#/etc/ntp.conf
#
driftfile /var/lib/ntp/ntp.drift
logfile /var/log/ntpd.log
statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable
server 101.201.72.121
server 1.cn.pool.ntp.org
server s1c.time.edu.cn
restrict -4 default kod notrap nomodify nopeer noquery
restrict 127.0.0.1
restrict 192.168.0.0 mask 255.255.0.0 nomodify
restrict 172.16.0.0 mask 255.240.0.0 nomodify
restrict 10.0.0.0 mask 255.0.0.0 nomodify
broadcastdelay 0.008
yum install ntp
chkconfig ntpd on
ntpdate -q 1.cn.pool.ntp.org
vi /etc/ntp.conf
service ntpd start
netstat -tlunp | grep ntp
ntpq -p
ntpstat
命令参数详见：https://www.cnblogs.com/GYoungBean/p/4225465.html