Subject: Optimistic DAD _again!_

From: "Nick 'Sharkey' Moore" <[email-masked]>
Date: Thu, 19 Feb 2004 19:52:28 +1100

Hi IPv6ers,

	You might recall some time ago I stirred up some interest
in my Optimistic DAD draft, which seeks to eliminate DAD delay
without significantly increasing the risk involved in address
collision.  In the meantime it's picked up a couple of independant
implementations[1] and a couple of conference publications[2].

	It was debated fairly thoroughly in MobileIP WG, 
(I presented the idea to the WG in San Francisco[3]) but
has since been judged to be outside the scope of that group,
as it is applies to any situation needing fast address 
configuration, not just MobileIP.

	IPv6 WG seems the proper place for it to be developed
further, and I'd like to open it up for debate here with the
aim of moving it towards standardization.

The latest version is:
	<draft-moore-ipv6-optimistic-dad-04.txt>
... and it's _still_ only 13 pages long.

Please let me know what you think ... and if there's enough
interest maybe we can discuss it further at Seoul.

-----Nick 'sharkey' Moore.

[1] One by our team at Monash, one by Ed Remmel of Elmic Systems
[2] See <http://bluesky.zoic.org/sharkey/> for refs ...
[3] ... and for slides from these presentations.
-- 
Nick Moore, Resarch Fellow        | <[email-masked]>
Monash University CTIE	          | <http://www.ctie.monash.edu.au/ipv6/>
Australian Telecommunications CRC | <http://www.telecommunications.crc.org.au/>

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From: "James Kempf" <[email-masked]>
Date: Thu, 19 Feb 2004 15:24:50 -0800

Hi Nick,

I'd certainly be interested in hearing about this and having the IPv6 group
take it up, since the MIP group declined to take it up. I haven't read the
draft in a while, but I will try to take a look at it before the meeting. If
there is enough interest, I am not sure whether it would be a standalone
item or rather folded into 2642bis, though. Do you have a preference? What
do the WG chairs think?

            jak

----- Original Message ----- 
From: "Nick 'Sharkey' Moore" <[email-masked]>
To: <[email-masked]>
Sent: Thursday, February 19, 2004 12:52 AM
Subject: Optimistic DAD _again!_

> Australian Telecommunications CRC |
<http://www.telecommunications.crc.org.au/>

---

From: JINMEI Tatuya / 神明達哉 <[email-masked]>
Date: Mon, 23 Feb 2004 18:52:15 +0900

>>>>> On Thu, 19 Feb 2004 19:52:28 +1100, 
>>>>> "Nick 'Sharkey' Moore" <[email-masked]> said:

> implementations[1] and a couple of conference publications[2].

(snip)

> interest maybe we can discuss it further at Seoul.

I'd like to know if there has been a consensus to pursue any sort of
DAD optimization in the first place.  There have surely been lots of
discussions related to this issue, and, as far as I can recall, the
idea of optimization has never been adopted.

One fundamental question that I remember is whether optimizing DAD
really makes much sense while there are other kinds of delays such as
random delay (up to 1 second) for the first RS and random delay at
routers before responding to an RS.  Without addressing the
fundamental question(s), we'd simply restart similar divergent
discussions, waisting lots of energy and time without seeing progress.

p.s. I've read the latest draft and have some (mainly editorial)
comments.  I'll post the comments in a separate message.

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

---

From: "Nick 'Sharkey' Moore" <[email-masked]>
Date: Mon, 23 Feb 2004 21:23:12 +1100

On 2004-02-23, JINMEI Tatuya / ?$B?@L@C#:H wrote:
> > in my Optimistic DAD draft, [...]

It's definitely one of the bigger issues in MobileIPv6, but I think
that the implications go beyond that which is why it's appropriate
to IPv6 WG.

> discussions, waisting lots of energy and time without seeing progress.

Yes.  My presentation at MobileIP WG at IETF-56 listed four component
delays in MobileIPv6 handovers:

	* Movement Detection Delay
	* Router Advertisement Delay
	* DAD Delay
	* Binding Update RTT

We've been working on the possible ways to eliminate each of these
delays ... Optimistic DAD is one solution to one delay.
You might find the stuff at <http://bluesky.zoic.org/sharkey/>
interesting ...

> comments.  I'll post the comments in a separate message.

Thanks!

-----Nick
-- 
Nick 'Sharkey' Moore  <[email-masked]>  <http://zoic.org/sharkey/>
"Heroism on command, senseless violence, and all the loathsome 
nonsense that goes by the name of patriotism -- how passionately 
I hate them!" -- Albert Einstein

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From: "James Kempf" <[email-masked]>
Date: Tue, 24 Feb 2004 23:10:14 -0800

The issue always has been where in IETF to get these collection of delays
addressed in a co-ordinated fashion. DNA was thought to be the venue, but it
has chosen not to. Given we have to address the delays piecemeal, then
OptiDAD seems like a place to start.

            jak