Chrony Time Drift Causes Authentication And TLS Failures

📖 ~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

Kerberos, TLS, and token validation fail due to significant system clock offset.

Environment & Reproduction

chronyd is inactive, misconfigured, or cannot reach trusted NTP sources.

Root Cause Analysis

Run systemctl status chronyd and confirm it starts automatically at boot.

Quick Triage

Run chronyc sources -v and chronyc tracking to evaluate sync quality.

Step-by-Step Diagnosis

If offset is large, use chronyc makestep and verify immediate correction.

Solution – Primary Fix

Configure valid internal or external NTP servers and restart chronyd.

Solution – Alternative Approaches

Allow required UDP/123 traffic where policy controls NTP egress or ingress.

Verification & Acceptance Criteria

Use journalctl -u chronyd -b for source reachability and discipline messages.

Rollback Plan

Confirm hwclock stays aligned for stable reboot behavior.

Prevention & Hardening

Time skew breaks distributed systems, certificates, and security controls.

Related Errors & Cross-Refs

Accurate time is mandatory for audit trail integrity and legal evidence.

Related tutorial: View the step-by-step tutorial for rhel-9.

View all rhel-9 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Monitor chrony offset and source reachability with strict alert thresholds.