RADIUS backend DNS resolution timed out

Logged when resolving a configured backend hostname or discovering a RADIUS DNS-SD service exceeds its effective deadline. The dns_name and dns_timeout fields identify the lookup and configured DNS deadline. DNS-SD also logs action_timeout when set and effective_timeout, which is the shorter of dns_timeout and the remaining action deadline. The effective_timeout_milliseconds field provides the effective deadline as a numeric value.

Check resolver reachability, latency, and the relevant DNS records. Adjust dns-timeout or the backend action timeout to cover normal lookup latency while detecting failed lookups promptly. A longer timeout delays fallback when DNS is unavailable.