• Specifying a TACACS+ Server Host
For a complete listing of all commands related to TACACS+, refer to the Security chapter in the Dell
Networking OS Command Reference Guide.
Choosing TACACS+ as the Authentication Method
One of the login authentication methods available is TACACS+ and the user’s name and password are
sent for authentication to the TACACS hosts specified.
To use TACACS+ to authenticate users, specify at least one TACACS+ server for the system to
communicate with and configure TACACS+ as one of your authentication methods.
To select TACACS+ as the login authentication method, use the following commands.
1. Configure a TACACS+ server host.
CONFIGURATION mode
tacacs-server host {ip-address | host}
Enter the IP address or host name of the TACACS+ server.
Use this command multiple times to configure multiple TACACS+ server hosts.
2. Enter a text string (up to 16 characters long) as the name of the method list you wish to use with the
TACAS+ authentication method.
CONFIGURATION mode
aaa authentication login {method-list-name | default} tacacs+ [...method3]
The TACACS+ method must not be the last method specified.
3. Enter LINE mode.
CONFIGURATION mode
line {aux 0 | console 0 | vty number [end-number]}
4. Assign the method-list to the terminal line.
LINE mode
login authentication {method-list-name | default}
Example of a Failed Authentication
To view the configuration, use the show config in LINE mode or the show running-config tacacs
+ command in EXEC Privilege mode.
If authentication fails using the primary method, Dell Networking OS employs the second method (or
third method, if necessary) automatically. For example, if the TACACS+ server is reachable, but the server
key is invalid, Dell Networking OS proceeds to the next authentication method. In the following example,
the TACACS+ is incorrect, but the user is still authenticated by the secondary method.
First bold line: Server key purposely changed to incorrect value.
Second bold line: User authenticated using the secondary method.
Dell(conf)#
Dell(conf)#do show run aaa
!
aaa authentication enable default tacacs+ enable
Security
813