[ntp:questions] Use ntp orphan mode to sync time two stand-alone computers

Brian Inglis Brian.Inglis at SystematicSw.ab.ca
Sun Aug 14 17:00:22 UTC 2016


On 2016-08-13 19:28, Jason Beach wrote:
> I have two arm-based Linux (ubuntu 14.04) computers, a Jetson TK1 and TX1
> that will fly on a multicopter and hence have no internet connection (they
> are networked together onboard).  They also do not have RTC's built-in but
> I have added a smll external one (https://www.adafruit.com/product/255) to
> the Jetston TK1.  The TK1's time gets set on boot from this RTC no problem
> (using a `sudo hwclock -s -f /dev/rtc0` in rc.local).  I am trying to get
> the TX1 to sync to the TK1's time using ntp.

> I see the reference time is way off (even though the system time is
> correct) - is that what's triggering the message `Server has gone too long
> without a sync`?  I don't care if the time isn't 100% exactly right as long
> as the two boards are synced together. Is there a way to force the two
> boards to sync regardless of when the last server sync was?

Remove all inaccessible internet servers as they will make it impossible
for the systems to sync; define each system to the other; then see docs
about setting up Orphan Mode:

http://doc.ntp.org/cgi-bin/htsearch?method=and&sort=score&restrict=4.2.6p5&words=orphan+mode

-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada


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