Draft: IPv6 Address Allocation and Assignment Policy - Current Policy Text

Contents

1. Introduction

1.1. Overview

2. Definitions

2.1. Internet Registry (IR)

2.2. Regional Internet Registry (RIR)

2.3. National Internet Registry (NIR)

2.4. Local Internet Registry (LIR)

2.5. Allocate

2.6. Assign

2.7. Utilisation

2.8. HD-Ratio

2.9. End Site

3. Goals of IPv6 address space management

3.1. Goals

3.2. Uniqueness

3.3. Registration

3.4. Aggregation

3.5. Conservation

3.6. Fairness

3.7. Minimised Overhead

3.8. Conflict of Goals

4. IPv6 Policy Principles

4.1. Address space not to be considered property

4.2. Routability not guaranteed

4.3. Minimum Allocation

4.4. Consideration of IPv4 Infrastructure

5. Policies for allocations and assignments

5.1. Initial allocation

5.1.1. Initial allocation criteria

5.1.2. Initial allocation size

5.2. Subsequent allocation

5.2.1. Subsequent allocation criteria

5.2.2. Applied HD-Ratio

5.2.3. Subsequent Allocation Size

5.3. LIR-to-ISP allocation

5.4. Assignment

5.4.1. Assignment address space size

5.4.2. Assignments shorter than a /48 to a single End Site

5.4.3. Assignment to operator's infrastructure

5.5. Registration

5.6. Reverse lookup

5.7. Existing IPv6 address space holders

6. Anycasting TLD and Tier 0/1 ENUM Nameservers

7. IPv6 Provider Independent (PI) Assignments

7.1. IPv6 Provider Independent (PI) Assignments for LIRs

8. References

9. Appendix A: HD-Ratio

10. Appendix B: Background information

10.1. Background

10.2. Why a joint policy?

10.3. The size of IPv6's address space

10.4. Acknowledgment

Contents

1.0 Introduction

2.0 Definitions

2.1 Internet Registry (IR)

2.2 Regional Internet Registry (RIR)

2.3 Local Internet Registry (LIR)

2.4 Sponsoring LIR

2.5 End User

2.6 End Site

2.7 Allocation

2.8 Sub-allocation

2.9 Aggregation

2.10 Utilisation

2.11 HD-Ratio

3.0 Goals of IPv6 Address Space Management

3.1 Uniqueness

3.2 Registration

3.3 Aggregation

3.4 Conservation

3.5 Fairness

3.6 Minimised Overhead

3.7 Conflict of Goals

4.0 IPv6 Policy Principles

4.1 Address Space Not to be Considered Property

4.2 Routability Not Guaranteed

4.3 Consideration of IPv4 Infrastructure

5.0 Policies for Allocations and Sub-allocations

5.1 Initial Allocation

5.1.1 Initial Allocation Criteria

5.1.2 Initial Allocation Size

5.1.3 Initial Allocations made to the LIR

5.1.4 Initial Allocations made to the End User

5.2 Additional Allocation

5.2.1 Additional Allocation Criteria

5.2.2 Applied HD-Ratio

5.2.3 Additional Allocation Size

5.3 Sub-allocations

5.3.1 Sub-allocations Made by the LIR or the End User

5.3.2 Sub-allocation Size

5.3.3 Sub-allocation to Operator's Infrastructure

5.4 Registration

5.5 Reverse Lookup

5.6 Existing IPv6 Address Space Holders

5.6.1 LIRs Holding an Allocation

5.6.2 End Users Holding an Allocation

6.0 Special Purposes

6.1 Allocations for Anycasting TLD and Tier 0/1 ENUM Nameservers

6.2 Allocations of Internet Exchange Points

6.3 Allocations for Internet DNS Root Servers

7.0 References

8.0 Appendix A: HD-Ratio

9.0 Appendix B: Background Information

9.1 Background

9.2 Acknowledgment

10.0 Attribution

1. Introduction

1.1. Overview

This document describes policies for the allocation and assignment of globally unique Internet Protocol version 6 (IPv6) address space.

[RFC 4291] designates 2000::/3 to be global unicast address space that the Internet Assigned Numbers Authority (IANA) may allocate to the RIRs. In accordance with [RFC 4291], IANA allocated initial ranges of global unicast IPv6 address space from the 2000::/3 address block to the RIRs. This document concerns the initial and subsequent allocations of the 2000::/3 unicast address space, for which RIRs formulate allocation and assignment policies. All bits to the left of /64 are in scope.

This policy is subject to future review and potential revision, subject to continuing experience in the administration of IPv6.

1.0 Introduction

This document describes policies for the allocation and sub-allocation of globally unique Internet Protocol version 6 (IPv6) address space.

