Re: [Ntp] Antw: Re: Antw: Re: New rev of the NTP port randomization I-D (Fwd: New Version Notification for draft-gont-ntp-port-randomization-01.txt)

Tony Finch <dot@dotat.at> Tue, 04 June 2019 13:12 UTC

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Date: Tue, 4 Jun 2019 14:12:13 +0100
From: Tony Finch <dot@dotat.at>
To: Hal Murray <hmurray@megapathdsl.net>
cc: Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>, "ntp@ietf.org" <ntp@ietf.org>
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Subject: Re: [Ntp] Antw: Re: Antw: Re: New rev of the NTP port randomization I-D (Fwd: New Version Notification for draft-gont-ntp-port-randomization-01.txt)
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Hal Murray <hmurray@megapathdsl.net> wrote:
>
> It looks like 64 bits to me.  You don't need to put an actual time in that
> slot.  Save the time, get a random number.  Put it in the packet and save it
> too.  When a reply arrives, compare the "time stamp" in the packet with the
> saved random number.  If they match, process using the saved time.
>
> There was a draft describing that a year or so ago.

OpenNTPD, Henning Brauer, 2004
https://www.openbsd.org/papers/ntpd_sucon04/mgp00011.html

Tony.
-- 
f.anthony.n.finch  <dot@dotat.at>  http://dotat.at/
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