Subject: RE: WLAN (was Re: IPv6 Host Configuration of Recursive DNS Server)

From: "Pascal Thubert \(pthubert\)" <[email-masked]>
Date: Wed, 23 Jun 2004 15:53:44 +0100

> If you have followed the discussion closely, you should have
> noticed that ARP is a lot better than ND in a typical
> environment where WLANs are used as leaf of the Internet.
> 
> So, as a short term solution, I'd like to suggest to use ARP,
> not ND, over WLAN.
> 
> As a long term solution, I already suggested
> 
> 	1. periodic beacons from routers
> 	2. unicast request from hosts to routers
> 	3. unicast reply from routers
> 
> is the way to go.
> 

That is one way. 

In fact there are many ways. 

For instance, a simple one is to have APs proxy ND for their associated
nodes. Basically they forward the multicast ND messages from the
associated nodes to the wire only, and in any case answer multicast ND
on behalf of their associated nodes. 

It may be a little more troublesome then it looks; but it shows that
there's at least one way to go that's not changing things as
dramatically as Ohta-san's proposal.

An other aspect is that 802.11 is not THE radio model. Should we make
each radio a new link type for IP? Or is there a common link type that
we can converge on by providing an adaptation layer (2.5) ?

Pascal

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From: Masataka Ohta <[email-masked]>
Date: Thu, 24 Jun 2004 06:48:20 +0900

> In fact there are many ways. 

Of course. However, as a short term solution, we don't have much
options.

Note that the solution should be conservative enough already
verified to work.

> For instance, a simple one is

Whice one? Short term one or long term one?

> to have APs proxy ND for their associated
> nodes.

APs can't. APs have no information on IP addresses of the
associated nodes merely because they are associated.

Considering that the essential role of ND is to find such
information, you need yet additional ND-like mechanism,
here.

> Basically they forward the multicast ND messages from the

Too bad.

The essential problem that RA is not received reliably is
unaddressed.

> dramatically as Ohta-san's proposal.

ND is the dramatical change now proven not to work well sometimes.

ARP is, to some extent, proven to work.

> An other aspect is that 802.11 is not THE radio model.

Right.

See my response to Christian on active and sector antennas.

> Should we make
> each radio a new link type for IP?

Wrong question.

We need separate mechanism for each link type not necessarily
radio. We may or may not reuse existing mechanisms.

> Or is there a common link type that

Wrong question.

We can't say, in advance, that some mechanism work for yet
unknown link type.

							Masataka Ohta