It also describes the policies for IPv6 address space allocated for special purposes, such as Internet Exchange Points and Internet Root Servers.

RFC 4291 designates 2000::/3 to be global unicast address space that the Internet Assigned Numbers Authority (IANA) may allocate to the RIRs. In accordance with RFC 4291, IANA allocated initial ranges of global unicast IPv6 address space from the 2000::/3 address block to the RIRs. This document describes the policies concerning the IPv6 allocations and sub-allocations as developed by the RIPE community.

2. Definitions

[Note: some of these definitions will be replaced by definitions from other RIR documents in order to be more consistent.]

The following terms and their definitions are of particular importance to the understanding of the goals, environment and policies described in this document.

Responsibility for management of IPv6 address spaces is distributed globally in accordance with the hierarchical structure shown below.

2.1. Internet Registry (IR)

An Internet Registry is an organisation that is responsible for distributing IP address space to its members or customers and for registering those distributions. IRs are classified according to their primary function and territorial scope within the hierarchical structure depicted in the figure above.

2.2. Regional Internet Registry (RIR)

Regional Internet Registries are established and authorised by respective regional communities and recognised by the IANA to serve and represent large geographical regions. The primary role of RIRs is to manage and distribute public Internet address space within their respective regions.

2.3. National Internet Registry (NIR)

A National Internet Registry primarily allocates address space to its members or constituents, which are generally LIRs organised at a national level. NIRs exist mostly in the Asia Pacific region.

2.4. Local Internet Registry (LIR)

A Local Internet Registry is an IR that primarily assigns address space to the users of the network services that it provides. LIRs are generally ISPs whose customers are primarily End Users and possibly other ISPs.

2.5. Allocate

To “allocate” means to distribute address space to IRs for the purpose of subsequent distribution by them.

2.6. Assign

To “assign” means to delegate address space to an ISP or End User for specific use within the Internet infrastructure they operate. Assignments must only be made for specific purposes documented by specific organisations and are not to be sub-assigned to other parties.

2.7. Utilisation

The actual usage of addresses within each assignment may be low when compared to IPv4 assignments. In IPv6, "utilisation" is only measured in terms of the bits to the left of the efficiency measurement unit (/56). In other words, "utilisation" effectively refers to the assignment of network prefixes to End Sites and not the number of addresses assigned within individual End Site assignments.

Throughout this document, the term "utilisation" refers to the assignment of network prefixes to End Sites and not the number of addresses assigned within individual subnets within those End Sites.

2.8. HD-Ratio

The HD-Ratio is a way of measuring the efficiency of address assignment [RFC 3194]. It is an adaptation of the H-Ratio originally defined in [RFC 1715] and is expressed as follows:

Log (number of allocated objects)

HD = ----------------------------------------------

Log (maximum number of allocatable objects)

where (in the case of this document) the objects are IPv6 site addresses assigned from an IPv6 prefix of a given size.

2.9. End Site

An End Site is defined as an End User (subscriber) who has a business or legal relationship (same or associated entities) with a service provider that involves:

• that service provider assigning address space to the End User
• that service provider providing transit service for the End User to other sites
• that service provider carrying the End User's traffic
• that service provider advertising an aggregate prefix route that contains the End User's assignment

2.0 Definitions

The following terms and their definitions are of particular importance to the understanding of the goals, environment and policies described in this document.

Responsibility for management of IPv6 address spaces is distributed globally in accordance with the hierarchical structure shown below.

2.1 Internet Registry (IR)

An Internet Registry is an organisation that is responsible for distributing IP address space to its members or customers and for registering those distributions. IRs are classified according to their primary function and territorial scope within the hierarchical structure depicted in the figure above.

2.2 Regional Internet Registry (RIR)

Regional Internet Registries are established and authorised by their respective regional communities and recognised by IANA to serve and represent large geographical regions. The primary role of RIRs is to manage and distribute public Internet address space within their service regions.

2.3 Local Internet Registry (LIR)

A Local Internet Registry (LIR) is an IR that primarily sub-allocates address space to the users of the network services that it provides.

2.4 Sponsoring LIR

Members of the RIPE NCC (LIRs) can request allocations on behalf of a third party, and the RIPE NCC will allocate resources directly to this third party. In these cases, the role of the LIR is to facilitate the administrative processes and to maintain a link between the RIPE NCC and the third party that holds the resources. An LIR fulfilling this role is called the Sponsoring LIR for the third party. Third parties can choose another LIR to be their Sponsoring LIR at any time.

2.5 End User

End Users are the private persons or organisations that can receive sub-allocations from an LIR or allocations from the RIPE NCC via a Sponsoring LIR.

2.6 End Site

An End Site is defined as an LIR's or End User's network, device, POP or customer. Sub-allocations made to End Sites are considered to be in use by the End Site and should not be further sub-allocated.

