I think you follow Nanog, and the recent lawsuit filed over
renumbering.
Plaintiff claimed they didn't have enough time to renumber.
What does one stupid company after themselve creating
situation where they
forced their biggest client out and then wanting to hurt
their former client
as much as possible, but can't because of court order, and now crying
"wolf" (did they look at the mirror?) in public has anything
to do with
standards for renumbering?
I took a look at the NANOG list archives. William is putting it
very mildly here.
This related to a pleading for a Temporary Restraining Order
to protect the customer of the ISP for a short period of time
in order to allow them to perform an orderly transition.
its
matter of proper scripting.
Or you tell your users to use smtp.example.com as the address
for outgoing email service. Then you write an SPF rule to state
that the address smtp.example.com maps to is a legitimate
address.
Job done now and forever.
Also, UUnet gives 6 months standard to return address
space--personal
experience. Specific enough?
UUNET gives 12 months or more to renumber. ARIN gives 12
months to renumber
Other ISPs have their own standards (usually less then 12
month). European
people said their "unpublished" standards is up to 6 months
AFTER client
already left that they can continue to use old ip addresses
and renumber.
There is a big interest in making this easy since otherwise it
would create a perverse incentive for folk going out to get
their own allocations in order to protect themselves from abuse
by their ISP.
Phill