AAA supports configuring different authentication, authorization, and accounting methods for different
types of users in an ISP domain. The NAS determines the ISP domain and access type of a user, and uses
the methods configured for the access type in the domain to control the user's access.
AAA also supports configuring a set of default methods for an ISP domain. These default methods are
used for users for whom no specific AAA methods are configured.
The device supports the following authentication methods:
No authentication—This method trusts all users and does not perform authentication. For security
purposes, do not use this method.
Local authentication—The NAS authenticates users by itself, based on the locally configured user
information including the usernames, passwords, and attributes. Local authentication allows high
speed and low cost, but the amount of information that can be stored is limited by the size of the
Remote authentication—The NAS works with a RADIUS, HWTACACS, or LDAP server to
authenticate users. Remote authentication provides centralized information management, high
capacity, high reliability, and support for centralized authentication service for multiple NASs. You
can configure backup methods to be used when the remote server is not available.
The device supports the following authorization methods:
No authorization—The NAS performs no authorization exchange. After passing authentication,
non-login users can access the network, FTP users are authorized access to the root directory of the
NAS but cannot access it, and login users only obtain the default user role.
Local authorization—The NAS performs authorization according to the user attributes locally
configured for users.
Remote authorization—The NAS works with a RADIUS, HWTACACS, or LDAP server to authorize
users. RADIUS authorization is bound with RADIUS authentication. RADIUS authorization can work
only after RADIUS authentication is successful, and the authorization information is included in the
Access-Accept packet. HWTACACS authorization is separate from HWTACACS authentication,
and the authorization information is included in the authorization response after successful
authentication. You can configure backup methods to be used when the remote server is not
The device supports the following accounting methods:
No accounting—The NAS does not perform accounting for the users.
Local accounting—Local accounting is implemented on the NAS. It counts and controls the number
of concurrent users who use the same local user account, but does not provide statistics for
Remote accounting—The NAS works with a RADIUS server or HWTACACS server for accounting.
You can configure backup methods to be used when the remote server is not available.
In addition, the device provides the following services for login users to enhance device security:
Command authorization—Enables the NAS to defer to the authorization server to determine
whether a command entered by a login user is permitted, and allows login users to execute only
authorized commands. For more information about command authorization, see Fundamentals
Command accounting—When command authorization is disabled, command accounting enables
the accounting server to record all valid commands executed on the device. When command
authorization is enabled, command accounting enables the accounting server to record all