Setting up Time Server
Chrony is the now the default network time protocol for RHEL/Centos 7. Chrony is an alternative NTP client and server that is designed specifically for systems that are not online all the time.
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Install Chrony
yum -y install chrony
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Edit /etc/chrony.conf . Specifically, add the “allow network” line so your clients can connect to this server locally.
server 0.centos.pool.ntp.org iburst
server 1.centos.pool.ntp.org iburst
server 2.centos.pool.ntp.org iburst
server 3.centos.pool.ntp.org iburst
stratumweight 0
driftfile /var/lib/chrony/drift
rtcsync
makestep 10 3
# Allow NTP client access from local network.
allow 192.168.88.0/24
# Listen for commands only on localhost.
bindcmdaddress 127.0.0.1
bindcmdaddress ::1
keyfile /etc/chrony.keys
commandkey 1
generatecommandkey
noclientlog
logchange 0.5
logdir /var/log/chrony
- On the clients, edit /etc/chrony.conf
# specify chrony server
server ntp.gracie.net
driftfile /var/lib/chrony/drift
logdir /var/log/chrony
log measurements statistics tracking
keyfile /etc/chrony.keys
commandkey 24
initstepslew 20 master
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Start chronyd
systemctl start chronyd
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Enable chronyd on boot
systemctl enable chronyd
Using Chrony
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Checking chrony tracking
chronyc tracking
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Checking chrony sources
chronyc sources
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Checking chrony source statistics
chronyc sourcestats
Written on November 19, 2015