[Pool] Leap second is coming

Arnold Schekkerman ntp-list at mallos.nl
Sun Apr 19 13:46:38 UTC 2015


Hi,

On 18-04-15 20:44, Hal Murray wrote:
>> 	Apparently the majority of my upstream servers do not send the leap second
>> info - at least my "ntpq -c rv" does not show the "tai" value: 
> 
> There are two levels of leap info.  The normal NTP packet exchange has a 2 
> bit field that encodes 4 states:
>   my clock is no good
>   my clock is good, no leap
>   leap insert
>   leap delete
> 
> The leap insert/delete apply to the end of the current day.

If I understand the spec (section 7.3 of RFC5905) correctly, the leap indicator
refers to the last minute of the *last day* of the current month.

  "LI Leap Indicator (leap): 2-bit integer warning of an impending leap
   second to be inserted or deleted in the last minute of the current
   month with values defined in Figure 9."

>> 	How can I tell which upstream servers announce the upcoming
>> leap second?
> 
> Wait until the day the leap will happen.  :)

Or, if I understand correctly and things are implemented that way, wait until 1st
of June :)

If a majority of upstream servers does not announce the leap info on the last day
of June, you can temporarily remove those servers from your list. That way, your
server will set its leap indicator bits correctly.

Arnold


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