Cisco WS-C3550-12G Software Configuration Manual page 153

Chapter 6 Administering the Switch
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.
Beginning in privileged EXEC mode, follow these steps to configure login authentication:
Command
Step 1
configure terminal
Step 2
aaa new-model
Step 3 aaa authentication login {default |
list-name} method1 [method2...]
Step 4
line [console | tty | vty] line-number
[ending-line-number]
Step 5
login authentication {default |
list-name}
Step 6
end
Step 7 show running-config
Step 8
copy running-config startup-config
78-11194-03
Purpose
Enter global configuration mode.
Enable AAA.
Create a login authentication method list.
To create a default list that is used when a named list is not specified
•
in the login authentication command, use the default keyword
followed by the methods that are to be used in default situations. The
default method list is automatically applied to all interfaces.
• For list-name, specify a character string to name the list you are
creating.
For method1..., specify the actual method the authentication
•
algorithm tries. The additional methods of authentication are used
only if the previous method returns an error, not if it fails.
Select one of these methods:
• line—Use the line password for authentication. You must define a
line password before you can use this authentication method. Use the
password password line configuration command.
• local—Use the local username database for authentication. You must
enter username information into the database. Use the username
password global configuration command.
tacacs+—Uses TACACS+ authentication. You must configure the
•
TACACS+ server before you can use this authentication method.
Enter line configuration mode, and configure the lines to which you want
to apply the authentication list.
Apply the authentication list to a line or set of lines.
• If you specify default, use the default list created with the aaa
authentication login command.
• For list-name, specify the list created with the aaa authentication
login command.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Catalyst 3550 Multilayer Switch Software Configuration Guide
Controlling Switch Access with TACACS+
6-15