[ntp:questions] prefer keyword and server failover

David Woolley david at ex.djwhome.demon.co.uk.invalid
Sun Apr 27 10:45:56 UTC 2008

Andrew Stone wrote:
> I would like to configure my ntp client to use 2 servers only. I want
+ it to receive updates from only one of them, but then use the other when
+ that one fails. What is the best way to do this? Will setting the
+ primary server to use the 'prefer' keyword work?

I'm not 100% sure, but I think that the two clocks need to be mutually 
truechimers, otherwise both may get rejected, as prefer only seems to be 
applied after the falsetickers are excluded.

That *shouldn't* be a problem, but then your requirement shouldn't be 
needed, either, so I wonder if one or both of the time sources isn't a 

Knowing what is wrong with the second time source would help people to 
make sensible suggestions.

Note that, in normal configurations, ntpd uses a weighted average of 
several truechimers, certainly at least two of them.

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