This allows you to assign a symbolic name to an AuthBy clause and its configuration. This allows you to refer to it by name in an Auth-Type check item when authenticating a user.

The most common use of this is to create a “System” authenticator, typically with an <AuthBy UNIX> clause. A typical example configuration file that uses this feature might be:

<Realm DEFAULT>
      <AuthBy FILE>
      </AuthBy>
</Realm>
<AuthBy UNIX>
      Identifier System
</AuthBy>

You can then have something like this in your users file:

DEFAULT Auth-Type = System
      Framed-IP-Netmask .....
      ...........

In this example, all users in all realms will match the DEFAULT user in the users file. This will in turn check their user name and password against a UNIX password file as configured by the AuthBy UNIX clause in the configuration file. If the password checks out, they will get the RADIUS attributes specified in the second and subsequent lines of the DEFAULT user entry in the users file (in this example, Framed-IP-Netmask).