Re: Broadband Forum liaison to IETF on IPv6 security

[Eric Levy-Abegnoli <[e-mail]>]

Mikael Abrahamsson a écrit :
> On Thu, 5 Nov 2009, Dunn, Jeffrey H. wrote:
>
>> I may be missing something, but it appears that, in the cases 
>> described, the two hosts downstream of two separate cable modems are 
>> off link to each other. This brings up the question: Do there two 
>> cable modems constitute two virtual interfaces, like two VLANs on the 
>> same physical router interface? If so, this is an architectural, 
>> rather than an implementation, question. Thoughts?
>
> This is basically "forced forwarding" for the L2 aggregation layer. 
> It's often done on ETTH deployments as well as cable environments, in 
> IPv4 it's done in conjunction with local-proxy-arp (in your IP subnet, 
> the ISP router will answer all ARP requests with its own MAC and all 
> traffic between clients within the subnet is done via the router which 
> does not send out ICMP redirects).
>
> In my mind it's unsuitable for clients to run SLAAC in these 
> environments and the only real alternative is full DHCPv6(-PD) with 
> SAVI-like functionality in the L2 equipment along the way (in v4 the 
> L2 equipment does DHCP-snooping and installs L3 filters accordingly).
>
The initial question mentionned link-local duplicate. For a reason: ther 
are not assigned by DHCPv6 which preq their existence and unicity. SLACC 
is your only choice.
Eric