{"id":1919,"date":"2017-03-15T22:45:40","date_gmt":"2017-03-15T14:45:40","guid":{"rendered":"http:\/\/cn.hostease.com\/xueyuan\/?p=1919"},"modified":"2017-03-15T22:45:40","modified_gmt":"2017-03-15T14:45:40","slug":"linux%e7%b3%bb%e7%bb%9fntp%e6%9c%8d%e5%8a%a1%e7%bb%86%e8%8a%82%e8%af%a6%e8%bf%b0","status":"publish","type":"post","link":"https:\/\/cn.hostease.com\/xueyuan\/jishu\/linux%e7%b3%bb%e7%bb%9fntp%e6%9c%8d%e5%8a%a1%e7%bb%86%e8%8a%82%e8%af%a6%e8%bf%b0\/","title":{"rendered":"Linux\u7cfb\u7edfNTP\u670d\u52a1\u7ec6\u8282\u8be6\u8ff0"},"content":{"rendered":"<p>\u5728Linux\u7cfb\u7edf\u91cc\u8bbe\u7f6eNTP\u670d\u52a1\u5e76\u4e0d\u96be\uff0c\u4f46\u662fNTP\u672c\u8eab\u786e\u662f\u4e00\u4e2a\u5f88\u590d\u6742\u7684\u534f\u8bae. \u4f60\u90fd\u4e86\u89e3\u7ec6\u8282\u4e48\uff1f<\/p>\n<p>1. \u65f6\u95f4\u548c\u65f6\u533a<\/p>\n<p>date\u547d\u4ee4\u53ef\u663e\u793a\u65f6\u95f4\u4e0e\u5e02\u533a<\/p>\n<p>[root@T_PV1_DB ~]# date<\/p>\n<p>Tue Feb\u00a0 7 16:32:16 CST 2017<\/p>\n<p>[root@T_PV1_DB ~]# cat \/etc\/sysconfig\/clock<\/p>\n<p>ZONE=&#8221;Asia\/Shanghai&#8221;<\/p>\n<p>CST=true<\/p>\n<p>\u5728\u5730\u7403\u73af\u7ed5\u592a\u9633\u65cb\u8f6c\u768424\u4e2a\u5c0f\u65f6\u4e2d,\u4e16\u754c\u5404\u5730\u65e5\u51fa\u65e5\u843d\u7684\u65f6\u95f4\u662f\u4e0d\u4e00\u6837\u7684.\u6240\u4ee5\u6211\u4eec\u624d\u6709\u5212\u5206\u65f6\u533a(timezone) \u7684\u5fc5\u8981,\u4e5f\u5c31\u662f\u628a\u5168\u7403\u5212\u5206\u621024\u4e2a\u4e0d\u540c\u7684\u65f6\u533a. \u6240\u4ee5\u6211\u4eec\u53ef\u4ee5\u628a\u65f6\u95f4\u7684\u5b9a\u4e49\u7406\u89e3\u4e3a\u4e00\u4e2a\u65f6\u95f4\u7684\u503c\u52a0\u4e0a\u6240\u5728\u5730\u7684\u65f6\u533a(\u6ce8\u610f\u8fd9\u4e2a\u6240\u5728\u5730\u53ef\u4ee5\u7cbe\u786e\u5230\u57ce\u5e02)<\/p>\n<p>\u683c\u6797\u5a01\u6cbb\u65f6\u95f4(GMT), \u5b83\u4e5f\u5c31\u662f0\u65f6\u533a\u65f6\u95f4. \u4f46\u662f\u6211\u4eec\u5728\u8ba1\u7b97\u673a\u4e2d\u7ecf\u5e38\u770b\u5230\u7684\u662fUTC. \u5b83\u662fCoordinated Universal Time\u7684\u7b80\u5199. \u867d\u7136\u53ef\u4ee5\u8ba4\u4e3aUTC\u548cGMT\u7684\u503c\u76f8\u7b49(\u8bef\u5dee\u76f8\u5f53\u4e4b\u5c0f),\u4f46\u662fUTC\u5df2\u7ecf\u88ab\u8ba4\u5b9a\u4e3a\u662f\u56fd\u9645\u6807\u51c6,\u6240\u4ee5\u6211\u4eec\u90fd\u5e94\u8be5\u9075\u5b88\u6807\u51c6\u53ea\u4f7f\u7528UTC<\/p>\n<p>\u90a3\u4e48\u5047\u5982\u73b0\u5728\u4e2d\u56fd\u5f53\u5730\u7684\u65f6\u95f4\u662f\u665a\u4e0a8\u70b9\u7684\u8bdd,\u6211\u4eec\u53ef\u4ee5\u6709\u4e0b\u9762\u4e24\u79cd\u8868\u793a\u65b9\u5f0f<\/p>\n<p>20:00 CST<\/p>\n<p>12:00 UTC<\/p>\n<p>\u8fd9\u91cc\u7684CST\u662fChinese Standard Time,\u4e5f\u5c31\u662f\u6211\u4eec\u901a\u5e38\u6240\u8bf4\u7684\u5317\u4eac\u65f6\u95f4\u4e86. \u56e0\u4e3a\u4e2d\u56fd\u5904\u5728UTC+8\u65f6\u533a<\/p>\n<p>\u5982\u679c\u65f6\u533a\u8bbe\u7f6e\u9519\u4e86\uff0c\u4f60\u770b\u5230\u7684\u65e5\u5fd7\u65f6\u95f4\u4e5f\u4e0d\u6b63\u786e\u4e86\u3002<\/p>\n<p>\u8865\u5145\uff1a<\/p>\n<p>CST\u540c\u65f6\u53ef\u4ee5\u4ee3\u8868\u5982\u4e0b 4 \u4e2a\u4e0d\u540c\u7684\u65f6\u533a\uff1a<\/p>\n<p>Central Standard Time (USA) UT-6:00<\/p>\n<p>Central Standard Time (Australia) UT+9:30<\/p>\n<p>China Standard Time UT+8:00<\/p>\n<p>Cuba Standard Time UT-4:00<\/p>\n<p>\u53ef\u89c1\uff0cCST\u53ef\u4ee5\u540c\u65f6\u8868\u793a\u7f8e\u56fd\uff0c\u6fb3\u5927\u5229\u4e9a\uff0c\u4e2d\u56fd\uff0c\u53e4\u5df4\u56db\u4e2a\u56fd\u5bb6\u7684\u6807\u51c6\u65f6\u95f4\u3002<\/p>\n<p>2\u3001ntp\u7684\u914d\u7f6e<\/p>\n<p>#cat \u00a0\/etc\/ntp.conf<\/p>\n<ul>\n<li>restrict\u00a0default\u00a0kod\u00a0nomodify\u00a0notrap\u00a0nopeer\u00a0noquery<\/li>\n<li>restrict\u00a0-6\u00a0default\u00a0kod\u00a0nomodify\u00a0notrap\u00a0nopeer\u00a0noquery<\/li>\n<li>restrict\u00a011.107.13.100\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\/\/\u5141\u8bb8\u8be5NTP\u670d\u52a1\u5668\u8fdb\u5165<\/li>\n<li>restrict\u00a011.80.81.1 