Troubleshoot ntp issues

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Home > CentOS > CentOS 6.x > Time server configuration > Troubleshoot ntp issues

ntpd process dies on VMs

ntpd process will die on VM if VM is suspended and later resumed. This will cause serious problems as VM will not realize it was suspended and the time would be wrong. Thus ensuring VMs have correct time after they are resumed requires special setup. One simple option is to create a executable shell script which restarts ntpd and put it in /etc/cron.hourly to be run every hour. This way in the worst case within an hour after resuming ntpd will start again and start correcting the clock.


stratum always 16, no suitable server found

This happens when ISP or local machine firewall blocks ntp (UDP port 1230). The only solution is to add exception for the port in local firewall or ask ISP to allow the port. Other option is to try and use other ISP for ntp time synchronization.



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