[ntp:questions] Re: New to NTPD
Richard B. Gilbert
rgilbert88 at comcast.net
Wed May 10 01:17:51 UTC 2006
Ted Gervais wrote:
> On Tue, 9 May 2006, Richard B. Gilbert wrote:
>
>
> -snip-
>
>>> remote refid st t when poll reach delay
>>> offset jitter
>>> ==============================================================================
>>> +clock.via.net .GPS. 1 u 223 256 377 101.718
>>> 21.183 5.465
>>> gnomon.cc.colum .USNO. 1 u 483 1024 301 55.229
>>> 26.100 2.439
>>> -NAVOBS1.MIT.EDU .PSC. 1 u 11 256 377 60.820
>>> 28.740 2.602
>>> +ntp3.usv.ro .PPS. 1 u 15 256 377 173.654
>>> 26.977 1.469
>>> *clock.xmission. .GPS. 1 u 216 256 377 88.717
>>> 23.674 4.681
>>> +c-24-130-58-99. .GPS. 1 u 83 256 377 118.072
>>> 23.165 1.358
>
>
>> <big snip>
>>
>> You seem to have very large round trip delays to the servers you have
>> chosen. Shorter delays are better. The error in transmitting time
<snip>
>
> Alright. I made some changes to the servers (as you mentioned).. how
> does this look now? It has only been running 30 mins at this time:
> ---------
> remote refid st t when poll reach delay offset
> jitter
> ==============================================================================
>
> mircx.com 129.6.15.29 2 u 23 128 7 70.362 27.808
> 7.917
> neate.neateroll 199.212.17.15 3 u 24 128 7 80.833 14.010
> 6.666
> d221-85-115.com 132.246.168.9 2 u 17 128 7 41.316 25.977
> 2.463
> ----------------
>
<snip>
Your reach field shows that only the three most recent polls were
successful!!!! This is not good. Did you disconnect the network cable
or have a network problem? That is probably why none of the three
servers has been selected.
Can you find a fourth server? Four are the minimum required to protect
against one falseticker. Five protect against two falsetickers and
seven against three. With only three servers, the failure of one
leaves you with only two. It is written that a man with two clocks can
never be certain what time it is!!
You need to let that system run for a while, perhaps for as long as a
full day to reach a stable state with good synchronization.
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