About User Accounts and RBAC
You can create and manage users accounts and assign roles that limit access to operations on the Cisco NX-OS device. RBAC allows you to define the rules for an assign role that restrict the authorization that the user has to access management operations.
User Accounts
You can configure up to a maximum of 256 user accounts. By default, the user account does not expire unless you explicitly configure it to expire. The expire option determines the date when the user account is disabled.
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, root, rpc, rpcuser, xfs, gdm, mtsuser, ftpuser, man, and sys.
Note |
User passwords are not displayed in the configuration files. |
Caution |
Usernames must begin with an alphanumeric character and can contain only these special characters: ( + = . _ \ -). The # and ! symbols are not supported. If the username contains characters that are not allowed, the specified user is unable to log in. |
Characteristics of Strong Passwords
A strong password has the following characteristics:
Note |
Special characters, such as the dollar sign ($) or the percent sign (%), can be used in Cisco Nexus device passwords. |
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Is at least eight characters long
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Does not contain many consecutive characters (such as abcd)
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Does not contain many repeating characters (such as aaabbb)
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Does not contain dictionary words
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Does not contain proper names
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Contains both uppercase and lowercase characters
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Contains numbers
The following are examples of strong passwords:
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If2CoM18
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2004AsdfLkj30
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Cb1955S21
Note |
Clear text passwords cannot include these special characters at the beginning of the password: quotation marks (" or '), vertical bars (|), or right angle brackets (>). If a password is trivial (such as a short, easy-to-decipher password), the Cisco NX-OS software will reject your password configuration if password-strength checking is enabled. Be sure to configure a strong password as shown in the sample configuration. Passwords are case-sensitive. |
Note |
All printable ASCII characters are supported in the password string if they are enclosed in quotation marks. |
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 virtual routing and forwarding instances (VRFs), VLANs, and interfaces.
The Cisco NX-OS software provides the following user roles:
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network-admin—Complete read-and-write access to the entire Cisco NX-OS device
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network-operator or vdc-operator—Complete read access to the entire Cisco NX-OS device
Note
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The Cisco Nexus 9000 Series switches do not support multiple VDCs; however, the vdc-operator role is available and has the same privileges and limitations as the network-operator role.
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The Cisco Nexus 9000 Series switches support a single VDC due to which the vdc-admin has the same privileges and limitations as the network-admin.
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Note |
You cannot change the user roles. |
Note |
Some show commands may be hidden from network-operator users. In addition, some non-show commands (such as telnet ) may be available for this user role. |
Note |
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 user also has RoleB, which has access to the configuration commands. In this case, the user has access to the configuration commands. |
User Role Rules
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
- A command or group of commands defined in a regular expression.
- Feature group
- Default or user-defined group of features.
- OID
- An SNMP object identifier (OID).
The command, feature, and feature group 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 the rules. The Cisco NX-OS software also supports the predefined feature group L3 that you can use.
SNMP OID is supported for RBAC. You can configure a read-only or read-and-write rule for an SNMP OID.
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.