[ntp:questions] prefer keyword and server failover

Danny Mayer mayer at ntp.isc.org
Mon Apr 28 02:57:28 UTC 2008

David Woolley wrote:
> Richard B. Gilbert wrote:
>> Sort of!  Two servers is generally a poor choice.  If they differ, as 
>> they inevitably will, which one should you believe?  'Prefer' will tell 
> If they differ enough for voting to apply, both will be rejected.  If 
> they are mutually true chimers and you don't use prefer, ntpd will use a 
> combination of the time from both of them.

No, it will choose one and use it until it decides that it is worse than 
another one or they are all declared bad. It never combines both. The 
real problem here is that it has no idea whether or not one is better 
than the other when you only have two of them.


>> your client which one to believe but with a couple more servers ntpd 
>> should be able to figure out which one is closest to being correct!

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