[ntp:questions] losing time fast

unruh unruh at invalid.ca
Sat Jul 14 21:56:14 UTC 2012


On 2012-07-13, E-Mail Sent to this address will be added to the BlackLists <Null at BlackList.Anitech-Systems.invalid> wrote:
> unruh wrote:
>> Fritz Wuehler wrote:
>>> That's all very nice but it says on the ntp.org page to
>>>  use a national server if you have one.  Mine happens to
>>>  not be very good but that doesn't mean I shouldn't use
>>>  it if it was good.
>>
>> No idea where it says that, but if it does it is bad
>>   advice in your situation.
>>  IF you are a server for a bunch of other machines that
>>   really need accurate time (eg stock traders, airlines,etc)
>>   then it might be good advice.
>>  For a home user who has spent no time trying to figure
>>   out what his requirements are who sits on an adsl line say,
>>   it is terrible advice, since it clogs up the national server.
>
>
> Geographicly Local Pool Servers (of any stratum):
><http://www.pool.ntp.org/en/use.html>
> ... <BlockQuote>
> As pool.ntp.org will assign you timeservers from all over
>   the world, time quality will not be ideal.
>  You get a bit better result if you use the continental
>   zones (For example europe, north-america, oceania
>   or asia.pool.ntp.org), and even better time if you use
>   the country zone (like ch.pool.ntp.org in Switzerland)
>   - for all these zones, you can again use the 0, 1 or 2
>      prefixes, like 0.ch.pool.ntp.org.
></BlockQuote> ...

Clearly a total miscommunication. I had thought that you were advocating
using a server like nist.org, a national stratum 1 primary timeserver, when you were
advocating using the pool local to your own country. I certainly have no
objection to the latter. It is good advice ( although some have said it
occurs automatically now). So, if that is what you meant, I totally
withdraw my objections. 

>
>
>
>
> Hand configuration of Stratum One Servers
>  (instead of, or in addition to pool servers):
>
><http://support.ntp.org/bin/view/Servers/RulesOfEngagement>
><BlockQuote>
> As the load on the hosts supporting NTP primary (stratum 1)
>   time service is heavy and always increasing,
>   clients should avoid using the primary servers whenever possible.

Precisely what I was trying to say.

>
>  In most cases the accuracy of the NTP secondary (stratum 2) servers
>   is only slightly degraded relative to the primary servers,
>    and as a group, the secondary servers may be just as reliable.
>
>  As a general rule, a secondary server should use a primary server
>   only under the following conditions:
>
>  The secondary server provides synchronization to a sizable population
>   of other servers and clients on the order of 100 or more.
>
>  The server operates with at least two and preferably three other
>   secondary servers in a common synchronization subnet designed to
>   provide reliable service, even if some servers or the lines
>   connecting them fail.
>
>  The administration(s) that operates these servers coordinates
>   other servers within the region, in order to reduce the
>   resources required outside that region.
>
>  Note that at least some interregional resources are required
>   in order to ensure reliable service.
></BlockQuote> ...
>



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