Configuring TACACS+ Servers

The TACACS+ Servers table lets you configure up to two TACACS+ servers. You need to configure a TACACS+ server when you want to use TACACS+ for user authentication, authorization, and accounting.

You can configure two TACACS+ servers for 1:1 redundancy (active/redundant). If the primary server fails, the device uses the secondary server.

The TACACS+ server is configured using two tables with parent-child relationship:

TACACS+ Servers table (parent): Defines settings to connect to the server such as address, port, shared secret, and local interface. The table is described below.
TACACS+ Access Level Mapping (child): Defines user access level mapping between TACACS+ privilege levels and the device's user levels (Security Administrator, Administrator, and Monitor). For more information, see Configuring TACACS+ Access Level Mapping.

The following procedure describes how to configure TACACS+ servers through the Web interface. You can also configure it through ini file [TacacsPlusServers] or CLI (configure system > tacacs-settings > tacacsplus-servers).

To configure a TACACS+ server:
1. Open the TACACS+ Servers table (Setup menu > IP Network tab > AAA Servers folder > TACACS+ Servers).
2. Click New; the following dialog box appears:

3. Configure a TACACS+ server according to the parameters described in the table below.
4. Click Apply.
5. Save your settings to flash memory.

TACACS+ Servers Table Parameter Descriptions

Parameter

Description

'Index'
[Index]

Defines an index number for the new table row.

Note:

Each row must have a unique index.
The parameter is mandatory.

'Address'

address

[Address]

Defines the address of the TACACS+ server.

The address can be an IP address or an FQDN.

By default, no address is defined (i.e., 0.0.0.0).

Note: The IP version (IPv4 or IPv6) of the server address and the IP Interface must match.

'Port'

port

[Port]

Defines the TACACS+ server port.

The valid value is 0 to 65535. The default is 49.

'Shared Secret'

shared-secret

[SharedSecret]

Defines the shared secret (password) for authenticating the device with the TACACS+ server. This should be a cryptically strong password. The shared secret is also used by the server to authenticate and verify TACACS+ messages sent by the device (i.e., message integrity).

The valid value is a string of up to 48 characters. By default, no value is defined.

Note: The password cannot include wide characters.

'Interface Name'

interface-name

[InterfaceName]

Assigns an IP Interface from the IP Interfaces table (see Configuring IP Network Interfaces) through which the device communicates with the TACACS+ server.

By default, no value is defined.

Note: The IP version (IPv4 or IPv6) of the server address and the IP Interface must match.

'Server Timeout'

server-timeout

[ServerTimeout]

Defines the maximum time (in seconds) that the device waits for a response from the TACACS+ server. If the device does not receive a response within this timeout, it marks the server as unreachable and attempts to connect to the secondary TACACS+ server (if configured). If the device still cannot establish connectivity with any TACACS+ server, it falls back to the Local Users table for authentication, depending on configuration (see the 'Fallback to Local Users' parameter).

The valid value is 1 to 65535. The default is 5.