ignoring leap second announcements - NTP

This is a discussion on ignoring leap second announcements - NTP ; What would be the proper way to let ntpd ignore leap second announcements from external sources, and only trust the leapsecond information in ntpkey_leap and/or announcements from selected refclocks? My documentation search skills seem to fall short in this area. ...

+ Reply to Thread
Results 1 to 4 of 4

Thread: ignoring leap second announcements

  1. ignoring leap second announcements

    What would be the proper way to let ntpd ignore leap second
    announcements from external sources, and only trust the
    leapsecond information in ntpkey_leap and/or announcements
    from selected refclocks?

    My documentation search skills seem to fall short in this area.

    N

  2. Re: ignoring leap second announcements

    Nero Imhard wrote:
    > What would be the proper way to let ntpd ignore leap second
    > announcements from external sources, and only trust the
    > leapsecond information in ntpkey_leap and/or announcements
    > from selected refclocks?
    >
    > My documentation search skills seem to fall short in this area.
    >
    > N


    Your best bet, unless you are able and willing to modify the NTP source
    code, is to avoid using external servers that incorrectly announce leap
    seconds.

    If you are able and willing to modify the NTP source code, it should be
    possible to add "ENABLE LEAP SECOND" and "DISABLE LEAP SECOND". You
    would "ENABLE" when a leap second was expected and "DISABLE" at all
    other times. I believe that upcoming leap seconds are announced several
    months in advance so it should not be to much of a problem to ENABLE on
    the proper day and DISABLE after the deed is done.

  3. Re: ignoring leap second announcements

    Richard B. Gilbert wrote:
    > other times. I believe that upcoming leap seconds are announced several
    > months in advance so it should not be to much of a problem to ENABLE on
    > the proper day and DISABLE after the deed is done.


    Yeah, IERS just announced the next leap second, which will take place at
    the end of December 2008. Generally leap seconds are announced about six
    months before they are inserted, so you have plenty of time to prepare.

    Tapio

  4. Re: ignoring leap second announcements

    Hello Tapio,

    On Saturday, July 5, 2008 at 23:18:16 +0300, Tapio Sokura wrote:

    > Yeah, IERS just announced the next leap second, which will take place
    > at the end of December 2008.


    The NIST has not yet updated its official leap-seconds.list, but here
    comes one that can be used in the meantime. It lists the December 2008
    leap, and is authoritative until just before the next open date at the
    end of June 2009.


    ------ >8 ------ leap-seconds.3424118400 ------ >8 ------
    # Last Update of leap second values: 4 July 2008
    #$ 3424118400
    # Updated through IERS Bulletin C36
    # File expires on: 28 Jun 2009
    #@ 3455136000
    #
    2272060800 10 # 1 Jan 1972
    2287785600 11 # 1 Jul 1972
    2303683200 12 # 1 Jan 1973
    2335219200 13 # 1 Jan 1974
    2366755200 14 # 1 Jan 1975
    2398291200 15 # 1 Jan 1976
    2429913600 16 # 1 Jan 1977
    2461449600 17 # 1 Jan 1978
    2492985600 18 # 1 Jan 1979
    2524521600 19 # 1 Jan 1980
    2571782400 20 # 1 Jul 1981
    2603318400 21 # 1 Jul 1982
    2634854400 22 # 1 Jul 1983
    2698012800 23 # 1 Jul 1985
    2776982400 24 # 1 Jan 1988
    2840140800 25 # 1 Jan 1990
    2871676800 26 # 1 Jan 1991
    2918937600 27 # 1 Jul 1992
    2950473600 28 # 1 Jul 1993
    2982009600 29 # 1 Jul 1994
    3029443200 30 # 1 Jan 1996
    3076704000 31 # 1 Jul 1997
    3124137600 32 # 1 Jan 1999
    3345062400 33 # 1 Jan 2006
    3439756800 34 # 1 Jan 2009
    #
    #h c7284bf ac8af4cd de049744 71c8086b 7a1b7850
    ---------------- >8 ----------------- >8 ----------------


    And my signature on the file:

    ------- >8 ------- leap-seconds.3424118400.asc ------- >8 -------
    -----BEGIN PGP SIGNATURE-----

    iD8DBQBIhbzrRoHb5pXXHtgRAmpqAJ9QC3Xe+DwEMVfR3WRROz VUOgOx/wCfRgmE
    O6tK54YJu4rsGrxNl9EsFsM=
    =VBka
    -----END PGP SIGNATURE-----
    ------------------ >8 --------------------- >8 ------------------


    For ntp-stable releases: place the leap-seconds.3424118400 file into
    , and create an "ntpkey_leap" symlink to it. You must have
    a minimal autokey setup: A , host cert and key, and at least
    one "crypto" command in ntp.conf

    For ntp-dev: place the leap-seconds.3424118400 file into /etc, and
    create an "ntp.leap" symlink to it.


    With this file and ntp-stable, you are guaranteed to leap in time. With
    ntp-dev, you are additionally guaranteed to ignore any other leap
    announcement from external sources until 28 June 2009. Because of course
    such other announcement can only be wrong.


    Serge.
    --
    Serge point Bets arobase laposte point net

+ Reply to Thread