Synchronizing NTP in WAN and LAN - NTP

This is a discussion on Synchronizing NTP in WAN and LAN - NTP ; Hi All, I have a problem in synchronizing the time in LAN and WAN in our system. Only one of my system is connected to the WAN and the other systems in the LAN get their time from the NTP ...

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Thread: Synchronizing NTP in WAN and LAN

  1. Synchronizing NTP in WAN and LAN

    Hi All,

    I have a problem in synchronizing the time in LAN and WAN in our system.

    Only one of my system is connected to the WAN and the other systems in
    the LAN get their time from the NTP server running in the main system.

    I have two problems in this setup.

    1.The timeZone is always UTC in the LAN(Isn't it NTP's job to update
    timezone information?? )
    2. When ever the time zone is changed in the main system ,how to
    update it in the systems connected in the LAN.

    Forgive me if I am absurd since i am new to NTP.

    Regards
    Deepak

  2. Re: Synchronizing NTP in WAN and LAN

    >>> In article , peerlessdeepaks@gmail.com (Deepak Pandian) writes:

    Deepak> 1.The timeZone is always UTC in the LAN(Isn't it NTP's job to update
    Deepak> timezone information?? )

    NTP knows nothing about timezone information.

    Deepak> 2. When ever the time zone is changed in
    Deepak> the main system ,how to update it in the systems connected in the
    Deepak> LAN.

    That should be handled by the OS patch mechanism.
    --
    Harlan Stenn
    http://ntpforum.isc.org - be a member!

  3. Re: Synchronizing NTP in WAN and LAN

    On 2008-05-22, Deepak Pandian wrote:

    > Only one of my system is connected to the WAN and the other systems in
    > the LAN get their time from the NTP server running in the main system.
    >
    > I have two problems in this setup.


    You have a misunderstanding of how NTP works.

    > 1.The timeZone is always UTC in the LAN (Isn't it NTP's job to update
    > timezone information?? )
    >
    > 2. When ever the time zone is changed in the main system ,how to
    > update it in the systems connected in the LAN.


    NTP synchronizes clocks to a common time-base across a network. The most
    commonly used time-base is UTC.

    Most OS clocks are set to UTC. Display of this time in the correct time
    zone is handled by the appropriate userland, or system, utilities. Time
    zone changes are handled by the tools included with your OS.

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

  4. Re: Synchronizing NTP in WAN and LAN

    Hi,

    Thanks .


    > Most OS clocks are set to UTC. Display of this time in the correct time
    > zone is handled by the appropriate userland, or system, utilities. Time
    > zone changes are handled by the tools included with your OS.
    >



    It seems the OS reads the time zone information from a configured
    file.Is there any other protocol which can instruct the clients
    connected to it on timezone.

    Regards
    Deepak

  5. Re: Synchronizing NTP in WAN and LAN

    Deepak Pandian wrote:

    >
    > It seems the OS reads the time zone information from a configured
    > file.Is there any other protocol which can instruct the clients
    > connected to it on timezone.


    This depends on the OS. Some will require a reboot after such a change,
    as the file is read into an environment variable during startup. Others
    read the file every time. Some of those actually use a link to the file.

    For Windows, there may be something in group policies management, but
    note that the timezone is a property of each user.

    For Unix, any tool for remotely updating files, e.g. ftp, sftp, rsync,
    or even rsh, telnet, ssh, might be appropriate.

    Note that Unix users can override the timezone in their initialisation
    scripts, and you cannot predict how they will do this.

    Actually, why do you want to do this? For a normal modern Unix system,
    using the Olsen package, you should be setting the timezone when you
    install the system and updating the timezone database files when a
    significant legislation change changes the rules. Note, messing with
    the timezone files yourself may mean that an upgrade fails to update the
    file you've played with.

    Older Unix systems normally only need updating with legislation changes
    (provided you can specify the rules in terms of nth week or last week,
    but, unlike Olsen based systems, you cannot specify rule changes into
    the indefinite future.

    For Windows, legislation changes are implemented using Windows Update.

    If you are trying to move the clock an hour twice a year, with any
    operating capable of running ntpd, you are not using it properly.

