NTPd : Configure NTP Server

2014/07/08

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 iburst server ntp2.jst.mfeed.ad.jp iburst server ntp3.jst.mfeed.ad.jp iburst [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