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\/\/\u6ca1\u6709\u4efb\u4f55\u4f55\u53c3\u6578\u7684\u8a71\uff0c\u9019\u8868\u793a\u300e<span class=\"text_import2\">\u8be5IP\u6216\u7f51\u6bb5\u4e0d\u53d7\u4efb\u4f55\u9650\u5236<\/span>\u300f<\/li>\n<li>restrict\u00a0202.112.1.199<\/li>\n<li>restrict\u00a0127.0.0.1<\/li>\n<li>restrict\u00a0-6\u00a0::1<\/li>\n<li>restrict\u00a0192.168.0.0\u00a0mask\u00a0255.255.0.0\u00a0nomodify \u00a0\/\/\u8be5\u7f51\u6bb5\u53ef\u4ee5\u8fdb\u884c<span id=\"result_box\" lang=\"zh-cn\" xml:lang=\"zh-cn\">\u6821\u65f6<\/span><\/li>\n<li>restrict 0.0.0.0 mask 0.0.0.0 notrust \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \/\/<span lang=\"zh-cn\" xml:lang=\"zh-cn\">\u62d2\u7edd\u6ca1\u6709\u8ba4\u8bc1\u7684\u7528\u6237\u7aef<\/span><\/li>\n<li>server\u00a0time-nw.nist.gov\u00a0prefer \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\/\/prefer \u8be5\u670d\u52a1\u5668\u4f18\u5148<\/li>\n<li>server\u00a00.rhel.pool.ntp.org\u00a0 iburst \u00a0 \u00a0 \u00a0 \u00a0\/\/\u8bbe\u5b9a\u65f6\u95f4\u670d\u52a1\u5668<\/li>\n<li>server\u00a01.rhel.pool.ntp.org\u00a0 iburst<\/li>\n<li>server\u00a02.rhel.pool.ntp.org\u00a0 iburst<\/li>\n<li>fudge\u00a0 \u00a0127.127.1.0\u00a0stratum\u00a06<\/li>\n<li>driftfile\u00a0\/var\/lib\/ntp\/drift<\/li>\n<li>keys\u00a0\/etc\/ntp\/keys<\/li>\n<li>broadcastdelay 0.008<\/li>\n<\/ul>\n<p>\u4e0a\u8fb9\u53ea\u662f\u7b80\u5355\u8bbe\u7f6e\uff0c\u6ca1\u6709\u8003\u8651\u5b89\u5168\u65b9\u9762\u5982\u8ba4\u8bc1\u7b49\u7b49\u3002<\/p>\n<p>\u6743\u9650\u7ba1\u7406\u4f7f\u7528 restrict \u516c\u5f0f\u5982\u4e0b\uff1a<br \/>\n<strong>restrict IP mask [\u53c2\u6570]<\/strong>\u00a0\/\u00a0<strong>restrict 192.168.0.0 mask 255.255.0.0 nomodify<\/strong><\/p>\n<p><span lang=\"zh-cn\" xml:lang=\"zh-cn\">\u5176\u4e2d<\/span><span lang=\"zh-cn\" xml:lang=\"zh-cn\">\u53c2\u6570\u4e3b\u8981\u6709\u5e95\u4e0b\u8fd9\u4e9b\uff1a<\/p>\n<p>*\u00a0ignore\uff1a\u62d2\u7edd\u6240\u6709\u7c7b\u578b\u7684NTP\u7684\u8fde\u7ebf;<br \/>\n*\u00a0nomodfiy\uff1a\u7528\u6237\u7aef\u4e0d\u80fd\u4f7f\u7528NTPC\u4e0entpq\u8fd9\u4e24\u652f\u7a0b\u5f0f\u6765\u4fee\u6539\u4f3a\u670d\u5668\u7684\u65f6\u95f4\u53c2\u6570\uff0c\u4f46\u4f7f\u7528\u8005\u7aef\u4ecd\u53ef\u900f\u8fc7\u8fd9\u90e8\u4e3b\u673a\u6765\u8fdb\u884c\u7f51\u8def\u6821\u65f6\u7684;<br \/>\n*\u00a0<span class=\"hps\">noquery<\/span>\uff1a\u7528\u6237\u7aef\u4e0d\u80fd\u591f\u4f7f\u7528ntpq\uff0cNTPC\u7b49\u6307\u4ee4\u6765\u67e5\u8be2\u53d1\u8868\u4f3a\u670d\u5668\uff0c\u7b49\u4e8e\u4e0d\u63d0\u4f9b\u7684NTP\u7684\u7f51\u8def\u6821\u65f6\u5e42;<br \/>\n*\u00a0<span class=\"hps\">notrap<\/span>\uff1a\u4e0d\u63d0\u4f9b\u9677\u9631\u8fd9\u4e2a\u8fdc\u7aef\u4e8b\u4ef6\u90ae\u7bb1\uff08\u8fdc\u7a0b\u4e8b\u4ef6\u65e5\u5fd7\uff09\u7684\u529f\u80fd\u3002<br \/>\n*\u00a0<span class=\"hps\">notrust<\/span>\uff1a\u62d2\u7edd\u6ca1\u6709\u8ba4\u8bc1\u7684\u7528\u6237\u7aef\u3002<br \/>\n<\/span><\/p>\n<p><span lang=\"zh-cn\" xml:lang=\"zh-cn\">\u914d\u7f6e\u6587\u4ef6\u4e2d\u7684driftfile\u662f\u4ec0\u4e48?<br \/>\n\u6211\u4eec\u6bcf\u4e00\u4e2asystem clock\u7684\u9891\u7387\u90fd\u6709\u5c0f\u5c0f\u7684\u8bef\u5dee,\u8fd9\u4e2a\u5c31\u662f\u4e3a\u4ec0\u4e48\u673a\u5668\u8fd0\u884c\u4e00\u6bb5\u65f6\u95f4\u540e\u4f1a\u4e0d\u7cbe\u786e. NTP\u4f1a\u81ea\u52a8\u6765\u76d1\u6d4b\u6211\u4eec\u65f6\u949f\u7684\u8bef\u5dee\u503c\u5e76\u4e88\u4ee5\u8c03\u6574.\u4f46\u95ee\u9898\u662f\u8fd9\u662f\u4e00\u4e2a\u5197\u957f\u7684\u8fc7\u7a0b,\u6240\u4ee5\u5b83\u4f1a\u628a\u8bb0\u5f55\u4e0b\u6765\u7684\u8bef\u5dee\u5148\u5199\u5165driftfile.