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Re: Need trusted NTP Sources
From: Jay Ashworth <jra () baylink com>
Date: Sun, 9 Feb 2014 15:16:25 -0500 (EST)

----- Original Message -----
From: "Saku Ytti" <saku () ytti fi>

In the architecture I described, though, is it really true that the
odds of the common types of failure are higher than with only one?

I think so, lets assume arbitrarily that probability of NTP server not
starting to give incorrect time is 99% over 1 year time.
Then either of two servers not giving incorrect time is 0.99**2 i.e. 98%, so
two NTP servers would be 1% point more likely to give incorrect time than one
over 1 year time.

That's only true if the two devices have common failure modes, though,
is it not?
Jay R. Ashworth                  Baylink                       jra () baylink com
Designer                     The Things I Think                       RFC 2100
Ashworth & Associates       http://www.bcp38.info          2000 Land Rover DII
St Petersburg FL USA      BCP38: Ask For It By Name!           +1 727 647 1274

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