Re: [DNA] [Issue 15] [Issue 16] DAD and MLD Interaction

["Nick 'Sharkey' Moore" <sharkey@zoic.org>]

On 2005-06-20, James Kempf wrote:
> 
> No, but unfortunately the oDAD document doesn't say anything about this.
> Most implementors of oDAD will probably send it out when the state change to
> Optimistic happens, because the draft says that, but when combined with DNA,
> I suspect there may be some confusion unless we make it clear.

G'day James,

	OptiDAD got a "discuss" from IESG, so there's a last round
of revision happening some time Real Soon Now.  If there's something
you reckon needs clarification, now's the time to discuss it!

> Note that even if we do change the state to Optimistic, there is still the
> issue I raised about the node originating packets with a topologically
> incorrect source address if it has moved to a new IP link. The only way to
> prevent that from happening is to make the addresses Tentative (and suppress
> the DAD NS until after the RA returns) until the node actually finds out in
> the RA whether it actually has moved to a new IP link or not.

Yeah, I think the safest thing is to Deprecate any addresses at Link
Down, and Tentative/Optimistic them at Link Up.  That should allow
source address selection to behave correctly in the case of multiple
interface devices as well.

-----N