Fail2ban blocks internal health checks after noisy auth failures

A brute-force defense rule works, but its source grouping catches internal monitoring traffic by mistake.

• Identify the primary failure signal in the Incident Response scenario.
• Separate visible symptoms from the underlying technical dependency.
• Describe the safest recovery path and the follow-up prevention work.

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.

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