How to configure ntp server on CentOS8?

What you will read?

To set up an NTP (Network Time Protocol) server on CentOS 8, you’ll use chrony, which is the default NTP client/server in CentOS 8.

Step 1 – Install `chrony`

If it’s not already installed:

sudo dnf install chrony -y

Enable and start the service:

sudo systemctl enable chronyd
sudo systemctl start chronyd

Edit the config file:

sudo nano /etc/chrony.conf

Look for the default NTP pool lines and keep or change them based on your region:

server 0.centos.pool.ntp.org iburst
server 1.centos.pool.ntp.org iburst
server 2.centos.pool.ntp.org iburst

Then add this line to allow your LAN clients to sync:

allow 192.168.0.0/16

You can change the subnet to match your network.

Also make sure local stratum is enabled so your server can serve time if it’s offline:

local stratum 10

Save and close the file.

Restart the chrony daemon:

sudo systemctl restart chronyd

Check server status:

chronyc sources

This will show the current time sources and sync status.

If firewalld is enabled, open the NTP port:

sudo firewall-cmd --permanent --add-service=ntp
sudo firewall-cmd --reload

On a client machine, point it to your new NTP server:

sudo chronyc add server your-server-ip

Or modify the client’s /etc/chrony.conf to include:

server your-server-ip iburst

Then restart chrony on the client:

sudo systemctl restart chronyd

Check sync status from client:

chronyc tracking