When Sign-on Splash-page is used with a RADIUS server, Dashboard must be able to communicate with the RADIUS server. Dashboard, which acts as the RADIUS client, sends authentication requests (RADIUS Access Requests) to the public IP address of the configured RADIUS server.
The source IP addresses used by Dashboard may change over time. As a precaution, Dashboard periodically tests the configured RADIUS server to verify accessibility. Specifically, Dashboard sends an Access Request message with 'meraki-ping' as the username and 'ping-test' as the password. If the RADIUS server replies with an Access-Accept or Access-Reject, Dashboard knows the server is reachable.
In the event that Dashboard does not receive a response after 6 attempts (one every 20 seconds), it will assume the RADIUS server is unreachable and an email will be sent to the Dashboard administrator. The email will contain the IP address of the server that failed, all of the IP addresses that may attempt to contact the RADIUS server, and a link to the appropriate Configure > Access control page where they are listed.
If you received this email, please verify the following: