A county lookup of a Service DNS name fails inside a Pod before any TCP connection is attempted. Where should triage start?
Select an answer to reveal the explanation.
Short Explanation
If the name never resolves, you’re still in the phonebook chapter—check CoreDNS before blaming the highway. DNS failures and TCP refusals are different villains.
Full Explanation
If a county lookup of a Service DNS name fails inside a Pod before any TCP connection is attempted, triage should start with the CoreDNS path—CoreDNS Pods, ConfigMap, and Service DNS records—to separate name resolution failures from later TCP issues. You are still in the phonebook chapter. Replacing the CNI plugin immediately without checking DNS Pods jumps to the dataplane before proving resolution works. Increasing the Service targetPort until DNS names resolve confuses port mapping with DNS and cannot fix resolution. Deleting all NetworkPolicies cluster-wide as the first DNS fix is reckless and usually irrelevant to CoreDNS outages. Exam caveat: Test with FQDN versus short name; search-path issues can look like DNS outages. Distinguish NXDOMAIN from timeout. Operational check: Check CoreDNS pods/logs, run dig/nslookup from a debug pod to the Service FQDN, fix DNS, then test TCP only after names resolve for the county app. In municipal production practice, record the finding in the incident ticket with command output snippets, confirm the fix under change control, and re-validate the user-facing civic service before closing the change window. In municipal production practice, record the finding in the incident ticket with command output snippets, confirm the fix under change control, and re-validate the user-facing civic service before closing the change window.