Re: NTP Synchronisation Problem

From: Scott McMillan (smcm_at_usa.net)
Date: 06/16/04

  • Next message: cbmart: "HP/Compaq Dual Port NIC on 5.0.5" 
    Date: Wed, 16 Jun 2004 11:37:26 -0400

    On Wed, 16 Jun 2004 15:43:15 +0100, "itandt"
    <ITandT_Shannon@hotmail.com> wrote:

    <reverted top posting>

    >"Ian Wilson" <scobloke2@infotop.co.uk> wrote in message
    >news:caphlj$4m6$1@sparta.btinternet.com...
    >> itandt wrote:
    >> > Hi all
    >> > I am trying to get my SCO Openserver 5 Unix platform to accept an NTP
    >> > broadcast from a PC running Windows which is connected to an Internet
    >time
    >> > source.
    >> >
    >> > So far the solution has eluded me.
    >> > I have configured ntp.conf in /etc as well as resolv.conf, ntp.drift,
    >hosts
    >> > I have set the local time source to have a stratum of 10 but cannot get
    >the
    >> > time to synchronise with the Windows box.
    >> >
    >> > I start NTP using xntpd -bdd and can see Unix confirming the server ip
    >for
    >> > the Windows box but it won't synchronise.
    >> > Could anyone here please assist?
    >> >
    >>
    >> You dont say which version of Windows or include any config files so its
    >> hard to say what the problem is. However ...
    >>
    >>
    >> 1) Windows has no native support for NTP, Some versions can act as an
    >> SNTP client to an NTP server. SNTP is not NTP. Windows also has its own
    >> native proprietary time sync protocol (Windows Time Service) but this is
    >> not NTP. NTP is capable of continuously syncing time to milliseconds
    >> across continents withe relatively low network loading. AFAIK Windows
    >> Time service doesn't take into account clock drift, clock reliability,
    >> network latency and other factors. My feeling is that feeding NTP with a
    >> lower quality time service is not really optimal.
    >>
    >> 2) NTP is not based on broadcasts. NTP clients poll their servers at
    >> intervals determined dynamically by network latency, clock drift, server
    >> consistency and other factors.
    >>
    >> 3) For good NTP operation you really need three independant sources of
    >> NTP time. With less than this its impossible to tell a good clock from a
    >> bad clock.
    >>
    >> In all the sites I've done this, Windows systems get time from Unix
    >> systems, not the other way around. Because NTP is more accurate than
    >> WTS. On non trivial LANS, I'd select three servers as NTP peers, all
    >> others would have these three as sources in their NTP conf. The three
    >> NTP servers would each have at least three upstream (lower stratum)
    >> Internet time providers (or radio/gsm/etc clocks)
    >>
    >> What NTP software are you running on the Windows box?
    >> On the SCO box, what does ntpq -p tell you?
    >
    >Windows box is runing "tardis", available from http://www.kaska.demon.co.uk/
    >This takes a time source from the net and broadcasts NTP signals over your
    >network, as well as setting the time on the local box.
    >I am testing this on a Windows 2000 Professional workstation but will
    >ultimately deploy on a Windows 2000 Server.
    >It is definitely broadcasting an NTP pulse. Every 8 seconds.
    >
    >ntpq -p reports:
    >
    > remote refid st t when poll reach delay offset
    >disp
    >============================================================================
    >==
    >*LOCAL(10) LOCAL(1) 10 l 27 64 377 0.00 0.000
    >200.00
    >

    According to the website:

    "Tardis 2000 running on a central server can be used as a master time
    source for the domain by running the appropriate version of Tardis or
    K9 on the other workstations."

    So, your SCO box may not be able to get the time from Tardis.
    However, have you tried the broadcastclient and/or mulitcastclient
    options to ntpd (man ntpd)? I've not used them myself so I have no
    pointers for you.

    Scott McMillan

  • Next message: cbmart: "HP/Compaq Dual Port NIC on 5.0.5"

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