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Network L4 NETWORK-012 · 23 min

After an Anycast DNS switch, only a certain region keeps getting the old IP

A situation where the global switch is done but cache and regional resolver differences send only some users to the old endpoint.

NetworkPlatform ReliabilityLevel 4Pro23 min
Scenario

A scenario that narrows down the root cause, centered on reading propagation delay and regional cache differences, in the situation of only a certain region continuing to get the old IP after an Anycast DNS switch.

What to check first
  • Identify the primary failure signal in the DNS Propagation 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

Choose the smallest safe recovery action first, then record the prevention work that reduces repeat incidents.

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.