At 8:20 AM -0800 2/19/08, David Conrad wrote:
What incentive to a holder of early allocations is there to return address space voluntarily?
No incentive at all, unless they don't need them anymore. In that case, RFC2050 applies (which you and Kim and Mark and Daniel and Jon Postel coauthored, right?): "IP addresses are valid as long as the criteria continues to be met. The IANA reserves the right to invalidate any IP assignments once it is determined the the requirement for the address space no longer exists. In the event of address invalidation, reasonable efforts will be made by the appropriate registry to inform the organization that the addresses have been returned to the free pool of IPv4 address space." I understand that quite a few allocations were made prior to RFC 2050, but they certainly don't predates Jon's involvement as the IANA or the original collaborative spirit of the Internet community. To be clear, many of those who received early allocations are making use of them in some manner, and I haven't seen in any policies or proposals any suggestion that organizations actually using addresses shouldn't keep on using them. The discussion has been on why most of those who haven't been making use of their early assignments haven't actually returned them to the free pool (we've had some successes over the last ten years, including the recent address returns that Leo discusses here: http://blog.icann.org/?p=271) but these add up to a very small percentage of the potentially unused space in the early allocations. What we now face is the simply reality of whether enabling a financial incentive for those who don't adhere to the community spirit incentive is overall worthwhile for the Internet. Some will say this has certain unsavory aspects to it (such as discouraging altruistic return of address space) but that shouldn't preclude it from being considered at all. /John