2.7 Allocation

To “allocate” means to distribute address space to LIRs or End Users for the purpose of subsequent distribution by them.

2.8 Sub-allocation

To “sub-allocate” means to distribute address space to customers or members for the purpose of subsequent distribution (sub-allocation) or usage by them.

2.9 Aggregation

To “aggregate” means to register multiple sub-allocations that are of the same size and are used for the same purpose in one RIPE Database object.

2.10 Utilisation

The actual usage of addresses within each sub-allocation may be low when compared to IPv4. In IPv6, “utilisation” is only measured in terms of the bits to the left of the efficiency measurement unit (/56). In other words, “utilisation” effectively refers to the sub-allocation of network prefixes to End Sites and not the number of addresses in use within the /56.

2.11 HD-Ratio

The HD-Ratio is a way of measuring the efficiency of address sub-allocation (RFC 3194). It is an adaptation of the H-Ratio originally defined in RFC 1715 and is expressed as follows:

Log (number of allocated objects)

HD = ----------------------------------------------

Log (maximum number of allocatable objects)

Where (in the case of this document) the objects are IPv6 networks sub-allocated from an IPv6 prefix of a given size.

More details are found in Appendix A.

3. Goals of IPv6 address space management

3.1. Goals

IPv6 address space is a public resource that must be managed in a prudent manner with regards to the long-term interests of the Internet. Responsible address space management involves balancing a set of sometimes competing goals. The following are the goals relevant to IPv6 address policy.

3.2. Uniqueness

Every assignment and/or allocation of address space must guarantee uniqueness worldwide. This is an absolute requirement for ensuring that every public host on the Internet can be uniquely identified.

3.3. Registration

Internet address space must be registered in a registry database accessible to appropriate members of the Internet community. This is necessary to ensure the uniqueness of each Internet address and to provide reference information for Internet troubleshooting at all levels, ranging from all RIRs and IRs to End Users.

The goal of registration should be applied within the context of reasonable privacy considerations and applicable laws.

3.4. Aggregation

Wherever possible, address space should be distributed in a hierarchical manner, according to the topology of network infrastructure. This is necessary to permit the aggregation of routing information by ISPs and to limit the expansion of Internet routing tables.

This goal is particularly important in IPv6 addressing, where the size of the total address pool creates significant implications for both internal and external routing.

IPv6 address policies should seek to avoid fragmentation of address ranges.

Further, RIRs should apply practices that maximise the potential for subsequent allocations to be made contiguous with past allocations currently held. However, there can be no guarantee of contiguous allocation.

3.5. Conservation

Although IPv6 provides an extremely large pool of address space, address policies should avoid unnecessarily wasteful practices. Requests for address space should be supported by appropriate documentation and stockpiling of unused addresses should be avoided.

3.6. Fairness

All policies and practices relating to the use of public address space should apply fairly and equitably to all existing and potential members of the Internet community, regardless of their location, nationality, size, or any other factor.

3.7. Minimised overhead

It is desirable to minimise the overhead associated with obtaining address space. Overhead includes the need to go back to RIRs for additional space too frequently, the overhead associated with managing address space that grows through a number of small successive incremental expansions rather than through fewer, but larger, expansions.

3.8. Conflict of goals

The goals described above will often conflict with each other, or with the needs of individual IRs or End Users. All IRs evaluating requests for allocations and assignments must make judgments, seeking to balance the needs of the applicant with the needs of the Internet community as a whole.

In IPv6 address policy, the goal of aggregation is considered to be the most important.

3.0 Goals of IPv6 Address Space Management

IPv6 address space is a public resource that must be managed in a prudent manner with regards to the long-term interests of the Internet. Responsible address space management involves balancing a set of sometimes competing goals. The following are the goals relevant to IPv6 address policy.

3.1 Uniqueness

Every allocation or sub-allocation of address space must be globally unique. This is an absolute requirement for ensuring that every public host on the Internet can be uniquely identified.

3.2 Registration

All allocations, sub-allocations or aggregations must be registered in the RIPE Database. This is necessary to ensure uniqueness and to support network operations.

Only allocations, sub-allocations or aggregations registered in the RIPE Database are considered valid. Registering objects in the database is the final step in making an allocation, sub-allocation or aggregation. Registration data (range, contact information, status, etc.) has to be maintained and must be correct at all times.

3.3 Aggregation

Wherever possible, address space should be distributed in a hierarchical manner, according to the topology of network infrastructure. This is necessary to permit the aggregation of routing information by ISPs and to limit the expansion of Internet routing tables.

This goal is particularly important in IPv6 addressing, where the size of the total address pool creates significant implications for both internal and external routing.

