General Information

Synchronizing time to a central time server and also keeping in sync with a peer server.

This type of setup would be a tier two NTP setup, allowing for redundancy if the central source of time is lost. The two peers could agree on a time and provide it locally to other servers.

Setting up a local NTP server in order to practice the objective of synchronizing time.

Install the ntp package

yum install ntp

Enable and start ntpd

systemctl enable ntpd
systemctl start ntpd

Query NTP to view status

ntpq -p

• -p →

NTP Statistics

ntpstat

Configure NTP Pool Sources

vim /etc/ntpd.conf
 
# Comment out other servers, add the below
server 127.127.1.0

• 127.127.1.0 → Special IP address that syncs to the local server's clock

Restart the service for the change to apply

systemctl restart ntpd

Open the firewall for NTP

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

Setup a NTP client to peer/sync with the NTP server.

Install required package

yum install ntp

Enable and start the service

systemctl enable ntpd
systemctl start ntpd

Edit the NTP config file

vim /etc/ntp.conf
 
# Comment out all server lines, add peer for the newly created NTP server
peer 192.168.1.200

Restart the service

systemctl restart ntpd

Open the firewall for ntp

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