1、[root@byrd ~]# find / -name "ntpdate"/usr/sbin/ntpdate/etc/rc.d/init.d/ntpdate/etc/sysconfig/ntpdate[root@byrd ~]#
2、[byrd@nginx ~]$ /usr/sbin/ntpdate 210.72.145.4426 Mar 13:29:55 ntpdate[31944]: bind() fails: Permission denied[root@nginx ~]# /usr/sbin/ntpdate 210.72.145.4426 Mar 13:30:21 ntpdate[31963]: no server suitable for synchronization found[root@nginx ~]# /usr/sbin/ntpdate time.windows.com26 Mar 13:31:05 ntpdate[31964]: no server suitable for synchronization found
3、[root@nginx ~]# ntpdate -d time.windows.com26 Mar 13:33:59 ntpdate[31968]: ntpdate [email protected] Sat Nov 23 18:20:12 UTC 2013 (1)Looking for host time.windows.com and service ntphost found : 65.55.56.206transmit(65.55.56.206)transmit(65.55.56.206)transmit(65.55.56.206)transmit(65.55.56.206)transmit(65.55.56.206)65.55.56.206: Server dropped: no dataserver 65.55.56.206, port 123stratum 0, precision 0, leap 00, trust 000refid [65.55.56.206], delay 0.00000, dispersion 64.00000transmitted 4, in filter 4reference time: 00000000.00000000 Thu, Feb 7 2036 14:28:16.000originate timestamp: 00000000.00000000 Thu, Feb 7 2036 14:28:16.000transmit timestamp: d6dce54b.365b28c1 Wed, Mar 26 2014 13:34:03.212filter 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 0.000000delay 0.00000, dispersion 64.00000offset 0.00000026 Mar 13:34:04 ntpdate[31968]: no server suitable for synchronization found
4、[root@nginx ~]# ntpdate -d time.windows.com26 Mar 13:53:38 ntpdate[32382]: ntpdate [email protected] Sat Nov 23 18:20:12 UTC 2013 (1)Looking for host time.windows.com and service ntphost found : 64.4.10.33transmit(64.4.10.33)receive(64.4.10.33)transmit(64.4.10.33)receive(64.4.10.33)transmit(64.4.10.33)receive(64.4.10.33)transmit(64.4.10.33)transmit(64.4.10.33)server 64.4.10.33, port 123stratum 2, precision -6, leap 00, trust 000refid [64.4.10.33], delay 0.24284, dispersion 8.01073transmitted 4, in filter 4reference time: d6dce8c8.aa822c95 Wed, Mar 26 2014 13:48:56.666originate timestamp: d6dce9e3.62928ee3 Wed, Mar 26 2014 13:53:39.385transmit timestamp: d6dce9e3.7b92f8de Wed, Mar 26 2014 13:53:39.482filter delay: 0.24370 0.24359 0.24284 0.00000 0.00000 0.00000 0.00000 0.00000 filter offset: 0.017055 0.017701 0.003164 0.000000 0.000000 0.000000 0.000000 0.000000delay 0.24284, dispersion 8.01073offset 0.00316426 Mar 13:53:40 ntpdate[32382]: adjust time server 64.4.10.33 offset 0.003164 sec
5、原因：①：开启防火墙后可以收到回应包，证明是防火墙的原因，生产环境中，开启udp123端口即可;②：可能的因素是在/etc/ntp.conf中禁止了相关notrust参数。1。检查ntp的版本，如果你使用的是ntp4.2（包括4.2）之后的版本，在restrict的定义中使用了notrust的话，会导致以上错误。使用以下命令检查ntp的版本：
6、下面是来自ntp官方网站的说明：The behavior of notrust changed between versions 4.1 and 4.2.In 4.1 (and earlier) notrust meant "Don't trust this host/subnet for time".In 4.2 (and later) notrust means "Ignore all NTP packets that are not cryptographically authenticated." This forces remote time servers to authenticate themselves to your (client) ntpd解决：把notrust去掉。补充内容（非原创）：当用ntpdate -d 来查询时会发现导致 no server suitable for synchronization found 的错误的信息有以下2个：错误1.Server dropped: Strata too high在ntp客户端运行ntpdate serverIP，出现no server suitable for synchronization found的错误。在ntp客户端用ntpdate –d serverIP查看，发现有“Server dropped: strata too high”的错误，并且显示“stratum 16”。而正常情况下stratum这个值得范围是“0~15”。这是因为NTP server还没有和其自身或者它的server同步上。以下的定义是让NTP Server和其自身保持同步，如果在/ntp.conf中定义的server都不可用时，将使用local时间作为ntp服务提供给ntp客户端。
