Subject: [DNA] DNA meeting at IETF71

From: Suresh Krishnan <[email-masked]>
Date: Mon, 18 Feb 2008 01:22:18 -0500

Hi Folks,
   We have been allocated an 1 hour slot for dna at the IETF71 meeting 
in Philadelphia. We would like to discuss the way forward for both the 
complete and simple dna solutions at this meeting. Please take some time 
to review these documents and send your comments to the ML or mention 
them at the meeting. Once these documents are out of our way, we can 
discuss the further work to be done in the wg.

Thanks
Suresh

---

From: Bernard Aboba <[email-masked]>
Date: Mon, 18 Feb 2008 10:17:19 -0800

Will there be revisions of the simple and/or complete dna documents
submitted prior to IETF 71? 

-----Original Message-----
From: [email-masked]
[mailto:[email-masked]] On Behalf Of Suresh Krishnan
Sent: Sunday, February 17, 2008 10:22 PM
To: Dna
Cc: Greg Daley
Subject: [DNA] DNA meeting at IETF71

Hi Folks,

Thanks
Suresh

---

From: Suresh Krishnan <[email-masked]>
Date: Mon, 18 Feb 2008 13:21:43 -0500

Hi Bernard,
   I am currently working on the simple dna document. I believe that I 
can address all your comments in the new revision. I plan to have it out 
by this Friday. As far as the complete dna document, I have not been 
able to get a time commitment from the editor. I am exploring other ways 
forward for this.

Thanks
Suresh

---

From: JinHyeock Choi <[email-masked]>
Date: Thu, 21 Feb 2008 00:56:19 +0900

Dear Suresh

thanks for your trouble.

> able to get a time commitment from the editor. I am exploring other ways

When updating the draft, kindly describe DNA procedure, especially the
link identification mechanism, more thoroughly. From the previous
discussion with Bernard, I got the impression that there are a few
things in the current draft which no longer holds such as

   o  All routers on the link advertise the same subnet prefixes.

Also Bernard informed that 'NS/NA exchange with a router confirms only
the information from that router and does not guarantee the validity
of information from other routers'. I assume this is also missing in
the draft.

I think there should be a way to indicate a DNA link.

In a DNA link, a host should be informed that simple DNA is supported
in the link. Otherwise the host has no way to determine whether to use
simple DNA or ordinary ND. The simplest way may be `when advertising
an RA, a simple DNA router should indicate that the RA is from a
simple DNA router with, for example, a DNA bit'

Thanks in advance for your kind consideration.

Best Regards

JinHyeock

---

From: Bernard Aboba <[email-masked]>
Date: Wed, 20 Feb 2008 11:37:14 -0800

Comments below. 

> of information from other routers'. I assume this is also missing in

I agree that the document needs to more clearly describe the simple

DNA mechanism.  

> I think there should be a way to indicate a DNA link.

One question for simple DNA is whether we are attempting to determine
a "link" or just connectivity to a particular router interface.  This is a subtle,
but potentially important difference.  My impression had been that the goal
was the latter. 

> in the link. 

If the goal is only to determine whether a given router interface is reachable,
then I don't think this is needed.  

> Otherwise the host has no way to determine whether to use
> simple DNA or ordinary ND. 

Given that NUD uses unicast packets, would there be situations in
which "simple DNA" is not supported on a link, but "ordinary ND" is? 

One of the design principles of "simple DNA" is that it is never slower than 
normal IPv6 address acquisition process (e.g. RS./RA + DHCPv6 if necessary). 
If that is true, then should not be a need to make this determination.  Simple
DNA is attempted, and if it fails, it fails.  

> The simplest way may be `when advertising

If we start with the assumption that simple DNA should work with existing
routers, then modifications like this are precluded.

---

From: JinHyeock Choi <[email-masked]>
Date: Fri, 22 Feb 2008 01:08:49 +0900

Dear Bernard

Thanks for your kind feedback. Please find my in line comments.

> but potentially important difference.

I agree. The difference is subtle but important.

> My impression had been that the goal
> was the latter.

Previously the first was the goal. DNA scheme was supposed to verify a
host's current IP configuration such as IP address by checking for
link change.

If that no longer holds and now the second is the goal, WG would
better make a clear and explicit declaration accordingly. Also we need
to discuss pro & con of two.

> which "simple DNA" is not supported on a link, but "ordinary ND" is?

Before discussing this in detail, we'd better make it clear how simple
DNA operates. However, allow me to express my impression based on the
current draft.

I assume that
a simple DNA host determines a link change
when it receives an RA with no known prefix from below.

   Additionally, where a host receives a solicited router advertisement
   after sending an RS for the purpose of detecting network attachment,
   and this prefix contains only prefixes which are disjoint from known
   advertised prefixes, the host SHOULD conclude with high probability
   that it has moved to a different link.

However, in non DNA link, it doesn't mean a link change to receive
an RA with no known prefix, so a host would better not to decide
a link change  based on prefix comparison.

> DNA is attempted, and if it fails, it fails.

I understand that DNA aims to improve not only speed but also precision.
When a host receives a solicited RA, it need to make a different decision
according to whether it's in DNA link or not.

For example, when the host receives an RA with no known prefix,
if it's in a DAN link, it can assume with high probability a link change.
However, if it's not in a DNA link, there is no guarantee of high probability.

Thanks for your kind consideration.

Best Regards

JinHyeock

---

From: Sathya Narayanan <[email-masked]>
Date: Fri, 22 Feb 2008 09:34:27 -0800

Hello Suresh

I have been monitoring the activity on the mailing list for the most 
part. I don't remember seeing any discussion on the "complete" document 
- I am assuming by complete you mean draft-ietf-dna-protocol-06.txt - I 
will be happy to do any work that needs to be done on that document or 
on the simple solution for that matter. I will read the new revision you 
are going to submit and provide comments before the meeting.

Thanks
Sathya

Suresh Krishnan wrote:
> can address all your comments in the new revision. I plan to have it 
> out by this Friday. As far as the complete dna document, I have not 
> been able to get a time commitment from the editor. I am exploring 
> other ways forward for this.
>
> Thanks
> Suresh
>
> Bernard Aboba wrote:
>>    We have been allocated an 1 hour slot for dna at the IETF71 
>> meeting in Philadelphia. We would like to discuss the way forward for 
>> both the complete and simple dna solutions at this meeting. Please 
>> take some time to review these documents and send your comments to 
>> the ML or mention them at the meeting. Once these documents are out 
>> of our way, we can discuss the further work to be done in the wg.
>>
>> Thanks
>> Suresh
>>
>