Re: Forwarding Packets With Link Local Destination Addresses

Carsten Bormann <cabo@tzi.org> Fri, 08 January 2021 09:45 UTC

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Subject: Re: Forwarding Packets With Link Local Destination Addresses
From: Carsten Bormann <cabo@tzi.org>
In-Reply-To: <CAJE_bqfSkvpT0PfbGxPmJ450+_DWH_66O9h=pbRkn36mB27sBA@mail.gmail.com>
Date: Fri, 8 Jan 2021 10:45:03 +0100
Cc: Fernando Gont <fgont@si6networks.com>, Ron Bonica <rbonica=40juniper.net@dmarc.ietf.org>, "6man@ietf.org" <6man@ietf.org>
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On 8. Jan 2021, at 01:56, 神明達哉 <jinmei@wide.ad.jp> wrote:
> 
> we
> could allow the following:
> 
> - A node sends a packet with a routing header that would route the
>  packet to a global address (D1) and then to a link-local (final)
>  destination (D2).
> - The packet leaves the source link and is delivered to the interface
>  corresponding to the global address D1.
> - The receiving node now sets D2 as the destination address of the
>  IPv6 header and forwards the packet to the link where the packet is
>  delivered to D2 (so it does not forward the packet to "other link”).

This is about a hypothetical, but:
How would it know which of its many links that is?

(Imagine D2 being …::1, or some other likely If-ID.
Even if not: Would D1 have to ND that address on all its links?)

(And how exactly would D2 reply?)

Grüße, Carsten