Re: [6lowpan] -nd-15: Joining the all-nodes multicast address

On 2/25/11 5:28 AM, Colin O'Flynn wrote:
> Hi Anders,
>
> RFC4861 uses the same wording, where it means you just listen on the
> all-nodes multicast address. There is no explicit join method.
>
> I'm not sure in which RFC it describes joining the multicast group. I would
> guess RFC4291 as that describes multicast addressing, but there might be
> somewhere better.

It is in RFC 2710 on MLD; it describes that "join" implies.

MLD has an explicit exception for all-nodes as in
    The link-scope all-nodes address (FF02::1) is handled as a special
    case.  The node starts in Idle Listener state for that address on
    every interface, never transitions to another state, and never sends
    a Report or Done for that address.

For other multicast addresses, including link-locals, the expectation is 
that the host would join using MLD.

Note that 6lowpan-nd doesn't require hosts to join the solicited node 
multicast address; that would have required sending MLD reports to 
comply with RFC 2710.

    Erik

> Regards,
>
>    -Colin
>
> -----Original Message-----
> From: 6lowpan-bounces@ietf.org [mailto:6lowpan-bounces@ietf.org] On Behalf
> Of Anders Brandt
> Sent: February 25, 2011 11:18 AM
> To: zach@sensinode.com; 6lowpan
> Subject: [6lowpan] -nd-15: Joining the all-nodes multicast address
>
> Having read the doc carefully, I have a question:
>
> Section 5.2 says "A host MUST join the all-nodes multicast address"
>
> Does this mean:
> "A host must use some multicast control signaling protocol to inform the
> default router that it wants to receive traffic sent to the all-nodes
> multicast address.
> The host must accept messages sent to the all-nodes multicast address"
>
> OR:
>
> "A host must accept messages sent to the all-nodes multicast address
> within the link-local range of the host"
>
> Thanks,
>    Anders
>
> -----Original Message-----
> From: 6lowpan-bounces@ietf.org [mailto:6lowpan-bounces@ietf.org] On
> Behalf Of Carsten Bormann
> Sent: 17. februar 2011 16:58
> To: 6lowpan
> Subject: [6lowpan] Working Group Last call for draft-ietf-6lowpan-nd-15
>
> In September/October, we had the first WGLC on 6LoWPAN-ND, which
> resulted in a number of detailed comments and two resulting
> fine-tuning iterations of the draft.
>
> draft-ietf-6lowpan-nd-15.txt has been out for two months now.
> I understand it has taken part in several interops with multiple
> implementations in this period; no issues came up.
>
> We now start the Working Group Last Call on:
>
>     http://tools.ietf.org/html/draft-ietf-6lowpan-nd-15
>
> The document is planned to be submitted by this Working Group to the
> IESG for publication as a Standards-Track Document.
>
> This is a two-week Working-Group Last-Call, ending on Thursday,
> 2011-03-03 at 2359 UTC.
>
> Please review the changes to the document carefully once more, and
> send your comments to the 6lowpan list.  Please also do indicate to
> the list if you are all-OK with the document.
>
> Gruesse, Carsten
>
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