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

Miroslav Lichvar <mlichvar@redhat.com> Mon, 02 September 2019 09:59 UTC

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Date: Mon, 2 Sep 2019 11:58:54 +0200
From: Miroslav Lichvar <mlichvar@redhat.com>
To: ntp@ietf.org
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References: <Ulrich.Windl@rz.uni-regensburg.de> <5D6CB84E020000A100033405@gwsmtp.uni-regensburg.de> <20190902093750.DA05940605C@ip-64-139-1-69.sjc.megapath.net>
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Subject: Re: [Ntp] Antw: Re: Antw: Re: Calls for Adoption -- NTP Extension Field drafts -- Four separate drafts
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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)

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

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.

-- 
Miroslav Lichvar