The NTP Daemon on RHEL 6

Installation

Check that NTP services is started at boot.

$ chkconfig ntpdate --list
ntpdate         0:off 1:off 2:off 3:off 4:off 5:off 6:off

If not automatically started.

$ chkconfig ntpdate on

If NTP service is not running, start it.

$ service ntpdate start

Configuration

Default configuration is almost always sufficient.

$cat /etc/ntp.conf
# For more information about this file, see the man pages
# ntp.conf(5), ntp_acc(5), ntp_auth(5), ntp_clock(5), ntp_misc(5), ntp_mon(5).
...
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
server 0.rhel.pool.ntp.org iburst
server 1.rhel.pool.ntp.org iburst
server 2.rhel.pool.ntp.org iburst
server 3.rhel.pool.ntp.org iburst
...

Test

Check system clock against a reliable source.

$ date
Tue Jan 21 07:07:06 CET 2014