2.2.1.2 Ensure ntp is configured - 'restrict -4'

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. This recommendation only applies if ntp is 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 nomodify notrap nopeer noquery

restrict -6 default kod nomodify notrap nopeer noquery

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

server <remote-server>

Configure ntp to run as the ntp user by adding or editing the following file:

/etc/init.d/ntp: RUNASUSER=ntp

See Also

https://workbench.cisecurity.org/files/1866

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b., CSCv6|6.1

Plugin: Unix

Control ID: 6f00c5052b985bf79ba87897cd98fa3534531acb34e76c3f809f21ea388de625