The Content Analysis System (CAS) must be configured to synchronize system clocks within and between systems.

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 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.

DoW-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 DoW 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 NTP is enabled and syncing with the following steps:

1. Log on to the SSH CLI with an administrative account. 2. Enter "enable" and provide the password. 3. Enter "show clock". 4. Review the output for the NTP status.

If the line for NTP does not state "Enabled, syncing", or if NTP is not configured with a symmetric key, this is a finding.

Configure NTP to be enabled and synchronize the system clock with the following steps:

1. Log on to the SSH CLI with an administrative account. 2. Enter "enable", enter the password, and then enter "configure terminal". 3. Enable the NTP service by entering "ntp enable". 4. Add the authoritative time sources by entering: "ntp server [FIRSTNTPSERVER]" "ntp server [SECONDNTPSERVER]" (Replace the bracketed text with the IP addresses or hostnames of primary and secondary NTP servers.) 5. Force an immediate time synchronization by entering "ntp update-now". 6. Enter "exit" and then "exit" again to leave configuration mode.