nanog mailing list archives

Re: Need trusted NTP Sources


From: Bryan Seitz <seitz () bsd-unix net>
Date: Fri, 7 Feb 2014 23:35:25 -0500

On Fri, Feb 07, 2014 at 03:32:22PM -0500, Anthony Williams wrote:

 With a quick and easy mod, another option for $35 is a Sure Electronics
GPS board.

GPS: http://www.sureelectronics.net/goods.php?id=99

Mod: http://www.satsignal.eu/ntp/Sure-GPS.htm

-Alby


On 2/7/2014 1:14 PM, Jared Mauch wrote:
Having a number of NTP servers will help you detect false tickers which may be critical.

If you want something that is "cheap" as in you for your home, I can recommend this: ~$350 w/ antenna, etc..

The SureGPS is decent fun but i've had this device lose sync / crap out randomly as well.  
I am using the Garmin 18X-LVC + a low power server with pretty good success.

(Requires PPS soldering + USB pigtail for power, pretty easy mod)

[seitz@ntp-gps ~]$ ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 clock.fmt.he.ne .CDMA.           1 u   53   64  377   76.692    0.976   0.291
 time-a.timefreq .ACTS.           1 u   39   64  377   48.140   -0.896   0.348
 time-b.timefreq .ACTS.           1 u   56   64  377   48.800   -0.986   0.430
 time-b.nist.gov .ACTS.           1 u   48   64  377    7.333    3.630   0.562
oGPS_NMEA(1)     .PPS.            0 l    4   16  377    0.000    0.002   0.000

* GPS is on a http://us.shuttle.com/barebone/Models/XS36VL.html - chosen for the dual external serial ports.

-- 
             
Bryan G. Seitz


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