Cisco MDS 9000 Series Configuration Manual page 80

Allowing Users to Specify a RADIUS Server at Login
Note
Allowing Users to Specify a RADIUS Server at Login
By default, an MDS switch forwards an authentication request to the first server in the RADIUS server group.
You can configure the switch to allow the user to specify which RADIUS server to send the authenticate
request by enabling the directed request option. If you enable this option, the user can log in as
username@hostname , where the hostname is the name of a configured RADIUS server.
Note User specified logins are supported only for Telnet sessions.
To allow users logging into an MDS switch to select a RADIUS server for authentication, follow these steps:
Procedure
Step 1 switch# configure terminal
Enters configuration mode.
Step 2
switch(config)# radius-server directed-request
Allows users to specify a RADIUS server to send the authentication request when logging in.
Step 3 switch(config)# no radius-server directed-request
Reverts to sending the authentication request to the first server in the server group (default).
Example
You can use the show tacacs-server directed-request command to display the RADIUS directed
request configuration.
switch# show radius-server directed-request
disabled
About Vendor-Specific Attributes
The Internet Engineering Task Force (IETF) draft standard specifies a method for communicating
vendor-specific attributes (VSAs) between the network access server and the RADIUS server. The IETF uses
attribute 26. VSAs allow vendors to support their own extended attributes that are not suitable for general
use. The Cisco RADIUS implementation supports one vendor-specific option using the format recommended
in the specification. The Cisco vendor ID is 9, and the supported option is vendor type 1, which is named
cisco-avpair. The value is a string with the following format:
Cisco MDS 9000 Series Security Configuration Guide, Release 8.x
62
A configured username and password is optional (see the
section).
Configuring Security Features on an External AAA Server
Configuring Test Username, on page 73