Title

The SEL-2740S must be configured to maintain internal system clocks with a backup authoritative time server. (Cat II impact)

Discussion

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 utilize 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.

Check Content

To ensure SEL-2740S NTP servers are configured do the following: 1. Log in with Permission Level 3 rights into parent OTSDN Controller. 2. Go to the "configuration object" page and select the desired switch. 3. Check NTP Server IP addresses in the settings fields that both a primary and backup NTP server is configured. 4. Check NTP flows for the SEL-2740S DUT and additional neighbor devices exist and are correct. If the SEL-2740S is not configured to maintain internal system clocks with a backup authoritative time server, this is a finding.

Fix Text

Configure NTP Servers during node adoption with the following steps: 1. Go to the "configuration object" page and select desired switch. 2. Enter the NTP Server IP addresses in appropriate settings fields for primary and backup NTP server(s). 3. Click "Submit". 4. Create NTP Flows to/from NTP server to/from node.

Additional Identifiers

Rule ID: SV-102389r1_rule

Vulnerability ID: V-92301

Group Title: SRG-APP-000373-NDM-000298

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.