RE: dual stack & IPv6 on by default

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

>However, this rule *is* somewhat problematic with multihomed 
>hosts as well as in cases where network interfaces are set up 
>on-demand. In the former case, the packets apparently have to 
>be replicated to all links that have no default routers. In 
>the latter case, an application might trigger an on-demand 
>network interface setup. However, the packets from the 
>application would still be directed on-link, since it takes a 
>little while to receive and process a router advertisement. An 
>implementation that caches the routing decision will have 
>problems with this.

Good point.  But isn't it up to the implementation for links that had to
deal with on-demand.  As long as I have route for a link then I should
apply it?  The problem would be if the link information was not applied
before the on-demand was accessed in a multi-home manner.  But then I
would assume destination unreachable would be the response to the
application, though it should say link not known IMO.  So isn't the
multi-home scenario a two step problem.  1) the on-demand NIC has to see
the link before used by the app, and 2) the implementation must be able
to propogate attributes for multiple interfaces?

/jim