Enhancements in Release F.02.02

TACACS+ Authentication for Centralized Control of Switch Access Security

Using the Encryption KeyGeneral 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.

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

Note

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 and authentication results will be unpredictable.

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 in the switch must be identical to the encryption key configured in the corresponding TACACS+ server. If the key is the same for all TACACS+ servers the switch will use for authentication, then configure a global key in the switch. If the key is different for one or more of these servers, use "per-server" keys in the switch. (If you configure both a global key and one or more per-server keys, the per-server keys will override the global key for the specified servers.)

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