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Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter9 Configuring Switch-Based Authenticatio n
Controlling Switch Access with TACACS+
Beginning in privileged EXEC mode, follow these steps to identify the IP host or host maintaining
TACACS+ server and optionally set the encryption key:
To remove the specified TACACS+ server name or address, use the no tacacs-server host hostname
global configuration command. To remove a server group from the configuration list, use the no aaa
group server tacacs+ group-name global configuration command. To remove the IP address of a
TACACS+ server, use the no server ip-address server group subconfiguration command.
Configuring TACACS+ Login Authentication
To configure AAA authentication, you define a named list of authentication methods and then apply that
list to various ports. 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 port before any of the defined 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 ports except those that have a named
method list explicitly defined. A defined method list overrides the default method list.
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
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 tacacs-server host hostname [port
integer] [timeout integer] [key string]
Identify the IP host or hosts maintaining a TACACS+ server. Enter this
command multiple times to create a list of preferred hosts. The software
searches for hosts in the order in which you specify them.
•For hostname, specify the name or IP address of the host.
•(Optional) For port integer, specify a server port number. The default
is port 49. The range is 1 to 65535.
•(Optional) For timeout integer, specify a time in seconds the switch
waits for a response from the daemon before it times out and declares
an error. The default is 5 seconds. The range is 1 to 1000 seconds.
•(Optional) For key string, specify the encryption key for encrypting
and decrypting all traffic between the switch and the TACACS+
daemon. You must configure the same key on the TACACS+ daemon
for encryption to be successful.
Step3 aaa new-model Enable AAA.
Step4 aaa group server tacacs+ group-name (Optional) Define the AAA server-group with a group name.
This command puts the switch in a server group subconfiguration mode.
Step5 server ip-address (Optional) Associate a particular TACACS+ server with the defined server
group. Repeat this step for each TACACS+ server in the AAA server
group.
Each server in the group must be previously defined in Step 2.
Step6 end Return to privileged EXEC mode.
Step7 show tacacs Verify your entries.
Step8 copy running-config startup-config (Optional) Save your entries in the configuration file.