{"description": "Depending on specific functional requirements of a concrete\nproduction environment, the Ubuntu 22.04 system can be\nconfigured to utilize the services of the <tt>chronyd</tt> NTP daemon (the\ndefault), or services of the <tt>ntpd</tt> NTP daemon. Refer to\n\nfor more detailed comparison of the features of both of the choices, and for\nfurther guidance how to choose between the two NTP daemons.\n<br />\nAdditional NTP servers can be specified for time synchronization. To do so,\nperform the following:\n<ul>\n<li> if the system is configured to use the <tt>chronyd</tt> as the NTP daemon\n(the default), edit the file <tt>/etc/chrony/chrony.conf</tt> as follows,</li>\n<li> if the system is configured to use the <tt>ntpd</tt> as the NTP daemon,\nedit the file <tt>/etc/ntp.conf</tt> as documented below.</li>\n</ul>\nAdd additional lines of the following form, substituting the IP address or\nhostname of a remote NTP server for <em>ntpserver</em>:\n<pre>server <i>ntpserver</i></pre>", "rationale": "Specifying additional NTP servers increases the availability of\naccurate time data, in the event that one of the specified servers becomes\nunavailable. This is typical for a system acting as an NTP server for\nother systems.", "severity": "medium", "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)", "AU-12(1)"], "nist-csf": ["PR.PT-1"], "pcidss": ["Req-10.4.3"], "ism": ["0988", "1405"]}, "control_references": {"ism": ["0988", "1405"]}, "components": [], "identifiers": {}, "ocil_clause": null, "ocil": null, "oval_external_content": null, "fixtext": "", "checktext": "", "vuldiscussion": "", "srg_requirement": "", "warnings": [], "conflicts": [], "requires": [], "policy_specific_content": {}, "platform": "package[chrony] or package[ntp]", "platforms": ["package[chrony] or package[ntp]"], "sce_metadata": {}, "inherited_platforms": ["system_with_kernel"], "cpe_platform_names": ["package_chrony_or_package_ntp"], "inherited_cpe_platform_names": ["system_with_kernel"], "bash_conditional": null, "fixes": {}, "title": "Specify Additional Remote NTP Servers", "definition_location": "/aptdata/openscap/scap-security-guide/linux_os/guide/services/ntp/chronyd_or_ntpd_specify_multiple_servers/rule.yml", "template": null}