Re: Comments on draft-wbeebee-ipv6-cpe-router-01.txt

["Ole Troan" <otroan@employees.org>]

> No apologies needed!  Thanks for the quick reply back. So now, you from AT&T and Shin from NTT, Japan are on the same page wrt global IPv6 address on the WAN interface. Shin has also asked for a global IPv6 address as a must for the WAN interface. From the -00 version of our draft we have been saying the WAN interface acquires a global address. Further, Mikael on this thread has said he wants the WAN interface to only acquire a link-local but the CPE Router spawn an Loopback interface to which a global IPv6 address is assigned - we have already said in our draft this Loopback interface is optional and your deployment can ignore using it. I'd also like to point out that the configuration required by Mikael is essentially the same as assigning a global IPv6 address to the WAN interface.
>
> Yes, there was a reason why we didn't add text in the Numbered model to say that the global IPv6 address for the WAN interface may be assigned from the IA_PD. We wanted to be careful about it. Here is an example.  The IA_PD obtained by the CPE Router is a /56. The CPE Router sub-delegates this prefix to a /64 for the LAN interface(s). So if a naïve implementation picked a global address for the WAN from the /64, then the WAN and the LAN are in the same IPv6 subnet - that's wrong because the WAN and LAN interface(s) are physically different network segments for the CPE Router and hence they must have different subnets to route traffic between them. What one has to do is pick a global address for the WAN interface from the /56 IA_PD. We can add new text to the Numbered model to cover your suggestion.
>

this model is not supported by RFC3633.

/ot