Rule version HYCU-ND-000440 · STIG v1 · 2026-05-23
The loss of connectivity to a particular authoritative time source will result in the loss of time synchronization (free-run mode) and increasingly inaccurate time stamps on audit events and other functions.
Multiple time sources provide redundancy by including a secondary source. Time synchronization is usually a hierarchy; clients synchronize time to a local source while that source synchronizes its time to a more accurate source. The network device must use an authoritative time server and/or be configured to use redundant authoritative time sources. This requirement is related to the comparison done in CCI-001891.
DOD-approved solutions consist of a combination of a primary and secondary time source using a combination or multiple instances of the following: a time server designated for the appropriate DOD network (NIPRNet/SIPRNet); United States Naval Observatory (USNO) time servers; and/or the Global Positioning System (GPS). The secondary time source must be located in a different geographic region than the primary time source.
Satisfies: SRG-APP-000920-NDM-000320, SRG-APP-000925-NDM-000330
Verify the "chronyd" service is up and running, execute the following command: systemctl status chronyd
If service is not active (running), this is a finding.
To verify chronyd has synced time and can reach the servers execute the following command: chronyc sources
If there are not two NTP servers listed, this is a finding.
If the "Reach" value is lower than "377" for the source with S column marked with "*" this is a finding.
Start the time synchronization by logging on to the HYCU console and executing the following command: sudo systemctl restart chronyd
Additional assistance can be found at: https://support.hycu.com/hc/en-us/articles/115005424345-HYCU-system-time