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Catalyst2950 and Catalyst2955 Switch Software Configuration Guide
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Chapter9 Configuring Switch-Ba sed Authentication Controlling Switch Access with RADIUS
This example shows how to configure one RADIUS server to be used for authentication and another to
be used for accounting:
Switch(config)# radius-server host 172.29.36.49 auth-port 1612 key rad1
Switch(config)# radius-server host 172.20.36.50 acct-port 1618 key rad2
This example shows how to configure host1 as the RADIUS server and to use the default ports for both
authentication and accounting:
Switch(config)# radius-server host host1
Note You also need to configure some settings on the RADIUS server. These settings include the IP address
of the switch and the key string to be shared by both the server and the switch. For more information,
refer to the RADIUS server documentation.
Configuring RADIUS Login Authentication
To configure AAA authentication, you define a named list of authentication methods and then apply that
list to various interfaces. The method list defines the types of authentication to be performed and the
sequence in which they are performed; it must be applied to a specific in terface before an y of th e def ined
authentication methods are performed. The only exception is the default method list (which, by
coincidence, is named default). The default method list is automatically applied to all interfaces except
those that have a named method list explicitly defined.
A method list describes the sequence and authentication methods to be queried to authenticate a user.
You can designate one or more security protocols to be used for authentication, thus ensuring a backup
system for authentication in case the initial method fails. The software uses the first method listed to
authenticate users; if that method fails to respond, the software selects the next authentication method in
the method list. This process continues until there is successful communication with a listed
authentication method or until all defined methods are exhausted. If authentication fails at any point in
this cycle—meaning that the security server or local username database responds by denying the user
access—the authentication process stops, and no other authentication methods are attempted.