Re: Fwd: Re: note from the iesg plenary

[Erik Nordmark <Erik.Nordmark@eng.sun.com>]

> I know that this subject has been discussed several times.  I believe
> the scenario that Margaret is concerned about is based on this
> diagram she posted to IPNG several months ago (correct me if I am
> wrong, Margaret):
> 
> ==========================================================
>  SITEA
>              Host1                      Host2
>                |                         |
>        ______._|_________    ___.______._|_____________
>        Link1 |                  |      |       Link2
>              |                (down)   | 
>              |                  |      |
>              |+-----------------+      |
>              ||                        |
> ============R1========================R3===================
>  SITEB       |                         |
>              |                         |
>         _____|_________________________|________________
>                                                  Link3
> 
> 
> ===========================================================

But I think there is another issue even when the path isn't down.
Suppose the metric/preferences on the routes are such that when sending to
the global address of H2 from H1 that the packets pass through site B.
Then it is even worse since H1 and H2 have both a path inside the site
and one outside, but if H1 doesn't have a global source address they
will fail to communicate.

Thus I think this needs to be captured in the notion of convex - packets
sent to a global address in the site can not leave the site.

  Erik