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NTPd : Configure NTP Server
2014/08/02 |
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Install NTPd and Configure NTP server for time adjustment.
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| [1] | Install and Configure NTPd. |
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[root@dlp ~]#
yum -y install ntp
[root@dlp ~]#
vi /etc/ntp.conf # line 19: 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 to your timezone # 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 /etc/rc.d/init.d/ntpd start Starting ntpd: [ OK ] [root@dlp ~]# chkconfig ntpd on |
| [2] | If Iptables is running, allow NTP port. NTP uses 123/UDP. For "-I INPUT 5" section below, Replace it to your own environment. |
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[root@dlp ~]# iptables -I INPUT 5 -p udp -m state --state NEW -m udp --dport 123 -j ACCEPT |
| [3] | Verify it works normally like follows. |
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[root@dlp ~]# ntpq -p
remote refid st t when poll reach delay offset jitter
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+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
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