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Thread: Changing time on DHCP server

  1. #1

    Default Changing time on DHCP server

    Good Day All,

    I have a DHCP server who's system time is ahead by about two hours.
    I want to enable NTP on this machine to keep the time correct from now on.

    What are the risks of moving the time back on this server to get the time correct.

    I was thinking of doing the following, but can't seem to find any documentation on what the impact would be:
    1. Stop the DHCP service
    2. Run ntpdate -s [IP of NTP server]
    3. Configure and enable NTP
    4. Start DHCP service

    Could someone please provide some advice?

    TIA

  2. #2
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    Default Re: Changing time on DHCP server

    I find it hard to think of any time issue would affect DHCP unless your server is part of an LDAP or AD Domain.
    Assuming your DHCP server is "standalone"
    You should be able to just re-configure your system time and although shouldn't be needed if it makes you feel better to reboot.

    You can easily make your change using YaST > System > Date & Time.

    Double-check and be certain your time zone is correct, it's a common cause of an incorrect offset. This must be set correctly or all your time settings will be thrown off (and things like using NTP won't help).

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  3. #3
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    Default Re: Changing time on DHCP server

    Also depends on the openSUSE version. I've seen reports where people activated both chrony and ntp, resulting in the system time being 2 hours off.
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  4. #4
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    Lightbulb Re: Changing time on DHCP server

    @Darrynl:

    System time depends on UNIX® or, not UNIX®:
    1. In the UNIX® world – and therefore, Linux also – the System Time [Hardware Clock] (for PC based systems, the BIOS clock) is usually set to UTC.
    2. For the Redmond world, the System Time is normally set to Local Time «but, there's a Registry value which can be changed to line up with the UNIX® world» …


    Why set System Time to UTC?
    • If the System Time is set to UTC then, all the Time Stamps (at System level) are UTC. Usually, when the user queries a Time Stamp, a value corrected to the Local Time is displayed.
    • This means that, across all the networked systems, regardless of where they are on Planet Earth or, in Outer Space, the Time Stamps are consistent – across ALL systems …


    In your case, Time Stamps “off” by 2 hours is similar to what happens when, Central European Summer Time is being compared against UTC …

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