记录一下
/usr/sbin/ntpdate -d time.windows.com
29 Dec 22:15:42 ntpdate[3744]: ntpdate [email protected] Tue May 31 10:09:22 UTC 2016 (1)
Looking for host time.windows.com and service ntp
host found : 52.169.179.91
transmit(52.169.179.91)
transmit(52.169.179.91)
transmit(52.169.179.91)
transmit(52.169.179.91)
transmit(52.169.179.91)
52.169.179.91: Server dropped: no data
server 52.169.179.91, port 123
stratum 0, precision 0, leap 00, trust 000
refid [52.169.179.91], delay 0.00000, dispersion 64.00000
transmitted 4, in filter 4
reference time: 00000000.00000000 Mon, Jan 1 1900 8:05:43.000
originate timestamp: 00000000.00000000 Mon, Jan 1 1900 8:05:43.000
transmit timestamp: dc0f9911.af8c98c3 Thu, Dec 29 2016 22:15:45.685
filter delay: 0.00000 0.00000 0.00000 0.00000
0.00000 0.00000 0.00000 0.00000
filter offset: 0.000000 0.000000 0.000000 0.000000
0.000000 0.000000 0.000000 0.000000
delay 0.00000, dispersion 64.00000
offset 0.000000
29 Dec 22:15:46 ntpdate[3744]: no server suitable for synchronization found
解决方法：
yum install ntp
/etc/init.d/ntpd start
# /usr/sbin/ntpdate time.windows.com
29 Dec 22:24:39 ntpdate[3805]: the NTP socket is in use, exiting
/etc/init.d/ntpd stop
/usr/sbin/ntpdate cn.pool.ntp.org
29 Dec 14:26:50 ntpdate[3820]: step time server 42.96.167.209 offset -28703.604438 sec
成功解决，具体原因还有待查。