IPv6 address policies should seek to avoid fragmentation of address ranges.

Further, IRs should apply practices that maximise the potential for subsequent allocations to be made contiguous with past allocations currently held. However, there can be no guarantee of contiguous allocation.

3.4 Conservation

Although IPv6 provides an extremely large pool of address space, address policies should avoid unnecessarily wasteful practices. Requests for address space should be supported by appropriate documentation and stockpiling of unused addresses should be avoided.

3.5 Fairness

All policies and practices relating to the use of public address space should apply fairly and equitably to all existing and potential members of the Internet community, regardless of their location, nationality, size or any other factor.

3.6 Minimised Overhead

It is desirable to minimise the overhead associated with obtaining address space. Overhead includes the need to go back to IRs for additional address space too frequently and the administrative work associated with managing address space that grows through a number of small, incremental expansions rather than through fewer, but larger, expansions.

3.7 Conflict of Goals

The goals described above will often conflict with each other, or with the needs of IRs or their customers. When IRs evaluate allocation requests, they must balance the needs of the applicant with the needs of the Internet community as a whole.

In IPv6 address policy, the goal of aggregation is considered to be the most important.

4. IPv6 Policy Principles

To address the goals described in the previous section, the policies in this document discuss and follow the basic principles described below.

4.1. Address space not to be considered property

It is contrary to the goals of this document and is not in the interests of the Internet community as a whole for address space to be considered freehold property.

The policies in this document are based upon the understanding that globally unique IPv6 unicast address space is licensed for use rather than owned. Specifically, IP addresses will be allocated and assigned on a license basis, with licenses subject to renewal on a periodic basis. The granting of a license is subject to specific conditions applied at the start or renewal of the license.

RIRs will generally renew licenses automatically, provided requesting organisations are making a “good faith” effort at meeting the criteria under which they qualified for or were granted an allocation or assignment. However, in those cases where a requesting organisation is not using the address space as intended, or is showing bad faith in following through on the associated obligation, RIRs reserve the right to not renew the license. Note that when a license is renewed, the new license will be evaluated under and governed by the applicable IPv6 address policies in place at the time of renewal, which may differ from the policy in place at the time of the original allocation or assignment.

4.2. Routability not guaranteed

There is no guarantee that any address allocation or assignment will be globally routable.

However, RIRs must apply procedures that reduce the possibility of fragmented address space which may lead to a loss of routability.

4.3. Minimum allocation

The minimum allocation size for IPv6 address space is /32.

4.4. Consideration of IPv4 infrastructure

Where an existing IPv4 service provider requests IPv6 space for eventual transition of existing services to IPv6, the number of present IPv4 customers may be used to justify a larger request than would be justified if based solely on the IPv6 infrastructure.

4.0 IPv6 Policy Principles

To address the goals described in the previous section, the policies in this document discuss and follow the basic principles described below.

4.1 Address Space Not to be Considered Property

The policies in this document are based upon the understanding that globally unique IPv6 unicast address space is registered for use rather than owned as an asset.

It is contrary to the goals of this document and not in the interests of the Internet community for address space to be considered freehold property.

Specifically, IP addresses are allocated based on demonstrated and justified need. These allocations are registered in the RIPE Database. The allocation is only valid for as long as the original criteria under which the organisation qualified for an allocation are still valid.

In cases where the organisation is not using the address space as intended, or is not complying with the policies and/or the responsibilities associated with it, the RIPE NCC reserves the right to deregister the address space.

When requesting additional address space or changes to existing address space, these requests will be evaluated according to the IPv6 policies that are current at that time.

4.2 Routability Not Guaranteed

There is no guarantee that any address allocation or sub-allocation will be globally routable.

However, IRs must apply procedures that reduce the possibility of fragmented address space, which may lead to a loss of routability.

4.3 Consideration of IPv4 Infrastructure

Where an existing IPv4 service provider requests IPv6 space to transition existing services to IPv6, the number of current IPv4 customers may be used to justify a larger request than would be justified if based solely on the IPv6 infrastructure.

5. Policies for Allocations and Assignments

5.1. Initial allocation

5.1.1. Initial allocation criteria

To qualify for an initial allocation of IPv6 address space, an organisation must:

a) be an LIR;

b) have a plan for making sub-allocations to other organisations and/or End Site assignments within two years.

5.1.2. Initial allocation size

Organisations that meet the initial allocation criteria are eligible to receive an initial allocation of /32. For allocations up to /29 no additional documentation is necessary.

Organisations may qualify for an initial allocation greater than /29 by submitting documentation that reasonably justifies the request. If so, the allocation size will be based on the number of existing users and the extent of the organisation's infrastructure.

