[arin-ppml] ARIN-prop-127: Shared Transition Space for IPv4 Address Extension

[George Bonser]

> 
> It allows a NAT444 to look something like this:
> [device]-(RFC1918)-[CPE]-(this space)-[CGN]-(Global Addressing)-
> {Internet}
> 
> The idea is to avoid collisions between networks on the LAN and WAN
> sides of the CPE when adding a layer of NAT44. By definition this
> space should never be routed (and therefor never contribute to
> communication with outside networks).
> 
> But I could be missing your point..?
> ~Chris

No, I was misunderstanding a portion of what was going on.  Ok, so the
idea is to mitigate RFC1918 collisions between customers within the
provider's domain by providing a "safe" NAT block to use. 

Still, my major source of discomfort is enabling v4 forever.