The Network Time Protocol (NTP) is designed to synchronize system clocks across a variety of systems and use a source that is highly accurate. More information on NTP can be found at http://www.ntp.org. NTP can be configured to be a client and/or a server. Rationale: It is recommended that physical systems and virtual guests lacking direct access to the physical hosts clock be configured as NTP clients to synchronize their clocks (especially to support time sensitive security mechanisms like Kerberos). This also ensures log files have consistent time records across the enterprise, which aids in forensic investigations. Fix: install ntp: # yum install ntp Ensure the following lines are in /etc/ntp.conf: restrict -4 default kod nomodify notrap nopeer noquery restrict -6 default kod nomodify notrap nopeer noquery Also, make sure /etc/ntp.conf has at least one NTP server specified: server Note: is the IP address or hostname of a trusted time server. Configuring an NTP server is outside the scope of this benchmark.

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install ntp: # yum install ntp Ensure the following lines are in /etc/ntp.conf: restrict -4 default kod nomodify notrap nopeer noquery restrict -6 default kod nomodify notrap nopeer noquery Also, make sure /etc/ntp.conf has at least one NTP server specified: server ntp-server Note: ntp-server is the IP address or hostname of a trusted time server. Configuring an NTP server is outside the scope of this benchmark.