You can create and manage users accounts and assign roles that limit access to operations on the Cisco Nexus 5000 Series switch. RBAC allows you to define the rules for an assign role that restrict the authorization that the user has to access management operations.
The following words are reserved and cannot be used to configure users: bin, daemon, adm, lp, sync, shutdown, halt, mail, news, uucp, operator, games, gopher, ftp, nobody, nscd, mailnull, rpc, rpcuser, xfs, gdm, mtsuser, ftpuser, man, and sys.
User passwords are not displayed in the configuration files.
The Cisco Nexus 5000 Series switch does not support all numeric usernames, whether created with TACACS+ or RADIUS, or created locally. Local users with all numeric names cannot be created. If an all numeric user name exists on an AAA server and is entered during login, the user is not logged in.
Characteristics of Strong Passwords
A strong password has the following characteristics:
At least eight characters long
Does not contain many consecutive characters (such as "abcd")
Does not contain many repeating characters (such as "aaabbb")
Does not contain dictionary words
Does not contain proper names
Contains both uppercase and lowercase characters
The following are examples of strong passwords:
Clear text passwords can contain alphanumeric characters only. Special characters, such as the dollar sign ($) or the percent sign (%), are not allowed.
If a password is trivial (such as a short, easy-to-decipher password), the Cisco Nexus 5000 Series switch will reject your password configuration. Be sure to configure a strong password as shown in the sample configuration. Passwords are case sensitive.
About User Roles
User roles contain rules that define the operations allowed for the user who is assigned the role. Each user role can contain multiple rules and each user can have multiple roles. For example, if role1 allows access only to configuration operations, and role2 allows access only to debug operations, then users who belong to both role1 and role2 can access configuration and debug operations. You can also limit access to specific VSANs, VLANs and interfaces.
The Cisco Nexus 5000 Series switch provides the following default user roles:
network-admin (superuser)—Complete read and write access to the entire Cisco Nexus 5000 Series switch.
network-operator—Complete read access to the Cisco Nexus 5000 Series switch.
If you belong to multiple roles, you can execute a combination of all the commands permitted by these roles. Access to a command takes priority over being denied access to a command. For example, suppose a user has RoleA, which denied access to the configuration commands. However, the users also has RoleB, which has access to the configuration commands. In this case, the users has access to the configuration commands.
The rule is the basic element of a role. A rule defines what operations the role allows the user to perform. You can apply rules for the following parameters:
Command—A command or group of commands defined in a regular expression.
Feature—Commands that apply to a function provided by the Cisco Nexus 5000 Series switch.
Enter the show role feature command to display the feature names available for this parameter.
Feature group—Default or user-defined group of features.
Enter the show role feature-group command to display the default feature groups available for this parameter.
These parameters create a hierarchical relationship. The most basic control parameter is the command. The next control parameter is the feature, which represents all commands associated with the feature. The last control parameter is the feature group. The feature group combines related features and allows you to easily manage of the rules.
You can configure up to 256 rules for each role. The user-specified rule number determines the order in which the rules are applied. Rules are applied in descending order. For example, if a role has three rules, rule 3 is applied before rule 2, which is applied before rule 1.
About User Role Policies
You can define user role policies to limit the switch resources that the user can access. You can define user role policies to limit access to interfaces, VLANs and VSANs.
User role policies are constrained by the rules defined for the role. For example, if you define an interface policy to permit access to specific interfaces, the user will not have access to the interfaces unless you configure a command rule for the role to permit the interface command.
If a command rule permits access to specific resources (interfaces, VLANs or VSANs), the user is permitted to access these resources, even if they are not listed in the user role policies associated with that user.
Guidelines and Limitations for User Accounts
User account and RBAC have the following configuration guidelines and limitations:
You can add up to 256 rules to a user role.
You can assign a maximum of 64 user roles to a user account.
A user account must have at least one user role.
Configuring User Accounts
You can create a maximum of 256 user accounts on a Cisco Nexus 5000 Series switch. User accounts have the following attributes:
User accounts can have a maximum of 64 user roles.
Changes to user account attributes do not take effect until the user logs in and creates a new session.
Each user role can have up to 256 rules. You can assign a user role to more that one user account.
The rule number you specify determines the order in which the rules are applied. Rules are applied in descending order. For example, if a role has three rules, rule 3 is applied before rule 2, which is applied before rule 1.