[ntp:questions] Syncing and peering for a multi-continent deployment
david-taylor at blueyonder.co.uk.invalid
Wed Apr 17 04:16:57 UTC 2013
On 10/04/2013 03:07, Blair Zajac wrote:
> Thanks Charles,
> OK. So unless I go for some GPS-based clocks in my servers, each data
> center will use close stratum-2 servers and the stratum-3 clocks will
> not peer with clocks in my other datacenters.
> Regarding peering, then should each stratum-3 server in a single data
> center use all 4-7 upstream clocks? Or should the 4-7 be split between
> the three stratum-3 servers? The diagram at  suggests they should be
> split? If that's the case, then how are falsetickers identified?
>  http://www.ntp.org/ntpfaq/NTP-s-config-adv.htm#AEN3101
That diagram (figure 5) shows each of the local prime servers being fed
from just two external sources, but as you say, 4-7 would be more
sensible. If it were me, I would go for one, two or three servers you
know you can trust being in common across the stratum-3 servers, and
fill in the rest with the "pool" directive. This will fill up the
servers with up to 10 external sources, which are dropped and an
alternative automatically selected if the source goes bad.
I have information on my Web page about low-cost stratum-1 servers using
Windows, FreeBSD and Raspberry Pi PCs.
More information about the questions