In message <78697910-F7A6-4D53-AD93-377FCE66006D@arin.net>, John Curran writes:
On Feb 10, 2011, at 10:31 PM, Jack Bates wrote:
On 2/10/2011 8:15 PM, John Curran wrote:
I'm not certain that you could rely on any organizations statements made= today to provide any assurance that circumstances would not change in the futu= re and result in the address space being returned to ARIN or transferred per cu= rrent policy. =20 An official statement from the DoD? I'm sure we could hold them to it as = a community. Is it too much for us to ask the US government to give us assu= rance that we can safely utilize huge chunks of address space assigned to t= hem for purposes such as LSN without fear? :)
In organizations of all sizes, positions and policies change,=20 with revised statements as a result. One thing that does not change, however, is contractual commitments, and in this one case I can state that there is a commitment to return IPv4=20 address blocks to ARIN for reuse by the community if they no=20 longer needed.
If you'd like to reserve a large block for purposes of LSN=20 without any concern of future address conflict, it would be=20 best to actually reserve it via community-developed policy.
The first half of Class E would work. There are 134+ million addresses there and you only have to be able to route it between the CPE and the LSN / 6rd BR. The CPE signals that it support Class E (DHCP/PPP option) and the ISP only assigns a address from the block if it knows the path is Class E clean. Anyone that can't work with double NAT would clear the option and it would be on by default. It should be possible to patch all existing CPE devices to support this without flash memory constraints. The same can't be said for upgrading then to support IPv6. It does require the whole world to upgrade to be useful. It can be done incrementally. It will significiantly reduce the remaining IPv4 consumption rate. Those CPE's that turn on 6to4 automatically now have another well known address range where it is known not to work. It doesn't clash with address ranges already in use by customers. It can be used with 6rd so that IPv6 can be deployed over it for ISP's that have boxes that can't be upgraded to IPv6. It gives them a little more breathing room.
FYI, /John
John Curran President and CEO ARIN -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: marka@isc.org