Windows server sync to LocalCLK - NTP

This is a discussion on Windows server sync to LocalCLK - NTP ; Hi folks, I tried to start an NTP server on a XP Home box. The time source of this box is the local clock. Now I have a linux box that tries to sync with this xp box but it ...

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Thread: Windows server sync to LocalCLK

  1. Windows server sync to LocalCLK

    Hi folks,

    I tried to start an NTP server on a XP Home box. The time source of this
    box is the local clock. Now I have a linux box that tries to sync with
    this xp box but it doesn't work for at least 5 minutes of the NTP
    service starting. It returns error about stratum being too high.

    I've searched around and people are saying that it takes about 5-8
    minutes before the server trusts the local clock as the source. Nobody
    has said why or if there is a way to fix this.

    Can someone provide me with a solution to my problem or even a
    explanation as to why I have to wait 5-8 minutes for the clock to sync.


    Thanks for any help you may provide.

    John.

  2. Re: Windows server sync to LocalCLK

    Hi John,

    >I tried to start an NTP server on a XP Home box. The time source of this
    >box is the local clock. Now I have a linux box that tries to sync with


    Have you disabled the NTP client that comes bundled
    with XP?

    --tony

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  3. Re: Windows server sync to LocalCLK

    Tony Rutkowski wrote:
    > Hi John,
    >
    >
    >>I tried to start an NTP server on a XP Home box. The time source of this
    >>box is the local clock. Now I have a linux box that tries to sync with

    >
    >
    > Have you disabled the NTP client that comes bundled
    > with XP?
    >
    > --tony
    >
    > _______________________________________________
    > questions mailing list
    > questions@lists.ntp.isc.org
    > https://lists.ntp.isc.org/mailman/listinfo/questions
    >



    Hi tony,

    if you mean the Windows Time Service then yes, it has been disabled. If
    not, what is the name of the NTP client?

    Thanks,

    John.

  4. Re: Windows server sync to LocalCLK

    John wrote:
    > Hi folks,
    >
    > I tried to start an NTP server on a XP Home box. The time source of this
    > box is the local clock. Now I have a linux box that tries to sync with
    > this xp box but it doesn't work for at least 5 minutes of the NTP
    > service starting. It returns error about stratum being too high.
    >
    > I've searched around and people are saying that it takes about 5-8
    > minutes before the server trusts the local clock as the source. Nobody
    > has said why or if there is a way to fix this.
    >
    > Can someone provide me with a solution to my problem or even a
    > explanation as to why I have to wait 5-8 minutes for the clock to sync.


    First make sure that the Windows Time Service has been disabled.

    You didn't say where you got your version of ntp or what version it is.
    Is this the one that Meinberg has made available?

    Please post your ntp.conf file.

    When you say that the time source of this box is the local clock do you
    mean that you do not have any external sources? If so it will take time
    before it decides to use the local clock and make it available. That's
    by design. If this is your configuration is there a reason why you are
    NOT using external ntp servers as time sources?

    Danny
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  5. Re: Windows server sync to LocalCLK

    John wrote:
    > Hi folks,
    >
    > I tried to start an NTP server on a XP Home box. The time source of this
    > box is the local clock. Now I have a linux box that tries to sync with
    > this xp box but it doesn't work for at least 5 minutes of the NTP
    > service starting. It returns error about stratum being too high.
    >
    > I've searched around and people are saying that it takes about 5-8
    > minutes before the server trusts the local clock as the source. Nobody
    > has said why or if there is a way to fix this.
    >
    > Can someone provide me with a solution to my problem or even a
    > explanation as to why I have to wait 5-8 minutes for the clock to sync.
    >
    >
    > Thanks for any help you may provide.
    >
    > John.


    The problem is that the server hasn't a clue what time it is and your
    Linux box knows it! Clearly, you don't care what time it is. Why are
    you using NTP? To synchronize clocks with each other? Rdate should be
    able to do that.

