Re: New Version Notification for draft-hinden-ipv4flag-00.txt

Nick Hilliard <nick@foobar.org> Sat, 18 November 2017 13:15 UTC

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Date: Sat, 18 Nov 2017 13:15:34 +0000
From: Nick Hilliard <nick@foobar.org>
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To: Lorenzo Colitti <lorenzo@google.com>
CC: Simon Hobson <linux@thehobsons.co.uk>, IETF IPv6 Mailing List <ipv6@ietf.org>
Subject: Re: New Version Notification for draft-hinden-ipv4flag-00.txt
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Lorenzo Colitti wrote:
> On Sat, 18 Nov 2017, 20:10 Simon Hobson, <linux@thehobsons.co.uk>; wrote:
>     Doesn't that come with exactly the same problem as described ? If
>     *ANY* router on the network provides IPv6 only, then it'll signal
>     that there's no IPv4 on the network even though there may well be.
> 
> It would be up to the administrator to ensure that no router sent the
> option unless the network were truly IPv4-only. So the situation you
> describe would be a configuration error.

there would also be a SAVI implication here; otherwise any connected
host on an l2 domain would be able to disable ipv4 on any host that was
listening to a flag of this form.

These and other issues were brought up before in the context of the
sunset4 draft.

Nick