5.2. Subsequent allocation

Organisations that hold an existing IPv6 allocation may receive a subsequent allocation in accordance with the following policies.

5.2.1. Subsequent allocation criteria

Subsequent allocation will be provided when an organisation (i.e. ISP/LIR) satisfies the evaluation threshold of past address utilisation in terms of the number of sites in units of /56 assignments. The HD-Ratio [RFC 3194] is used to determine the utilisation thresholds that justify the allocation of additional address as described below.

5.2.2. Applied HD-Ratio

The HD-Ratio value of 0.94 is adopted as indicating an acceptable address utilisation for justifying the allocation of additional address space. Appendix A provides a table showing the number of assignments that are necessary to achieve an acceptable utilisation value for a given address block size.

5.2.3. Subsequent allocation size

When an organisation has achieved an acceptable utilisation for its allocated address space, it is immediately eligible to obtain an additional allocation that results in a doubling of the address space allocated to it. Where possible, the allocation will be made from an adjacent address block, meaning that its existing allocation is extended by one bit to the left.

If an organisation needs more address space, it must provide documentation justifying its requirements for a two-year period. The allocation made will be based on this requirement.

5.3. LIR-to-ISP allocation

There is no specific policy for an organisation (LIR) to allocate address space to subordinate ISPs. Each LIR organisation may develop its own policy for subordinate ISPs to encourage optimum utilisation of the total address block allocated to the LIR. However, all /48 assignments to End Sites are required to be registered either by the LIR or its subordinate ISPs in such a way that the RIR/NIR can properly evaluate the HD-Ratio when a subsequent allocation becomes necessary.

5.4. Assignment

LIRs must make IPv6 assignments in accordance with the following provisions.

5.4.1. Assignment address space size

End Users are assigned an End Site assignment from their LIR or ISP. The size of the assignment is a local decision for the LIR or ISP to make, using a minimum value of a /64 (only one subnet is anticipated for the End Site).

5.4.2. Assignments shorter than a /48 to a single End Site

When a single End Site requires an assignment shorter than a /48, it must request the assignment with documentation or materials that justify the request. Requests for multiple or additional prefixes exceeding a /48 assignment for a single End Site will be processed and reviewed (i.e., evaluation of justification) at the RIR/NIR level.

Note: There is no experience at the present time with the assignment of multiple network prefixes to the same End Site. Having the RIR review all such assignments is intended to be a temporary measure until some experience has been gained and some common policies can be developed. In addition, additional work at defining policies in this space will likely be carried out in the near future.

5.4.3. Assignment to operator's infrastructure

An organisation (i.e. ISP/LIR) may assign a network prefix per PoP as the service infrastructure of an IPv6 service operator. Each assignment to a PoP is regarded as one assignment regardless of the number of users using the PoP. A separate assignment can be obtained for the in-house operations of the operator.

5.5 Registration

When an organisation holding an IPv6 address allocation makes IPv6 address assignments, it must register these assignments in the appropriate RIR database.

These registrations can either be made as individual assignments or by inserting a object with a status value of 'AGGREGATED-BY-LIR' where the assignment-size attribute contains the size of the individual assignments made to End Users.When more than a /48 is assigned to an organisation, it must be registered in the database as a separate object with status 'ASSIGNED'.

In case of an audit or when making a request for a subsequent allocation, the LIR must be able to present statistics showing the number of individual assignments made in all objects with a status of 'AGGREGATED-BY-LIR' in such a way the RIR is able to calculate and verify the actual HD-ratio.

5.6. Reverse lookup

When an RIR/NIR delegates IPv6 address space to an organisation, it also delegates the responsibility to manage the reverse lookup zone that corresponds to the allocated IPv6 address space. Each organisation should properly manage its reverse lookup zone. When making an address assignment, the organisation must delegate to an assignee organisation, upon request, the responsibility to manage the reverse lookup zone that corresponds to the assigned address.

5.7. Existing IPv6 address space holders

LIRs that hold one or more IPv6 allocations are able to request extension of each of these allocations up to a /29 without providing further documentation.

The RIPE NCC should allocate the new address space contiguously with the LIRs' existing allocations and avoid allocating non-contiguous space under this policy section.

5.0 Policies for Allocations and Sub-allocations

The RIPE NCC will make allocations to LIRs or End Users (via a Sponsoring LIR) according to sections 5.1 and 5.2 below.

5.1 Initial Allocation

5.1.1 Initial Allocation Criteria

To qualify for an initial allocation of IPv6 address space, an LIR or an End User must have a plan for making sub-allocations to other customers and/or End Sites within two years.

5.1.2 Initial Allocation Size

Allocations made by the RIPE NCC to the LIR have a minimum allocation size of a /32 and may be up to a /29 with no additional documentation required.

