RE: Comments on draft-yourtchenko-colitti-nd-reduce-multicast

"Hemant Singh (shemant)" <shemant@cisco.com> Fri, 21 February 2014 19:24 UTC

Return-Path: <shemant@cisco.com>
X-Original-To: ipv6@ietfa.amsl.com
Delivered-To: ipv6@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id AF49D1A0561 for <ipv6@ietfa.amsl.com>; Fri, 21 Feb 2014 11:24:43 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -15.049
X-Spam-Level:
X-Spam-Status: No, score=-15.049 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_HI=-5, RP_MATCHES_RCVD=-0.548, SPF_PASS=-0.001, USER_IN_DEF_DKIM_WL=-7.5] autolearn=ham
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 ATScFQIyHbgp for <ipv6@ietfa.amsl.com>; Fri, 21 Feb 2014 11:24:41 -0800 (PST)
Received: from rcdn-iport-5.cisco.com (rcdn-iport-5.cisco.com [173.37.86.76]) by ietfa.amsl.com (Postfix) with ESMTP id 7CD841A054A for <ipv6@ietf.org>; Fri, 21 Feb 2014 11:24:41 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=2517; q=dns/txt; s=iport; t=1393010678; x=1394220278; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-transfer-encoding:mime-version; bh=jj9jbN0Iuh1bhs5Lts4Evm3/RuE0ptrZNdo7uBWddoc=; b=N7V/Pum76n7wGY0Dp2Vk9y2HYVDIBHFmWYjD6RLfdMnJRZJonM5INIre Lb9B+boyRyWfwb9qM5c0LMH6xV8JAWKTQJbr50MhEVriyComsTr6Psahh 1BhjyZThqQjt6S8tfg3A2whFScV4qeGVCJDhMYMiFlGQSSHwa9QEJLmGl k=;
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: AgQFAMenB1OtJV2Y/2dsb2JhbABagwY7V8A9gQ8WdIIlAQEBBAEBATc0CwwEAgEIDgMEAQELFAkHJwsUCQgCBA4FCId9DcsfEwSOMzEHBoMegRQEqluDLYIq
X-IronPort-AV: E=Sophos;i="4.97,520,1389744000"; d="scan'208";a="305684422"
Received: from rcdn-core-1.cisco.com ([173.37.93.152]) by rcdn-iport-5.cisco.com with ESMTP; 21 Feb 2014 19:24:37 +0000
Received: from xhc-aln-x03.cisco.com (xhc-aln-x03.cisco.com [173.36.12.77]) by rcdn-core-1.cisco.com (8.14.5/8.14.5) with ESMTP id s1LJOb9s025711 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL); Fri, 21 Feb 2014 19:24:37 GMT
Received: from xmb-rcd-x06.cisco.com ([169.254.6.236]) by xhc-aln-x03.cisco.com ([173.36.12.77]) with mapi id 14.03.0123.003; Fri, 21 Feb 2014 13:24:37 -0600
From: "Hemant Singh (shemant)" <shemant@cisco.com>
To: Ole Troan <otroan@employees.org>
Subject: RE: Comments on draft-yourtchenko-colitti-nd-reduce-multicast
Thread-Topic: Comments on draft-yourtchenko-colitti-nd-reduce-multicast
Thread-Index: AQHPLg2r7NCj0C4O60mg5b5bMD7HkJq/uMUQgACleYD//7AWIIAACkvA
Date: Fri, 21 Feb 2014 19:24:36 +0000
Message-ID: <75B6FA9F576969419E42BECB86CB1B89115F9D68@xmb-rcd-x06.cisco.com>
References: <5305AF13.5060201@acm.org> <75B6FA9F576969419E42BECB86CB1B89115F99A9@xmb-rcd-x06.cisco.com> <2730F679-46FC-416E-8DBB-D74676E637CA@employees.org> <75B6FA9F576969419E42BECB86CB1B89115F9CC5@xmb-rcd-x06.cisco.com>
In-Reply-To: <75B6FA9F576969419E42BECB86CB1B89115F9CC5@xmb-rcd-x06.cisco.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [10.131.78.102]
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Archived-At: http://mailarchive.ietf.org/arch/msg/ipv6/BkXXwqchWnilE4WtUWTYyfDkPh0
Cc: Erik Nordmark <nordmark@acm.org>, "Andrew Yourtchenko (ayourtch)" <ayourtch@cisco.com>, 6man WG <ipv6@ietf.org>
X-BeenThere: ipv6@ietf.org
X-Mailman-Version: 2.1.15
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: <http://www.ietf.org/mail-archive/web/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, 21 Feb 2014 19:24:43 -0000

Sigh and humble apologies.  One typo in my email below. 

Change 

Now the host has to send a packet out an interface and the packet destination in the host's Neighbor Cache

To

Now the host has to send a packet out an interface and the packet destination is NOT in the host's Neighbor Cache

Thanks,

Hemant

-----Original Message-----
From: ipv6 [mailto:ipv6-bounces@ietf.org] On Behalf Of Hemant Singh (shemant)
Sent: Friday, February 21, 2014 1:57 PM
To: Ole Troan
Cc: Erik Nordmark; Andrew Yourtchenko (ayourtch); 6man WG
Subject: RE: Comments on draft-yourtchenko-colitti-nd-reduce-multicast

Ole,

-----Original Message-----
From: Ole Troan [mailto:otroan@employees.org] 
Sent: Friday, February 21, 2014 12:32 PM
To: Hemant Singh (shemant)
Cc: Erik Nordmark; 6man WG; Lorenzo Colitti; Andrew Yourtchenko (ayourtch)
Subject: Re: Comments on draft-yourtchenko-colitti-nd-reduce-multicast

>RFC4861:
>   Note, however, that a Prefix Information option
>   with the on-link flag set to zero conveys no information concerning
>   on-link determination and MUST NOT be interpreted to mean that
>   addresses covered by the prefix are off-link.  

The RA has the A-bit set and the L-bit cleared.  So as per the specification text above the L-bit is zero and the host does not get any on/off--link determination from the L-bit for the addresses covered by the prefix in the PIO.   The host configures its ipv6 address from the PIO in the RA using SLAAC.  Now the host has to send a packet out an interface and the packet destination in the host's Neighbor Cache.  The packet destination also matches the host's prefix to a /64.  So what does the host do?  

Issue 

(a) an address resolution NS (assuming the destination is on-link) due to SLAAC operation.

or

(b) send the packet to the default router(s).  The L-bit has conveyed no on- or off-link information.  So doesn't the host resort to (a) above.  If the host choses to go to operation (b) what signaled to the host that the destination is off-link?   If the host picked (a), why is that?

If you can't determine one concrete choice from the two above, we have an ambiguity. 

Hemant
 

--------------------------------------------------------------------
IETF IPv6 working group mailing list
ipv6@ietf.org
Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6
--------------------------------------------------------------------