[ntp:questions] Re: NTP, Mac OS X & Cisco 837 - some stats:
Richard B. Gilbert
rgilbert88 at comcast.net
Wed Apr 20 12:52:16 UTC 2005
viz wrote:
>Some interesting stats come up with ntpq -p:
>
> ntpq -p
> remote refid st t when poll reach delay offset
>jitter
>============================================================================
>==
>+bm1.asia.apple. time1.euro.appl 2 u 118 128 377 127.025 -227.69
>401.635
>+mel001.pacific. murgon.cs.mu.oz 2 u 101 128 377 36.358 -219.35
>435.265
>+marvin.ci.com.a .PPS. 1 u 63 128 377 36.375 -246.40
>40.575
>*murgon.cs.mu.oz .GPS. 1 u 114 128 377 32.412 -231.68
>410.731
>+ntp1.cs.mu.oz.a .GPS. 1 u 114 128 377 42.499 -228.29
>418.720
>-bob.greenwood.w ntp.hobart.nml. 2 u 124 128 377 206.531 -169.20
>474.324
>-ntp1.tpgi.com.a murgon.cs.mu.oz 2 u 120 128 377 21.104 -285.12
>415.440
>+levy.catalyst.n gen1.ihug.co.nz 3 u 120 128 377 62.818 -226.84
>414.083
>
>
>ntpq -p
> remote refid st t when poll reach delay offset
>jitter
>============================================================================
>==
>-bm1.asia.apple. time2.euro.appl 2 u 92m 256 377 129.815 -8.807
>8.620
>-mel001.pacific. murgon.cs.mu.oz 2 u 92m 256 377 38.591 0.902
>0.220
>-marvin.ci.com.a .PPS. 1 u 93m 256 377 87.344 -41.230
>32.827
>*murgon.cs.mu.oz .GPS. 1 u 92m 256 377 33.880 -13.720
>2.081
>+ntp1.cs.mu.oz.a .GPS. 1 u 92m 256 377 34.493 -13.122
>4.711
>+bob.greenwood.w ntp.hobart.nml. 2 u 92m 256 377 87.686 -13.215
>1.836
>-ntp1.tpgi.com.a murgon.cs.mu.oz 2 u 92m 256 367 26.237 -68.400
>1.196
>+levy.catalyst.n gen3.ihug.co.nz 3 u 93m 256 377 57.825 -14.396
>3.948
>
>
>
>ntpq -p
> remote refid st t when poll reach delay offset
>jitter
>============================================================================
>==
>-bm1.asia.apple. time1.euro.appl 2 u 107m 128 36 129.001 -18.558
>4.063
>+mel001.pacific. murgon.cs.mu.oz 2 u 105m 128 37 43.009 -24.018
>10.079
>-marvin.ci.com.a .PPS. 1 u 104m 128 37 63.324 -41.983
>161.509
>+murgon.cs.mu.oz .GPS. 1 u 106m 128 37 35.328 -24.333
>4.102
>*ntp1.cs.mu.oz.a .GPS. 1 u 106m 128 37 44.048 -21.404
>0.326
>-bob.greenwood.w ntp.hobart.nml. 2 u 105m 128 37 95.627 -31.444
>12.165
>xntp1.tpgi.com.a ntp1.tip.csiro. 2 u 104m 128 37 23.700 -81.640
>10.341
>-levy.catalyst.n msltime.irl.cri 2 u 105m 128 37 56.696 -31.656
>10.730
>
>The jitter numbers have a huge range - any ideas why?
>
>/viz
>
>
>
I suspect it might have something to do with your poll intervals! Those
servers were last polled 105 minutes ago! It looks as if your minpoll
is still 12 and maxpoll is still 17. NTP can't work very well with such
a misconfiguration! Minpoll should be six and maxpoll should be ten.
These are the default values if they are not specified.
I believe another post in this thread mentioned a template configuration
file in /etc/private (?) that was copied over the /etc/ntp.conf file
every time ntpd was started. Fix that file or fix /etc/ntp.conf and
start ntpd by hand!!!! I believe that, having done so, you will see
much quicker synchronization and much tighter (smaller offsets)
synchronization. Your poll intervals should then start at 64 seconds
and ramp up to 1024 seconds as ntpd locks in.
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