NTP Server CentOS 7

NTPD - Configure NTP Server

Install NTPd and Configure NTP server for time adjustment. NTP uses 123/UDP

[root@dlp ~]#

yum -y install ntp

[root@dlp ~]#

vi /etc/ntp.conf

# line 18: add the network range you allow to receive requests

restrict 10.0.0.0 mask 255.255.255.0 nomodify notrap

# change servers for synchronization

#

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

server ntp1.jst.mfeed.ad.jp
server ntp2.jst.mfeed.ad.jp
server ntp3.jst.mfeed.ad.jp

[root@dlp ~]# systemctl start ntpd 

[root@dlp ~]# systemctl enable ntpd 

ln -s '/usr/lib/systemd/system/ntpd.service' '/etc/systemd/system/multi-user.target.wants/ntpd.service'

[root@dlp ~]# ntpq -p

     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
+ntp1.jst.mfeed. 172.29.1.100     2 u   29   64    1   18.826   -0.126   0.000
+ntp2.jst.mfeed. 172.29.2.50      2 u   28   64    1   21.592    0.018   0.000
*ntp3.jst.mfeed. 133.243.236.18   2 u   28   64    1   22.666   -1.033   0.000

Configure NTP Client : CentOS

It's the time synchronization on CentOS Client.

[root@dlp ~]# 

ntpdate ntp1.jst.mfeed.ad.jp 

9 Jul 00:46:26 ntpdate[18687]: adjust time server 210.173.160.27 offset -0.000716 sec