[ntp:questions] Synchronizing using servers in stratum 1 and 2

David Woolley david at djwhome.demon.co.uk
Sun Feb 11 17:57:53 UTC 2007

In article <45cf33d4$0$321$e4fe514c at news.xs4all.nl>,
Timo Ruiter <timo.ruiter at xs4all.nl> wrote:

> When you are assigned *one* stratum-1 server and *two* stratum-2 servers 
> your clock will obviously synchronize to the stratum-1 server. But that 

It will synchronize to a mixture of the times from all three servers, but
weighted in favour of the stratum 1 one, I believe.  Although it only
reports one server as reference source, it actually makes use of timing
information from several of them.

> being the case, what is the use of the two stratum-2 servers, assuming 
> that the stratum-1 server will not go off-line?

They can outvote the stratum one server if it is giving the wrong time.
Note that some people reckon that you need four servers for this to
work reliably.

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