Default Radius Configuration; Identifying The Radius Server Host - Cisco 3845 - Security Bundle Router Software Manual

Controlling Switch Access with RADIUS
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Default RADIUS Configuration

RADIUS and AAA are disabled by default.
To prevent a lapse in security, you cannot configure RADIUS through a network management
application. When enabled, RADIUS can authenticate users accessing the switch through the CLI.

Identifying the RADIUS Server Host

Switch-to-RADIUS-server communication involves several components:
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You identify RADIUS security servers by their hostname or IP address, hostname and specific UDP port
numbers, or their IP address and specific UDP port numbers. The combination of the IP address and the
UDP port number creates a unique identifier, allowing different ports to be individually defined as
RADIUS hosts providing a specific AAA service. This unique identifier enables RADIUS requests to be
sent to multiple UDP ports on a server at the same IP address.
If two different host entries on the same RADIUS server are configured for the same service—for
example, accounting—the second host entry configured acts as a fail-over backup to the first one. Using
this example, if the first host entry fails to provide accounting services, the switch tries the second host
entry configured on the same device for accounting services. (The RADIUS host entries are tried in the
order that they are configured.)
A RADIUS server and the switch use a shared secret text string to encrypt passwords and exchange
responses. To configure RADIUS to use the AAA security commands, you must specify the host running
the RADIUS server daemon and a secret text (key) string that it shares with the switch.
The timeout, retransmission, and encryption key values can be configured globally for all RADIUS
servers, on a per-server basis, or in some combination of global and per-server settings. To apply these
settings globally to all RADIUS servers communicating with the switch, use the three unique global
configuration commands: radius-server timeout, radius-server retransmit, and radius-server key. To
apply these values on a specific RADIUS server, use the radius-server host global configuration
command.
You can configure the switch to use AAA server groups to group existing server hosts for authentication.
For more information, see the
Cisco ME 3800X and 3600X Switch Software Configuration Guide
8-20
Configuring the Switch for Vendor-Proprietary RADIUS Server Communication, page 8-29
(optional)
Configuring RADIUS Server Load Balancing, page 8-30
Hostname or IP address
Authentication destination port
Accounting destination port
Key string
Timeout period
Retransmission value
"Defining AAA Server Groups" section on page
Chapter 8 Configuring Switch-Based Authentication
(optional)
8-24.
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