2.2.1.4 Ensure ntp is configured

Information

ntp is a daemon which implements the Network Time Protocol (NTP). It 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.

Notes:

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If chrony or systemd-timesyncd are used, ntp should be removed and this section skipped

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This recommendation only applies if ntp is in use on the system

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Only one time synchronization method should be in use on the system

If ntp is in use on the system proper configuration is vital to ensuring time synchronization is working properly.

Solution

Add or edit restrict lines in /etc/ntp.conf to match the following:

restrict -4 default kod limited nomodify notrap nopeer noquery
restrict -6 default kod limited nomodify notrap nopeer noquery

Add or edit server or pool lines to /etc/ntp.conf as appropriate:

server <remote-server>

Add or edit the NTPD_OPTIONS in /etc/sysconfig/ntp to include '-u ntp:ntp':

NTPD_OPTIONS="-u ntp:ntp"

See Also

https://workbench.cisecurity.org/benchmarks/8498

Item Details

Category: AUDIT AND ACCOUNTABILITY

References: 800-53|AU-7, 800-53|AU-8, CSCv7|6.1

Plugin: Unix

Control ID: 29fd13ad070fdda037df13a3418840e594cd0acaed589a224908ed373a7609f9