Switch authentication enables you to control how people access the switch.
By default switch authentication is controlled locally by the user password and the enable password.
You can configure the switch to use an authentication server, such as a RADIUS or TACACS+ server, for authentication.
After you have configured RADIUS or TACACS+, it is important to have local authentication enabled to log in to the switch if the authentication server is down.
Configuration for authentication is sometimes required for options such as Secure Shell (SSH) Telnet and 802.1X port authorization.
Switch authentication specifies how users are verified before being allowed to access the user or privileged mode command-line interface ...