Oracle Linux 10 – chronyd not synchronizing system time with NTP sources – Fix & Prevention

📖 ~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

Clock drift causes authentication errors and certificate validation failures.

Environment & Reproduction

Common in restricted networks or after firewall updates.

systemctl status chronyd
chronyc tracking
chronyc sources -v

Root Cause Analysis

NTP egress blocking, invalid servers, or disabled service prevents sync.

Quick Triage

Assess chronyd status and NTP reachability rapidly.

journalctl -u chronyd -n 60
firewall-cmd --list-services
chronyc activity

Step-by-Step Diagnosis

Validate chrony config and UDP 123 traffic.

grep -E '^(server|pool)' /etc/chrony.conf
firewall-cmd --query-service=ntp
chronyc sourcestats -v

Solution – Primary Fix

Enable chronyd, allow NTP service, and step clock if required.

systemctl enable --now chronyd
firewall-cmd --add-service=ntp --permanent
firewall-cmd --reload
chronyc makestep

Solution – Alternative Approaches

Use internal stratum hosts for controlled synchronization.

chronyd -q 'server ntp.internal iburst'
timedatectl set-ntp true

Verification & Acceptance Criteria

System reports synchronized with stable offset.

timedatectl status
chronyc tracking
chronyc sources -v

Rollback Plan

Revert chrony and firewall changes if policy requires alternate source paths.

cp -a /root/chrony.conf.bak /etc/chrony.conf
firewall-cmd --remove-service=ntp --permanent
firewall-cmd --reload

Prevention & Hardening

Monitor drift and source health with regular checks.

systemctl is-enabled chronyd
chronyc tracking | tee /var/log/chrony-health.log

Related Errors & Cross-Refs

Often linked to Kerberos skew and TLS handshake failures.

Related tutorial: View the step-by-step tutorial for oracle-linux-10.

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Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Oracle Linux time synchronization best practices.