Allocations made by the RIPE NCC to the End User have a minimum allocation size of a /32.

LIRs or End Users may qualify for a larger initial allocation by submitting documentation that reasonably justifies the request. If so, the allocation size will be based on the number of existing users, the extent of the organisation's infrastructure and by taking into account growth plans for up to two years in the future.

/48 allocations can be made by the RIPE NCC to End Users that do not expect to ever need more or for special purposes. Special purposes are covered in section 6 of this policy. When an organisation requests a /48 allocation, it must specifically mention in its request that it does not plan to use anything larger in the foreseeable future.

5.1.3 Initial Allocations made to the LIR

To qualify for an allocation, an LIR must submit a request to the RIPE NCC for evaluation.

5.1.4 Initial Allocations made to the End User

To qualify for an allocation, an End User must meet the requirements of the policies described in the RIPE Document ripe-452 or its updates.

The RIPE NCC will allocate the prefix directly to the End User upon a request properly submitted to the RIPE NCC by the Sponsoring LIR.

5.2 Additional Allocation

Organisations that hold an existing IPv6 allocation may receive an additional allocation in accordance with the following policies.

5.2.1 Additional Allocation Criteria

A /32 (or larger when documented) additional allocation may be provided when different routing requirements are demonstrated.

An additional allocation will also be provided when an LIR or End User satisfies the evaluation threshold of past address utilisation in terms of the number of sites in units of /56s. The HD-Ratio (RFC 3194) is used to determine the utilisation thresholds that justify the allocation of additional addresses as described below.

5.2.2 Applied HD-Ratio

The HD-Ratio value of 0.94 is adopted as an acceptable utilisation level for justifying the allocation of additional address space. Appendix A provides a table showing the number of sub-allocations that are necessary to achieve an acceptable utilisation level for a given address block size.

5.2.3 Additional Allocation Size

When an LIR or an End User has achieved an acceptable utilisation level for its allocated address space, it is immediately eligible to receive an additional allocation that results in a doubling of the address space allocated to it. If an LIR or End User needs more address space, it must provide documentation justifying its requirements for a two-year period. The allocation made will be based on this requirement or, where possible, based on the usage of the previous two years.

Where possible, the additional allocation will be made from an adjacent address block, meaning that its existing allocation is extended by one or more bits to the left. An exception is the case when an additional allocation is needed for different routing requirements.

5.3 Sub-allocations

5.3.1 Sub-allocations Made by the LIR or End User

An LIR or End User can make a sub-allocation to a customer encouraging optimum utilisation of the total address block allocated. When more than a /48 is to be sub-allocated to the same customer, the LIR or the End User (via the Sponsoring LIR) must request an approval from the RIPE NCC.

5.3.2 Sub-allocation Size

End Sites or End Users are sub-allocated an IPv6 block. The size of the sub-allocation is a local decision for the LIR or End User to make, using the minimum value of a /64 (if only one subnet is anticipated for the End Site).

A sub-allocation of a /56 or shorter is recommended when two or more subnets are anticipated for the End Site.

5.3.3 Sub-allocation to Operator's Infrastructure

An LIR or an End User may sub-allocate a network prefix per point of presence (PoP) as the service infrastructure of an IPv6 service operator. Each sub-allocation to a PoP is regarded as one regardless of the number of users using the PoP. A separate sub-allocation can be obtained for the operator's in-house operations.

5.4 Registration

When an LIR or an End User holding an IPv6 address allocation makes allocations, sub-allocations or aggregations, these must be registered in the RIPE Database. Multiple sub-allocations which have the same justification can be aggregated. The status “AGGREGATED” can be used in the RIPE Database as long as the inet6num object includes an attribute showing the sub-allocation size within that aggregation. The sub-allocation size can be a number between 48 and 64. Aggregations are multiple contiguous sub-allocations of the same size made to different End Sites for the same purpose. Sub-allocations larger than a /48 cannot be part of an aggregation. These must be registered separately in the RIPE Database.

In the case of an audit or when making a request for a subsequent allocation, the LIR or the End User must be able to present statistics showing the number of individual sub-allocations made in all objects with a status of “AGGREGATED” in such a way that the RIR is able to calculate and verify the actual HD-Ratio.

5.5 Reverse Lookup

When an RIR allocates IPv6 address space to an LIR or an End User, it also delegates the responsibility to manage the reverse lookup zone that corresponds to the allocated IPv6 address space. Each LIR or End User should properly manage its reverse lookup zone. When making sub-allocations, the LIR or the End User can delegate to its customer, upon request, the responsibility to manage the reverse lookup zone that corresponds to the sub-allocated block.

