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Re: [Ntp] Antw: Re: Antw: [EXT] Local time in NTPv5?

Danny Mayer <mayer@pdmconsulting.net> Sun, 31 July 2022 22:28 UTC

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Date: Sun, 31 Jul 2022 18:27:36 -0400
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To: Hal Murray <halmurray@sonic.net>, Miroslav Lichvar <mlichvar@redhat.com>
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Subject: Re: [Ntp] Antw: Re: Antw: [EXT] Local time in NTPv5?
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On 7/29/22 12:27 PM, Hal Murray wrote:
> mlichvar@redhat.com said:
>> You mean the TZ POSIX string (option 100) from RFC4833? That looks like it
>> could work, even for announcing the DST change.
>> So, I guess the question is now are there any use cases for the local time in
>> NTP without DHCP?
That's irrelevant. NTP knows nothing about time zones.
> That only works if the DHCP servers in use actually support it.
>
> Is there a tool for poking at DHCP servers to see what they provide?  I poked
> around a bit but diddn't find one.
>
> I scanned the man page for the ISC DHCP server and didn't find any mention of
> NTP or time zones.  (ntp was mentioned as a logging option.)

DHCP supports NTP server provisioning. I worked with the DHCP WG on it a 
number of years ago. I don't know the RFC number.


> If a client gets its IP Address from a server, does it latch on to that server
> and ignore others?  Or will it try broadcasting to find other servers before
> giving up?  Can we setup a DHCP server that only provides time zone info?
>
Read the DHCP RFCs. I don't know if there is provisioning for time zones.

Danny

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