    NTP was designed to synchronize clocks to UTC and it does that very well
    when properly configured. Synchronizing clocks TO EACH OTHER was not a
    design objective but rather a happy consequence of the postulate that
    "things equal to the same thing are equal to each other."

    You can set up something called "orphan mode" using NTP. In orphan
    mode, one clock is selected more or less at random to act as the time
    source for the herd. Orphan mode is a recent addition.


  6. Re: Windows server sync to LocalCLK

    John,

    John wrote:
    > Hi tony,
    >
    > if you mean the Windows Time Service then yes, it has been disabled. If
    > not, what is the name of the NTP client?


    The NTP service is displayed in the Windows service manager as "Network Time
    Protocol".

    If you have installed the NTP service using the GUI installer provided by
    Meinberg then w32time (the Windows Time Service) should have been disabled
    during installation.

    If you run your time server with local clock as the only reference then it
    may indeed take a few minutes until the NTP service claims to be
    synchronized.

    Once the time server claims to be synchronized you can speed up
    synchronization of the clients if you append the "iburst" keyword to the
    server line int ntp.conf, e.g.:

    server my-time-server iburst

    Martin
    --
    Martin Burnicki

    Meinberg Funkuhren
    Bad Pyrmont
    Germany

  7. Re: Windows server sync to LocalCLK

    On 2007-06-13, John wrote:

    > I tried to start an NTP server on a XP Home box. The time source of this
    > box is the local clock.


    The Undisciplined Local Clock (LocalCLK) is not a real time source. It
    is intended to allow an ntpd to serve time to others in a "time-island"
    or in the event that connectivity to real sources of time is lost.

    If you have external network connectivity you really ought to use some
    (i.e. 4, or more) remote time servers. But that's your choice.

    > Now I have a linux box that tries to sync with this xp box


    You really ought to do it the other way around. But that's your choice.

    > but it doesn't work for at least 5 minutes of the NTP service
    > starting. It returns error about stratum being too high.


    ntpd can not serve time to others until it is synced to a source of
    time.

    > I've searched around and people are saying that it takes about 5-8
    > minutes before the server trusts the local clock as the source. Nobody
    > has said why or if there is a way to fix this.


    We've covered this question before in the news-group.

    ntpd has to poll a time source 4 times before it collects enough data to
    make the time source a candidate for use.

    The default minimum poll period is 64 seconds.

    The first poll occurs immediately after ntpd starts up.

    4 polls takes ntpd_start_up_time + ( 3 * minimum_poll_period ) or ~ 200
    seconds (3 1/3 minutes)

    If you set "minpoll" to 4 the minimum poll period becomes 16 seconds.
    This reduces the intial "sync" time to a bit under one minute.

    server 127.127.1.0 minpoll 2
    fudge 127.127.1.0 stratum 10

    --
    Steve Kostecke
    NTP Public Services Project - http://support.ntp.org/

  8. Re: Windows server sync to LocalCLK

    John wrote:
    > Hi folks,
    >
    > I tried to start an NTP server on a XP Home box. The time source of this
    > box is the local clock. Now I have a linux box that tries to sync with
    > this xp box but it doesn't work for at least 5 minutes of the NTP
    > service starting. It returns error about stratum being too high.
    >
    > I've searched around and people are saying that it takes about 5-8
    > minutes before the server trusts the local clock as the source. Nobody
    > has said why or if there is a way to fix this.
    >
    > Can someone provide me with a solution to my problem or even a
    > explanation as to why I have to wait 5-8 minutes for the clock to sync.
    >
    >
    > Thanks for any help you may provide.
    >
    > John.



    Guys,

    thanks for the answers.

    I totally agree with everything you say in the fact that we should be
    using an external timesource and if anything, using the linux box as the
    server.

    Unfortunately an external timesource is not an option as the box won't
    have an external internet connection and also no GPS clock etc.....

    I used the minpoll option as recommended and it has made a big
    difference so I might just stick with that but if my boss decides its
    not good enough then i'll move over to another piece of software that is
    more appropriate to what I want to do.

    Thanks for your help guys,

    John

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