_______________________________________________________________________ prop-097-v001: Global Policy for post exhaustion IPv4 allocation mechanisms by the IANA _______________________________________________________________________ Authors: Alejandro Acosta Nicolas Antoniello S. Moonesamy Douglas Onyango Medel Ramirez Masato Yamanishi Note: The co-authors are actively seeking authors from all regions to ensure all RIR community's needs are met. We encourage interested community members to become co-authors of this proposal. Version: 1 Date: 25 January 2011 1. Introduction ---------------- This proposal describes the process that IANA will follow to allocate IPv4 resources to Regional Internet Registries (RIRs) after the central pool of addresses is exhausted. The processes for how IPv4 space may be placed in the IANA Recovered IPv4 Pool is out of the scope of this proposal. 2. Definitions -------------- 2.1 IPv4 address holdings IPv4 address holdings are all unallocated IPv4 address space held by an RIR. 2.2 Aggregated address blocks Aggregated address blocks are contiguous prefixes that can be aggregated on natural bit boundaries. 3. Summary of the current problem ---------------------------------- An earlier global policy proposal authored by a team consisting of people from each of the five RIRs reached consensus at four RIRs, and was subsequently endorsed by these RIRs' Boards. In the APNIC region, this was prop-069, "Global policy proposal for the allocation of IPv4 blocks to Regional Internet Registries". To see the proposal reference number for this proposal in all five RIRs, see Appendix A. The version approved in the fifth region was substantially rewritten by that community to meet some of their concerns. However, given the nature of the rewrites, it would have been difficult to reconcile that version with the version that reached concensus in the other four RIRs. Therefore, some members of the ARIN community wrote a new global proposal, "Global Policy for IPv4 Allocations by the IANA Post Exhaustion", which has been adopted in the ARIN region. It is under discussion in the AfriNIC, APNIC and RIPE regions. In the APNIC region, it is prop-086. To see the proposal reference number for this proposal in all five RIRs, see Appendix A. However, there are significant issues with prop-086. These are: - The reclamation pool could be exhausted by RIR(s) with high allocation rates after the first (or first few) allocation period(s). There are two main reasons RIRs will have differing allocation rates after the IANA pool is exhausted: 1. Rate of Internet growth in the region 2. Policies developed by different regions governing how the last part of their IPv4 addresses are to be managed. In response to IPv4 exhaustion, some RIR communities have chosen to apply policies to a part of their last IPv4 addresses that aim to assist with a smooth transition to IPv6. An effect of such policies is that it can slow down the consumption of IPv4 addresses allocated under these policies. This side effect would put RIRs that have chosen to adopt such policies at a disadvantage, as they will take far longer to qualify for space under prop-086 compared to RIRs that have chosen not to adopt such policies. Therefore, to ensure that regional variation in runout policy amongst RIRs is accounted for, it is important to have an IANA redistribution method that can continue to provide resources to RIRs over more than one (or only a few) allocation periods. - The definitions of when an RIR is considered to be "exhausted", and therefore eligible for space from IANA, should be more flexible given the very different RIR policy environments and the number of addresses available at any given time. - Under the redistribution formula proposed in prop-086, it is possible for one RIR to be the single eligible RIR in the first IANA allocation period and for that RIR to claim the entire reclamation pool. It is also possible that only one RIR could be eligible during subsequent allocation periods, and take the total IANA pool available at that time. To prevent this from happening, it is better to have a formula that would allow eligible RIRs to take only a certain fraction of the IANA pool at each allocation period. A problem with both prop-069 and prop-086 is related to the policy for the return of addresses by the RIRs to IANA: - In prop-069, the return of addresses to the reclamation pool was mandatory. This restriction was of significant concern to the ARIN community. - In prop-086, return of addresses by RIRs is optional, but there is nothing to prevent an RIR which has contributed nothing towards IANA's return pool from claiming part, or indeed all, of the return pool. - Because of the two above issues, this new proposal separates the return of address space to the IANA from the redistribution of that space by the IANA. Instead, the authors of this new proposal treat the return and redistribution as two separate issues that should be treated as separate policies. 4. Situation in other RIRs --------------------------- This proposal will be submitted to all RIRs with a view to becoming global policy. 5. Details ----------- Upon adoption of this IPv4 address policy by the ICANN Board of Directors, the IANA shall establish a Recovered IPv4 Pool to be utilized post RIR IPv4 exhaustion as defined in Section 1. The Recovered IPv4 Pool will initially contain any fragments that may be left over in the IANA. It will also hold any space returned to the IANA by any other means. 5.1 Recovered IPv4 Pool The Recovered IPv4 Pool will be administered by the IANA. It will contain: a. Any fragments left over in the IANA inventory after the last /8s of IPv4 space are delegated to the RIRs - The IANA inventory excludes "Special use IPv4 addresses" as defined in BCP 153 and any addresses allocated by the IANA for experimental use. b. Any IPv4 space returned to the IANA by any means. The Recovered IPv4 Pool will stay inactive until the first RIR exhausts its inventory of IPv4 address space as defined in Sections 5.3b below. Once active, IP addresses from the Recovered IPv4 Pool will be allocated as stated in Section 5.2 below. 