Insertion of IPv6 Segment Routing Headers in a Controlled Domain
Mark Smith <markzzzsmith@gmail.com> Wed, 29 March 2017 19:58 UTC
Return-Path: <markzzzsmith@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 463A41298AF for <ipv6@ietfa.amsl.com>; Wed, 29 Mar 2017 12:58:40 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.498
X-Spam-Level:
X-Spam-Status: No, score=-1.498 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, FROM_LOCAL_NOVOWEL=0.5, HK_RANDOM_ENVFROM=0.001, HK_RANDOM_FROM=0.001, SPF_PASS=-0.001] autolearn=no autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
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 fbgHwHL8xHPm for <ipv6@ietfa.amsl.com>; Wed, 29 Mar 2017 12:58:39 -0700 (PDT)
Received: from mail-vk0-x229.google.com (mail-vk0-x229.google.com [IPv6:2607:f8b0:400c:c05::229]) (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 D238F12989C for <ipv6@ietf.org>; Wed, 29 Mar 2017 12:58:38 -0700 (PDT)
Received: by mail-vk0-x229.google.com with SMTP id s68so30993260vke.3 for <ipv6@ietf.org>; Wed, 29 Mar 2017 12:58:38 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=dsTH74Uil0PuFEQkt72LkahUimvnULfRquXH4dpbQig=; b=mb7xOiPyUNr3IkeZc4E0HwEs9a1J6AuAxukIeDoKxxg58HsZwdr9qk9hDh2Sfj+E69 riTFoAJW89syhzMqszwHlqLRuuiVMjy6dzu2DWvs6LdDWKcccF/HV6bW3iKi7ybENZXp 6ErXtoi3cAf5Ib6UF24TkM+xhITKXwn2FNGe3hEvC7aYikwGtFy3+8axfe/fsa2U8A4P RthaoFWeo0gWXv4zStvscW+cXO15WbwjWQ1GjZIfbO4gn8WKCFem5cTeG/Zc38K8yd5Q Xt9zwm1VU++8/uNoHAGjZgRyhf5+G2EefRATZ6q03usElADKpdiMShmscWI8z/I0bD9N C7UA==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=dsTH74Uil0PuFEQkt72LkahUimvnULfRquXH4dpbQig=; b=rJa4YQlXedngAbIw6aGOBW6GR7DnqHauCU/BPpyErIIgdGMI8hOXw94qnUCyHo0/Du C16FPbS+hAaJB+eGKpEnr7VD9T/IZUE6TkDeiy878pdcDhwpUxtKtJd2rsBDO/pUyFHx 4WYi9+V6iF0/relRtWM/J7fPcwuYW1NIXLwePtPaARRS1ESHZk5lV4zmWVrC7nLSPY3G wW9PwtUCezLUyrhM+VMHMXrgwJMddePI9uY4C0ot9fOHrn3KaFnHwH69xEyrXUKH8664 xD0Ola1W6RsqczwnwY12Yah1sEe2ek0/6Fr5EVydyI4g/b20MpxyTK0t2Sr1K5mhQSNx MArA==
X-Gm-Message-State: AFeK/H06JlH1eMHyNrpZLZasDMHFCUalaKFpYZUagJNNW+82ki0LLP0Yuk6ETcBgw5npSULg152+bbj84omm+w==
X-Received: by 10.176.64.34 with SMTP id h31mr1233672uad.89.1490817517753; Wed, 29 Mar 2017 12:58:37 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.159.36.181 with HTTP; Wed, 29 Mar 2017 12:58:07 -0700 (PDT)
From: Mark Smith <markzzzsmith@gmail.com>
Date: Thu, 30 Mar 2017 06:58:07 +1100
Message-ID: <CAO42Z2y2+ouu+M_UW0PbY-bRpg+Ev0LTqYBjFj9FXFoYoaOiRA@mail.gmail.com>
Subject: Insertion of IPv6 Segment Routing Headers in a Controlled Domain
To: 6man WG <ipv6@ietf.org>
Content-Type: text/plain; charset="UTF-8"
Archived-At: <https://mailarchive.ietf.org/arch/msg/ipv6/UI0PfqrWco4Hpbvm8keGR8FabRg>
X-BeenThere: ipv6@ietf.org
X-Mailman-Version: 2.1.22
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: Wed, 29 Mar 2017 19:58:40 -0000
So having further about this, I have fundamental question that it isn't answering. Why can't IPv6-in-IPv6 encapsulation be used for this? What is missing from IPv6 that "requires" that EH insertion is used instead of much simpler, off-the-shelf encapsulation/decapsulation? For example, using IPv6-in-IPv6 encapsulation, I don't think an SRH is needed at all in the "2. Source Domain and Packet Journey" example. When node 2 realises that the link between itself and 3 has failed, it encapsulates the original SA=1, DA=9 packet in a new IPv6 header ("tunnelling" it). The new IPv6 header has an SA=2, DA=5, and is sent towards node 4. Node 4 forwards the packet onto node 5 using conventional destination address based IPv6 forwarding. Node 5 receives the packet, and as it is DA=5, decapsulates