------------------------------------------------------------------------ prop-099-v002: IPv6 Reservation for Large Networks ------------------------------------------------------------------------ Authors: Xing Li Song Jiang, Xiaomin Zhou, Haijin Li 1. Introduction --------------- This proposal extends the IPv6 request process to allow large ISPs to request multiple prefixes within a single, contiguous, reserved space. Such a request must justify each prefix allocation in terms of specific demonstrated needs (in the same manner as a normal IPv6 allocation request); and must justify the total requested reservation in terms of documented architectural plans and projected space requirements for a period of up to 5 years. 2. Summary of the current problem --------------------------------- The current IPv6 address allocation and assignment policy (apnic-089-v010) states that 5.2.3 Larger initial allocations Initial allocations larger than /32 may be justified if: a. The organization provides comprehensive documentation of planned IPv6 infrastructure which would require a larger allocation; or b. The organization provides comprehensive documentation of all of the following: o its existing IPv4 infrastructure and customer base, o its intention to provide its existing IPv4 services via IPv6, and o its intention to move some of its existing IPv4 customers to IPv6 within two years. In either case, an allocation will be made which fulfills the calculated address requirement, in accordance with the HD-Ratio based utilization policy. Large networks are facing challenges deploying IPv6 networks. The current slow start policy is to allocate a /32 and then reduce the bit mask one bit at a time on subsequent allocations (i.e. /31, /30, /29 etc.). This approach is designed to maximise global routing aggregation, however, it causes fragmentation and complexity in the internal routing configuration of very large networks. This is particularly a problem in large networks with many POPs growing at different rates. Also, the IPv6 Address Allocation and Assignment Policy (Section 5.2.3 Larger initial allocations) does not take into account long-term future growth. A partial solution is available after prop-083 (Alternative criteria for subsequent IPv6 allocations) [1] where additional prefixes can be delegated to an organization¡¯s disparate networks. However, this does not address the specific needs of organizations with very large non-disparate networks. These require a large address space over which they can design their network on a longer planning window (up to 5 years). 3. Situation in other RIRs -------------------------- No similar policy or policy proposal is available in the other RIRs. 4. Details of the proposal --------------------------- 4.1 Multiple prefix request Each IPv6 request will be able to specify any number of prefixes, although each must be separately justified according to specific demonstrated needs. Conventional allocation policies will be applied in assessment of each prefix requested. In particular, existing IPv4 infrastructure can be considered, and the current minimum allocation size will apply to each prefix. Each request may specify a proposed map of requested prefixes within the reserved space, based on expected growth forecasts for each prefix. As the allocated prefixes grow and become aggregatable, external routing should be aggregated whenever possible. 4.2 Subsequent allocations Subsequent allocations within the reserved space can be requested and made according to Section 5.3 of the IPv6 address allocation and assignment policy. Subsequent allocation requests can include extensions to previously allocated prefixes and/or new prefixes as needed. 4.3 Reservation request Each IPv6 request will be able to specify a proposed reservation for the entire network, to contain all allocated prefixes, and room for their future growth. The requested reservation may accommodate projected network growth for up to 5 years, based on supporting information, which may include long-term network plans such as: - Network architecture o Number of POPs and the growth rate of each based on past records and future projection o IPv6 address assignment plan that covers the initial and the end deployment within the planning window o List of equipment and devices to be deployed in the network and, - Environmental factors such as: o Market size and market share o Population and economic growth of service region 4.4 Reservation term Each reservation will be subject to expiry after 2 years, unless renewed by a request, which provides an update of network deployment and projections. No reservation will be expired or cancelled by APNIC without prior contact with the holder. 4.5 Registration In case of a multiple-prefix allocation, only the individual allocated prefixes will be registered in whois, or included in resource certificates; the reservation itself will not be registered, however it may be separately documented. 4.6 Suggested modifications of the current policy Suggest to add bullet 'c' in the current policy 5.2.3 Larger initial allocations Initial allocations larger than /32 may be justified if: a. The organization provides comprehensive documentation of planned IPv6 infrastructure which would require a larger allocation; or b. The organization provides comprehensive documentation of all of the following: o its existing IPv4 infrastructure and customer base, o its intention to provide its existing IPv4 services via IPv6, and o its intention to move some of its existing IPv4 customers to IPv6 within two years; or c. The organization provides comprehensive documentation of long term (up to 5 years) IPv6 infrastructure which would require a larger allocation: o Larger initial allocation will be via a multiple-prefix request, conventional allocation policies will be applied in assessment of each prefix requested, subsequent allocation requests can include extensions to previously allocated prefixes and/or new prefixes as needed; o Each IPv6 request will be able to specify a proposed reservation for the entire network, to contain all allocated prefixes, and room for their future growth; o In case of a multiple-prefix allocation, only the individual allocated prefixes will be registered in whois, or included in resource certificates; the reservation itself will not be registered, however it may be separately documented. In either case, an allocation will be made which fulfills the calculated address requirement, in accordance with the HD-Ratio based utilization policy. 5. Advantages and disadvantages of the proposal ------------------------------------------------ Advantages: - This proposal enables large networks to make long-term network plans and reduce internal routing complexities. - The reserved space is aggregated, and can be globally routed as a single prefix once the space is fully allocated. - The proposal allows long-term growth forecasts to be taken into account in the allocation process, without making allocation commitments based on those forecasts Disadvantages: - Initial allocation from the reserved space could be made in multiple disaggregated prefixes that have to be announced separately on the global routing table. However, as more allocations are made, the announcement could eventually converge to a smaller number of prefixes, or even to a single prefix. - Additional work for APNIC Secretariat to manage the request process, and regular renewals of reservations. The APNIC EC may want to look at the cost implication, which is out of scope of this policy proposal. 6. Effect on APNIC Members --------------------------- APNIC account holders with large networks will be able to submit their long-term network plan and receive IPv6 allocations in stages according to that plan. 7. Effect on NIRs ----------------- The proposal allows NIRs to choose when to adopt this policy for their Members.