IETF Logo Mail Archive

Re: Forwarding Packets With Link Local Destination Addresses

神明達哉 <jinmei@wide.ad.jp> Fri, 08 January 2021 14:41 UTC

Return-Path: <jinmei.tatuya@gmail.com>
X-Original-To: ipv6@ietfa.amsl.com
Delivered-To: ipv6@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id BAF9C3A0E93 for <ipv6@ietfa.amsl.com>; Fri, 8 Jan 2021 06:41:07 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.402
X-Spam-Level:
X-Spam-Status: No, score=-1.402 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, FREEMAIL_FORGED_FROMDOMAIN=0.249, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.248, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=no autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 1S6_k9RJKj8H for <ipv6@ietfa.amsl.com>; Fri, 8 Jan 2021 06:41:05 -0800 (PST)
Received: from mail-ua1-f51.google.com (mail-ua1-f51.google.com [209.85.222.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id B862A3A09ED for <6man@ietf.org>; Fri, 8 Jan 2021 06:41:05 -0800 (PST)
Received: by mail-ua1-f51.google.com with SMTP id t15so3486307ual.6 for <6man@ietf.org>; Fri, 08 Jan 2021 06:41:05 -0800 (PST)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=2c2OTBojvEqQDqxABksXRRWyzwY2SdpLNaa+BzzNuAQ=; b=KorlOaCxiJemWxGpBpE90mz8HnWftrFH/SRZUgCIoTHRTRiS1+MVUf5A/6tSEgnYdq Nlquw4oPkaWuj2yx5HkIvBn8Y/QFi4zwfXj8ZGRXO3z7c0JZNlgikJibbg0Et+tsujhh UclI3OYFupcvswqXALvQS9PpgyF1W/sJMBp7FKAClOgU78HQyJNgesMtM310E/u7Hlno oMYo31zNkcqQ9YcaGu8fiWqcSPvjQbdeAEcdYgvFZhtZo5wtj+LF+iQgvN87CPtwu4Tv 0AqO86/f4C4gv4gw/P2eUBP61+3urgpQieWHuMedHvYF6A998Xe/t67CBxV6VpNmM9h2 Db3w==
X-Gm-Message-State: AOAM5331pa1t+zLYzOTMXwnvEiQVzXPbtRiqxQ/tqh1QIEwY8VDzVvUd PxgHOWN2pzXPWQLitCR19pWX50nkOAMVa+uGkDw=
X-Google-Smtp-Source: ABdhPJwGQbfft7mCPxxARiNvftfKhI7lNPzcnTVVT0+OHSOAv3uB83Ck0QJ62ExTAK8SmDkJXfWD5TJw7zhYdKKIRms=
X-Received: by 2002:ab0:a9a:: with SMTP id d26mr3167512uak.75.1610116864727; Fri, 08 Jan 2021 06:41:04 -0800 (PST)
MIME-Version: 1.0
References: <DM6PR05MB6348A18046C5DDC7CF2AED76AEAF0@DM6PR05MB6348.namprd05.prod.outlook.com> <fc2600de-308a-7162-db12-d1d906302494@si6networks.com> <CAJE_bqfSkvpT0PfbGxPmJ450+_DWH_66O9h=pbRkn36mB27sBA@mail.gmail.com> <3F8BB900-B77E-473D-8DF2-02FEA3E2BA32@tzi.org>
In-Reply-To: <3F8BB900-B77E-473D-8DF2-02FEA3E2BA32@tzi.org>
From: =?UTF-8?B?56We5piO6YGU5ZOJ?= <jinmei@wide.ad.jp>
Date: Fri, 8 Jan 2021 06:40:53 -0800
Message-ID: <CAJE_bqfpAS0rM4NKuiVu679Dj5f1zYU7iF7ujriiRnM1CYQN-A@mail.gmail.com>
Subject: Re: Forwarding Packets With Link Local Destination Addresses
To: Carsten Bormann <cabo@tzi.org>
Cc: Ron Bonica <rbonica=40juniper.net@dmarc.ietf.org>, Fernando Gont <fgont@si6networks.com>, "6man@ietf.org" <6man@ietf.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: <https://mailarchive.ietf.org/arch/msg/ipv6/2lleaL5fQdTTWiednRJSORHX6Ss>
X-BeenThere: ipv6@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "IPv6 Maintenance Working Group \(6man\)" <ipv6.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ipv6>, <mailto:ipv6-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ipv6/>
List-Post: <mailto:ipv6@ietf.org>
List-Help: <mailto:ipv6-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ipv6>, <mailto:ipv6-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 08 Jan 2021 14:41:08 -0000

At Fri, 8 Jan 2021 10:45:03 +0100,
Carsten Bormann <cabo@tzi.org> wrote:

> > 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?

It would be "the link where the packet is delivered to D2".

> (And how exactly would D2 reply?)

It's tricky (and nearly impossible in practice) as RFC 4007 explains:

   [...]  This will help the receiving node send a
   "response" packet with the final destination of the received packet
   as the source address without breaking its source zone.

--
JINMEI, Tatuya

v2.2.0 | Report a Bug | By Email