5.6 Existing IPv6 Address Space Holders

5.6.1 LIRs Holding an Allocation

LIRs that hold one or more IPv6 allocations are able to request extension of each of these allocations up to a /29 without providing further documentation.

The RIPE NCC should allocate the new address space contiguously with the LIR's existing allocations and avoid allocating non-contiguous space.

5.6.2 End Users Holding an Allocation

The RIPE NCC has previously made IPv6 assignments. These assignments have been transformed automatically by the RIPE NCC in IPv6 allocations.

End Users holding an allocation lower than a /32 (except those made for special purposes) can request an extension of this allocation to a /32. Where this extension is not possible, the organisation has the option to return the allocation and automatically receive a /32 (or larger if justified).

6. Anycasting TLD and Tier 0/1 ENUM Nameservers

The organisations applicable under this policy are TLD managers, as recorded in the IANA's Root Zone Database and ENUM administrators, as assigned by the ITU. The organisation may receive up to four /48 prefixes per TLD and four /48 prefixes per ENUM. These prefixes must be used for the sole purpose of anycasting authoritative DNS servers for the stated TLD/ENUM, as described in BCP126/RFC 4786.

Assignments for authoritative TLD or ENUM Tier 0/1 DNS lookup services are subject to the policies described in the RIPE Document entitled "Contractual Requirements for Provider Independent Resource Holders in the RIPE NCC Service Region".

Anycasting assignments are registered with a status of 'ASSIGNED ANYCAST' in the RIPE Database and must be returned to the RIPE NCC if not in use for infrastructure providing authoritative TLD or ENUM Tier 0/1 DNS lookup services any longer.

6.0 Special Purposes

Allocations made by the RIPE NCC for these special purposes are subject to the policies described in the RIPE Document ripe-452 or its updates.

These allocations will be made from a separate “designated block” to facilitate filtering practices and must be returned to the RIPE NCC if no longer in use for the purpose they were allocated for.

6.1 Allocations for Anycasting TLD and Tier 0/1 ENUM Nameservers

The organisations applicable under this policy are TLD managers, as recorded in the IANA's Root Zone Database and ENUM administrators, as assigned by the ITU. The organisation may receive up to four /48 prefixes per TLD and four /48 prefixes per ENUM. These prefixes must be used for the sole purpose of anycasting authoritative DNS servers for the stated TLD/ENUM, as described in BCP 126/RFC 4786.

These allocations are registered with a status of “ALLOCATED-FOR-ANYCAST” or “ALLOCATED-FOR-ENUM” in the RIPE Database and must be returned to the RIPE NCC if no longer in use for infrastructure providing authoritative TLD or ENUM Tier 0/1 DNS lookup services.

6.2 Allocations for Internet Exchange Points

The organisations applicable under this policy are Internet Exchange Points (IXPs), which are defined as a physical network infrastructure (layer 2) operated by a single entity whose purpose is to facilitate the exchange of Internet traffic between ISPs. These organisations must have at least three ISPs connected and there must be a clear and open policy for others to join.

These organisations may receive one /48 allocation. The prefix must be used for the sole purpose of operating the IXP. The allocation is registered with a status of “ALLOCATED-FOR-IXP” in the RIPE Database and must be returned to the RIPE NCC if no longer in use for IXP services.

[section 6.2 replace ripe-451]

6.3 Allocations for Internet DNS Root Servers

DNS resolvers and resolving name servers need to be pre-configured with the network addresses of the root name servers. This makes these addresses special and not easily changed.

Each (current or future) Internet DNS root server (as listed in the DNS root-servers.net zone) in the RIPE NCC service region will be allocated a block of IPv6 address space for the purpose of root server operations. The size of the block shall be the same as the size of the minimum allocation to LIRs at the time of the root server allocation.

The allocated prefix must be used for root server operations and support functions directly related to these operations, such as monitoring, statistics, etc. The allocated prefix is bound to the root server service itself and is not associated with the organisation(s) that operate the root server at a particular point in time. The allocation is registered with a status of “ALLOCATED-FOR-INTERNET-DNS-ROOT” in the RIPE Database.

These organisations should not use the address space to provide any services that are not related to the root server.

If the operational responsibility for a root server moves to a new organisation, the RIPE NCC should be notified so it can make the necessary updates to reflect this change.

If the new location of the root server is outside the RIPE NCC service region, the address space must be returned to the RIPE NCC and a new allocation or assignment must be requested from the appropriate RIR.

If a root server stops operating completely, the address space must be returned to the RIPE NCC. The RIPE NCC will mark the prefix as "reserved" for a suitably long period of time.

[section 6.3 replace ripe-233]

7. IPv6 Provider Independent (PI) Assignments

To qualify for IPv6 PI address space, an organisation must meet the requirements of the policies described in the RIPE NCC document entitled “Contractual Requirements for Provider Independent Resources Holders in the RIPE NCC Service Region”.

