documentation_complete: true


title: 'Specify Additional Remote NTP Servers'

description: |-
    Additional NTP servers can be specified for time synchronization
    in the file <tt>/etc/ntp.conf</tt>.  To do so, add additional lines of the
    following form, substituting the IP address or hostname of a remote NTP server for
    <em>ntpserver</em>:
    <pre>server <i>ntpserver</i></pre>

rationale: |-
    Specifying additional NTP servers increases the availability of
    accurate time data, in the event that one of the specified servers becomes
    unavailable. This is typical for a system acting as an NTP server for
    other systems.

severity: unknown

identifiers:
    cce@rhel8: CCE-86488-4
    cce@sle12: CCE-91660-1
    cce@sle15: CCE-91297-2

references:
    cis-csc: 1,14,15,16,3,5,6
    cobit5: APO11.04,BAI03.05,DSS05.04,DSS05.07,MEA02.01
    isa-62443-2009: 4.3.3.3.9,4.3.3.5.8,4.3.4.4.7,4.4.2.1,4.4.2.2,4.4.2.4
    isa-62443-2013: 'SR 2.10,SR 2.11,SR 2.12,SR 2.8,SR 2.9'
    iso27001-2013: A.12.4.1,A.12.4.2,A.12.4.3,A.12.4.4,A.12.7.1
    nist: CM-6(a),AU-8(1)(a),AU-8(2)
    nist-csf: PR.PT-1
    pcidss: Req-10.4.3
