IETF Logo Mail Archive

Re: fe80::/16 on specific link layers

神明達哉 <jinmei@wide.ad.jp> Fri, 28 July 2017 18:27 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 AA892131D1A for <ipv6@ietfa.amsl.com>; Fri, 28 Jul 2017 11:27:58 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.4
X-Spam-Level:
X-Spam-Status: No, score=-2.4 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, FREEMAIL_FORGED_FROMDOMAIN=0.199, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=ham 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 n7DlDPUiPE8x for <ipv6@ietfa.amsl.com>; Fri, 28 Jul 2017 11:27:57 -0700 (PDT)
Received: from mail-qk0-x232.google.com (mail-qk0-x232.google.com [IPv6:2607:f8b0:400d:c09::232]) (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 088EB131C89 for <ipv6@ietf.org>; Fri, 28 Jul 2017 11:27:57 -0700 (PDT)
Received: by mail-qk0-x232.google.com with SMTP id d145so117079944qkc.2 for <ipv6@ietf.org>; Fri, 28 Jul 2017 11:27:56 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=Q7GT8lWIDxzJdp5Yasg2kQ6PGe2B+i/12IIk2M4v7TE=; b=G66b28+W1RMdiyf24QXE5zqB+GGJZrkI2JH5+68Ufm9pKg2FQJROxmfL1M7+kjt7aK +h+Gu7Dw0GCTjaW+36dzVMtIBqQfEsNOB78+BjGT6hI3Vwd/dYsnxahi80fOJ6As7W1e iW7Dr7z+XUIrnRouen9itfqmJgwj7CP2WfFi7JFvb1DQwh/3A0ZporA/Bn3pI4d5+cHv sVKRMP7tKk9NTOJTNLxEjS+UeZghL/E2cChi3yXbZZuoRQZg5hY7bjzWsVcmDeyppHTi 0DAjdKe1nrR3U2iFzTBwnyETYpOefrZ4fL9Z+hYcrEOoUvvPKRt/WIgSetFbK4PtFRnY m8kQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=Q7GT8lWIDxzJdp5Yasg2kQ6PGe2B+i/12IIk2M4v7TE=; b=D9bOSF+EvHA9jm/kIcgmgu2LQIiXK7StdoKU4rOU6IEwa+37hV61OFNWO4qGZ5MINW AzoM+/Xh3S6RqEs/BCNQvx8rgQ0iTH1IZflNzJpDu+NopxXVGIuSoF7bjYBbZ3bmX0vQ hJ7MvTodHL8lasCOD6okK6P4GCfzx5mq4N+sK1t7kfzm/L4Oz/cHdl86Aa6D8t8jc6Et OViNkm3gF3AbhM4rFe2b9l7zZb6708BScvjsfgXV0LZIjPAhFfH4BxcZa4fUaxmXFJj8 76YOtS0XZMVaOgV7L0HQmM7+pqFiINQ0gC6wMa54xONUshpEFaFAo9SKsdi7vvS5gcQ+ lRug==
X-Gm-Message-State: AIVw113vDLTTZc6jZFrIp6psCR1W/vgDRWagpgE6TQ6RwMvE+GP1/kw0 yCKYjCIAfA8VfmTjhJbRV+nIagZSnQ==
X-Received: by 10.55.144.130 with SMTP id s124mr11956409qkd.136.1501266476086; Fri, 28 Jul 2017 11:27:56 -0700 (PDT)
MIME-Version: 1.0
Sender: jinmei.tatuya@gmail.com
Received: by 10.237.60.60 with HTTP; Fri, 28 Jul 2017 11:27:55 -0700 (PDT)
In-Reply-To: <93fd6e1d18f244a095906cf7af8a1ae2@XCH15-06-08.nw.nos.boeing.com>
References: <93fd6e1d18f244a095906cf7af8a1ae2@XCH15-06-08.nw.nos.boeing.com>
From: 神明達哉 <jinmei@wide.ad.jp>
Date: Fri, 28 Jul 2017 11:27:55 -0700
X-Google-Sender-Auth: 2nPHQFi60OWdUzIhMIvqpNUrrLE
Message-ID: <CAJE_bqey4+sqLJFYj4pgEi7sizPh5Uta2Pd9Nnm_Hvadj1gWEQ@mail.gmail.com>
Subject: Re: fe80::/16 on specific link layers
To: "Templin, Fred L" <Fred.L.Templin@boeing.com>
Cc: "ipv6@ietf.org" <ipv6@ietf.org>
Content-Type: text/plain; charset="UTF-8"
Archived-At: <https://mailarchive.ietf.org/arch/msg/ipv6/fuzpfBXJHeBfsEddMBtgIpGjKvk>
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: Fri, 28 Jul 2017 18:27:59 -0000

At Fri, 28 Jul 2017 14:30:01 +0000,
"Templin, Fred L" <Fred.L.Templin@boeing.com> wrote:

> Hi, I am seriously considering the use of fe80::/16 on a specific link layer
> so that the network part is 16 bits and the "host" part is 112 bits.
>
> Taking AERO for example, for the IPv6 prefix 2001:db8:1:2::/64 the
> corresponding LL address is fe80:2001:db8:1:2::/16.
>
> The question is what would break if we did this? The link layer would
> know how to deal with it, but would the IPv6 layer be able to handle it?
> And, what about apps that deal with IPv6 LL's?

It would break BSD-variant implementations, which internally use the
2nd 16-bit field of link-local addresses to identify the corresponding
link, e.g., fe80:1::abcd means fe80::abcd in link "#1".  (It's an
internal form and doesn't appear on wire).

Yes, that's an ugly implementation-specific hack and you could blame
the designer of the idea.  But I'm afraid we can't simply ignore the
deployment base as a matter of practice.

--
JINMEI, Tatuya

v2.46.0 | Report a Bug | By Email | System Status