How to Speed up NTP initial synchronization
Open the NT P configuration file /etc/ntp.conf in a text editor such as vi or nano, or create a new one if it does not already exist:
# nano /etc/ntp.conf
To speed the initial synchronization up, add the iburst directive at the end of each server line:
server 0.rhel.pool.ntp.org iburst
server 1.rhel.pool.ntp.org iburst
server 2.rhel.pool.ntp.org iburst
server 1.rhel.pool.ntp.org iburst
server 2.rhel.pool.ntp.org iburst
