Re: [v6ops] new draft: draft-yc-v6ops-solicited-ra-unicast

Erik Nordmark <nordmark@acm.org> Wed, 22 July 2015 22:22 UTC

Return-Path: <nordmark@acm.org>
X-Original-To: v6ops@ietfa.amsl.com
Delivered-To: v6ops@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id A0B891B2F46 for <v6ops@ietfa.amsl.com>; Wed, 22 Jul 2015 15:22:09 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.935
X-Spam-Level:
X-Spam-Status: No, score=-1.935 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, SPF_SOFTFAIL=0.665] autolearn=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 on2YjRWVcPCD for <v6ops@ietfa.amsl.com>; Wed, 22 Jul 2015 15:22:08 -0700 (PDT)
Received: from d.mail.sonic.net (d.mail.sonic.net [64.142.111.50]) (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 487331B2F44 for <v6ops@ietf.org>; Wed, 22 Jul 2015 15:22:08 -0700 (PDT)
Received: from [31.133.138.67] (dhcp-8943.meeting.ietf.org [31.133.138.67] (may be forged)) (authenticated bits=0) by d.mail.sonic.net (8.15.1/8.15.1) with ESMTPSA id t6MMLpoQ007415 (version=TLSv1.2 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Wed, 22 Jul 2015 15:21:53 -0700
To: Mark Smith <markzzzsmith@gmail.com>, Erik Kline <ek@google.com>
References: <201507071147.t67Bl13m009348@irp-lnx1.cisco.com> <CAO42Z2x7mNFbB_w_+W+80pY+LeCAKXaOBXMmQvkcaMSWhwW60g@mail.gmail.com> <EF21B630-5D0A-415A-A93F-9058900CC80C@cisco.com> <CAO42Z2zAqMXhBZ2wa=q0wtHGhMpMWU9TSjfFyd2quiki9w0oSw@mail.gmail.com> <85CADAA2-8DF2-4A6B-812B-7A77081936F5@cisco.com> <CAO42Z2w3fOxGJHasKqYZRfGZ2u=7FnZBm+jgLtgDvfZ7HYW=iw@mail.gmail.com> <CAO42Z2z+DwOin23HQTysrZ9dNP924+LQ-vOExmJc_xZUEB4yCQ@mail.gmail.com> <228248C6-94FE-4C9C-A875-F732EFDC6601@cisco.com> <CAAedzxqapiWuy4Gk5t3zEe3XmaLyRc3nc5=aA1ED0tzfeXckbA@mail.gmail.com> <CAKD1Yr3Hn9qJTaM0v3+hr7NfQbLc=mOWYGwrTK-XXxKp5v+dpg@mail.gmail.com> <CAAedzxpdFsCy2Y7U0gFmQeHEvJjNj-243g_ffoJsVUeRz5RpZw@mail.gmail.com> <CAKD1Yr1uR+HyBTB=Yhy5hGs1Z6Wv=HT3wwFgLYDosDJ7a78-PA@mail.gmail.com> <D1D2A832.1B7D8F%sgundave@cisco.com> <CAAedzxoX1dD3MQO5YCS6+u1esThW0sVv=JMmivJXZ92FKZ0sZg@mail.gmail.com> <CAO42Z2w8D+G7ONS5uXDP2kgf4da2JgiHHubEMt3TVumfFbkWOA@mail.gmail.com>
From: Erik Nordmark <nordmark@acm.org>
Message-ID: <55B0177F.8050703@acm.org>
Date: Thu, 23 Jul 2015 00:21:51 +0200
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:38.0) Gecko/20100101 Thunderbird/38.1.0
MIME-Version: 1.0
In-Reply-To: <CAO42Z2w8D+G7ONS5uXDP2kgf4da2JgiHHubEMt3TVumfFbkWOA@mail.gmail.com>
Content-Type: text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding: 7bit
X-Sonic-CAuth: UmFuZG9tSVY98wPbqrdhMAKsA+PGp8SM89Duok6WL/ueJ0qM273efGZIzKHMQq2mc/NTrVjXnklcteYdg46m844UUh4VJdv1
Archived-At: <http://mailarchive.ietf.org/arch/msg/v6ops/M4ElaGGs04QDcQp-pUV3AlQSNXE>
Cc: "draft-yc-v6ops-solicited-ra-unicast@tools.ietf.org" <draft-yc-v6ops-solicited-ra-unicast@tools.ietf.org>, v6ops list <v6ops@ietf.org>
Subject: Re: [v6ops] new draft: draft-yc-v6ops-solicited-ra-unicast
X-BeenThere: v6ops@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: v6ops discussion list <v6ops.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/v6ops>, <mailto:v6ops-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/v6ops/>
List-Post: <mailto:v6ops@ietf.org>
List-Help: <mailto:v6ops-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/v6ops>, <mailto:v6ops-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 22 Jul 2015 22:22:09 -0000

On 7/21/15 1:25 PM, Mark Smith wrote:
>
> I thought that could be an option, however I encountered RSes without
> the Source Link Layer Option, which means if RFC6085 is to be used,
> the link-layer header has to be available to get the source link-layer
> address from.
>
> After I wondered about the efficiency benefit of using multicasts for
> solicited RAs, Fred asked me to do some testing/investigation. I wrote
> up what I found here, the few unusual RS cases I saw the following,
> which I put down some thoughts about handling via e.g., RFC6085.
>
> o  RSes with a :: source address
>
> o  RSes with a link-local source addresses, but no Source Link-Layer
> Address Option

Yes, both of those are important (I had forgotten about the second one).

As you say, an implementation might be able to use the link-layer header 
and unicast back a packet. If the source was :: then that approach would 
rely on sending to the multicast ff02::1 while the link-layer 
destination is unicast.

If not, then the implementation needs to multicast the RA.

    Erik

>
> https://www.ietf.org/mail-archive/web/v6ops/current/msg22464.html
>
>
>
>
> https://www.ietf.org/mail-archive/web/v6ops/current/msg22464.html
>
>> But I would not say it's sufficient, if only from an "explicit
>> clarity" standpoint.  I think explicit mention of RAs and the other
>> discussion is helpful for implementors not inclined to dig to great
>> depths or just seeking explicit confirmation.
>>
>
>
>
>> _______________________________________________
>> v6ops mailing list
>> v6ops@ietf.org
>> https://www.ietf.org/mailman/listinfo/v6ops
> _______________________________________________
> v6ops mailing list
> v6ops@ietf.org
> https://www.ietf.org/mailman/listinfo/v6ops
>