我们在其中一个系统上配置了NTP客户端。 客户端有一组可与之同步的服务器。
但是,我们选择的首选服务器是内部主服务器,IP 169.254.1.51。
ntp.conf的内容如下: -
# --- CLIENT NETWORK ------- # --- USER SETTINGS BEGIN --- server 10.241.34.2 iburst server 10.241.34.3 iburst server 10.241.34.4 iburst restrict 10.241.34.2 mask 255.255.255.255 nomodify notrap noquery restrict 10.241.34.3 mask 255.255.255.255 nomodify notrap noquery restrict 10.241.34.4 mask 255.255.255.255 nomodify notrap noquery # --- USER SETTINGS END --- # --- NTP MULTICASTCLIENT --- restrict 169.254.0.0 mask 255.255.0.0 nomodify notrap # internal network # --- INTERNAL TIMESERVERS BEGIN----- server 169.254.1.51 burst iburst minpoll 4 maxpoll 6 prefer #Internal master Server # --- GENERAL CONFIGURATION --- server 127.127.1.0 iburst minpoll 4 # local clock fudge 127.127.1.0 stratum 10 tinker step 0
以上是配置部分。 但是,当我们在配置并重新启动系统后检查syslog时,我们发现客户端正在与外部服务器同步而不是在syslog中的ntpq输出中捕获的prefer服务器
Mar 22 05:52:48 Node ntpcheck: remote refid st t when poll reach delay offset jitter Mar 22 05:52:48 Node ntpcheck: ============================================================================== Mar 22 05:52:48 Node ntpcheck: *10.241.34.2 10.240.33.1 4 u 2 64 1 0.192 -519.50 5.769 Mar 22 05:52:48 Node ntpcheck: 10.241.34.3 10.241.34.2 5 u 1 64 1 0.172 -523.79 8.912 Mar 22 05:52:48 Node ntpcheck: 10.241.34.4 10.241.34.2 5 u 2 64 1 0.207 -520.73 8.082 Mar 22 05:52:48 Node ntpcheck: 169.254.1.51 LOCAL(0) 11 u 1 16 1 0.113 -0.043 2.099 Mar 22 05:52:48 Node ntpcheck: 127.127.1.0 .LOCL. 10 l 14 16 1 0.000 0.000 0.001}
此外,以下消息消息在syslog中持续泛滥
Mar 22 06:51:11 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:51:27 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:51:45 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:52:03 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:52:20 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:52:35 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:52:51 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:53:06 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:53:20 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:53:23 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:53:38 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:53:53 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:54:11 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:54:29 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:54:47 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:55:02 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:55:20 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:55:21 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:55:35 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:55:53 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:56:10 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:56:28 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:56:46 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:57:03 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:57:21 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:57:38 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:57:54 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:58:09 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:58:24 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:58:42 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:58:59 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:59:15 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 06:59:30 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 06:59:46 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4 Mar 22 07:00:02 Node ntpd[31292]: synchronized to LOCAL(0), stratum 10 Mar 22 07:00:17 Node ntpd[31292]: synchronized to 10.241.34.2, stratum 4
我们尝试检查NTP论坛,并确定它在定义要与之同步的服务器时使用以下参数 (参考: - https://www.eecis.udel.edu/~mills/ntp/html/warp.html): -
然而,在ntpq输出中,prefer服务器具有更好的偏移和抖动,即使它没有被选中。
在这种情况下,是否有可能确定拒绝首选服务器的依据。