Re: [DNA] WG LC comments on draft-ietf-dna-goals-01.txt

[JinHyeock Choi <jinchoe@samsung.com>]

Dear Pekka

> > The name of the draft is 'Detecting Network Attachment in
> > IPv6 Goals' and I thought that was explicit enough. :-)
> >
> > Do you still think we need an additional statement? If so,
> > I will add it in the Introduction.
> 
> Please do.  The change may be as simple as changing "IP"
> on the second line of introduction to "IPv6", just as a
> reminder.

ok. I did this. 
 
> If you want to put there more, I would suggest also changing
> the second last line of introduction:
> 
> >    Detecting Network Attachment (DNA).  DNA schemes should be precise,
> 
> s/Attachment (DNA)/Attachment for IPv6 (DNA)/
> 
> Or, alternatively, to add to the end of introduction:
> 
>     This draft considered the DNA procedure only from IPv6 point
>     of view, unless otherwise explicitly mentioned.  Hence, the
>     term "IP" is to be understood to denote IPv6 by default.
> 
> Or something like that.

I added the above at the end of introduction. 

> >>    3. With regard to goal G10, which currently states that ...
> >>
> >>>      DNA schemes should take into consideration the case where a host
> >>>      is attached to more than one link at the same time.
> >>
> >>      ... should we add "or multiple times to the same link"?
> >
> > G10 is about the special case that a host is attached to multiple links
> > at the same time and hears different RAs from different links.
> >
> > I see few reason to add "or multiple times to the same link". I think
> > that's a different case and we may obscure the main issue, 'multiple
> > attachment', if we add that.
> 
> Well, I was thinking about the situation where the host is
> connected through several interfaces to the same link.
> In some way, this is a special case of a host being connected
> through several interfaces to several different links.
> 
> I am not sure how to formulate that properly, but IMHO the whole
> continuum should be covered by G10.  I don't see it covered
> by the other goals.

DNA scheme is run per-interface because some IP configuration, 
such as IPv6 address, is interface specific. 

There arise complexities if an interface of a host is attached to 
multiple links at the same time. For example, the presence of 
a different link identifier doesn't mean that the host is disconnected 
from the current link. 
 
However, when multiple interfaces of a host are connected to the 
same link, it will result in few problem. Each interface may run DNA 
scheme to check for link change and update its IP configuration in 
case of a link change. 

I think the expression 'multiple interfaces' in G10 is confusing. 
I propose to change G 10 as

   G10 Hosts in particular wireless environments may perceive routers
      reachable on different links.  DNA schemes should take into
      consideration the case where a host is attached to more than one
      link at the same time.

Also, as Alper pointed, we'd better explicitly mention that DNA is 
run per-interface. I added the following in Introduction.  

   ..........................of its IP configuration, is called Detecting Network
   Attachment (DNA).

   DNA scheme is run per interface because some IP configuration, such
   as IPv6 address, is interface specific.  When a host has multiple
   interfaces, each interface separately check for link change to verify
   each one's IP configuration.
 
The updated draft is available at 

http://www.diffeo.com/drafts/draft-ietf-dna-goals-02.txt

Best Regards

JinHyeock