You can configure the router to send traps to SNMP when a RADIUS preauthentication server fails to respond to messages. To do so, you use the same procedure and commands as you do to configure SNMP traps for a RADIUS authentication server.
For example, to enable SNMP traps when a particular RADIUS preauthentication server fails to respond to Access-Request messages, use the radius trap auth-server-not-responding enable command.
For more information, see Configuring SNMP Traps .