[DNA] Re: Analysis of IPv6 Relocation Delays

[Christian Vogt <chvogt@tm.uka.de>]

Hi Greg.

 > I guess that the primary issue is with regard to snooping switches,
 > since otherwise multicast delivery will succeed.
 > The problem is that a host cannot necessarily know if snooping
 > is in place, when it arrives at a point-of-attachment.

Right.

 > Perhaps it would be good to mention this in the draft (referring
 > also to the snoop draft).

Yes, I added this paragraph to the "Brief Analysis" section (for the 01 
version).  "[*]" is a reference to draft-ietf-magma-snoop-12.txt.

    ++++
    Transmission of MLD Reports can lead to undesired signaling overhead.
    Furthermore, with respect to router discovery and address auto-
    configuration, MLD Reports have a benefit only in the presence of
    snooping switches [*].  The crux is that a mobile node usually does
    not know a new link's topology at attachment time, so it seems that
    omission of MLD Reports would become feasible only with appropriate
    support from the link layer.
    ++++

Bye,
- Christian

-- 
Christian Vogt, Institute of Telematics, University of Karlsruhe
www.tm.uka.de/~chvogt/pubkey/


Greg Daley wrote:
> Hi Christian,
> 
> Thanks for the draft, and your efforts in raising this for discussion.
> 
> This is definitely an important issue.
> 
> I guess that the primary issue is with regard to snooping switches,
> since otherwise multicast delivery will succeed.
> The problem is that a host cannot necessarily know if snooping
> is in place, when it arrives at a point-of-attachment.
> 
> Perhaps it would be good to mention this in the draft (referring
> also to the snoop draft).
> 
> Thanks Again,
> 
> Greg
> 
> Christian Vogt wrote:
> 
>> Hi everybody,
>>
>> as I had mentioned on this list before, we wrote a little draft on the
>> latency of IPv6 relocation due to delayed MLD Reports.  Here is the
>> abstract:
>>
>>    Mobile nodes require fast IPv6 relocation.  Yet, router discovery,
>>    address auto-configuration, and support for TSLLAOs depend on delayed
>>    MLD signaling, defeating existing optimizations in many situations.
>>
>>    This document identifies problematic situations.  It proposes delay
>>    relaxations for MLD Reports or use of optimistic addresses prior to
>>    the initial Neighbor Solicitation to improve them.
>>
>> Until the draft becomes available at the official repository, you can
>> access it here:
>>
>> http://doc.tm.uka.de/2005/draft-vogt-dna-relocation-00.txt
>>
>> Note that the purpose of this draft is NOT to evolve itself within the
>> DNA WG.  Rather, it is supposed to be a basis for a mailing-list
>> discussion and maybe provide some text for existing WG documents.
>>
>> Regards,
>> - Christian
>>
>> -- 
>> Christian Vogt, Institute of Telematics, University of Karlsruhe
>> www.tm.uka.de/~chvogt/pubkey/