[time-nuts] NTP Leap indicator set to 1 ! problems continue

[Steven Sommars]

This is written at 2021-11-30 15:45

2021-11-27 00:00:00   NTP servers start advertising leap=1.
2021-11-28 00:00:00   Many of these servers execute leap procedure.  Leap=0
no longer advertised (mostly)
2021-11-30 00:00:00   *Another set of NTP servers start advertising leap=1.*
2021-12-01 00:00:00   (predicted).  Many of the second set of NTP servers
execute leap procedure.
2021-12-01 00:00:00   (?)  Unknown number of clients will execute leap
procedure.

By convention NTP servers wait until the last day of the month before
advertising leap=1.   Beginning 2021-11-30 00:00:00 I've seen 81 public NTP
servers with the leap flag set.
The flag flips between 0 and 1 on some servers.

In older NTP implementations a single bad leap=1 indicator could propagate
to other NTP servers.  That may be happening now.
(Newer ntpd versions implement a majority rule).

I'm working with the NTP Pool folks.  Perhaps some of the bad flags can be
cleared.
However, it is likely that some NTP clients will execute a leap second
procedure in about 8 hours.

NOTE:  In past days this discussion would happen on the NTP mailing lists (
lists.ntp.org), but that mailing list is long dead.

Steve Sommars