The Juniper EX switch must be configured to synchronize internal information system clocks using redundant authoritative time sources.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-253920	SRG-APP-000373-NDM-000298	JUEX-NM-000430	SV-253920r1018769_rule	2025-03-07	2

Description
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.

Description

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.

ℹ️ Check
Determine if the network device is configured to synchronize internal information system clocks with the primary and secondary time sources. Verify the Network Time Protocol (NTP) configuration. [edit system ntp] authentication-key 1 type sha256 value "PSK"; ## SECRET-DATA authentication-key 2 type sha1 value "PSK"; ## SECRET-DATA server <address 1> key 1 prefer; ## SECRET-DATA server <address 2> key 2; ## SECRET-DATA trusted-key [ 1 2 ]; source-address <lo0 or OOBM address>; If the network device is not configured to synchronize internal information system clocks with the primary and secondary time sources, this is a finding.

ℹ️ Check

Determine if the network device is configured to synchronize internal information system clocks with the primary and secondary time sources. Verify the Network Time Protocol (NTP) configuration. [edit system ntp] authentication-key 1 type sha256 value "PSK"; ## SECRET-DATA authentication-key 2 type sha1 value "PSK"; ## SECRET-DATA server <address 1> key 1 prefer; ## SECRET-DATA server <address 2> key 2; ## SECRET-DATA trusted-key [ 1 2 ]; source-address <lo0 or OOBM address>; If the network device is not configured to synchronize internal information system clocks with the primary and secondary time sources, this is a finding.

✔️ Fix
Configure the network device to synchronize internal information system clocks with the primary and secondary time sources. set system ntp authentication-key 1 type sha256 set system ntp authentication-key 1 value "PSK" set system ntp authentication-key 2 type sha1 set system ntp authentication-key 2 value "PSK" set system ntp server <address 1> key 1 set system ntp server <address 1> prefer set system ntp server <address 2> key 2 set system ntp trusted-key 1 set system ntp trusted-key 2 set system ntp source-address <lo0 or OOBM address>

✔️ Fix

Configure the network device to synchronize internal information system clocks with the primary and secondary time sources. set system ntp authentication-key 1 type sha256 set system ntp authentication-key 1 value "PSK" set system ntp authentication-key 2 type sha1 set system ntp authentication-key 2 value "PSK" set system ntp server <address 1> key 1 set system ntp server <address 1> prefer set system ntp server <address 2> key 2 set system ntp trusted-key 1 set system ntp trusted-key 2 set system ntp source-address <lo0 or OOBM address>