  6. Re: Synchronizing NTP in WAN and LAN

    David Woolley wrote:
    >
    > Older Unix systems normally only need updating with legislation changes
    > (provided you can specify the rules in terms of nth week or last week,
    > but, unlike Olsen based systems, you cannot specify rule changes into
    > the indefinite future.
    >
    > For Windows, legislation changes are implemented using Windows Update.
    >


    You can also use tools to update the timezone information. I needed to
    do this for W2K as it was not supported without a maintenance contract.
    I forget the name of the tool but it's in the resource kit.

    Danny

  7. Re: Synchronizing NTP in WAN and LAN

    peerlessdeepaks@gmail.com (Deepak Pandian) writes:

    >Hi All,


    >I have a problem in synchronizing the time in LAN and WAN in our system.


    >Only one of my system is connected to the WAN and the other systems in
    >the LAN get their time from the NTP server running in the main system.


    >I have two problems in this setup.


    >1.The timeZone is always UTC in the LAN(Isn't it NTP's job to update
    >timezone information?? )


    ntp operates on UTC. It is the job of the system to translate UTC to local
    time zone information. (Yes, I know Windows is ignorant of such things).

    >2. When ever the time zone is changed in the main system ,how to
    >update it in the systems connected in the LAN.


    Time zone information is not ntp's job.



    >Forgive me if I am absurd since i am new to NTP.


    Not absurd. Just running windows (which may or may not be absurd) whose
    timekeeping leaves something to be desired.


  8. Re: Synchronizing NTP in WAN and LAN

    peerlessdeepaks@gmail.com (Deepak Pandian) writes:

    >Hi,


    >Thanks .



    >> Most OS clocks are set to UTC. Display of this time in the correct time
    >> zone is handled by the appropriate userland, or system, utilities. Time
    >> zone changes are handled by the tools included with your OS.
    >>



    >It seems the OS reads the time zone information from a configured
    >file.Is there any other protocol which can instruct the clients
    >connected to it on timezone.


    Yes. There cannot be. ntp is used to synchronize clocks where one is in
    Ulan Bator and the other if Ohio-- if they tried to use timezone info, this
    could not be done reasonably. Under many operating systems, the system
    clock is also in UTC making synchronization easy. Windows, following DOS
    decided to use local time, which causes may difficulties. ntp has to kludge
    it.


    >Regards
    >Deepak


  9. Re: Synchronizing NTP in WAN and LAN

    Unruh wrote:
    > peerlessdeepaks@gmail.com (Deepak Pandian) writes:
    >
    >> Hi All,

    >
    >> I have a problem in synchronizing the time in LAN and WAN in our system.

    >
    >> Only one of my system is connected to the WAN and the other systems in
    >> the LAN get their time from the NTP server running in the main system.

    >
    >> I have two problems in this setup.

    >
    >> 1.The timeZone is always UTC in the LAN(Isn't it NTP's job to update
    >> timezone information?? )

    >
    > ntp operates on UTC. It is the job of the system to translate UTC to local
    > time zone information. (Yes, I know Windows is ignorant of such things).
    >


    Nope. Windows also uses UTC and converts based on the time zone. ntpd
    works fine on Windows systems.

    Danny

  10. Re: Synchronizing NTP in WAN and LAN

    Unruh wrote:
    []
    > ntp operates on UTC. It is the job of the system to translate UTC to
    > local time zone information. (Yes, I know Windows is ignorant of such
    > things).



    Unruh,

    Like many OSes, Windows uses UTC internally and translates it to the time
    zone specified by the user for display. Start, Control Panel, Date and
    Time, Time Zone provides the user interface for this, and there are
    programs like TZedit which allow you to alter the registry settings
    controlling winter and summer local-to-UTC rules.

    http://download.microsoft.com/downlo...52f/tzedit.exe

    This is the third time you have provided incorrect information about
    Windows.

    Thanks,
    David



  11. Re: Synchronizing NTP in WAN and LAN

    "David J Taylor" writes:

    >Unruh wrote:
    >[]
    >> ntp operates on UTC. It is the job of the system to translate UTC to
    >> local time zone information. (Yes, I know Windows is ignorant of such
    >> things).