\u8fd9\u6837\u5373\u4f7f\u4f60\u91cd\u65b0\u5f00\u673a\u4ee5\u540e\u4e4b\u524d\u7684\u8ba1\u7b97\u7ed3\u679c\u4e5f\u5c31\u4e0d\u4f1a\u4e22\u5931\u4e86\u3002<\/span><\/p>\n<p><span lang=\"zh-cn\" xml:lang=\"zh-cn\">\u00a0<\/span><\/p>\n<p>\u6700\u540e\uff0c\u522b\u5fd8\u4e86\u542f\u52a8NTP\u670d\u52a1\u5668<\/p>\n<p>\/etc\/init.d\/ntp start<\/p>\n<p>[root@localhost ~]# chkconfig ntpd on #\u5728\u8fd0\u884c\u7ea7\u522b2\u30013\u30014\u30015\u4e0a\u8bbe\u7f6e\u4e3a\u81ea\u52a8\u8fd0\u884c<\/p>\n<p>[root@localhost ~]# chkconfig &#8211;list ntpd<\/p>\n<p>ntpd 0:off 1:off 2:on 3:on 4:on 5:on 6:off<\/p>\n<p>&nbsp;<\/p>\n<p><strong>\u67e5\u770bntp\u670d\u52a1\u5668\u6709\u65e0\u548c\u4e0a\u5c42ntp\u8fde\u901a<\/strong><\/p>\n<p>&nbsp;<\/p>\n<pre>[root@localhost\u00a0~]#\u00a0ntpstat<\/pre>\n<pre>synchronised\u00a0to\u00a0NTP\u00a0server\u00a0(192.168.7.49)\u00a0at\u00a0stratum\u00a06<\/pre>\n<pre>\u00a0 \u00a0time\u00a0correct\u00a0to\u00a0within\u00a0440\u00a0ms<\/pre>\n<pre>\u00a0 \u00a0polling\u00a0server\u00a0every\u00a0128\u00a0s<\/pre>\n<pre>[root@localhost\u00a0~]#<\/pre>\n<p><strong>\u67e5\u770bntp\u670d\u52a1\u5668\u4e0e\u4e0a\u5c42ntp\u7684\u72b6\u6001<\/strong><\/p>\n<pre>[root@localhost\u00a0~]#\u00a0watch\u00a0ntpq\u00a0-p<\/pre>\n<pre>\u00a0 \u00a0 \u00a0remote\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0refid\u00a0 \u00a0 \u00a0 st\u00a0t\u00a0when\u00a0poll\u00a0reach\u00a0 \u00a0delay\u00a0 \u00a0offset\u00a0 jitter<\/pre>\n<pre>==============================================================================<\/pre>\n<pre>\u00a0192.168.7.49\u00a0 \u00a0 192.168.7.50\u00a0 \u00a0 \u00a05\u00a0u\u00a0 \u00a013\u00a0 \u00a064\u00a0 \u00a0 3\u00a0 \u00a0 5.853\u00a0 1137178\u00a0 \u00a02.696<\/pre>\n<p>3\u3001ntpd\u7684\u914d\u7f6e<\/p>\n<p><strong>\u914d\u7f6e\/etc\/sysconfig\/ntpd\u6587\u4ef6<\/strong><\/p>\n<p>ntp\u670d\u52a1\uff0c\u9ed8\u8ba4\u53ea\u4f1a\u540c\u6b65\u7cfb\u7edf\u65f6\u95f4\u3002\u5982\u679c\u60f3\u8981\u8ba9ntp\u540c\u65f6\u540c\u6b65\u786c\u4ef6\u65f6\u95f4\uff0c\u53ef\u4ee5\u8bbe\u7f6e\/etc\/sysconfig\/ntpd\u6587\u4ef6\uff0c\u5728\/etc\/sysconfig\/ntpd\u6587\u4ef6\u4e2d\uff0c\u6dfb\u52a0 SYNC_HWCLOCK=yes \u8fd9\u6837\uff0c\u5c31\u53ef\u4ee5\u8ba9\u786c\u4ef6\u65f6\u95f4\u4e0e\u7cfb\u7edf\u65f6\u95f4\u4e00\u8d77\u540c\u6b65\u3002<\/p>\n<p>#\u5141\u8bb8BIOS\u4e0e\u7cfb\u7edf\u65f6\u95f4\u540c\u6b65\uff0c\u4e5f\u53ef\u4ee5\u901a\u8fc7hwclock -w \u547d\u4ee4<\/p>\n<p>SYNC_HWCLOCK=yes<\/p>\n<p># Drop root to id &#8216;ntp:ntp&#8217; by default.<\/p>\n<p>OPTIONS=&#8221;-x -u ntp:ntp -p \/var\/run\/ntpd.pid -g&#8221;<\/p>\n<p>\u6709\u65f6\u4f1a\u5728messages\u65e5\u5fd7\u91cc\u770b\u5230NTP\u8fdb\u7a0b\u6b63\u5728\u505aDELETING\u52a8\u4f5c\uff0c\u4e0d\u8fc7NTP\u8fdb\u7a0b\u5e76\u4e0d\u4f1a\u771f\u6b63\u5220\u9664\u865a\u62df\u7f51\u7edc\u63a5\u53e3\uff0c\u4f46\u8fd9\u4e2a\u52a8\u4f5c\u4f1a\u9020\u6210\u7f51\u7edc\u77ed\u6682\u4e0d\u901a\u3002\u7ea2\u5e3d\u5b98\u65b9\u6709\u4e2a\u5bf9\u5e94\u7684\u89e3\u51b3\u529e\u6cd5\u662f\uff1a<\/p>\n<p>\u5c31\u662f\u5728\u8fd9\u4e2a\u6587\u4ef6\u91cc\u589e\u52a0-L\u53c2\u6570\u3002<\/p>\n<p>\u8fd8\u6709-x\u548c-g\u53c2\u6570\uff1a<\/p>\n<p><span lang=\"en-us\" xml:lang=\"en-us\">ntpd<\/span>\u670d\u52a1\u7684\u65b9\u5f0f\uff0c\u53c8\u6709\u4e24\u79cd\u7b56\u7565\uff0c\u4e00\u79cd\u662f\u5e73\u6ed1\u3001\u7f13\u6162\u7684\u6e10\u8fdb\u5f0f\u8c03\u6574\uff08<span lang=\"en-us\" xml:lang=\"en-us\">adjusts the clock in small steps<\/span>\u6240\u8c13\u7684\u5fae\u8c03\uff09\uff1b\u4e00\u79cd\u662f\u6b65\u8fdb\u5f0f\u8c03\u6574\uff08\u8df3\u8dc3\u5f0f\u8c03\u6574\uff09\u3002\u4e24\u79cd\u7b56\u7565\u7684\u533a\u522b\u5c31\u5728\u4e8e\uff0c\u5fae\u8c03\u65b9\u5f0f\u5728\u542f\u52a8<span lang=\"en-us\" xml:lang=\"en-us\">NTP<\/span>\u670d\u52a1\u65f6\u52a0\u4e86\u4e2a\u201c<span lang=\"en-us\" xml:lang=\"en-us\">-x<\/span>\u201d\u7684\u53c2\u6570\uff0c\u800c\u9ed8\u8ba4\u7684\u662f\u4e0d\u52a0\u201c<span lang=\"en-us\" xml:lang=\"en-us\">-x<\/span>\u201d\u53c2\u6570\u3002<\/p>\n<p><span