Linux and ULA support and default route

[sthaug at nethelp.no]

> At the end, the whole behavior is because some host have problems in
> handling situations where they have an IPv6 address configured and now
> internet connectivity. But the solution to this requires that the host
> is able to understand and work with RIO options, which seams to be "at
> the time" not generally the case.
> 
> Do we replace one evil by another?

I like Tore's solution of using ULA for local communication even when
the external link is down.

Steinar Haug, AS2116