OpenNTPD is a free and open-source implementation of the Network Time Protocol (NTP) that can be used to synchronize the local clock on a CentOS or Red Hat Linux system. To install OpenNTPD on your system, you will need to have the EPEL (Extra Packages for Enterprise Linux) repository configured.
Here are the steps to install OpenNTPD on a CentOS or Red Hat Linux system:
- Install the EPEL repository:
sudo yum install epel-release
- Install OpenNTPD:
sudo yum install openntpd
- Start the OpenNTPD service:
sudo systemctl start openntpd
- Enable the OpenNTPD service to start automatically at boot time:
sudo systemctl enable openntpd
- Verify that the local clock has been synchronized by checking the output of the following command:
ntpq -p
This command should display a list of NTP servers that the OpenNTPD service is currently synchronizing with, along with the current offset of the local clock relative to each server.
By default, OpenNTPD will automatically choose NTP servers from a list of public NTP servers maintained by the OpenNTPD project. However, you can also configure OpenNTPD to use specific NTP servers by editing the /etc/ntpd.conf file.
For more information on using OpenNTPD to synchronize the local clock, you can refer to the OpenNTPD documentation and the ntpd man page.