[e2e] Overly Overlay; Peer to peer is commonplace

[Randy Bush]

>   - that IP addresses should reflect topology because topology is stable, 
> because putting in fiber requires backhoes,

aside from issues of large address users not wishing to renumber when
changing providers, ...

this misses that layer three topology is at least one, and sometimes two,
levels of remapping above glass.  carriers swap glass, common l3 paths can
be across multiple carriers mapping onto multiple swaps, ...  it gets quite
grotty down there.

randy