How to Troubleshoot Kubernetes Pods That Cannot Reach a DNS Service

Pods may fail DNS queries when cluster DNS is overloaded, network policy blocks port 53, node-local caching is unhealthy, or resolver configuration points elsewhere. Workloads may fail only intermittently.

What to check

Check DNS service endpoints, CoreDNS health and logs, pod resolver configuration, network policies, node placement, and query latency. Test from affected namespaces and compare TCP and UDP behavior.

Recommended next step

Restore the DNS path and ensure capacity and policy support the workload. Add alerts for failed queries and test service discovery after network or cluster upgrades.

How Informatix Systems can help

Informatix Systems provides Kubernetes and container network services. We can review the setup, trace the issue through relevant systems, and help plan a practical correction. Contact us with the platform involved, when the issue began, and non-sensitive error details.