[time-nuts] more of a time distribution question

[Majdi S. Abbas]

On Thu, Mar 30, 2017 at 09:37:50AM -0700, jimlux wrote:
> Running NTP (in some flavor) would be the obvious approach, but I'm in an
> environment where there's no "outside" connectivity.. Could I make one of
> the beaglebones be the NTP server, and the others be the clients?

	Disciplining them all to a specific free-running host would 
require the use of the LOCAL reference clock:

	http://doc.ntp.org/4.1.2/driver1.htm

	However, the LOCAL refclock is deprecated, and it is recommended
that you use orphan mode instead, which is its intended replacement:

	https://www.eecis.udel.edu/~mills/ntp/html/orphan.html

	http://support.ntp.org/bin/view/Support/OrphanMode

	Orphan mode is designed for your use case, and allows for more
redundancy than making them all clients of a single host.  I'd go that
route.

> (I've seen some "add a GPS to a Rpi to make a NTP server" projects, and I
> could probably leverage that)

	You could do that, but you don't really have to -- you can keep
them synchronized at least to each other reasonably well this way.

> I've also got a laptop (a mac, as it happens).. what's involved in making
> *that* be a NTP server (e.g. the Mac might get its time from a NTP server at
> some higher stratum, and then it propagates it down).

	OSX already runs ntpd; you should just need to tweak their
default configuration.

	--msa