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K8s L6 K8S 1491 · 12 min

A Cilium upgrade completes and east-west traffic still drops because the remote-node identity cache kept the old cluster id for one peered segment

Policy and endpoints look healthy, but one segment still evaluates traffic against a stale remote identity mapping.

K8sPlatform ReliabilityLevel 6Pro12 min
Scenario

Cross-cluster service calls fail only between one peered segment after a Cilium control-plane upgrade.

What to check first
  • Identify the primary failure signal in the The Upgrade Finished Cleanly and One Part of the Cluster Still Called Its Neighbor by the Name It Used Before the Reorganization scenario.
  • Separate visible symptoms from the underlying technical dependency.
  • Describe the safest recovery path and the follow-up prevention work.
Checking checklist
  1. Summarize the current impact and the last known change.
  2. Collect direct evidence from logs, runtime state, and configuration before changing anything.
  3. Separate immediate recovery from permanent prevention work.
Recovery and prevention

Inspect remote identity caches and cluster-id propagation before widening the allow policy.

Questions worth viewing together
Should I translate commands, logs, or product names?

No. Keep commands, logs, file names, APIs, and product names unchanged, then explain the reasoning in the selected UI language.

What should the answer focus on?

State the root cause, the evidence that supports it, and the safest recovery direction.

Why can the scenario remain in the original language?

The source scenario is treated as an incident artifact. Guidance, checklist, hints, and explanations can be localized around it.