[ntp:questions] Re: Leap second hangover?

David J Taylor david-taylor at blueyonder.co.not-this-bit.nor-this-part.uk
Sat Jul 1 12:35:37 UTC 2006

Karel Sandler wrote:
> "David J Taylor" wrote:
>> Two of my PCs have show a great NTP instability since 0000UTC this
>> morning, just like the events which happened on January 1st after
>> the leap second insertion.  Please see:
>>  http://www.david-taylor.myby.co.uk/mrtg/daily_ntp.html
>> At 06:00 UTC I restarted the NTP servers on those systems (Bacchus
>> and Stamsund), rewriting the ntp.drift file with a known good value
>> for the PCs in question.
>> Unfortunately, I didn't note which servers (in addition to my own
>> simple stratum 1 server - Pixie) those PC were clients to,
> A change of a syspeer is probably recorded in the
> Eventlog/Application.
> Karel Sandler

Thanks - they are indeed recorded there.

On both problem PCs, at 01:00 a positive leap second is inserted.  Arrgh!

Now the announcement wasn't coming from my own stratum 1 server (at least 
I hope it wasn't, as not all client PCs were affected).

On PC Bacchus, a positive leap second was detected by NTP at 09:10 (clock) 
on June 06, the event log does not show which server provided this duff 
information.  The NTP on that server was restarted on March 04 and was 
using NTP UK pool servers, plus ntp2c.mcc.ac.uk.

On PC Stamsund, a positive leap second was detected by NTP at 09:17 
(clock) on June 6.  Its servers included UK pool servers, and 

[Suggestion to the developers: log which server suggested the leap-second]

[Suggestion to the developers: provide some sort of "majority vote 
required" before a leap-second is actually inserted]

All my systems are using the server ntp2c.mcc.ac.uk, so I presume that is 
not is sending out the spurious message.  How can I find out if a server 
is sending out a leap-second required message?  I can only assume 
something in the UK pool of servers was incorrectly sending the 
leap-second message, and may still be.

[Suggestion to NTP pool maintainers: list erroneous servers like this if 


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