Re: Home network topology

[Rémi Denis-Courmont <rdenis@simphalempin.com>]

Le Wednesday 12 March 2008 05:11:24 Brian E Carpenter, vous avez écrit :
> On 2008-03-12 08:48, Rémi Denis-Courmont wrote:
> ...
>
> > For instance, 6to4rd is now proposing that only a /64 be assigned to a
> > given customer. If we expect the home to be fully bridged, that's fine.
> > Otherwise, there's going to be an interesting problem.
>
> Why do you think we originally recommended /48 for all SOHO customers,
> with some recent pressure to accept /56 as well?

Well, for subnetting, obviously, but I don't remember seeing a document that 
said how to do that subnetting in an unmanaged network.

> Clearly prefix delegation has to be automated, though.

Precisely. And there will also be interesting problems when people try to do 
link-local multicast discovery. There has to be a reason why 802.11 is pretty 
much designed to be bridged with 802.3.

If CPEs needs to be not only PD "clients" but also PD "servers", and if they 
need some basic form of in-site multicast routing/bridging, this may need to 
be specified. Even if we mandate /56, without standard way to use more 
than /64, people will resort to bridging and... address translation.

> Bridging is bound to fail, if we see non-802 networks in the home.

Right. Then I'm afraid 64rd is a non-starter in its /64 form.

-- 
Rémi Denis-Courmont