    >Unruh,


    >Like many OSes, Windows uses UTC internally and translates it to the time
    >zone specified by the user for display. Start, Control Panel, Date and
    >Time, Time Zone provides the user interface for this, and there are
    >programs like TZedit which allow you to alter the registry settings
    >controlling winter and summer local-to-UTC rules.


    > http://download.microsoft.com/downlo...52f/tzedit.exe


    >This is the third time you have provided incorrect information about
    >Windows.


    I will try to improve.


    >Thanks,
    >David




  12. Re: Synchronizing NTP in WAN and LAN

    David J Taylor wrote:

    > Like many OSes, Windows uses UTC internally and translates it to the time
    > zone specified by the user for display. Start, Control Panel, Date and
    > Time, Time Zone provides the user interface for this, and there are
    > programs like TZedit which allow you to alter the registry settings
    > controlling winter and summer local-to-UTC rules.


    Where does this legend stem from ?

    There seems to be a difference in what TZ the RTC reflects.
    ( At least the SuSE installer regularly ask if the RTC shows
    UTC or Local Time )

    uwe

  13. Re: Synchronizing NTP in WAN and LAN

    Uwe Klein wrote:
    > David J Taylor wrote:
    >
    >> Like many OSes, Windows uses UTC internally and translates it to the
    >> time zone specified by the user for display. Start, Control Panel,
    >> Date and Time, Time Zone provides the user interface for this, and
    >> there are programs like TZedit which allow you to alter the registry
    >> settings controlling winter and summer local-to-UTC rules.

    >
    > Where does this legend stem from ?


    Windows. Specifically Windows 3.x, 95, 98, ME, and 98SE. Also MS-DOS
    (these versions of Windows are really DOS extenders). These are all
    basically single timezone systems. Even NT (i.e. NT, 2000, 2003, XP,
    Vista) stores filesystem times in local time, at least for FAT and VFAT.
    >
    > There seems to be a difference in what TZ the RTC reflects.
    > ( At least the SuSE installer regularly ask if the RTC shows
    > UTC or Local Time )


    Windows continues to default to RTC = local time, partly for consistency
    and partly because they are optimised for ordinary people, who have
    problems with the concept of UTC, even in the UK. (I failed to convince
    the managing committee of my block of flats that electromechanical solar
    time lighting control clocks were not supposed to be reset when the
    clocks changed!)

  14. Re: Synchronizing NTP in WAN and LAN

    Uwe Klein wrote:
    > David J Taylor wrote:
    >
    >> Like many OSes, Windows uses UTC internally and translates it to the
    >> time zone specified by the user for display. Start, Control Panel,
    >> Date and Time, Time Zone provides the user interface for this, and
    >> there are programs like TZedit which allow you to alter the registry
    >> settings controlling winter and summer local-to-UTC rules.

    >
    > Where does this legend stem from ?


    It's not a legend - it's directly what you get from calls to the OS.

    http://msdn.microsoft.com/en-us/libr...90(VS.85).aspx

    and, for example, the need to use the GetLocalTime function to convert
    that value into local time:

    http://msdn.microsoft.com/en-us/libr...50(VS.85).aspx


    > There seems to be a difference in what TZ the RTC reflects.
    > ( At least the SuSE installer regularly ask if the RTC shows
    > UTC or Local Time )
    >
    > uwe


    The RTC runs in local time.

    Cheers,
    David



  15. Re: Synchronizing NTP in WAN and LAN

    Thank you very much for the info ( from Davidē )

    My last "intimate" contact to 'Windows was with win3.1/NVdos7
    ( and that system still lives )
    I've changed over to Unix/Linux in ~95.

    uwe


  16. Re: Synchronizing NTP in WAN and LAN

    Uwe Klein wrote:
    > Thank you very much for the info ( from Davidē )
    >
    > My last "intimate" contact to 'Windows was with win3.1/NVdos7
    > ( and that system still lives )
    > I've changed over to Unix/Linux in ~95.
    >
    > uwe


    You're welcome Uwe. I started with Windows NT in 1992, having come from a
    background of VMS various UNIX environments, CP/M, DOS and Windows 3.x.
    It's the 32-bit version of Windows which has been my main environment for
    the past 15 years, though, and it's a pleasure to program and use (for me,
    at least).

    Cheers,
    David



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