How Install/Configure a new NTP server

Purpose

This document describes how to install/configure an NTP server.

Target Audience

This document is intended for use by Systems Administrators who wish to install and configure an NTP server.

Prerequisites

Hardened Linux 6 system

Installing a new NTP server

Install the required packages

# yum install ntp

# vi /etc/ntp.conf

// If the system is using the IPV4 not IPV6, comment the following lines:

#restrict -6 default kod nomodify notrap nopeer noquery

#restrict -6 ::1

Add your preferred external time servers.

For me, I comment the default time servers and I add the following:

server time.nist.gov

Make sure that your /etc/sysconfig/ntpd has the following line:

OPTIONS="-u ntp:ntp -p /var/run/ntpd.pid -g"

Start the NTP Daemon

# service ntpd start

# chkconfig ntpd on

Test the sync to the external NTP server

To print a list of the peers known to the server as well as a summary of their state:

# ntpq –p

Search for “*”, * = current time source

Manual Sync the system

# ntpdate  -bs  time.nist.gov

Finishing up

You have now successfully configured a new NTP server.