The RADIUS validation server will shut off if connectivity to the User Store(s) defined in the settings is lost. Service resumes once the connection is re-established. For this reason, redundant connections are recommended. Usernames and passwords are never cached on the VIP Enterprise Gateway.
If connectivity to the VIP Cloud is lost from the VIP Enterprise Gateway but user store connectivity is uninterrupted, the optional Business Continuity feature can be enabled to send an email alert and (also optional) allow second-factor authentications to continue.
See VIP Enterprise Gateway Business Continuity