[ntp:questions] Number of servers needed to detect one falseticker?

Miroslav Lichvar mlichvar at redhat.com
Tue Jan 4 18:44:20 UTC 2011


I'm wondering about the section 5.3.3 on the ntp support web


It says and explains that minimum number of servers to detect one
falseticker is four, is that really correct? I understand that four is
better for reliability, but from the algorithm description
(http://www.eecis.udel.edu/~mills/ntp/html/select.html) and my tests
with a simulated falseticker it seems that three is enough.

Also, while running with two servers might be the worst configuration
for ntpd, it still could be prefered over the configuration with only
one server by users who would rather have two sources marked as
falsetickers and know a problem needs to be fixed than unknowingly
follow a bad truechimer.

Is it possible to reword that section?


Miroslav Lichvar

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