[ntp:questions] Keeping NTP Honest

Unruh unruh-spam at physics.ubc.ca
Fri Jul 10 19:40:18 UTC 2009

Evandro Menezes <evandro at mailinator.com> writes:

>As I mentioned before, in some cases, NTP relies too much on low-
>stratum servers, even when they're blatantly wrong.  For instance, the
>last leap second event, when many pool servers were poorly configured.

>Mulling over that, I wondered how I could tip NTP to scale down the
>poll period in such cases.  So I tried this trick and it seems to work
>fairly well when only one server is kaput:

>server   pool.ntp.org iburst maxpoll 6
>server 0.pool.ntp.org
>server 1.pool.ntp.org
>server 2.pool.ntp.org
>server 3.pool.ntp.org

>By having one server that remains polled every 64s, NTP could realize
>more quickly that there was something rotten in Denmark.  However, if
>that one server is neither selected nor a candidate, this trick
>doesn't work.  I'd hesitate to make it the preferred server though.

And you have at least a 1/5 chance that IT is the bad server. What do
you do then?



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