Re: [IPv6] RFC 6724 shouldn't prefer partial reachability over reachability

Kyle Rose <krose@krose.org> Sat, 25 November 2023 00:11 UTC

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From: Kyle Rose <krose@krose.org>
Date: Fri, 24 Nov 2023 19:11:06 -0500
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To: Ed Horley <ed@hexabuild.io>
Cc: Mark Smith <markzzzsmith@gmail.com>, 6man WG <ipv6@ietf.org>
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Subject: Re: [IPv6] RFC 6724 shouldn't prefer partial reachability over reachability
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On Fri, Nov 24, 2023 at 5:49 PM Ed Horley <ed@hexabuild.io> wrote:

> Other option is to just remove the ULA prefix entirely from 6724 and then
> the OS doesn’t see it as any different then GUA
>

That won't work for any deployment that doesn't NAT/NPT ULA space (which is
most of them) because without the label distinction a ULA source and GUA
destination might be chosen, resulting in one of several obvious classes of
unreachability in one direction or the other.

ULA and GUA must be treated differently for purposes of address selection:
what remains in dispute is exactly *how* that treatment should differ, not
*whether* it should.

Kyle