lang=\"en-us\" xml:lang=\"en-us\">\u00a0<\/span><\/p>\n<p>\u5047\u5982\u4f7f\u7528\u4e86<span lang=\"en-us\" xml:lang=\"en-us\">-x<\/span>\u9009\u9879\uff0c\u90a3\u4e48<span lang=\"en-us\" xml:lang=\"en-us\">ntpd<\/span>\u53ea\u505a\u5fae\u8c03\uff0c\u4e0d\u8df3\u8dc3\u8c03\u6574\u65f6\u95f4\uff0c\u4f46\u662f\u8981\u6ce8\u610f\uff0c<span lang=\"en-us\" xml:lang=\"en-us\">-x<\/span>\u53c2\u6570\u7684\u8d1f\u4f5c\u7528\uff1a\u5f53\u65f6\u949f\u5dee\u5927\u7684\u65f6\u5019\uff0c\u540c\u6b65\u65f6\u95f4\u5c06\u82b1\u8d39\u5f88\u957f\u7684\u65f6\u95f4\u3002<span lang=\"en-us\" xml:lang=\"en-us\">-x<\/span>\u4e5f\u6709\u4e00\u4e2a\u9608\u503c\uff0c\u5c31\u662f<span lang=\"en-us\" xml:lang=\"en-us\">600s<\/span>\uff0c\u5f53\u7cfb\u7edf\u65f6\u949f\u4e0e\u6807\u51c6\u65f6\u95f4\u5dee\u8ddd\u5927\u4e8e<span lang=\"en-us\" xml:lang=\"en-us\">600s<\/span>\u65f6\uff0c<span lang=\"en-us\" xml:lang=\"en-us\">ntpd<\/span>\u4f1a\u4f7f\u7528\u8f83\u5927<span lang=\"en-us\" xml:lang=\"en-us\">\u201c<\/span>\u6b65\u8fdb\u503c<span lang=\"en-us\" xml:lang=\"en-us\">\u201d<\/span>\u7684\u65b9\u5f0f\u6765\u8c03\u6574\u65f6\u95f4\uff0c\u5c06\u65f6\u949f<span lang=\"en-us\" xml:lang=\"en-us\">\u201c<\/span>\u6b65\u8fdb<span lang=\"en-us\" xml:lang=\"en-us\">\u201d<\/span>\u8c03\u6574\u5230\u6b63\u786e\u65f6\u95f4\u3002<\/p>\n<p><span lang=\"en-us\" xml:lang=\"en-us\">\u00a0<\/span><\/p>\n<p>\u5047\u5982\u4e0d\u4f7f\u7528<span lang=\"en-us\" xml:lang=\"en-us\">-x<\/span>\u9009\u9879\uff0c\u90a3\u4e48<span lang=\"en-us\" xml:lang=\"en-us\">ntpd<\/span>\u5728\u65f6\u949f\u5dee\u8ddd\u5c0f\u4e8e<span lang=\"en-us\" xml:lang=\"en-us\">128ms<\/span>\u65f6\uff0c\u4f7f\u7528\u5fae\u8c03\u65b9\u5f0f\u8c03\u6574\u65f6\u95f4\uff0c\u5f53\u65f6\u5dee\u5927\u4e8e<span lang=\"en-us\" xml:lang=\"en-us\">128ms<\/span>\u65f6\uff0c\u4f7f\u7528<span lang=\"en-us\" xml:lang=\"en-us\">\u201c<\/span>\u8df3\u8dc3<span lang=\"en-us\" xml:lang=\"en-us\">\u201d<\/span>\u5f0f\u8c03\u6574\u3002<\/p>\n<p><span lang=\"en-us\" xml:lang=\"en-us\">\u00a0<\/span><\/p>\n<p>\u8fd9\u4e24\u79cd\u65b9\u5f0f\u90fd\u4f1a\u5728\u672c\u5730\u65f6\u949f\u4e0e\u8fdc\u7aef\u7684NTP\u670d\u52a1\u5668\u65f6\u949f\u76f8\u5dee\u5927\u4e8e1000s\u65f6\uff0cntpd\u4f1a\u505c\u6b62\u5de5\u4f5c\u3002\u5728\u542f\u52a8NTP\u65f6\u52a0\u4e86\u53c2\u6570\u201c-g\u201d\u5c31\u53ef\u4ee5\u5ffd\u75651000S\u7684\u95ee\u9898\u3002<\/p>\n<p>4\u3001\u65f6\u95f4\u540c\u6b65<\/p>\n<p>\u5229\u7528crontab\u53ef\u4ee5\u8ba9LINUX NTP\u5b9a\u65f6\u66f4\u65b0\u65f6\u95f4<br \/>\n\u6ce8\uff1a\u8ba9linux\u8fd0\u884cntpdate\u66f4\u65b0\u65f6\u95f4\u65f6\uff0clinux\u4e0d\u80fd\u5f00\u542fNTP\u670d\u52a1\uff0c\u5426\u5219\u4f1a\u63d0\u793a\u7aef\u53e3\u88ab\u5360\u7528\uff1a\u5982\u4e0b<br \/>\n[root@ESXI ~]# ntpdate 1.rhel.pool.ntp.org<br \/>\n20 May 09:34:14 ntpdate[6747]: the NTP socket is in use, exiting<\/p>\n<p>\u5982\u679c\u60f3\u5b9a\u65f6\u8fdb\u884c\u65f6\u95f4\u6821\u51c6\uff0c\u53ef\u4ee5\u4f7f\u7528crond\u670d\u52a1\u6765\u5b9a\u65f6\u6267\u884c\u3002<br \/>\n\u7f16\u8f91 \/etc\/crontab \u6587\u4ef6<br \/>\n\u52a0\u5165\u4e0b\u9762\u4e00\u884c\uff1a<\/p>\n<p>30 8 * * * root \/usr\/sbin\/ntpdate 192.168.0.1; \/sbin\/hwclock -w \u00a0 \u00a0#192.168.0.1\u662fNTP\u670d\u52a1\u5668\u7684IP\u5730\u5740<br \/>\n\u7136\u540e\u91cd\u542fcrond\u670d\u52a1<br \/>\nservice crond restart<br \/>\n\u8fd9\u6837\uff0c\u6bcf\u5929 8:30 Linux \u7cfb\u7edf\u5c31\u4f1a\u81ea\u52a8\u7684\u8fdb\u884c\u7f51\u7edc\u65f6\u95f4\u6821\u51c6\u3002<\/p>\n<p>\u5982\u679c\u662fWINDOWS \uff0c\u5219\u9700\u8981\u6253\u5f00windows time\u670d\u52a1\u548cRPC\u7684\u4e8c\u4e2a\u670d\u52a1<br \/>\n\u5982\u679c\u5728\u6253\u5f00windows time \u670d\u52a1\uff0c\u65f6\u62a5 \u9519\u8bef1058\uff0c\u8fdb\u884c\u4e0b\u9762\u64cd\u4f5c<br \/>\n1.