new 6bone pTLA prefix proposal, comments by 4 March 2002 please

[itojun@iijlab.net]

>1. requiring existing pTLA /24 and /28 holders to renumber to a new /32, 
>unless justifying why it is not possible due to usage and/or address layout 
>issues, within 6 months (12 months?) of the change in policy.

	normally /24 or /28 pTLAs behave just like an ISP, and sub-allocates
	its address space (like /48) to childrens.  for example, WIDE
	(3ffe:500::/24) has 3 layers of address sub-allocation (/40 and
	then /48) under it.  it would be rather hard for those pTLAs to
	renumber all suballocated regions. (imagine renumbering x/8 to y/8,
	where there are suballocations like x.z.u.0/24)  is the scenario
	realistic in actual IPv6 operation?  isn't it too aggressive?
	(example: when sTLA gets more address space, they won't asked to return
	their previously allocated space)

itojun