Subject: RE: [Fwd: I-D ACTION:draft-lear-multi6-things-to-think-about-00.txt]

From: "Tony Li" <[email-masked]>
Date: Tue, 16 Dec 2003 09:31:31 -0800

|  > - Is the multi-homing solution IPv6 only or can it also be 
|  used with 
|  > IPv4?
|  > I know this is multi6, but it is probably interesting to 
|  know if the
|  > solution can be applied to IPv4
|  
|  To be honest, I think this is not important right now. Let's 
|  solve the 
|  task at hand first. If we after that figures out that it 
|  works for IPv4 
|  as well, all the better.

I'd submit that if it cannot be easily ported back to IPv4, that it
bears
closer examination.  v4 and v6 are architecturally very similar.  Any
solution that does not apply to both is either a kludge or is exploiting
an odd property of one of the two.  In either case, it would bear close
examination.  You know, the kind that you give things when the fire
alarm
in the building goes off... ?  ;-)

|  > - Does your solution applies to all type of sites?, for 
|  instance is 
|  > your
|  > solution suitable for very small sites? (does it requires an expert
|  > administrator o very powerful equipment) is your solution 
|  siutable for 
|  > very
|  > large sites?
|  
|  I think this might be a subjective judgment. Not sure it 
|  makes sense to 
|  take into account right now. But no strong feeling one way 
|  or the other.

I think that the question is valid, regardless.  However, I don't think
that this
is a _requirement_, which is what I think you were saying.

|  > - About incremental deployment, i think that there are 
|  different ideas 
|  > about
|  > what incremental deployment means.
|  
|  Maybe what we would need is to have each proposal include a 
|  description 
|  of how the proposal is implemented in a site/network?

Deployability is always a good thing for running code...  ;-)
Yes, I think any proposal needs to describe a plausible deployment
scenario.

Tony

---

From: Pekka Savola <[email-masked]>
Date: Wed, 17 Dec 2003 08:11:20 +0200 (EET)

On Tue, 16 Dec 2003, Tony Li wrote:
> bears closer examination.  v4 and v6 are architecturally very
> similar.  Any solution that does not apply to both is either a
> kludge or is exploiting an odd property of one of the two.  In
> either case, it would bear close examination.  You know, the kind
> that you give things when the fire alarm in the building goes off...
> ?  ;-)

I have to heartily disagree here.  IPv6 address *does* have more bits.  
Different problem spaces have leveraged that property before as well,
leading to solutions which are not easily backportable to IPv4.

Maybe one could reword this differently: the solution beas some 
thinking about if it doesn't rely on the 128bit address length of 
IPv6, and is not easily IPv4-capable.

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings

---

From: Brian E Carpenter <[email-masked]>
Date: Thu, 18 Dec 2003 09:54:17 +0100

> IPv6, and is not easily IPv4-capable.

Yes. But this is the IPv6 multihoming WG, so while applicability to
IPv4 is an interesting question to ask, it cannot be a decision
criterion.

I would counter-argue against Tony in another way. If we had variable
length addresses (as some people strongly suggested for IPng) a whole
new class of multihoming solutions might be available. But we don't,
so they aren't. Thus, you cannot argue that solutions *must* be independent 
of address length considerations.

(Please don't kick off a thread on variable length addresses... at
least not here.)

  Brian

---

From: Kurtis Lindqvist <[email-masked]>
Date: Thu, 18 Dec 2003 11:30:12 +0200 (EET)

> in the building goes off... ?  ;-)

Yes, but what I am saying (and so is Brian in the latest mail) is that is
not a target for this WG.

> Yes, I think any proposal needs to describe a plausible deployment

Yes.

- kurtis -

---

From: "Spencer Dawkins" <[email-masked]>
Date: Thu, 18 Dec 2003 06:52:42 -0600

I may be misunderstanding something here, so let me ask the question
before I expound.

