evolution of the 6-bone

[Matt Crawford]

Alain,

I can't quite accept your definition of Core Node, and I don't like
the name Leaf Node as you use it.  Specifically, I don't think a core
node should be required to provide a tunnel to everyone who asks.
Rather, the set of all Core Nodes should be defined so that at least
one will provide a tunnel to anyone who asks, and possibly the
connecting site occasionally will be required to re-home when the
Core reorganizes.

A Node which is not a Core Node may be an IPv6 provider to many other
sites.  I think the term "Leaf" isn't appropriate in this case.

Also, you may want to require that any two Core Nodes are connected
by an IPv6 path which includes only Core Nodes.