RE: dual stack & IPv6 on by default

["Bound, Jim" <Jim.Bound@hp.com>]

Hi Mika,


 
> > I think today this is the bottom line only answer.
> 
> That's too bad, because it means that the DNS resolver would 
> have do this for the whole candidate destination address 
> list. That takes time. I would much prefer do a route search only.

I agree with you and I still have reservations about source address
selection for those performance reasons.

> 
> > But your mail thread makes me wonder if we need to do more 
> and I think 
> > so.
> 
> RFC1122 clarified and corrected several small details in the 
> IPv4 specifications. I think the node requirements spec could 
> do the same for any fuzzy bits in the IPv6 specificatons.
> 
> > But it would have to be in the context of ND.  ND is a 
> requirement to 
> > use IPv6.
> 
> I agree. This is just a detail that needs to be clarified somehow.

Yes.  I can be done with new ICMP types or options.

> 
> > Feels like an edge that could be "do this if ND don't work"?
> 
> No. It's a very specific case of "how to implement the 
> following bit of next-hop determination" in a host with 
> multiple network interfaces and how it relates to RFC3484 and 
> destination address selection:
> 
> 	If the Default Router List is empty,
> 	the sender assumes that the destination is on-link.
> 
> Until there is a clear understanding, we are sticking with:
> 
> 	If the route search fails,
> 	the sender assumes the destination is unreachable.
> 
> I haven't seen comments from any other implementors. It would 
> be very interesting to hear if you have solved this and how 
> you implemented it.

Agreed.  Others need to jump in here.  I think we have a hole.

/jim
> 
> Thanks,
> 
> 	MikaL
> 
>