Overview of RBACWith Role-Based Access Control (RBAC), access and authorization is controlled based on a user’s role. Usersare granted permissions based on their user roles, not on their individual user ID. User roles are created forjob 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 caninherit permissions when you create a new user role, restrict or add commands a user can enter and theactions the user can perform. This allows for greater flexibility in assigning permissions for each command toeach role and as a result, it is easier and much more efficient to administer user rights. If a user’s role matchesone 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 thehierarchical RBAC model. Essentially, a constrained model puts some limitations around each role’spermissions 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 specificcommand settings, and the permissions allowed by the privilege and role commands. The role commandallows you to change permissions based on the role. You can modify the permissions specific to thatcommand 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 needto 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. Forinformation about these topics, see Audit and Security Logs.Privilege-or-Role Mode versus Role-only ModeBy default, the system provides access to commands determined by the user’s role or by the user’s privilegelevel. 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. Tochange to more secure mode, use role-based AAA authorization. When role-based only AAA authorization isconfigured, access to commands is determined only by the user’s role. For more information, seeConfiguring Role-based Only AAA Authorization.Configuring Role-based Only AAA AuthorizationYou can configure authorization so that access to commands is determined only by the user’s role. If the userhas no user role, access to the system is denied as the user will not be able to login successfully. When youenable role-based only AAA authorization using the aaa authorization role-only command in Configurationmode, the Dell Networking OS checks to ensure that you do not lock yourself out and that the userauthentication is available for all terminal lines.Pre-requisitesBefore you enable role-based only AAA authorization:Security 969
