[ntp:questions] NTP on local networks

Charles Elliott elliott.ch at verizon.net
Wed Aug 1 00:26:27 UTC 2012


Unruh had the correct advice: Buy a (cheap) GPS device for a master clock
and propagate the correct time.  If something is worth doing, it is worth
doing right.  Become a force, develop a reputation, for progress, one of the
foundations of Western Civilization.

The new BU-353, not the old one you can find for about $30, but the one that
costs about $42, at USGlobalSat.com will do the job within a half second or
better, and it is trivial to set up.  All you need is a free USB port and a
window, or preferably a thin roof, that faces the satellites. The Sure
(search for Sure Electronics) GPS demo board is supposed to give much more
accurate time, but it is a pain to set up.

There are beaucoup people on this list that know a lot more about GPS clocks
than I and most are willing to help, if you just ask.  Meinberg at
www.meinberg.de sells lots of very accurate clocks, and there are several
other places like it.  Search for GPS clocks or NTP clocks.

Charles Elliott



> -----Original Message-----
> From: questions-bounces+elliott.ch=verizon.net at lists.ntp.org
> [mailto:questions-bounces+elliott.ch=verizon.net at lists.ntp.org] On
> Behalf Of Will Shackleford
> Sent: Monday, July 30, 2012 11:47 AM
> To: questions at lists.ntp.org
> Subject: [ntp:questions] NTP on local networks
> 
> 
> We have several computers  with several different operating systems on
> a local network with no radios and no internet connection.
> The main goal is to keep them synchronized with each other.
> 
> One frustration I have had is that clients tend to refuse to connect to
> servers on the network that are "not good enough". I assume "not good
> enough" means too high a stratum although the error messages are not
> that clear.
> 
> My current solution is to take a laptop to another room with an
> internet connection, let it sit for an hour and then bring it back to
> connect the local network where finally the other computers will accept
> it and synchronize with it.
> 
> 
> Questions:
> 
> How can I configure a client/peer to always accept a server as "good
> enough" or atleast always accept the server when no other server can be
> contacted? (please answer for any platform below you can)
> 
> 
> Fedora 6:
> Fedora 10:
> Fedora 14:
> Ubuntu 11.04:
> Windows XP:
> 
> 
> How can I configure a server to always consider itself "good enough"
> and report that (lie if necessary) so that any badly configured client
> will still connect?(please answer for any platform below you can)
> 
> 
> Fedora 6:
> Fedora 10:
> Fedora 14:
> Ubuntu 11.04:
> Windows XP:
> 
> 
> 
> Just for my own curiosity, why is just refusing to do what the operator
> wants the default behavior for clients/peers? Why not always
> synchronize as well as you can with whichever peers/hosts you can
> contact?
> 
> 
> 
> 
> 
> 
> 
> 
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