------------------------------------------------------------------------ prop-101-v001: Removing multihoming requirement for IPv6 portable assignments ------------------------------------------------------------------------ Author: David Woodgate 1. Introduction ---------------- This a proposal to change the "IPv6 address allocation and assignment policy" to allow portable (that is, provider independent or PI) assignments of IPv6 address blocks to be made by APNIC to any organization with due justification and payment of standard fees, removing the current requirement that the requestor is or plans to be multihomed. 2. Summary of the current problem ---------------------------------- Current APNIC policy only permits portable assignments of IPv6 addresses to be made to an organization "if it is currently multihomed or plans to be multihomed within three months." [1] This requirement may unnecessarily complicate the implementation of IPv6 in some networks that are large or complex and use static assignment of addresses. It is therefore proposed to remove this requirement. IPv6 models tend to assume widespread assignment of registered IPv6 addresses to equipment throughout a network; so if provider assigned IPv6 addresses have been used in an organization's network, then any change of ISP would require a renumbering of the entire network. Such renumbering may be feasible if the network is small or dynamically assigned (for example, through use of prefix-delegation), but renumbering a large, statically-assigned network would be a significant operational challenge, and may not be practically possible. Although it is likely that many large networks would be multihomed, there will be technical or commercial reasons why some will not be; currently those networks cannot obtain portable IPv6 assignments from APNIC, and would need to use assignments from their ISPs, and accept the associated difficulties of future renumbering if they do so. This consideration and complexity could significantly delay IPv6 use by the affected organisations, which is not desirable. There is a risk that removing the multihoming requirement could cause a significant increase in demand for portable assignments, which in turn could cause the Internet routing tables to grow beyond manageable levels. It is not feasible to quickly generate any realistic model of likely demand increase which would arise from the proposed policy change, but it is argued that any such increase would only be of a scale to produce a manageable impact on global routing, for reasons including: - Organizations would only be likely to seek portable addressing if they believed it were essential for their operations, as provider assigned IPv6 addressing would be likely to be offered automatically and at no additional cost with their Internet services from their ISP; - APNIC membership fees would be expected to naturally discourage unnecessary requests, as these would be a far greater cost than that for provider assigned addressing; - Many or most organizations that require portable addressing will be multihomed, so the demand increase caused by removing the multihomed requirement should be small; - Only a limited set of an ISP's products is likely to allow customers to use portable assignments if they are singly-homed. 3. Situation in other RIRs --------------------------- APNIC is now the only RIR remaining with an absolute requirement for multihoming for portable address assignments. AfriNIC: The "Policy for IPv6 ProviderIndependent (PI) Assignment for End-Sites" [2] does not mention any requirement for multihoming; ARIN: Section 6.5.8 of the "ARIN Number Resource Policy Manual" [3] only identifies multihoming as one of several alternative criteria for direct IPv6 assignment to end-user organizations; LACNIC: There is no mention of multihoming anywhere in the IPv6 section (Section 4) of the current LACNIC Policy Manual (v1.8 - 07/12/2011) [4]. RIPE: The latest version (RIPE-545 [5]) published in January 2012 of the "IPv6 Address Allocation and Assignment Policy" does not mention multihoming, removing the requirement that existed in previous versions of the document. 4. Details ----------- It is proposed that section 5.9.1 of APNIC's "IPv6 address allocation and assignment policy" (apnic-089-v010) is rewritten to remove the absolute multihoming requirement for portable assignments, and to incorporate the following conditions: A. Portable IPv6 assignments are to be made only to organizations that have either joined APNIC as members or have signed the non-member agreement, under the standard terms & conditions and paying the standard fees applicable for their respective category. B. An organization will be eligible for a portable assignment if they have previously justified an IPv4 portable assignment from APNIC. C. A request for an IPv6 portable assignment will need to be accompanied by a reasonable technical justification indicating why IPv6 addresses from an ISP or other LIR are unsuitable. D. The minimum IPv6 portable assignment to any organization is to be an address block of /48. A portable assignment of a block larger than a /48 can be made if it can be demonstrated that more than 32,768 /64 subnets (or equivalent) are required within its network or if numbering is required for 2 or more of the organization's sites operating distinct and unconnected networks. E. In order to minimise routing table impacts: (a) Only one IPv6 address block is to be given to an organization upon an initial request for a portable assignment; subnets of this block may be assigned by the organization to its different sites if needed; (b) It is recommended that the APNIC Secretariat applies sparse allocation methodologies so that any subsequent requests from an organization for additional portable addressing would be accommodated where possible through a change of prefix mask of a previous assignment (for example, 2001:db8:1000::/48 -> 2001:db8:1000::/44), rather than through allocation of a new prefix. An additional prefix should only be allocated where it is not possible to simply change the prefix mask. (c) Any subsequent request for an additional portable assignment to an organization must be accompanied by information demonstrating: (i) Why an additional portable assignment is required, and why an assignment from from an ISP or other LIR cannot be used for this purpose instead; (ii) That the use of previous portable IPv6 allocations generated the minimum possible number of global routing announcements and the maximum aggregation of that block; (iii) How the additional assignment would be managed to minimise the growth of the global IPv6 routing table. F. An organization must only use portable assignments made under this policy to address its own networks. An organization must not use portable assignments to address the networks or sites of other organizations. 5. Pros/Cons ------------- Advantages: - This proposal would provide access to portable IPv6 addresses for all organizations with valid needs, removing a potential impediment to industry standard IPv6 addressing for large singly-homed networks - This change would align APNIC with the policies of all other RIRs on portable assignments Disadvantages: - There would be a risk of an unmanageably large increase in global IPv6 routing table size and APNIC workload if there were to be a substantial and widespread increase in demand for portable assignments arising from the removal of the multihoming requirement - But demand is expected to be limited by the requirements specified in section 4 for justifications and APNIC standard fees, as well as other industry factors such as the capability of Internet services to support portable addressing. 6. Effect on APNIC ------------------- The impact of this proposal on the APNIC Secretariat would depend on the increase of demand for portable assignments. Even if demand is eventually large, it is unlikely that there will be an significant change in hostmaster workloads for a long time because of the slow rate of take up of IPv6, and so there should be sufficient time to identify and take steps to modify policies and processes if necessary to manage the increase. 7. Effect on NIRs ------------------ This proposal specifically applies to portable assignments made by APNIC. It would be the choice of each NIR as to whether they would adopt a similar policy. 8. References: --------------- [1] Section 5.9.1, IPv6 address allocation and assignment policy, http://www.apnic.net/policy/ipv6-address-policy#5.9 [2] http://www.afrinic.net/docs/policies/AFPUB-2007-v6-001.htm [3] https://www.arin.net/policy/nrpm.html#six58 [4] http://www.lacnic.net/en/politicas/manual5.html [5] http://www.ripe.net/ripe/docs/ripe-545