Subject: RE: [rfc2462bis] relationship between M/O flags and related protocols

From: "Christian Huitema" <[email-masked]>
Date: Tue, 18 May 2004 15:17:00 -0700

> I'm certainly not implying any API.
> Why do you think the text with the forward reference to "a separate
> document"
> implies any API?

The forward reference is asking the implementers to manage an extraneous state variable. As far as ND is concerned, the host can be entirely conformant and interoperate fine with others without that state variable. So, the only reason for the state variable is to facilitate the implementation of something else than ND, which will use the value of the state variable. For that you need some form of API.

-- Christian Huitema

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From: Erik Nordmark <[email-masked]>
Date: Wed, 19 May 2004 10:56:39 -0700 (PDT)

> The forward reference is asking the implementers to manage an extraneous
> state variable. As far as ND is concerned, the host can be entirely
> conformant and interoperate fine with others without that state variable.
> So, the only reason for the state variable is to facilitate the
> implementation of something else than ND, which will use the value of the
> state variable. For that you need some form of API.

Christian,

I'm confused. You had propopsed text which still had the ManagedFlag
in there. Your proposal was:
     On receipt of a valid Router Advertisement (as defined in
     [DISCOVERY]), a host copies the value of the advertisement's M bit
     into ManagedFlag, which saves the mostly recently received value of
     the M bit.

So if you think that the existence of the ManagedFlag implies that there
is an API (which I don't think FWIW) then shouldn't you argue that
all existance of ManagedFlag (and OtherConfigFlag) should be removed
from the document? (and not just the above paragraph)
Hence I'm confused.

My concern is that in removing all mention of the state transitions
we are removing information from the document, yet we haven't shown
that that information is incorrect.
(We haven't shown that it is needed either, but the approach seems to
be leave things unchanged unless there is a reasonably strong case.)

  Erik

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From: JINMEI Tatuya / 神明達哉 <[email-masked]>
Date: Fri, 21 May 2004 14:40:40 +0900

>>>>> On Wed, 19 May 2004 10:56:39 -0700 (PDT), 
>>>>> Erik Nordmark <[email-masked]> said:

> from the document? (and not just the above paragraph)

I was also confused about the same point, so I asked a question to
clarify the intention in a separate message...but I've not seen a
response to it.

> be leave things unchanged unless there is a reasonably strong case.)

Assuming it's okay for Christian to mention other documents on
details, can you live with the last proposal from Ralph?

       The details of how a host uses the M flag from a valid Router
       Advertisement it receives will be described in a separate document.

Or, if you feel happier by mentioning changes of the M bit explicitly,
we could alternatively say

     The details of how a host uses the M flag, including any use of
     the "on" and "off" transitions for this flag, to control the use
     of DHCPv6 for address assignment will be described in a separate
     document.
(based on a previous text from Ralph)

This way, we can avoid the use of the "possibly extraneous state
variable" which is internal information in the implementation, while
keeping the essential idea about external behavior.

					JINMEI, Tatuya
					Communication Platform Lab.
					Corporate R&D Center, Toshiba Corp.
					[email-masked]

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From: Erik Nordmark <[email-masked]>
Date: Fri, 21 May 2004 09:43:58 -0700 (PDT)

> keeping the essential idea about external behavior.

The text above is fine with me.

  Erik

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From: Ralph Droms <[email-masked]>
Date: Fri, 21 May 2004 13:10:14 -0400

This text is fine with me, too.

- Ralph