CIS Control 8.4: Standardize Time Synchronization
Accurate time synchronization across your enterprise assets is critical for forensic analysis, audit logging, and regulatory compliance. CIS Control 8.4 requires at least two synchronized time sources to ensure consistent, reliable timestamps across your entire infrastructure—a foundational element of any mature security posture.
What this means
This control mandates that organizations configure and maintain at least two synchronized time sources (such as NTP servers or atomic clocks) across all enterprise assets that support time synchronization. Consistent time across systems prevents log tampering, enables accurate incident reconstruction, and ensures compliance with frameworks like SOC 2, ISO 27001, and HIPAA that depend on reliable audit trails.
How to comply
- 1.Identify all enterprise assets capable of time synchronization, including servers, endpoints, network devices, and cloud resources.
- 2.Deploy at least two redundant, geographically distributed time sources (primary and secondary NTP servers or higher-accuracy alternatives).
- 3.Configure all in-scope systems to synchronize with both time sources to eliminate single points of failure.
- 4.Set appropriate time synchronization intervals (typically 15–60 minutes for most environments) to maintain accuracy without creating excessive network load.
- 5.Monitor time drift and synchronization status using centralized logging or SIEM tools to detect misconfigurations or clock skew.
- 6.Document your time synchronization architecture, including source selection, update policies, and monitoring procedures.
- 7.Test failover behavior regularly to confirm that systems automatically switch to the secondary time source if the primary fails.
Evidence auditors look for
- NTP server configuration files showing at least two synchronized time sources with redundancy settings.
- System logs or monitoring dashboards displaying time synchronization status across all critical assets.
- Network packet captures confirming NTP communication between endpoints and time sources.
- Audit logs with consistent timestamps across multiple systems, demonstrating synchronized clocks.
- Change management records documenting time synchronization deployment, updates, and maintenance.
- Incident response logs showing accurate timestamps that enabled successful forensic analysis.
- Monitoring alerts configured to notify teams of time drift exceeding acceptable thresholds.
Frequently asked questions
When will FAQs be available?
The FAQ for this control is currently being prepared.
GRCWatch automatically discovers all systems requiring time synchronization, monitors NTP configuration and clock drift across your infrastructure in real-time, and generates audit-ready evidence showing compliance with CIS 8.4—eliminating manual verification work for your security team.
See how GRCWatch handles this control automatically
Start free trial