\u8fd0\u884c cmd \u8fdb\u5165\u547d\u4ee4\u884c\uff0c\u7136\u540e\u952e\u5165<br \/>\nw32tm \/register\u00a0 \u8fdb\u884c\u6ce8\u518c<br \/>\n\u6b63\u786e\u7684\u54cd\u5e94\u4e3a\uff1aW32Time \u6210\u529f\u6ce8\u518c\u3002<\/p>\n<p>2.\u5982\u679c\u4e0a\u4e00\u6b65\u6b63\u786e\uff0c\u7528 net start &#8220;windows time&#8221; \u6216 net start w32time \u542f\u52a8\u670d\u52a1\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>5\u3001Linux\u7684\u786c\u4ef6\u65f6\u95f4<\/p>\n<p>Linux\u786c\u4ef6\u65f6\u95f4\u7684\u8bbe\u7f6e<\/p>\n<p>\u786c\u4ef6\u65f6\u95f4\u7684\u8bbe\u7f6e\uff0c\u53ef\u4ee5\u7528hwclock\u6216\u8005clock\u547d\u4ee4\u3002\u5176\u4e2d\uff0cclock\u548chwclock\u7528\u6cd5\u76f8\u8fd1\uff0c\u53ea\u7528\u4e00\u4e2a\u5c31 \u884c\uff0c\u53ea\u4e0d\u8fc7clock\u547d\u4ee4\u9664\u4e86\u652f\u6301x86\u786c\u4ef6\u4f53\u7cfb\u5916\uff0c\u8fd8\u652f\u6301Alpha\u786c\u4ef6\u4f53\u7cfb\u3002<\/p>\n<p>\/\/\u67e5\u770b\u786c\u4ef6\u65f6\u95f4 \u53ef\u4ee5\u662f\u7528 hwclock \uff0chwclock &#8211;show \u6216\u8005 hwclock -r<\/p>\n<p>[root@localhost\u00a0~]# hwclock &#8211;show<br \/>\n2008\u5e7412\u670812\u65e5 \u661f\u671f\u4e94 06\u65f652\u520607\u79d2\u00a0 -0.376932 seconds<\/p>\n<p>\/\/\u8bbe\u7f6e\u786c\u4ef6\u65f6\u95f4<\/p>\n<p>[root@localhost\u00a0~]# hwclock &#8211;set &#8211;date=&#8221;1\/25\/09 00:00&#8243; &lt;== \u6708\/\u65e5\/\u5e74\u65f6:\u5206:\u79d2<br \/>\n[root@localhost\u00a0~]# hwclock<br \/>\n2009\u5e7401\u670825\u65e5 \u661f\u671f\u65e5 00\u65f600\u520606\u79d2\u00a0 -0.870868 seconds<\/p>\n<p>\u51e0\u4e2a\u53c2\u6570\u548c\u547d\u4ee4\uff1a<\/p>\n<p>ntpq -p\u663e\u793a\u7ed3\u679c\u4e2d\u7684offset<\/p>\n<p>\u672c\u5730\u65f6\u95f4+offset=\u8fdc\u7a0b\u65f6\u95f4, \u56e0\u6b64\u5982\u679coffset\u4e3a\u8d1f\u6570, \u5219\u672c\u5730\u65f6\u949f\u6bd4\u8fdc\u7a0b\u5feb. offset\u503c0-500\uff0c\u63a5\u8fd10\u662f\u6b63\u5e38\u7684\u3002<\/p>\n<p>\u8fd0\u884cntpq -c asso, \u5982\u679c\u663e\u793asys.peer\u5219\u5df2\u7ecf\u5904\u4e8e\u540c\u6b65\u72b6\u6001\u4e86.<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.linuxidc.com\/upload\/2017_03\/170306111436271.jpg\" alt=\"\" \/><\/p>\n<p>\u4f7f\u7528\u4ee5\u4e0b\u547d\u4ee4\u68c0\u67e5ntp\u7684\u7248\u672c\uff1a # ntpq -c version<\/p>\n<p><strong>\u9519\u8bef\u95ee\u9898\u5904\u7406<\/strong><\/p>\n<p>\u7528\u4e8e\u6536\u96c6\u5b89\u88c5\uff0c\u914d\u7f6e\u548c\u5e94\u7528\u4e2d\u51fa\u73b0\u7684\u95ee\u9898<\/p>\n<p><strong>\u9519\u8bef1\uff1antpdate -u ip -&gt; no server suitable for synchronization found<\/strong><\/p>\n<p>\u5224\u65ad\uff1a\u5728ntp\u5ba2\u6237\u7aef\u7528ntpdate \u2013d serverIP\u67e5\u770b\uff0c\u53d1\u73b0\u6709\u201cServer dropped: strata too high\u201d\u7684\u9519\u8bef\uff0c\u5e76\u4e14\u663e\u793a\u201cstratum 16\u201d\u3002\u800c\u6b63\u5e38\u60c5\u51b5\u4e0bstratum\u8fd9\u4e2a\u503c\u5f97\u8303\u56f4\u662f\u201c0~15\u201d\u3002<\/p>\n<p>\u539f\u56e0\uff1aNTP server\u8fd8\u6ca1\u6709\u548c\u5176\u81ea\u8eab\u6216\u8005\u5b83\u7684server\u540c\u6b65\u4e0a\u3002\u5728ntp server\u4e0a\u91cd\u65b0\u542f\u52a8ntp\u670d\u52a1\u540e\uff0cntp server\u81ea\u8eab\u6216\u8005\u4e0e\u5176server\u7684\u540c\u6b65\u7684\u9700\u8981\u4e00\u4e2a\u65f6\u95f4\u6bb5\uff0c\u8fd9\u4e2a\u8fc7\u7a0b\u53ef\u80fd\u662f5\u5206\u949f\uff0c\u5728\u8fd9\u4e2a\u65f6\u95f4\u4e4b\u5185\u5728\u5ba2\u6237\u7aef\u8fd0\u884cntpdate\u547d\u4ee4\u65f6\u4f1a\u4ea7\u751fno server suitable for synchronization found\u7684\u9519\u8bef\u3002<\/p>\n<p>\u5904\u7406\uff1a\u7b49\u5f85\u51e0\u5206\u949f\u540e\uff0c\u91cd\u8bd5\u4e00\u822c\u89e3\u51b3\u3002<\/p>\n<p>\u5176\u5b83\u9020\u6210\u65e0\u6cd5\u6210\u529f\u66f4\u65b0\u7684\u539f\u56e0\uff1a<br \/>\n1\u3001\u5ba2\u6237\u7aef\u7684\u65e5\u671f\u5fc5\u987b\u8981\u8bbe\u7f6e\u6b63\u786e\uff0c\u4e0d\u80fd\u8d85\u51fa\u6b63\u5e38\u65f6\u95f424\u5c0f\u65f6\uff0c\u4e0d\u7136\u4f1a\u56e0\u4e3a\u5b89\u5168\u539f\u56e0\u88ab\u62d2\u7edd\u66f4\u65b0\u3002\u5176\u6b21\u5ba2\u6237\u7aef\u7684\u65f6\u533a\u5fc5\u987b\u8981\u8bbe\u7f6e\u597d\uff0c\u4ee5\u786e\u4fdd\u4e0d\u4f1a\u66f4\u65b0\u6210\u5176\u5b83\u65f6\u533a\u7684\u65f6\u95f4\u3002<br \/>\n2\u3001fudge 127.127.1.0 stratum 10 \u5982\u679c\u662fLINUX\u505a\u4e3aNTP\u670d\u52a1\u5668\uff0cstratum(\u5c42\u7ea7)\u7684\u503c\u4e0d\u80fd\u592a\u5927\uff0c\u5982\u679c\u8981\u5411\u4e0a\u7ea7NTP\u66f4\u65b0\u53ef\u4ee5\u8bbe\u62102<br \/>\n3\u3001LINUX\u7684NTP\u670d\u52a1\u5668\u5fc5\u987b\u8bb0\u5f97\u5c06\u4ece\u4e0a\u7ea7NTP\u66f4\u65b0\u7684\u65f6\u95f4\u4ece\u7cfb\u7edf\u65f6\u95f4\u5199\u5230\u786c\u4ef6\u91cc\u53bb hwclock &#8211;systohc<br \/>\nNTP\u4e00\u822c\u53ea\u4f1a\u540c\u6b65system clock. \u4f46\u662f\u5982\u679c\u6211\u4eec\u4e5f\u8981\u540c\u6b65RTC(hwclock)\u7684\u8bdd\u90a3\u4e48\u53ea\u9700\u8981\u628a\u4e0b\u9762\u7684\u9009\u9879\u6253\u5f00\u5c31\u53ef\u4ee5\u4e86<br \/>\n\u4ee3\u7801:<br \/>\n# vi \/etc\/sysconfig\/ntpd<br \/>\nSYNC_HWCLOCK=yes<br \/>\n4\u3001Linux\u5982\u679c\u5f00\u542f\u4e86NTP\u670d\u52a1\uff0c\u5219\u4e0d\u80fd\u624b\u52a8\u8fd0\u884cntpdate\u66f4\u65b0\u65f6\u95f4\uff08\u4f1a\u62a5\u7aef\u53e3\u88ab\u5360\u7528\uff09\uff0c\u5b83\u53ea\u80fd\u6839\u636e\/etc\/ntp.conf \u91ccserver \u5b57\u6bb5\u540e\u7684\u670d\u52a1\u5668\u5730\u5740\u6309\u4e00\u5b9a\u65f6\u95f4\u95f4\u9694\u81ea\u52a8\u5411\u4e0a\u7ea7NTP\u670d\u52a1\u5668\u66f4\u65b0\u65f6\u95f4\u3002\u53ef\u4ee5\u8fd0\u884c\u547d\u4ee4 ntpstat \u67e5\u770b\u6bcf\u6b21\u66f4\u65b0\u95f4\u9694\u5982\uff1a<br \/>\n[root@ESXI ~]# ntpstat<br \/>\nsynchronised to NTP server (210.72.145.44) at stratum 2\u00a0 \u00a0 #\u672cNTP\u670d\u52a1\u5668\u5c42\u6b21\u4e3a2\uff0c\u5df2\u5411210.72.145.44 NTP\u540c\u6b65\u8fc7<br \/>\ntime correct to within 93 ms\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0#\u65f6\u95f4\u6821\u6b63\u5230\u76f8\u5dee93ms\u4e4b\u5185<br \/>\npolling server every 1024 s\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 #\u6bcf1024\u79d2\u4f1a\u5411\u4e0a\u7ea7NTP\u8f6e\u8be2\u66f4\u65b0\u4e00\u6b21\u65f6\u95f4<\/p>\n<p>\u8865\u5145\uff1a<\/p>\n<p>ntpd\u3001ntpdate\u7684\u533a\u522b<\/p>\n<p>\u4e0b\u9762\u662f\u7f51\u4e0a\u5173\u4e8entpd\u4e0entpdate\u533a\u522b\u7684\u76f8\u5173\u8d44\u6599\u3002\u5982\u4e0b\u6240\u793a\u6240\u793a\uff1a<\/p>\n<p>\u4f7f\u7528\u4e4b\u524d\u5f97\u5f04\u6e05\u695a\u4e00\u4e2a\u95ee\u9898\uff0cntpd\u4e0entpdate\u5728\u66f4\u65b0\u65f6\u95f4\u65f6\u6709\u4ec0\u4e48\u533a\u522b\u3002ntpd\u4e0d\u4ec5\u4ec5\u662f\u65f6\u95f4\u540c\u6b65\u670d\u52a1\u5668\uff0c\u5b83\u8fd8\u53ef\u4ee5\u505a\u5ba2\u6237\u7aef\u4e0e\u6807\u51c6\u65f6\u95f4\u670d\u52a1\u5668\u8fdb\u884c\u540c\u6b65\u65f6\u95f4\uff0c\u800c\u4e14\u662f\u5e73\u6ed1\u540c\u6b65\uff0c\u5e76\u975entpdate\u7acb\u5373\u540c\u6b65\uff0c\u5728\u751f\u4ea7\u73af\u5883\u4e2d\u614e\u7528ntpdate\uff0c\u4e5f\u6b63\u5982\u6b64\u4e24\u8005\u4e0d\u53ef\u540c\u65f6\u8fd0\u884c\u3002<\/p>\n<p>\u65f6\u949f\u7684\u8dc3\u53d8\uff0c\u5bf9\u4e8e\u67d0\u4e9b\u7a0b\u5e8f\u4f1a\u5bfc\u81f4\u5f88\u4e25\u91cd\u7684\u95ee\u9898\u3002\u8bb8\u591a\u5e94\u7528\u7a0b\u5e8f\u4f9d\u8d56\u8fde\u7eed\u7684\u65f6\u949f\u2014\u2014\u6bd5\u7adf\uff0c\u8fd9\u662f\u4e00\u9879\u5e38\u89c1\u7684\u5047\u5b9a\uff0c\u5373\uff0c\u53d6\u5f97\u7684\u65f6\u95f4\u662f\u7ebf\u6027\u7684\uff0c\u4e00\u4e9b\u64cd\u4f5c\uff0c\u4f8b\u5982\u6570\u636e\u5e93\u4e8b\u52a1\uff0c\u901a\u5e38\u4f1a\u5730\u4f9d\u8d56\u8fd9\u6837\u7684\u4e8b\u5b9e\uff1a\u65f6\u95f4\u4e0d\u4f1a\u5f80\u56de\u8df3\u8dc3\u3002\u4e0d\u5e78\u7684\u662f\uff0cntpdate\u8c03\u6574\u65f6\u95f4\u7684\u65b9\u5f0f\u5c31\u662f\u6211\u4eec\u6240\u8bf4\u7684\u201d\u8dc3\u53d8\u201c\uff1a\u5728\u83b7\u5f97\u4e00\u4e2a\u65f6\u95f4\u4e4b\u540e\uff0cntpdate\u4f7f\u7528