The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.
The ntpd daemon can synchronise the system clock with remote NTP
servers, with local reference clocks, or with GPS and radio time signals.
ntpd provides a complete implementation of NTP version 4 (RFC 5905) and is also compatibility with
versions 3 (RFC 1305), 2 (RFC 1119), and 1 (RFC 1059).
You can configure ntpd to run in several different modes, as described
at http://doc.ntp.org/4.2.6p5/assoc.html, using both symmetric-key and public-key
cryptography, as described at http://doc.ntp.org/4.2.6p5/authopt.html.