4 Command Line Interface

authentication enable

This command defines the authentication method and precedence to use when changing from Exec command mode to Privileged Exec command mode with the enable command (see page 4-19). Use the no form to restore the default.

Syntax

authentication enable {[local] [radius] [tacacs]} no authentication enable

•local - Use local password only.

•radius - Use RADIUS server password only.

•tacacs - Use TACACS server password.

Default Setting

Local

Command Mode

Global Configuration

Command Usage

•RADIUS uses UDP while TACACS+ uses TCP. UDP only offers best effort delivery, while TCP offers a connection-oriented transport. Also, note that RADIUS encrypts only the password in the access-request packet from the client to the server, while TACACS+ encrypts the entire body of the packet.

•RADIUS and TACACS+ logon authentication assigns a specific privilege level for each user name and password pair. The user name, password, and privilege level must be configured on the authentication server.

•You can specify three authentication methods in a single command to indicate the authentication sequence. For example, if you enter “authentication enable radius tacacs local,” the user name and password on the RADIUS server is verified first. If the RADIUS server is not available, then authentication is attempted on the TACACS+ server. If the TACACS+ server is not available, the local user name and password is checked.

Example

Console(config)#authentication enable radius

Console(config)#

Related Commands

enable password - sets the password for changing command modes (4-26)

4-70