5.2 Allocation of returned IPv4 address space by the IANA a. Allocations from the IANA may begin once the pool is declared active. b. For the purposes of this policy, an "IPv4 allocation period" is defined as a 6-month period following 1 March or 1 September in each year. c. The IANA will calculate the size of the "IPv4 allocation unit" at the following times: - When the Recovered IPv4 Pool is first activated - At the beginning of each IPv4 allocation period To calculate the "IPv4 allocation unit" at these times, the IANA will use the following formula: IPv4 allocation unit = 1/10 of Recovered IPv4 pool, rounded down to the next CIDR (power-of-2) boundary. No RIR may get more than this calculation used to determine the IPv4 allocation unit even when they can justify a need for it. The minimum "IPv4 allocation unit" size will be a /24. If the calculation used to determine the IPv4 allocation unit results in a block smaller than a /24, the IANA will not distribute any addresses in that IPv4 allocation period. d. In each allocation period, each eligible RIR may issue one IPv4 request to the IANA. Providing that the RIR satisfies the allocation criteria described in section 5.3, the IANA will allocate a single allocation unit, composed of the smallest possible number of blocks available in its IPv4 address pool. 5.3 Allocation criteria a. To be eligible for an allocation from the Recovered IPv4 Pool, an RIR must: - Have returned addresses to the Recovered IPv4 Pool. - Report on the status of its IPv4 address pool as described in Section 5.4d below. - Have not already received an IPv4 allocation unit from the IANA during the current IPv4 allocation period. b. In addition, if the RIR is requesting its first allocation from the Recovered IPv4 Pool, it must: - Have less than a total of /9 in its unallocated IPv4 address pool c. If the RIR is requesting a subsequent allocation from the Recovered IPv4 Pool, it must: - Have less than 50% of the size of the current IANA IPv4 allocation unit remaining in its unallocated IPv4 address pool. d. RIRs are permitted to reserve up to one /10 of their unallocated IPv4 addresses for special purposes (such as policies tying IPv4 allocations to IPv6 deployment, or future use). Any reservations larger than a /10 will be considered to be "unallocated" and part of the RIR's total unallocated IPv4 address pool. 5.4 Reporting a. All allocated space is to be recorded in a publicly available IANA-published log of IPv4 address space transactions, with each log entry detailing the address blocks, the date of the allocation, and the recipient RIR. b. The IANA will maintain a public registry of the current disposition of all IPv4 address space, detailing all reservations and current allocations and current IANA-held address space that is unallocated. c. The IANA may make public announcements of IPv4 address block transactions that occur under this policy. The IANA will make appropriate modifications to the "Internet Protocol V4 Address Space" page of the IANA website [2] and may make announcements to its own appropriate announcement lists. The IANA announcements will be limited to which address ranges, the time of allocation, and to which Registry they have been allocated. d. To be eligible for address allocations, RIRs must report monthly, and at least for 3 months prior to any request, all address allocations made and the total of its IPv4 address holdings and reservations. 6. Pros/Cons ------------- Advantages: - The policy provides a mechanism for the ongoing distribution of IPv4 address space, while removing the areas of prop-069 that were problematic for the ARIN community, and removing the problematic areas of prop-086. That is, the proposal: - Permits regional variation in runout policy amongst RIRs to be accounted for in the distribution of the Recovered IPv4 Pool - Prevents the possibility of a single RIR being eligible to be allocated the entire Recovered IPv4 Pool in the first (and perhaps only) allocation period - Removes two areas of policy that have failed to reach agreement in previous attempts at this proposal: - How addresses should be placed in the Recovered IPv4 Pool - References to how transfers should or should not take place Disadvantages: - This proposal is unlikely to finish the global policy development process before the IANA pool exhausts. However, the exhaustion of the IANA pool is an independent event that will not affect this proposal's eventual implementation. - This proposal does not provide details of how address space may be returned to the IANA IPv4 Recovered Pool. However, since it limits the eligibility for addresses from the IPv4 Recovered Pool to those who have contributed to it, it will encourage RIRs to actively return addresses to IANA. 7. Effect on APNIC ------------------- This policy governs the allocation relationship between the IANA and the RIRs. It does not imply any change to allocation relationships between APNIC and its Members. 8. Effect on NIRs ------------------ This policy governs the allocation relationship between the IANA and the RIRs. It does not imply any change to allocation relationships between APNIC and the NIRs. 9. References -------------- [1] "Global Policy for the Allocation of the Remaining IPv4 Address Space" http://www.icann.org/en/general/allocation-remaining-ipv4-space.htm [2] "IANA IPv4 Address Space Registry", January 2011. http://www.iana.org/assignments/ipv4-address-space/ipv4-address-space.xml Appendix A ---------- Proposal number given to "Global policy proposal for the allocation of IPv4 blocks to Regional Internet Registries" in each of the five regions: AfriNIC: AFPUB-2009-v4-002 APNIC: prop-069 ARIN: ARIN-2009-3 LACNIC: LAC-2009-01 RIPE: RIPE 2009-01 Proposal number given to "Global Policy for IPv4 Allocations by the IANA Post Exhaustion" in each of the five regions: AfriNIC: AFPUB-2010-v4-006 APNIC: prop-086 ARIN: ARIN-2010-10 LACNIC: LAC-2010-04 RIPE: RIPE 2010-05