settimeofday(2)\u8bbe\u7f6e\u7cfb\u7edf\u65f6\u95f4\uff0c\u8fd9\u6709\u51e0\u4e2a\u975e\u5e38\u660e\u663e\u7684\u95ee\u9898\uff1a<\/p>\n<p>\u7b2c\u4e00\uff0c\u8fd9\u6837\u505a\u4e0d\u5b89\u5168\u3002ntpdate\u7684\u8bbe\u7f6e\u4f9d\u8d56\u4e8entp\u670d\u52a1\u5668\u7684\u5b89\u5168\u6027\uff0c\u653b\u51fb\u8005\u53ef\u4ee5\u5229\u7528\u4e00\u4e9b\u8f6f\u4ef6\u8bbe\u8ba1\u4e0a\u7684\u7f3a\u9677\uff0c\u62ff\u4e0bntp\u670d\u52a1\u5668\u5e76\u4ee4\u4e0e\u5176\u540c\u6b65\u7684\u670d\u52a1\u5668\u6267\u884c\u67d0\u4e9b\u6d88\u8017\u6027\u7684\u4efb\u52a1\u3002\u7531\u4e8entpdate\u91c7\u7528\u7684\u65b9\u5f0f\u662f\u8df3\u53d8\uff0c\u8ddf\u968f\u5b83\u7684\u670d\u52a1\u5668\u65e0\u6cd5\u77e5\u9053\u662f\u5426\u53d1\u751f\u4e86\u5f02\u5e38\uff08\u65f6\u95f4\u4e0d\u4e00\u6837\u7684\u65f6\u5019\uff0c\u552f\u4e00\u7684\u529e\u6cd5\u662f\u4ee5\u670d\u52a1\u5668\u4e3a\u51c6\uff09\u3002<\/p>\n<p>\u7b2c\u4e8c\uff0c\u8fd9\u6837\u505a\u4e0d\u7cbe\u786e\u3002\u4e00\u65e6ntp\u670d\u52a1\u5668\u5b95\u673a\uff0c\u8ddf\u968f\u5b83\u7684\u670d\u52a1\u5668\u4e5f\u5c31\u4f1a\u65e0\u6cd5\u540c\u6b65\u65f6\u95f4\u3002\u4e0e\u6b64\u4e0d\u540c\uff0cntpd\u4e0d\u4ec5\u80fd\u591f\u6821\u51c6\u8ba1\u7b97\u673a\u7684\u65f6\u95f4\uff0c\u800c\u4e14\u80fd\u591f\u6821\u51c6\u8ba1\u7b97\u673a\u7684\u65f6\u949f\u3002<\/p>\n<p>\u7b2c\u4e09\uff0c\u8fd9\u6837\u505a\u4e0d\u591f\u4f18\u96c5\u3002\u7531\u4e8e\u662f\u8df3\u53d8\uff0c\u800c\u4e0d\u662f\u4f7f\u65f6\u95f4\u53d8\u5feb\u6216\u53d8\u6162\uff0c\u4f9d\u8d56\u65f6\u5e8f\u7684\u7a0b\u5e8f\u4f1a\u51fa\u9519\uff08\u4f8b\u5982\uff0c\u5982\u679cntpdate\u53d1\u73b0\u4f60\u7684\u65f6\u95f4\u5feb\u4e86\uff0c\u5219\u53ef\u80fd\u4f1a\u7ecf\u5386\u4e24\u4e2a\u76f8\u540c\u7684\u65f6\u523b\uff0c\u5bf9\u67d0\u4e9b\u5e94\u7528\u800c\u8a00\uff0c\u8fd9\u662f\u81f4\u547d\u7684\uff09\u3002\u56e0\u800c\uff0c\u552f\u4e00\u4e00\u4e2a\u53ef\u4ee5\u4ee4\u65f6\u95f4\u53d1\u751f\u8df3\u53d8\u7684\u70b9\uff0c\u662f\u8ba1\u7b97\u673a\u521a\u521a\u542f\u52a8\uff0c\u4f46\u8fd8\u6ca1\u6709\u542f\u52a8\u5f88\u591a\u670d\u52a1\u7684\u90a3\u4e2a\u65f6\u5019\u3002\u5176\u4f59\u7684\u65f6\u5019\uff0c\u7406\u60f3\u7684\u505a\u6cd5\u662f\u4f7f\u7528ntpd\u6765\u6821\u51c6\u65f6\u949f\uff0c\u800c\u4e0d\u662f\u8c03\u6574\u8ba1\u7b97\u673a\u65f6\u949f\u4e0a\u7684\u65f6\u95f4\u3002<\/p>\n<p>NTPD \u5728\u548c\u65f6\u95f4\u670d\u52a1\u5668\u7684\u540c\u6b65\u8fc7\u7a0b\u4e2d\uff0c\u4f1a\u628a BIOS \u8ba1\u65f6\u5668\u7684\u632f\u8361\u9891\u7387\u504f\u5dee\u2014\u2014\u6216\u8005\u8bf4 Local Clock \u7684\u81ea\u7136\u6f02\u79fb(drift)\u2014\u2014\u8bb0\u5f55\u4e0b\u6765\u3002\u8fd9\u6837\u5373\u4f7f\u7f51\u7edc\u6709\u95ee\u9898\uff0c\u672c\u673a\u4ecd\u7136\u80fd\u7ef4\u6301\u4e00\u4e2a\u76f8\u5f53\u7cbe\u786e\u7684\u8d70\u65f6\u3002<\/p>\n<p>ntpq \u2013p \u53c2\u6570\u8be6\u89e3<\/p>\n<p>ntpq -p<\/p>\n<p>remote\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0refid\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0st\u00a0 \u00a0 \u00a0t when\u00a0 poll\u00a0 reach\u00a0 \u00a0 \u00a0delay\u00a0 \u00a0 \u00a0offset\u00a0 \u00a0 \u00a0jitter<\/p>\n<p>==================================================================<\/p>\n<p>*10.247.160.31 10.240.241.5\u00a0 \u00a0 \u00a04\u00a0 \u00a0 \u00a0u 53\u00a0 \u00a0 \u00a0 64\u00a0 \u00a0377\u00a0 \u00a0 \u00a00.240\u00a0 \u00a0 \u00a00.374\u00a0 \u00a0 \u00a00.240<\/p>\n<p>remote\uff1a\u54cd\u5e94\u8fd9\u4e2a\u8bf7\u6c42\u7684NTP\u670d\u52a1\u5668\u7684\u540d\u79f0\u3002<\/p>\n<p>refid\uff1aNTP\u670d\u52a1\u5668\u4f7f\u7528\u7684\u4e0a\u4e00\u7ea7ntp\u670d\u52a1\u5668\u3002<\/p>\n<p>st \uff1aremote\u8fdc\u7a0b\u670d\u52a1\u5668\u7684\u7ea7\u522b.\u7531\u4e8eNTP\u662f\u5c42\u578b\u7ed3\u6784,\u6709\u9876\u7aef\u7684\u670d\u52a1\u5668,\u591a\u5c42\u7684Relay Server\u518d\u5230\u5ba2\u6237\u7aef.