the inner SA=1, DA=9 packet. Node 5 then submits that packet to the standard IPv6 forwarding table, resulting in it being forwarded to Node 3, which then forwards it to Node 9. All of this is happening using conventional IPv6 destination based forwarding. Encapsulation is solving this problem by effectively creating a on-demand virtual link or tunnel between Node 2 and Node 5, getting the original packet past the failure point to a point along the original packet's forwarding path. Once there, it pops out of the virtual link and is sent along its way. I don't think the insertion of the EH and DA swapping method could be described the same way or could be described as simply. I think this IP-in-IPv6 encapsulation solution to the above example is better because: - there is no need for an additional header of any type - the path information is inherent in the DA of the outer IPv6 header when sent to node 5, and in the DA of the inner IPv6 packet (now "the packet") when being sent by node 5 to node 9. - Encapsulation/Decapsulation performed by nodes 2 and nodes 5 is conventional IPv6-in-IPv6 encapsulation, specified in RFC2473, now nearly 20 years old. - In this example, nodes 4, 5 and 3 could be off-the-shelf IPv6 devices that support conventional IPv6 forwarding and conventional IPv6-in-IPv6 encapsulation/decapsulation (i.e., "tunnelling"). - Encapsulation/decapsulation is a simpler, universal and proven operation (literally being done every time an IPv6 packet is being sent and received over any and all layer 2 links) compared to the DA address swapping that occurs at Nodes 2 and Nodes 5 in the described method. More complicated examples would may require more information to be carried about the path between the inner and outer IPv6 headers (although encapsulation inside encapsulation/tunnelling inside tunnelling probably be used at a greater packet overhead host, with simpler per-hop processing), however I don't think this example demonstrates why EH insertion is required. Regards, Mark.
- Insertion of IPv6 Segment Routing Headers in a Co… Mark Smith
- Re: Insertion of IPv6 Segment Routing Headers in … Mark Smith
- Re: Insertion of IPv6 Segment Routing Headers in … Dirk Steinberg
- Re: Insertion of IPv6 Segment Routing Headers in … Mark Smith
- Re: Insertion of IPv6 Segment Routing Headers in … Robert Raszuk
- Re: Insertion of IPv6 Segment Routing Headers in … Mark Smith
- Re: Insertion of IPv6 Segment Routing Headers in … Mark Smith
- Re: Insertion of IPv6 Segment Routing Headers in … Satoru Matsushima
- Re: Insertion of IPv6 Segment Routing Headers in … Satoru Matsushima
- Re: Insertion of IPv6 Segment Routing Headers in … Stefano Previdi (sprevidi)
- Re: Insertion of IPv6 Segment Routing Headers in … Satoru Matsushima
- Re: Insertion of IPv6 Segment Routing Headers in … Stefano Previdi (sprevidi)
- Re: Insertion of IPv6 Segment Routing Headers in … Satoru Matsushima
- Re: Insertion of IPv6 Segment Routing Headers in … Stefano Previdi (sprevidi)
- Re: Insertion of IPv6 Segment Routing Headers in … Dirk Steinberg
- Re: Insertion of IPv6 Segment Routing Headers in … John Leslie
- Re: Insertion of IPv6 Segment Routing Headers in … Brian E Carpenter
- Re: Insertion of IPv6 Segment Routing Headers in … Robert Raszuk
- Re: Insertion of IPv6 Segment Routing Headers in … Mark Smith
- Re: Insertion of IPv6 Segment Routing Headers in … Mark Smith
- Re: Insertion of IPv6 Segment Routing Headers in … Mark Smith
- Re: Insertion of IPv6 Segment Routing Headers in … Stefano Salsano
- Re: Insertion of IPv6 Segment Routing Headers in … Brian E Carpenter