Re: [Ntp] Antw: Re: Antw: [EXT] Re: CLOCK_TAI (was NTPv5: big picture)

[Martin Burnicki <[e-mail]>]

Ulrich Windl wrote:
>>>> Doug Arnold <[e-mail]> schrieb am 08.01.2021 um 16:17
> in
> Nachricht <[e-mail]>:
>> I think that the point of a leap smear is that no special handling of leap 
>> seconds is needed by the client.  It is introduced gradually over a number
> of 
>> polling periods.
> 
> But if you have two servers using leap smear, and to servers not using leap
> smear, all will claim to return the correct time one second after the leap
> event.

The general problem is admin have to be very careful when leap second
smearing comes into the game. Specifically in a mixed environment with
time servers that don't smear, and other time servers that smear in a
different way.

> With the same logic as claiming UNSYNC during theleap event for non-smearing
> servers, smearing servers should return UNSYNC until the time is "correct"
> again IMHO.

Sorry, that wouldn't be useful. If NTP servers smear the time, it's not
for the sake of the NTP servers but for the sake of the clients.

If you returned UNSYNC during the smear interval, the clients would stop
accepting the servers and not follow the smearing at all. Instead they
would re-synchronize to the servers and STEP the time after the leap
second, which is exactly what you want to avoid when smearing a leap second.


Martin
-- 
Martin Burnicki

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