
tacacs-server host 10.16.150.203 key <clear-text>
!
aaa authentication login ucraaa tacacs+ radius local
aaa authorization exec ucraaa tacacs+ radius local
aaa accounting commands role netadmin ucraaa start-stop tacacs+
!
Security
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