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Mid-SeniorTroubleshooting35m·Cloudflare, Amazon, Google, Netflix, Slack
Diagnose a DNS Outage
Diagnose a DNS outage affecting service discovery, analyzing the resolver chain, TTL behavior during failures, negative caching effects, and designing DNS failover strategies.
troubleshootingdebuggingdnsnetworkingincident response
## Problem
All inter-service communication in your infrastructure has stopped. Services report "connection refused" or "unknown host" errors when trying to reach each other. External domains (google.com, etc.) resolve normally. The issue started 15 minutes ago and affects all services. Diagnose the DNS failure, identify the failing component, and restore service communication.
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Design canvas, rubric, hints, and model solutions.
Constraints
SymptomSign up to view
DNS ResolutionSign up to view
TTLSign up to view
ImpactSign up to view