CentOS Stream 10 – Common Problem 061 – Diagnosis and Fix

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

Cluster nodes show clock skew of several seconds, breaking Kerberos and TLS validation.

Environment & Reproduction

Affects CentOS Stream 10 hosts behind firewalls that block outbound NTP.

Root Cause Analysis

Default NTP sources unreachable and chronyd falls back to local clock.

Quick Triage

Check sync state with `chronyc tracking` and reachability with `chronyc sources -v`.

Step-by-Step Diagnosis

Identify which configured NTP sources are unreachable.

Solution – Primary Fix

Configure internal NTP sources in /etc/chrony.conf and restart chronyd.

Solution – Alternative Approaches

Use ptp4l with hardware timestamping if sub-millisecond precision is required.

Verification & Acceptance Criteria

`chronyc tracking` reports `Leap status: Normal` and skew under 50ms.

Rollback Plan

Restore prior chrony.conf to revert to public NTP if internal sources become unreliable.

Prevention & Hardening

Open UDP/123 outbound in firewall policy for at least three NTP sources.

Related Errors & Cross-Refs

Related to Kerberos auth failures and TLS clock-skew rejections.

Related tutorial: View the step-by-step tutorial for centos-stream-10.

View all centos-stream-10 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

chrony manual for CentOS Stream 10.