[time-nuts] iPhone keeping better time?

Doug Calvert dfc-list at douglasfcalvert.net
Wed Nov 23 03:00:03 UTC 2011


On 11/16/2011 12:28 PM, David J Taylor wrote:
>> Apple run their own NTP servers and ship their Macs configured to use
>> them
>> to sync time.
> 
> Last time I looked those servers were either not working, or very
> broken! Apple should use the pool rather than create single poinst of
> failure.
> 

Their servers were not so bad the last time i monitored them. the
time.apple.com servers are stratum 2s. I think they sync to tick and
tock.apple.com in the us and the euro hosts sync with
truetime.euro.apple.com. I never bothered looking for the stratum one
server for the time.asia group.

dfc at ronin:/var/repos/ntp-dev$ host time.apple.com
time.apple.com has address 17.151.16.23
time.apple.com has address 17.151.16.22
time.apple.com has address 17.151.16.21
time.apple.com has address 17.151.16.20
time.apple.com has address 17.151.16.30
time.apple.com has address 17.151.16.28
time.apple.com has address 17.151.16.31
time.apple.com has address 17.151.16.29
time.apple.com has address 17.171.4.24
time.apple.com has address 17.171.4.22
time.apple.com has address 17.171.4.23
time.apple.com has address 17.171.4.21

dfc at ronin:/var/repos/ntp-dev$ host time.euro.apple.com
time.euro.apple.com has address 17.72.255.11
time.euro.apple.com has address 17.72.255.12

dfc at ronin:/var/repos/ntp-dev$ host time.asia.apple.com
time.asia.apple.com has address 17.82.253.7
time.asia.apple.com has address 17.83.253.7



Apple should use the pool? Apple should support/donate/take part in the
pool. But it would not be apple if they did not "think different":)



>> I believe the Mac NTP client is shipped with a very large maximum polling
>> interval. Try reducing it.
> 
> In which case they are not running the reference implementation, as the
> polling interval should automatically adjust to suit the need, and not
> normally require the user to fiddle with the settings.
> 

It is still the reference implementation just with different defaults. I
also think the minpoll is ridiculously high. If you add your own servers
/ config directives below the line that the GUI adds to
/private/etc/ntp.conf things work fine. I had autokey working on one up
until the most recent autokey change.




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