TACACS+ Authentication

How Authentication Operates

 

attempt limit without a successful authentication, the login session is

 

terminated and the operator at the requesting terminal must initiate a new

 

session before trying again.

 

 

Note

The switch’s menu allows you to configure only the local Operator and

 

Manager passwords, and not any usernames. In this case, all prompts for local

 

authentication will request only a local password. However, if you use the CLI

 

or the web browser interface to configure usernames for local access, you will

 

see a prompt for both a local username and a local password during local

 

authentication.

 

 

Note

Using the Encryption Key

General Operation

When used, the encryption key (sometimes termed “key”, “secret key”, or “secret”) helps to prevent unauthorized intruders on the network from reading username and password information in TACACS+ packets moving between the switch and a TACACS+ server. At the TACACS+ server, a key may include both of the following:

Global key: A general key assignment in the TACACS+ server application that applies to all TACACS-aware devices for which an individual key has not been configured.

Server-Specific key: A unique key assignment in the TACACS+ server application that applies to a specific TACACS-aware device.

Configure a key in the switch only if the TACACS+ server application has this exact same key configured for the switch. That is, if the key parameter in switch “X” does not exactly match the key setting for switch “X” in the TACACS+ server application, then communication between the switch and the TACACS+ server will fail.

Thus, on the TACACS+ server side, you have a choice as to how to implement a key. On the switch side, it is necessary only to enter the key parameter so that it exactly matches its counterpart in the server. For information on how to configure a general or individual key in the TACACS+ server, refer to the documentation you received with the application.

Encryption Options in the Switch

When configured, the encryption key causes the switch to encrypt the TACACS+ packets it sends to the server. When left at “null”, the TACACS+ packets are sent in clear text. The encryption key (or just “key”) you configure

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