Dave wrote: > On May 25, 9:28 am, Dave <[EMAIL PROTECTED]> wrote: > >>On May 24, 8:09 pm, "Richard B. Gilbert" <[EMAIL PROTECTED]> >>wrote: >> >> >> >> >>>Dave wrote: >>> >>>>On May 23, 1:16 pm, "Richard B. Gilbert" <[EMAIL PROTECTED]> >>>>wrote: >>> >>>>>Dave wrote: >>>> >>>>>>I'm experiencing large values of dispersion when I use 'ntpq -p': >>>>> >>>>>>3:22pm:ntp>ntpq -p >>>>>> remote refid st t when poll reach delay >>>>>>offset disp >>>>>>============================================================================== >>>>>>*10.2.100.10 .GPS. 1 u 25 64 377 0.46 >>>>>>943.557 439.36 >>>>>>3:22pm:ntp> >>>>> >>>>>>but when I look at the peerstats log file, my dispersion is low: >>>>> >>>>>>3:22pm:ntp>tail /var/ntp/ntpstats/peerstats.log >>>>>>54243 54804.018 10.2.100.10 9634 0.617563 0.00046 0.31154 >>>>>>54243 54868.013 10.2.100.10 9634 0.813226 0.00043 0.32210 >>>>>>54243 54932.018 10.2.100.10 9634 0.099169 0.00046 0.55225 >>>>>>54243 54996.010 10.2.100.10 9634 0.300057 0.00047 0.28690 >>>>>>54243 55060.014 10.2.100.10 9634 0.584358 0.00044 0.31111 >>>>>>54243 55124.009 10.2.100.10 9634 0.781632 0.00047 0.32353 >>>>>>54243 55188.014 10.2.100.10 9634 0.065932 0.00043 0.55287 >>>>>>54243 55252.013 10.2.100.10 9634 0.657674 0.00044 0.37859 >>>>>>54243 55316.018 10.2.100.10 9634 0.943557 0.00046 0.43936 >>>>>>54243 55380.013 10.2.100.10 9634 0.139388 0.00044 0.59772 >>>>>>3:23pm:ntp> >>>>> >>>>>>I'm also concerned with the large amount of maximum/estimated error >>>>>>when I use the xntpdc command 'kerninfo': >>>>> >>>>>>xntpdc> kerninfo >>>>>>pll offset: 0 us >>>>>>pll frequency: -391.137 ppm >>>>>>maximum error: 524704 us >>>>>>estimated error: 408368 us >>>>>>status: 0089 >>>>>>pll time constant: 2 >>>>>>precision: 1 us >>>>>>frequency tolerance: 512 ppm >>>>>>pps frequency: 0.000 ppm >>>>>>pps stability: 512.000 ppm >>>>>>pps jitter: 200 us >>>>>>calibration interval: 4 s >>>>>>calibration cycles: 0 >>>>>>jitter exceeded: 0 >>>>>>stability exceeded: 0 >>>>>>calibration errors: 0 >>>>>>xntpdc> >>>>> >>>>>>Here is the output of the pstats command: >>>>> >>>>>>xntpdc> pstats 10.2.100.10 >>>>>>remote host: 10.2.100.10 >>>>>>local interface: 10.2.100.5 >>>>>>time last received: 3s >>>>>>time until next send: 61s >>>>>>reachability change: 2947s >>>>>>packets sent: 59 >>>>>>packets received: 59 >>>>>>bad authentication: 0 >>>>>>bogus origin: 0 >>>>>>duplicate: 0 >>>>>>bad dispersion: 15 >>>>>>bad reference time: 0 >>>>>>candidate order: 1 >>>>>>xntpdc> >>>>> >>>>>>And lastly, my ntp.conf file: >>>>> >>>>>>3:25pm:inet>more ntp.conf >>>>>>server 10.2.100.10 # NTP server >>>>> >>>>>>driftfile /etc/ntp.drift # Drift available for next restart >>>>>>logfile /var/ntp/ntp.log # NTP logging >>>>> >>>>>>statsdir /var/ntp/ntpstats/ >>>>>>statistics loopstats peerstats clockstats >>>>>>filegen loopstats file loopstats.log type day link enable >>>>>>filegen peerstats file peerstats.log type day link enable >>>>>>filegen clockstats file clockstats.log type day link enable >>>>>>3:25pm:inet> >>>>> >>>>>>Anyone have any ideas? I have a GPS signal coming in to a Brandywine >>>>>>NTA-100, which is configured at 10.2.100.10. Thanks in advance! >>>>> >>>>>If you are using "X"ntpdc you would appear to be using a version that >>>>>may be as much as ten years old! Just what are you using and what are >>>>> you running it on? >>>> >>>>Wow you're right. Heres the version printout: >>>>xntpdc 3-5.93e Mon Sep 20 15:47:24 PDT 1999 (1) >>> >>>>I'm running this on a Sun Fire 4200, Solaris 10. Something this old >>>>comes installed on Solaris 10? >>> >>>Yup! >> >>>I think it has something to do with the fact that there is, as yet, no >>>RFC for NTP V4. There is a committee, God help us, working on one. I >>>think it has been about a year now with no visible results! >> >>>I'd suggest grabbing a more recent version of the code from somewhere. >>>Sun Freeware and Blastwave sites should both have Solaris versions more >>>recent than what Sun ships. There have been quite a few fixes and >>>enhancements since 3-5.93e. >> >>>If you want/are able to build your own, try the ntp.org web site; there >>>are links there to download the source to the stable and development >>>versions which are, I believe, at 4.2.something. >> >>I just downloaded ntp v4.2.4 from sunfreeware.com and I'll give that a >>try. I'll let you know how it goes! > > > > Ok so I have the new version loaded and its been running for about 24 > hours now. I still have a large amount of jitter (reported on by ntpq - > p): > 2:50pm:freadd_user>ntpq -p > remote refid st t when poll reach > delay offset jitter > ======================================================== > *10.2.100.10 .GPS. 1 u 3 64 377 0.461 > 91.914 385.406 > > > But using ntpdc, I see the correlation in the offset values (msec vs. > sec), but are jitter and dispersion supposed to mean the same thing/ > have anything to do with each other? >
Dispersion is the difference between your clock and the atomic clock which, in principle, is at the root of things. Jitter is a measure of the variation in round trip delays between the server and your system. _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