----- Original Message ----- 
From: "Brian E Carpenter" <[email-masked]>
To: "Multi6" <[email-masked]>
Sent: Thursday, December 18, 2003 2:54 AM
Subject: Re: [Fwd: I-D
ACTION:draft-lear-multi6-things-to-think-about-00.txt]

> IPv4 is an interesting question to ask, it cannot be a decision

I'm not sure what the difference between "bears some thinking about"
and "being a decision criterion" is in Brian's mind.

What I'm hoping Brian is saying is, "it's OK to notice whether a
proposal works for IPv4, on this mailing list, but 'doesn't work for
IPv4' can't be used to disqualify a proposal".

The reason I'm asking is, I've been very aware that multi6 was willing
to host discussions at the very edge of the WG's charter, because
multi6 was the "least wrong" place to have these discussions. Sean
Doran (former WG chair) said basically, "why the heck not?" on August
9, in the "loc/id split" thread.

If Brian is saying that discussions about IPv4 suitability don't
belong here, we need to find a place where they do belong.

I THOUGHT that Leslie asked Geoff to set up a mailing list after the
IAB workshop in Vienna, but the minutes at
http://www.ietf.org/proceedings/03jul/127.htm don't show this action
item. So, as Sean said, this is the least wrong place that exists
today - how wrong is it?

Spencer

---

From: Iljitsch van Beijnum <[email-masked]>
Date: Thu, 18 Dec 2003 15:21:19 +0100

> (Please don't kick off a thread on variable length addresses... at

Why not?

I think that if we can do what we need to do by using variable length 
addressing, then the annoyance of having to cram those inside an IPv6 
packet in a way that the packet remains routable is probably worth it.

There is lots more in the draft that I don't feel particularly 
comfortable with. For instance, the mobility questions.

---

From: Brian E Carpenter <[email-masked]>
Date: Fri, 19 Dec 2003 11:47:20 +0100

inline...

> IPv4' can't be used to disqualify a proposal".

That's what I think I'm saying.

> 9, in the "loc/id split" thread.

We do owe the WG a draft new charter where this should be clarified.
Working, working...

> belong here, we need to find a place where they do belong.

The current charter already says 
 This WG will consider the problem of how to multihome sites in
 IPv6. The multihoming approaches currently used in IPv4 can of course
 be used in IPv6, but IPv6 represents an opportunity for more scalable
 approaches. IPv6 differs from IPv4 in ways that may allow for
 different approaches to multihoming that are not immediately
 applicable to IPv4. 

So yes, I think specifics about IPv4 solutions belong elsewhere. But if
an IPv6 solution would also work for IPv4, that would be a fine result.

> item. So, as Sean said, this is the least wrong place that exists

Well, I think that list exists:
https://www1.ietf.org/mailman/listinfo/saad
but it has been quiet.

   Brian

---

From: Brian E Carpenter <[email-masked]>
Date: Fri, 19 Dec 2003 11:54:28 +0100

> packet in a way that the packet remains routable is probably worth it.

Having proposed exactly that in 1994 as an extension to IPv4, I can hardly
disagree. (See draft-carpenter-aeiou-00.txt if you can find it...)

But that class of solution doesn't change the address length seen by
the routing system, which IMHO is something we cannot reasonably
consider.

> comfortable with. For instance, the mobility questions.

Send text!

  Brian

---

From: "Spencer Dawkins" <[email-masked]>
Date: Fri, 19 Dec 2003 06:09:53 -0600

Wow. I missed this one completely. Thanks (and thanks to Marcelo, who
sent this privately).

----- Original Message ----- 
From: "Brian E Carpenter" <[email-masked]>
To: "Spencer Dawkins" <[email-masked]>
Cc: "Multi6" <[email-masked]>
Sent: Friday, December 19, 2003 4:47 AM
Subject: Re: [Fwd: I-D

> https://www1.ietf.org/mailman/listinfo/saad

Well, of course it's been quiet because all the discussion has been
happening over hear, annoying multi6! :-}