Concept Guide

The following example shows how to allow or deny a Telnet connection to a user. Users see a login prompt even if they cannot log in. No
access class is congured for the VTY line. It defaults from the local database.
Example of Conguring VTY Authorization Based on Access Class Retrieved from a Local Database (Per User)
DellEMC(conf)#user gooduser password abc privilege 10 access-class permitall
DellEMC(conf)#user baduser password abc privilege 10 access-class denyall
DellEMC(conf)#
DellEMC(conf)#aaa authentication login localmethod local
DellEMC(conf)#
DellEMC(conf)#line vty 0 9
DellEMC(config-line-vty)#login authentication localmethod
DellEMC(config-line-vty)#end
VTY Line Remote Authentication and Authorization
retrieves the access class from the VTY line.
The takes the access class from the VTY line and applies it to ALL users. does not need to know the identity of the incoming user and can
immediately apply the access class. If the authentication method is RADIUS, TACACS+, or line, and you have congured an access class for
the VTY line, immediately applies it. If the access-class is set to deny all or deny for the incoming subnet, closes the connection without
displaying the login prompt. The following example shows how to deny incoming connections from subnet 10.0.0.0 without displaying a login
prompt. The example uses TACACS+ as the authentication mechanism.
Example of Conguring VTY Authorization Based on Access Class Retrieved from the Line (Per Network Address)
DellEMC(conf)#ip access-list standard deny10
DellEMC(conf-ext-nacl)#permit 10.0.0.0/8
DellEMC(conf-ext-nacl)#deny any
DellEMC(conf)#
DellEMC(conf)#aaa authentication login tacacsmethod tacacs+
DellEMC(conf)#tacacs-server host 256.1.1.2 key Force10
DellEMC(conf)#
DellEMC(conf)#line vty 0 9
DellEMC(config-line-vty)#login authentication tacacsmethod
DellEMC(config-line-vty)#
DellEMC(config-line-vty)#access-class deny10
DellEMC(config-line-vty)#end
(same applies for radius and line authentication)
Role-Based Access Control
With Role-Based Access Control (RBAC), access and authorization is controlled based on a user’s role. Users are granted permissions
based on their user roles, not on their individual user ID. User roles are created for job functions and through those roles they acquire the
permissions to perform their associated job function.
This chapter consists of the following sections:
• Overview
• Privilege-or-Role Mode Versus Role-only Mode
• Conguring Role-based Only AAA Authorization
• System-Dened RBAC User Roles
• Creating a New User Role
• Modifying Command Permissions for Roles
• Adding and Deleting Users from a Role
• Role Accounting
• Conguring AAA Authentication for Roles
• Conguring AAA Authorization for Roles
Security
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