[ntp:questions] NTP on local networks

Kennedy, Paul P.Kennedy at fugro.com.au
Wed Aug 1 02:46:22 UTC 2012


Exactly so.  you can purchase a GPS receiver for well under $100 connect
it to a serial port + pps on any of the pc's and have microsecond
accuracy in a few hours.  This 'master' can then serve time to all other
PC's.  The systems will then behave for years of unattended use.  It is
a far more cost effective solution.

regards
pk


-----Original Message-----
From: questions-bounces+p.kennedy=fugro.com.au at lists.ntp.org
[mailto:questions-bounces+p.kennedy=fugro.com.au at lists.ntp.org] On
Behalf Of Charles Elliott
Sent: Wednesday, 1 August 2012 8:26 AM
To: 'Will Shackleford'; questions at lists.ntp.org
Subject: Re: [ntp:questions] NTP on local networks

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?
> 
> 
> 
> 
> 
> 
> 
> 
> _______________________________________________
> questions mailing list
> questions at lists.ntp.org
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