You can use the radius server itself as a client. There
are several utilities that come with the merit.edu radius
distribution, e.g., radcheck (to see if the radius server
is responding), radpwtst (an authentication test), etc.
I'm not sure if they are included with the Livingston
distribution. - R H
p.s. Don't forget to include the radius server itself
in the clients file or this won't work.