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Hello everyone, I don't quite understand the behaviour of the root dispersion of Windows NTP servers. I would like to set up a network of Windows-based and non-Windows-based devices. I would like to define a computer with Windows 10 (Enterprise LTSC version 1809) as the NTP server that is to supply non-Windows-based devices with Chronyd time service with a synchronised time. However, the computer is only a secondary reference and receives its time as a client from an external Windows NTP server. Unfortunately, this secondary server receives the time with too high a root dispersion (~10s fluctuation). According to the manufacturer, the devices with Chronyd time service that are supposed to connect to this time server only accept a root dispersion of less than 3s. How does the root dispersion generally behave in such an architecture? Is the root dispersion passed through over several levels or does it add up over several levels? Is it possible to forward the root dispersion on the secondary server with a value less than 3s without adjusting the root dispersion of the primary server? Maybe you can enlighten me about the behaviour or have an idea how I could implement this scenario. Best regards Tobias
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Hi TobiasHerczeg-9965
Regarding the NTP tracking tool, the Windows Time service (W32Time) synchronizes the date and time for all computers managed by Active Directory Domain Services (AD DS). This article covers the different tools and settings used to manage the Windows Time service.
See Windows Time service tools and settings | Microsoft Learn
Best Regards,
Ian Xue
If the Answer is helpful, please click "Accept Answer" and upvote it.
Hello Ian Xue, thank you for the answer. How do I have to configure my secondary reference which is synchronizing its time with the primary NTP server (working with local CMOS) to get a second level time source with a lower root dispersion (~2s) than published by the primary NTP server with local CMOS (root dispersion ~10s). Best regards Tobias
Hi TobiasHerczeg-9965
You can use the config LocalClockDispersion.
Does changing the local clock dispersion time on the secondary reference affect the root dispersion? Regarding to the explanation in the group policy changing the local clock dispersion does only affect the time when it is running with local CMOS time. Since the secondary reference gets its time from the primary server, changing the local clock dispersion has no influence on the root dispersion. Or am I not understanding something correctly here? I tried these recommendation as you can see in another comment. What do you say to this behaviour?
Hi TobiasHerczeg-9965, Thanks for your reply. I have done a lot of research but didn’t find any information regarding if changing the local clock dispersion time on the secondary reference affect the root dispersion. For deeper advisory issue, it is highly recommended to locate to Microsoft Phone Support for exact information. Support channel: Contact Us - Microsoft Support
