Subject: [DNA] Seeking WG input on Non-prefix link identifiers

From: Suresh Krishnan <[email-masked]>
Date: Fri, 14 Oct 2005 20:33:04 -0400 (EDT)

Hi Folks,
   Non-prefix link identifiers have a big effect on the DNA solution.

- A protocol for agreeing on non-prefix link identifiers needs
   to be specified.

- Additional options are required for transport
   (prefix linkids only require a flag).

- Precedence between identifier types needs to be established.

It's possible to undertake this work either now in the base draft,
or as an extension if required.

Further development of the current solution draft requires
determination of which path to take.

We'd like to make a consensus call starting
00:00 UTC Monday 17 October 2005

and ending
00:00 UTC Monday 31 October 2005

On the topic:

Should the working group develop non-prefix link identifiers as
part of the base DNA solution protocol?

Regards
Greg and Suresh

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From: Brett Pentland <[email-masked]>
Date: Sat, 29 Oct 2005 12:01:27 +1000

I don't think they are necessary.  If there's no global prefix
available to use for identification, then it seems that one ought
to be able to generate a ULA prefix just for identification purposes.

There might be a problem with links with no routers.  Thinking on
the fly now... What about non-router devices being able to perform
the DNA functions of a router?  They might respond to RSs with an RA
with the M and O flags both set to zero, the router lifetime set to
zero, and a PIO with a ULA prefix and both the L and A flags set to
zero.  Would that cause any configuration problems?  The zero lifetime
would prevent hosts from putting the device in their default routers
list.  L=0 would not cause hosts to think the prefix is "on-link".
A=0 would prevent hosts from trying to generate addresses from the
prefix.  Any other show stoppers?

Having non-prefix identifiers might make it possible to carry the
identifier in some layer 2 field as an optimization, and that might
be useful, but it would be specific to that l2 and so I'm not sure
that it's such a great idea.

Brett.

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From: JinHyeock Choi <[email-masked]>
Date: Mon, 31 Oct 2005 11:25:00 +0900

Dear Greg & Suresh

> part of the base DNA solution protocol?

I don't think it's necessary to include non-prefix link identifier as
part of the base DNA solution protocol.

IMHO, prefix based DNA solution will work for most of the cases. The
only exception I can think of is Ad-hoc network and I am not sure
whether DNA is needed at all in such an environment.

DNA detects the identity of the currently attached link to ascertain
the validity of IP configuration for Internet Connectivity. Whereas
it's not clear either what constitutes a Ad-Hoc link nor how Ad-Hoc
nodes will be connected to Internet.

Recently Autoconf WG is created to assign Ad-Hoc nodes a valid IP
address (and it may also consider Internet Gateway), so if we want to
work on DNA for Ad-Hoc network, we may need to wait till Autoconf
works are reasonably clarified.

So we'd better develop base DNA solution protocol based on prefix link
identifier and may develop non-prefix link identifier as an extension
if needs arise.

Thanks in advance for your kind consideration.

Best Regards

JinHyeock