It would appear, then, that a better definition for 'portable' needs to
come in existence. Which is why I particularly liked
draft-ietf-cidrd-addr-ownership-07.txt.
After re-reading draft-hubbard-registry-guidelines-01.txt, its not readily
apparent what 'portability' really means; I'm not so sure that it was the
goal of the authors to define portability.
It does state, however, that:
[snip]
2) Routability: Distribution of globally unique Internet addresses
in a hierarchical manner, permitting the routing scalability of
the addresses. This scalability is necessary to ensure proper
operation of Internet routing, although it must be stressed that
routability is in no way guaranteed with the allocation or
assignment of IPv4 addresses.
[snip]
Hence my earlier comment.
The topic is discussed in more detail in draft-ietf-cidrd-addr-ownership-07.txt:
[snip]
Since the Internet does not constrain its topology (or allowed
topology changes), we can either have address ownership for everyone
or a routable Internet, but not both, or we need to develop and
deploy new mechanisms (e.g., by decoupling the address owned by the
end users from those used by the Internet routing, and provide
mechanisms to translate between the two). In the absence of new
mechanisms, if we have address ownership ("portable" addresses) for
everyone, then the routing overhead will lead to a breakdown of the
routing system resulting in a fragmented (partitioned) Internet.
Alternately, we can have a routable Internet, but without address
ownership ("portable" addresses) for everyone.
[snip]
- paul