\u6240\u4ee5\u670d\u52a1\u5668\u4ece\u9ad8\u5230\u4f4e\u7ea7\u522b\u53ef\u4ee5\u8bbe\u5b9a\u4e3a1-16.\u4e3a\u4e86\u51cf\u7f13\u8d1f\u8377\u548c\u7f51\u7edc\u5835\u585e,\u539f\u5219\u4e0a\u5e94\u8be5\u907f\u514d\u76f4\u63a5\u8fde\u63a5\u5230\u7ea7\u522b\u4e3a1\u7684\u670d\u52a1\u5668\u7684.<\/p>\n<p>when: \u4e0a\u4e00\u6b21\u6210\u529f\u8bf7\u6c42\u4e4b\u540e\u5230\u73b0\u5728\u7684\u79d2\u6570\u3002<\/p>\n<p>poll : \u672c\u5730\u673a\u548c\u8fdc\u7a0b\u670d\u52a1\u5668\u591a\u5c11\u65f6\u95f4\u8fdb\u884c\u4e00\u6b21\u540c\u6b65(\u5355\u4f4d\u4e3a\u79d2).\u5728\u4e00\u5f00\u59cb\u8fd0\u884cNTP\u7684\u65f6\u5019\u8fd9\u4e2apoll\u503c\u4f1a\u6bd4\u8f83\u5c0f,\u90a3\u6837\u548c\u670d\u52a1\u5668\u540c\u6b65\u7684\u9891\u7387\u4e5f\u5c31\u589e\u52a0\u4e86,\u53ef\u4ee5\u5c3d\u5feb\u8c03\u6574\u5230\u6b63\u786e\u7684\u65f6\u95f4\u8303\u56f4\uff0c\u4e4b\u540epoll\u503c\u4f1a\u9010\u6e10\u589e\u5927,\u540c\u6b65\u7684\u9891\u7387\u4e5f\u5c31\u4f1a\u76f8\u5e94\u51cf\u5c0f<\/p>\n<p>reach:\u8fd9\u662f\u4e00\u4e2a\u516b\u8fdb\u5236\u503c,\u7528\u6765\u6d4b\u8bd5\u80fd\u5426\u548c\u670d\u52a1\u5668\u8fde\u63a5.\u6bcf\u6210\u529f\u8fde\u63a5\u4e00\u6b21\u5b83\u7684\u503c\u5c31\u4f1a\u589e\u52a0<\/p>\n<p>delay:\u4ece\u672c\u5730\u673a\u53d1\u9001\u540c\u6b65\u8981\u6c42\u5230ntp\u670d\u52a1\u5668\u7684round trip time<\/p>\n<p>offset\uff1a\u4e3b\u673a\u901a\u8fc7NTP\u65f6\u949f\u540c\u6b65\u4e0e\u6240\u540c\u6b65\u65f6\u95f4\u6e90\u7684\u65f6\u95f4\u504f\u79fb\u91cf\uff0c\u5355\u4f4d\u4e3a\u6beb\u79d2\uff08ms\uff09\u3002offset\u8d8a\u63a5\u8fd1\u4e8e0,\u4e3b\u673a\u548cntp\u670d\u52a1\u5668\u7684\u65f6\u95f4\u8d8a\u63a5\u8fd1<\/p>\n<p>jitter:\u8fd9\u662f\u4e00\u4e2a\u7528\u6765\u505a\u7edf\u8ba1\u7684\u503c.\u5b83\u7edf\u8ba1\u4e86\u5728\u7279\u5b9a\u4e2a\u8fde\u7eed\u7684\u8fde\u63a5\u6570\u91ccoffset\u7684\u5206\u5e03\u60c5\u51b5.\u7b80\u5355\u5730\u8bf4\u8fd9\u4e2a\u6570\u503c\u7684\u7edd\u5bf9\u503c\u8d8a\u5c0f\uff0c\u4e3b\u673a\u7684\u65f6\u95f4\u5c31\u8d8a\u7cbe\u786e<\/p>\n<p><strong>\u672c\u6587\u6c38\u4e45\u66f4\u65b0\u94fe\u63a5\u5730\u5740<\/strong>\uff1a<a href=\"https:\/\/www.linuxidc.com\/Linux\/2017-03\/141435.htm\">https:\/\/www.linuxidc.com\/Linux\/2017-03\/141435.htm<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728Linux\u7cfb\u7edf\u91cc\u8bbe\u7f6eNTP\u670d\u52a1\u5e76\u4e0d\u96be\uff0c\u4f46\u662fNTP\u672c\u8eab\u786e\u662f\u4e00\u4e2a\u5f88\u590d\u6742\u7684\u534f\u8bae. \u4f60\u90fd\u4e86\u89e3\u7ec6\u8282\u4e48\uff1f 1. \u65f6\u95f4\u548c\u65f6 &#8230; <a title=\"Linux\u7cfb\u7edfNTP\u670d\u52a1\u7ec6\u8282\u8be6\u8ff0\" class=\"read-more\" href=\"https:\/\/cn.hostease.com\/xueyuan\/jishu\/linux%e7%b3%bb%e7%bb%9fntp%e6%9c%8d%e5%8a%a1%e7%bb%86%e8%8a%82%e8%af%a6%e8%bf%b0\/\" aria-label=\"\u9605\u8bfb Linux\u7cfb\u7edfNTP\u670d\u52a1\u7ec6\u8282\u8be6\u8ff0\">\u9605\u8bfb\u66f4\u591a<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[49,5],"tags":[442],"class_list":["post-1919","post","type-post","status-publish","format-standard","hentry","category-linux","category-jishu","tag-ntp"],"aioseo_notices":[],"jetpack_featured_media_url":"","jetpack-related-posts":[],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/posts\/1919","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/comments?post=1919"}],"version-history":[{"count":1,"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/posts\/1919\/revisions"}],"predecessor-version":[{"id":1920,"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/posts\/1919\/revisions\/1920"}],"wp:attachment":[{"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/media?parent=1919"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/categories?post=1919"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cn.hostease.com\/xueyuan\/wp-json\/wp\/v2\/tags?post=1919"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}