Re: [6lowpan] Fwd: New Version Notification fordraft-chakrabarti-6lowpan-ipv6-nd-simple-00

[Jonathan Hui <[e-mail]>]

Hi Erik,

On Mar 23, 2010, at 2:12 PM, Erik Nordmark wrote:

> On 03/22/10 10:45 AM, Mathilde Durvy (mdurvy) wrote:
>> Hi Erik, Samita,
>>
>> Thanks for your draft. This proposal is much closer to what I had  
>> in mind
>> myself and I feel this is a great step forward!
>>
>> I have a few questions / comments:
>> - Assumptions: why do you assume that 6LR use RA to configure their  
>> global
>> addresses while host are allowed to use DHCPv6? In IPv6, routers are
>> typically ignoring received RAs... It is not very clear whether your
>> proposal allows the case where all addresses (host and 6LR) are  
>> assigned
>> using DHCPv6. It might also be that in a route-over situation the  
>> routing
>> protocol itself would take care of distributing well chosen
>> prefixes/addresses to allow prefix aggregation in routing tables or  
>> routing
>> messages.
>
> We just borrowed this from draft-ietf-6lowpan-nd-08.
>
> As I said during the presentation yesterday, I think the key thing  
> to standardize around ND is the host-router interaction. This router- 
> border interaction is, as you point out, something that can be done  
> in different ways.
>
> I think it makes sense to provide an optional way to perform the  
> router-border interaction as part of the ND work, while making it  
> clear that there are other ways to do those pieces such as the  
> routing protocol.
>
> But I don't think DHCPv6 can be used to assign the same prefix to  
> all the routers in the 6lowpan (DHCP prefix delegation would give  
> them all different prefixes which is not what we want.)

I think Mathilde was referring to using DHCPv6 to assign only IPv6  
addresses (not prefixes) and that the only router-border interaction  
is through the use of DHCPv6 relay agents.  I agree that DHCPv6 prefix  
delegation in 6LoWPAN networks doesn't make much sense in most  
situations.

--
Jonathan Hui