RE: WPD-6, WAA-8, and WAA-9 of draft-ietf-v6ops-ipv6-cpe-router-04

["Wes Beebee (wbeebee)" <wbeebee@cisco.com>]

>>This presented quite some difficulty for NTT as an operator - as they 
>>had to restrict themselves in what they could do in terms of address 
>>space conservation in order to support a strong host model CPE router
- 
>>and this warning was in a previous version of the CPE router 
>>specification.  We should actively discourage people from building and

>>using strong host model CPE routers.
>
>I guess I'm missing something obvious here.
>
>An unnumbered link can only occur i.c.w. prefix delegation (otherwise
the CPE wouln't have any 
>addresses at all).
>
>Now instead of assigning an address from its prefix to a virtual
interface, the CPE assigns the
> address to the uplink interface.
>
>This allows the CPE to implement the strong host model, and doesn't
require any cooperation from
> the ISP.
>
>So, what is wrong with that scenario?

Section 12.1 of RFC 3633 forbids it:

"the requesting router MUST NOT assign any delegated prefixes or subnets
from the delegated prefix(es) to the link through which it received the
DHCP message from the delegating router."

- Wes