Wow I just stopped ntpd and restarted, 1.3 seconds that time! I just bring it back with ntpdate...
C:\Program Files\NTP\bin>ntpdate -b 192.168.5.112 12 Feb 18:41:53 ntpdate[944]: Raised to realtime priority class 12 Feb 18:42:01 ntpdate[944]: step time server 192.168.5.112 offset 1.305816 sec Mark -----Original Message----- From: Mark C. Stephens Sent: Sunday, 12 February 2012 3:36 PM To: 'Ron Frazier (NTP)'; [email protected] Cc: [email protected] Subject: RE: [ntp:questions] how to force NTP to use GPS I have seen that a lot lately, sometimes as much as 500m/s when restarted. And then if you stop ntpd and restart a second time its all good again. Weirdness... -----Original Message----- From: Ron Frazier (NTP) [mailto:[email protected]] Sent: Sunday, 12 February 2012 10:57 AM To: [email protected] Cc: [email protected] Subject: Re: [ntp:questions] how to force NTP to use GPS On 02/11/2012 06:11 PM, Richard B. Gilbert wrote: > On 2/11/2012 4:14 PM, Ron Frazier (NTP) wrote: >> Hi all, >> >> I now have my USB GPS working at an acceptable level on both Windows >> and Linux using only NTPD. I have the GPS server line set as prefer, >> but there are other server lines which poll the internet. Sometimes, >> the system selects an internet clock rather than my GPS. How do I >> force NTP to use my GPS if it's available, no matter what (within >> reason). The only time I ever want it to select an internet server is >> if the GPS fails or is not plugged in. >> >> Sincerely, >> >> Ron >> > > ISTR a "prefer" keyword used to instruct NTPD to use a designated time > source if that source is available. Other sources configured will be > used only if the "preferred" source is not available or obviously > insane. Or something like that! It goes in NTPD.CONF IIRC. > > Hi Richard (and others), Thanks for the note. I have prefer on my gps line in ntp.conf. I have to do more testing. I thought I saw it select another clock anyway some time during the day. I know the GPS was available at the time and it wasn't insane. Also, something else strange just happened. I shut down NTPD for literally about only a minute to tweak the fudge factor in ntp.conf by about 5 ms. When I restarted it, the offset between the computer's clock and ALL my time sources including the GPS was about 160 ms. Before the shutdown, it was only about 2 ms. I don't think it should drift out 1/6 sec in one minute. I've restarted NTPD and I'll see what happens. Sincerely, Ron -- (PS - If you email me and don't get a quick response, don't be concerned. I get about 300 emails per day from alternate energy mailing lists and such. I don't always see new messages very quickly. If you need a reply and have not heard from me in 1 - 2 weeks, send your message again.) Ron Frazier timekeepingdude AT c3energy.com _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
