Install and configure NTP (Network Time Protocol) Server and NTP Client on CentOS 8 / RHEL 8 or higher Linux system.

This blog shows how to install and configure NTP (Network Time Protocol) Server and NTP Client on CentOS 8 / RHEL 8 or higher Linux system.

ntp server client

Configure NTP Server

Install Chrony to Configure NTP Server for Time Synchronization:

[root@sujit ~]# dnf -y install chrony

Edit Chrony configuration:

[root@sujit ~]# vi /etc/chrony.conf

# Use public servers from the pool.ntp.org project to change to your own NTP server or others in your timezone.

# Please consider joining the pool (http://www.pool.ntp.org/join.html).

pool 2.centos.pool.ntp.org iburst

server 0.np.pool.ntp.org iburst

server 0.asia.pool.ntp.org iburst

server 1.asia.pool.ntp.org iburst

server 2.asia.pool.ntp.org iburst

server 3.asia.pool.ntp.org iburst

pool ntp.nict.jp iburst

# Allow NTP client access from local network.

allow 192.168.0.0/16

Enable Chrony service:

[root@sujit ~]# systemctl enable --now chronyd

Make exception in firewall services and reload firewall:

If Firewalld is running, allow NTP service. NTP uses [123/UDP].

[root@sujit ~]# firewall-cmd --add-service=ntp --permanent

success

[root@sujit ~]# firewall-cmd --reload

success

Now use the server’s IP address in client’s time zone configuration.

Verify it works normally:

Command to check the NTP servers

[root@sujit ~]# chronyc sources

Command to check the NTP clients

[root@sujit ~]# chronyc clients

To display time synchronization status, install NTPSTAT:

[root@client ~]# dnf -y install ntpstat

Verify:

[root@client ~]# ntpstat

synchronised to NTP server (162.159.200.123) at stratum 4

time correct to within 79 ms

polling server every 512 s

Configure NTP Client

In linux, NTP Clients does not need to receive time synchronization requests from other hosts.

The configurations is mostly the same with server’s one.

Install Chrony to Configure NTP Server for Time Synchronization:

[root@client ~]# dnf -y install chrony

Edit Chrony configuration:

[root@client ~]# vi /etc/chrony.conf