Subject: [nemo] Aggregated prefixes and Proxy ND

From: Ville Nuorvala <[email-masked]>
Date: Wed, 1 Sep 2004 14:36:16 +0300 (EEST)

Hi,

while reading draft-ietf-nemo-basic-support-pre04.txt I started wondering
about how the HA actually should perform Proxy ND on behalf of the MR.

The thing is of course straight forward if the MR's HoA is from a prefix
advertised on the home link, but it all gets a bit complicated if it's
from a prefix that the MR advertises on its ingress interface.

Since the HoA will never be on the same link as the HA, should the HA
still do the DAD probe and perform Proxy ND for it? Then again, I guess
there isn't any harm in doing that, so perhaps it's ok for the HA to
always do Proxy ND for the MR.

Regards,
Ville
--
Ville Nuorvala
Research Assistant, Institute of Digital Communications,
Helsinki University of Technology
email: [email-masked], phone: +358 (0)9 451 5257

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From: Mattias Pettersson <[email-masked]>
Date: Wed, 01 Sep 2004 18:46:48 +0200

> always do Proxy ND for the MR.

If the MR's HoA is derived from the MNP, it does not belong to the home 
link, and no node attached on the home link will ever assume it is 
on-link, thus never do ND address resolution for it.

An implementation of IPv6/ND shouldn't even allow ND proxying for 
off-link prefixes.

This is my interpretation.

/Mattias

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From: Alexandru Petrescu <[email-masked]>
Date: Wed, 01 Sep 2004 20:50:19 +0200

Ville Nuorvala wrote:
> while reading draft-ietf-nemo-basic-support-pre04.txt I started 
> wondering about how the HA actually should perform Proxy ND on behalf
>  of the MR.
> 
> The thing is of course straight forward if the MR's HoA is from a 
> prefix advertised on the home link, but it all gets a bit complicated
>  if it's from a prefix that the MR advertises on its ingress 
> interface.

I agree.

>  still do the DAD probe and perform Proxy ND for it?

My personal view is no.  But there may be particular cases where it's
yes.  Co-authors may help clarify; reasons I remember relate to RO, like 
"RO is easier if HoA from ingress".

You may want to find a usually used thing that overstretches or breaks
when HA does proxy ND and DAD for the HoA of the ingress.  If you find
it, state it here and see...  For example, I don't know...

Alex