[Ntp] Antw: Re: Antw: Re: Antw: Re: Calls for Adoption -- NTP Extension Field drafts -- Four separate drafts

"Ulrich Windl" <Ulrich.Windl@rz.uni-regensburg.de> Mon, 02 September 2019 10:39 UTC

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Date: Mon, 02 Sep 2019 12:38:56 +0200
From: Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>
To: "ntp@ietf.org" <ntp@ietf.org>, mlichvar@redhat.com
References: <Ulrich.Windl@rz.uni-regensburg.de> <5D6CB84E020000A100033405@gwsmtp.uni-regensburg.de> <20190902093750.DA05940605C@ip-64-139-1-69.sjc.megapath.net> <20190902095854.GC15024@localhost> <EC0267640200002C6A6A8CFC@gwsmtp.uni-regensburg.de> <A7C4D27502000083822C0D04@gwsmtp.uni-regensburg.de> <D5F28766020000316A6A8CFC@gwsmtp.uni-regensburg.de> <2E18D20E0200009A822C0D04@gwsmtp.uni-regensburg.de> <4B834D170200006586EDC2A6@gwsmtp.uni-regensburg.de> <831B91BE020000B87ED719BE@gwsmtp.uni-regensburg.de> <5D6CB84E020000A100033405@gwsmtp.uni-regensburg.de> <6A31A7C90200006043047E14@gwsmtp.uni-regensburg.de> <87F2C84C0200007A6A6A8CFC@gwsmtp.uni-regensburg.de>
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Subject: [Ntp] Antw: Re: Antw: Re: Antw: Re: Calls for Adoption -- NTP Extension Field drafts -- Four separate drafts
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>>> Miroslav Lichvar <mlichvar@redhat.com> schrieb am 02.09.2019 um 11:58 in
Nachricht <20190902095854.GC15024@localhost>:
> On Mon, Sep 02, 2019 at 02:37:50AM ‑0700, Hal Murray wrote:
>> 
>> Ulrich.Windl@rz.uni‑regensburg.de said:
>> > But remember that a "node" is NOT "an IP address". With multi‑homed hosts

> you
>> > can have interesting synchronization loops... ;‑) 
>> 
>> Is there a problem with using an IPv6 address to identify a system?  (if
you 
> are multi‑homed, just pick one)

So in principle that ID could change at a server restart?

> 
> If the system has multiple addresses, its clients may not know all of
> them and may fail to detect loops. Addresses are no good.

Yes, especially if virtual IP addresses come and go.

> 
> We need each server (or rather the clock) to have an ID and extend the
> protocol to exchange this ID so clients (that operate also as servers)
> can reliably detect 1‑degree loops. The suggested‑refid EF basically
> does that.

Yes.

> 
> ‑‑ 
> Miroslav Lichvar
> 
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