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DHCP time server options RRS feed

  • Question

  • Hi,

    We have 3 Windows 2008 R2 DCs. DC A is PDC and sync time with the external time source. DC A is also DHCP server.

    There are two time options in DHCP: option 042 and option 004. My question is which option I should use and which time server (the PDC or external time source) should I put there ? 

    Please advise!

    Thanks in advance!


    Grace

    Tuesday, November 20, 2018 8:14 PM

All replies

  • Hi,

    If you would like to push NTP server settings to a non-windows device (Like IP Phone), use DHCP scope option 042. Do not use DHCP scope option 004 unless it is specifically mentioned in any documentation.

    Please refer to the link below:

    https://social.technet.microsoft.com/wiki/contents/articles/50924.active-directory-time-synchronization.aspx  

    Best regards,

    Travis


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    Wednesday, November 21, 2018 2:46 AM
    Moderator
  • Hi Travis,

    Thank you very much for your reply. One more question. Should I put the PDC IP in the option 042 or the external time source IP?

    Many thanks!


    Grace

    Wednesday, November 21, 2018 9:26 PM
  • Hi,

    NO, you shouldn't put the PDC IP in the two options.

    By default in Active Directory domain environment clients synchronize their time with domain controllers . Typically, this behavior does not need to be reconfigured.

    004 specifies servers that provide TIME/ITP (as per RFC 868). This is not a recommended protocol/service in a Windows environment.
    042 specifies servers that provide NTP/SNTP (RFC 1769).  This is the preferred time service in a Windows environment (assuming the absence of Active Directory which maintains the time on your behalf.

    Best regards,

    Travis


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    Thursday, November 22, 2018 6:47 AM
    Moderator
  • Hi,

    Just checking in to see if the information provided was helpful.

    Please let us know if you would like further assistance.

    Best Regards,

    Travis


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    Friday, November 23, 2018 11:26 PM
    Moderator