ntpq -p
remote refid st t when poll reach delay offset jitter
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+pool-test.ntp.o 216.218.254.202 2 u 259 1024 17 12.920 -106.39 111.972
+palpatine.steve 208.201.242.2 3 u 239 1024 17 16.959 -102.84 112.056
+grom.polpo.org 127.67.113.92 2 u 259 1024 17 17.362 -184.43 74.468
+paladin.latt.ne 204.123.2.72 2 u 378 1024 3 24.211 -106.97 61.825
+public-ntp1.iso 204.13.164.164 3 u 259 1024 17 33.080 -100.17 65.970
+nist1.symmetric .ACTS. 1 u 214 1024 17 17.548 -108.30 111.951
*nist1-sj.ustimi .ACTS. 1 u 245 1024 17 21.826 -111.02 63.313
抖动和偏移如何比延迟大得多？当ping时间为12ms时关闭100ms似乎很荒谬,我读错了吗？
事实上,我不确定ntp是否正在做任何事情来改变我的时钟 – 似乎有时间,但不一定设置任何东西.我怎么检查？
一些信息：
ntpdc> sysinfo system peer: nist1-sj.ustiming.org system peer mode: client leap indicator: 00 stratum: 2 precision: -11 root distance: 0.02182 s root dispersion: 0.15431 s reference ID: [216.171.124.36] reference time: d4dae2b5.3c32ce54 Fri,Mar 1 2013 0:17:57.235 system flags: auth monitor ntp kernel stats jitter: 0.045776 s stability: 0.000 ppm broadcastdelay: 0.000000 s authdelay: 0.000000 s more "c:\Program Files (x86)\NTP\etc\ntp.drift" 192.049 more "c:\Program Files (x86)\NTP\etc\ntp.conf" driftfile "C:\Program Files (x86)\NTP\etc\ntp.drift" server nist1.symmetricom.com iburst server nist1-sj.ustiming.org iburst server 149.20.68.17 iburst server 173.230.144.109 iburst server 65.19.178.219 iburst server 204.2.134.162 iburst server 173.230.144.109 iburst server 207.115.64.229 iburst
理想情况下,我想要一个距配置服务器的中位数不超过50毫秒的时间,如果它离得更远,我希望它能够步进.是否有任何我可以设置的配置选项会使ntp这样做？
http://www.ntp.org/ntpfaq/NTP-s-sw-clocks-quality.htm
http://www.ntp.org/ntpfaq/NTP-s-trouble.htm
Ideally I want a time that is no more than 50ms away from the median of the configured servers,if it ever gets further away I want it to step. Is there any config option that I can set that would make ntp do that?
NTP不会那样工作.它从列表中选择一个服务器,在’ntpq -p’输出的第一列中用’*'(星号,a.k.a.参考时间源)标记它,并尝试跟随它.在参考时间源变得无法到达的情况下,它将回退到”(合格候选者)服务器之一.
我建议：
>不在每台服务器上使用iburst
>选择最好的服务器,使用iburst并使用prefer标记,即“server tick.example.com iburst prefer”.
>只手动挑选3台关闭服务器.
>其余部分更多地使用区域池DNS名称(例如[0-3] .us.poo.ntp.org).
>拍摄至少4个参考服务器,但不超过9个.
>切勿配置“服务器127.127.1.0”(a.k.a.本地时钟)或“软糖”行.
默认情况下,“回转”与“步进”选项为128ms.如果时间偏移> 128ms,它将步而不是转.请参阅“ntpd”的“-x”参数(除非您的软件在时钟步进时出现异常情况,否则不应使用该参数).
除了“ntpq -p”之外,您还可以查看“ntpdc -c loopinfo”.
