Dell S4048T-ON, Configuration Manual

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Overview of RBAC
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. Each user can be assigned only a single role. Many users can have the same role.
The Dell Networking OS supports the constrained RBAC model. With a constrained RBAC model, you can inherit permissions when you
create a new user role, restrict or add commands a user can enter and the actions the user can perform. This allows for greater flexibility in
assigning permissions for each command to each role and as a result, it is easier and much more efficient to administer user rights. If a
user’s role matches one of the allowed user roles for that command, then command authorization is granted.
A constrained RBAC model provides for separation of duty and as a result, provides greater security than the hierarchical RBAC model.
Essentially, a constrained model puts some limitations around each role’s permissions to allow you to partition of tasks. However, some
inheritance is possible.
Default command permissions are based on CLI mode (such as configure, interface, router), any specific command settings, and the
permissions allowed by the privilege and role commands. The role command allows you to change permissions based on the role. You can
modify the permissions specific to that command and/or command option. For more information, see
Modifying Command Permissions for
Roles .
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 defined. To change to more secure mode, use role-based AAA authorization. When role-based
only AAA authorization is configured, access to commands is determined only by the user’s role. For more information, see
Configuring
Role-based Only AAA Authorization.
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 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, , or Local.
822 Security