Affected versions: Ubuntu 22.04 LTS

πŸ“– ~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

Certificates appear invalid and token-based auth fails when server time drifts beyond tolerance.

Environment & Reproduction

Seen in isolated networks with blocked NTP or conflicting time daemons.

Root Cause Analysis

NTP peers unreachable or multiple time services compete, preventing stable discipline of system clock.

Quick Triage

Check active time daemon and synchronization status immediately.

Step-by-Step Diagnosis

Validate NTP reachability, offset history, and service conflict state.

Illustrative mockup for ubuntu-22-04-lts β€” performance_monitor
Clock skew detected against NTP source β€” Illustrative mockup β€” Progressive Robot

Solution – Primary Fix

Use one time service, define reachable NTP servers, and force clock step when skew is large.

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Illustrative mockup for ubuntu-22-04-lts β€” log_or_config
Restored stable NTP synchronization β€” Illustrative mockup β€” Progressive Robot

Solution – Alternative Approaches

In minimal environments, keep systemd-timesyncd only and remove chrony package to avoid overlap.

Verification & Acceptance Criteria

Clock remains synchronized and TLS/auth flows stop reporting not-yet-valid or expired artifacts.

Rollback Plan

Re-enable prior time daemon setup if new policy conflicts with enterprise NTP architecture.

Prevention & Hardening

Monitor offset metrics and alert on sustained drift beyond operational thresholds.

Frequently appears with apt signature validation issues and Kerberos token failures.

Related tutorial: View the step-by-step tutorial for Ubuntu 22.04 LTS.

View all Ubuntu 22.04 LTS tutorials on the Tutorials Hub β†’

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Ubuntu time synchronization documentation for chrony and timesyncd.

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