Is there a way to display the status of the AAA login services from the login prompt (possibly thru a banner)? The goal would be to know which login credentials I need to use to access the device. For example, if I have radius configured for authentication, and the device cannot reach the radius server, it will displaying something like "RADIUS Servers dead", and then I'd know I have to use my fallback authentication method. I have various routers and switches, all running IOS.
You could use an EEM script to monitor the syslog events generated by the switch when the RADIUS server is marked dead/alive. In the event the RADIUS server is marked dead the script would re-write the login banner with an appropriate "RADIUS DEAD" message and when the server is alive re-write the banner with a "RADIUS ALIVE" message.