[ntp:questions] Stick to PPS, even if the prefer server fails

David Mills mills at udel.edu
Sun Mar 29 17:09:53 UTC 2009


That's not the point. No matter how much you trust the Cs, do you trust 
the seconds numbering? Say you reliably number the seconds and then 
disconnect the numbering source. Obviously, you have to reestablish 
nunmbering every time you reboot. Would you require renumbering when the 
daemon is restarted? Do you assume nothing happens that might torque the 
clock to another second, such as a stuck interrupt, or any hardware 
disruption. How long are you willing to wait before requiring 
renumbering? A day, a week, forever?

There is a really simple thing to do exactly as you wish. Use the 
configuration I recommended and enable orphan mode. This works only if 
the kernel PPS is operating.


alkopedia at googlemail.com wrote:

>On Mar 29, 5:12 am, mi... at udel.edu (David Mills) wrote:
>>The intended design to detect and suppress bad reference/PPS clocks is
>>at least two additional sources, that do not have to be reference
>>clocks. If the reference/PPS clock sails to the sunset, the selection
>>algorithm will vote it off and the PPS will follow.
>In my case I would trust my PPS signal much more than any other
>source. Why should I run a caesium frequency normal and not trust it?
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>questions at lists.ntp.org

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