------------------------------------------------------- prop-165-v004 Provision of IPv4 Address Space to IPv6-only Networks for Transitional Purpose Authors ------------------------------------------------------- Proposer: Tomohiro fujisaki.tomohiro@gmail.com Hiroki Kawabata / kawabata@nic.ad.jp 1. Problem statement ------------------------------------------------------- This proposal seeks to allow organizations that qualify for an initial IPv6 allocation to receive a limited IPv4 delegation, specifically a /24 block, upon request. As IPv6-only deployments become more common, network operators still require a small amount of IPv4 space for transition-related services including: - DNS resolvers - Mail gateways - Network monitoring systems - Logging systems - Access to legacy IPv4-only services Under the current policy framework, organizations deploying IPv6-only networks may face difficulties satisfying existing IPv4 justification requirements despite requiring only a minimal amount of IPv4 address space. This proposal intends to facilitate IPv6-only deployment while preserving the conservation principles governing APNIC's remaining IPv4 address pool. 2. Objective of policy change ------------------------------------------------------- The proposal aims to: - Support deployment of IPv6-only networks. - Reduce barriers for new IPv6 network operators. - Provide only the minimum IPv4 resources necessary for transitional functions. - Ensure that allocations made under this policy remain consistent with Final /8 conservation principles. - Prevent stockpiling, transfer, and speculative acquisition of IPv4 resources. - Maintain fair access to remaining IPv4 resources. - Allow the policy to automatically cease when IPv4 scarcity reaches a predefined threshold. 3. Situation in other regions ------------------------------------------------------- No Regional Internet Registry currently maintains a policy identical to this proposal. However, there are precedents where IPv4 allocation policies were specifically adjusted to facilitate IPv6 deployment activities. For example, ARIN implemented NRPM Section 4.10, Dedicated IPv4 Block to Facilitate IPv6 Deployment. Under this policy, IPv4 address space was reserved specifically for organizations deploying IPv6 transition infrastructure. Examples included Internet Exchange Points, IPv6 DNS infrastructure, and other services necessary to support IPv6 deployment. The principle behind ARIN's policy was that limited access to IPv4 resources should not become a barrier to IPv6 deployment. This proposal follows a similar principle. Organizations deploying IPv6-only networks may still require a small amount of IPv4 address space for transitional functions such as DNS resolution, mail gateways, monitoring systems, and interoperability with IPv4-only services. While the ARIN policy was developed in a different address availability environment, it demonstrates that the Internet community has previously recognized the need to use a limited amount of IPv4 resources to accelerate IPv6 deployment rather than impede it. Unlike historical policies developed when IPv4 inventories were larger, this proposal incorporates additional conservation measures appropriate to APNIC's current environment, including: - limitation to a single IPv4 /24 delegation; - inclusion within Final /8 eligibility limits; - prohibition of transfer; - periodic review of continued need; - mandatory return requirements; and - an automatic sunset mechanism linked to IPv4 pool depletion. These safeguards ensure that the proposal supports IPv6 deployment while maintaining responsible stewardship of APNIC's remaining IPv4 address pool. 4. Proposed policy solution ------------------------------------------------------- Add a new section to APNIC address management policy as follows. Eligibility: Organizations eligible to receive an initial IPv6 allocation under current APNIC policy may request a single IPv4 /24 delegation under this policy. Applicants must provide an IPv6-only Deployment Declaration describing: - the intended IPv6-only deployment; - the transitional services requiring IPv4 connectivity; and - acknowledgement of the conditions associated with the IPv4 delegation. No detailed host-based IPv4 justification shall be required. APNIC may request supporting information reasonably necessary to assess the declaration. Examples of supporting information may include: - documentation describing the IPv6-only deployment; - evidence of operation of IPv6-capable network equipment; - evidence of services operating within the declared IPv6-only environment. The purpose of such information is solely to demonstrate that the deployment described in the declaration exists or is being implemented. Delegation size: The maximum delegation size shall be one IPv4 /24. Only one delegation under this policy may be issued to any organization. Relationship with Final /8 Policy: IPv4 address space delegated under this policy: - shall be sourced from the Final /8 pool; - shall count toward the recipient's maximum IPv4 entitlement under current APNIC policy; and - shall not increase the total IPv4 holdings permitted to the recipient organization. Registry identification: IPv4 address space delegated under this policy shall be identified in APNIC registry records as having been delegated under this section. The delegation shall be linked to the corresponding IPv6 allocation used to qualify for the delegation. Conditions of use: The delegated IPv4 address block: - must be used primarily to support IPv6-only network operations and related transitional functions, as described in the applicant's deployment declaration; - must not be transferred; and - must not be reassigned or otherwise made available for use by another organization. Periodic review: APNIC may periodically request confirmation that: - the associated IPv6 allocation remains valid; - the IPv6-only deployment remains operational; and - the delegated IPv4 resources continue to be required for transitional purposes. APNIC may request an updated IPv6-only Deployment Declaration and supporting information as part of the review process. The review process shall be declaration-based and shall not require technical inspection of the member's network. Failure to provide such confirmation may result in revocation of the delegation. Return requirements: The IPv4 address block delegated under this policy must be returned if: - the associated IPv6 allocation is returned; - the IPv6-only deployment ceases operation; - the IPv4 resources are no longer required for transitional purposes; or - the conditions of this policy are no longer satisfied. Sunset provision: To preserve the remaining IPv4 address pool, APNIC shall cease issuing new delegations under this policy when one of the following conditions is met: 1. APNIC projects that the IPv4 address space available for delegation under the Final /8 Policy will be exhausted within six months, calculated using the average monthly IPv4 delegation rate observed during the preceding twelve-month period; or 2. The amount of IPv4 address space available for delegation under the Final /8 Policy falls below a minimum reserve level determined by the APNIC community. APNIC shall publish the projected exhaustion date and the amount of remaining Final /8 address space at least quarterly. Upon activation of the sunset provision: - no new delegations shall be issued under this policy; - existing delegations may continue subject to compliance with this policy; and - APNIC shall publish a notice indicating that the sunset condition has been triggered. Applications approved prior to activation of the sunset condition shall continue to be processed normally. Applications that have not yet been approved at the time the sunset condition is activated shall be assessed under the policies then in force. 5. Advantages / Disadvantages ------------------------------------------------------- Advantages: - Encourages deployment of IPv6-only networks. - Provides a practical solution for limited IPv4 operational requirements. - Limits IPv4 consumption to a single /24. - Preserves consistency with existing Final /8 principles. - Includes safeguards against transfer, reassignment, and stockpiling. - Uses a lightweight declaration-based review process. - Allows objective evidence where necessary. - Provides clear identification of resources delegated under this policy. - Includes a transparent and objective sunset mechanism. - Minimizes operational and compliance burden on both APNIC and resource holders. Disadvantages: - Requires additional administrative processing by APNIC. - Consumes a limited amount of remaining IPv4 address space. - Some compliance verification relies on declarations provided by resource holders. - Interpretation of "IPv6-only network support" may require operational judgement in specific cases. 6. Impact on resource holders ------------------------------------------------------- Minimal impact expected. Eligible organizations may obtain a single IPv4 /24 delegation to support IPv6-only deployment without detailed IPv4 host-count justification. Organizations receiving resources under this policy must comply with the declaration, review, and return requirements described above. 7. References ------------------------------------------------------- - ARIN Number Resource Policy Manual (NRPM), Section 4.10, Dedicated IPv4 Block to Facilitate IPv6 Deployment. - APNIC-127: IPv4 Policies. - APNIC Final /8 Policy.