Use apt-get or yum to install the NTP daemon.
[root@server1 ~]# yum install ntp
Ensure the /etc/ntp.conf file contains 4 NTP servers. Instead of "distro" being listed, the name of the distribution should be listed, such as ubuntu, redhat, or centos. Your NTPd server will get time from these 4 NTP servers.
[root@server1 ~]# cat /etc/ntp.conf . . . server 0.distro.pool.ntp.org iburst server 1.distro.pool.ntp.org iburst server 2.distro.pool.ntp.org iburst server 3.distro.pool.ntp.org iburst . . .
To confiure your local NTP server to allow other computers in your network to use the machine as the NTP server, enter your network address and prefix.
Start the NTP daemon, and ensure the daemon is active and running.
[root@server1 ~]# systemctl start ntpd [root@server1 ~]# systemctl status ntpd
Configure the NTP daemon to automatically start if the OS is rebooted.
[root@server1 ~]# systemctl enable ntpd
Use the date command to verify the NTP server is getting the correct date and time from the NTP pool.
[root@server1 ~]# date Mon Jan 01 00:01:01 CDT 2016
Client PCs in your network can now be configured to use your NTP server.
- Click here to configure a Linux PC to use your NTP server
NTP uses a term stratum to describe how far a device is from the reference clock.
- Stratum 0 is the reference clock.
- Stratum 1 are the ntp.pool servers.
- Stratum 2 is typically an internal NTP server.
- Stratum 3 and below are devices in the LAN that are configured to use the internal NTP server.
Stratum can be 16 layers deep maximum.