The RIPE NCC will assign the prefix directly to the End User organisations upon a request properly submitted to the RIPE NCC, either directly or through a sponsoring LIR.

The minimum size of the assignment is a /48. Organisations requesting a larger assignment (shorter prefix) must provide documentation justifying the need for additional subnets.

Additional assignments may also be made when the need is demonstrated and documented based on address usage, or because different routing requirements exist for additional assignments. When possible, these further assignments will be made from an adjacent address block.

Assignments will be made from a separate 'designated block' to facilitate filtering practices.

The PI assignment cannot be further assigned to other organisations.

7.1 IPv6 Provider Independent (PI) Assignments for LIRs

LIRs can qualify for an IPv6 PI assignment for parts of their own infrastructure that are not used for customer end sites. Where an LIR has an IPv6 allocation, the LIR must demonstrate the unique routing requirements for the PI assignment.

The LIR must return the IPv6 PI assignment within a period of six months if the original criteria on which the assignment was based are no longer valid.

If an organisation already received a PI assignment before becoming an LIR, the PI assignment should be returned upon receiving an IPv6 allocation if there are no specific routing requirements to justify both.

10. Appendix B: Background information

10.1. Background

The impetus for revising the 1999 provisional IPv6 policy started with the APNIC meeting held in Taiwan in August 2001. Follow-on discussions were held at the October 2001 RIPE and ARIN meetings. During these meetings, the participants recognised an urgent need for more detailed, complete policies. One result of the meetings was the establishment of a single mailing list to discuss a revised policy together with a desire to develop a general policy that all RIRs could use. This document does not provide details of individual discussions that lead to policies described in this document; detailed information can be found in the individual meeting minutes at the www.apnic.net, www.arin.net, and www.ripe.net web sites.

In September 2002 at the RIPE 43 Meeting in Rhodes, Greece, the RIPE community approved the policy allowing Internet experiments to receive temporary assignments. As a result, Section 6 was added to this document in January 2003.

10.2. Why a joint policy?

IPv6 addresses are a public resource that must be managed with consideration to the long-term interests of the Internet community. Although regional registries adopt allocation policies according to their own internal processes, address policies should largely be uniform across registries. Having significantly varying policies in different regions is undesirable because it can lead to situations where "registry shopping" can occur as requesting organisations request addresses from the registry that has the most favorable policy for their particular desires. This can lead to the policies in one region undermining the efforts of registries in other regions with regards to prudent stewardship of the address space. In cases where regional variations from the policy are deemed necessary, the preferred approach is to raise the issue in the other regional registries in order to develop a consensus approach that all registries can support.

10.3. The size of IPv6's address space

Compared to IPv4, IPv6 has a seemingly endless amount of address space. While superficially true, short-sighted and wasteful allocation policies could also result in the adoption of practices that lead to premature exhaustion of the address space.

It should be noted that the 128-bit address space is divided into three logical parts, with the usage of each component managed differently. The rightmost 64 bits, the Interface Identifier [RFC 4291], will often be a globally unique IEEE identifier (e.g., mac address). Although an "inefficient" way to use the Interface Identifier field from the perspective of maximizing the number of addressable nodes, the numbering scheme was explicitly chosen to simplify Stateless Address Autoconfiguration [RFC 2462].

The middle bits of an address indicate the subnet ID. This field may often be inefficiently utilised, but the operational benefits of a consistent width subnet field were deemed to be outweigh the drawbacks. This is a variable length field, determined by each LIR's local assignment policy.

10.4. Acknowledgment

The initial version of this document was produced by the JPNIC IPv6 policy drafting team consisting of Akihiro Inomata, Akinori Maemura, Kosuke Ito, Kuniaki Kondo, Takashi Arano, Tomohiro Fujisaki, and Toshiyuki Yamasaki. Special thanks goes out to this team, who worked over a holiday in order to produce an initial document quickly.

An editing team was then organised by representatives from each of the three RIRs (Takashi Arano, Chair of APNIC's Policy SIG, Thomas Narten, Chair of ARIN's IPv6 WG, and David Kessens, Chair of the RIPE IPv6 Working Group).

The editing team would like to acknowledge the contributions to this document of Takashi Arano, John Crain, Steve Deering, Gert Doering, Kosuke Ito, Richard Jimmerson, David Kessens, Mirjam Kuehne, Anne Lord, Jun Murai, Paul Mylotte, Thomas Narten, Ray Plzak, Dave Pratt, Stuart Prevost, Barbara Roseman, Gerard Ross, Paul Wilson, Cathy Wittbrodt and Wilfried Woeber.

9.0 Appendix B: Background information

9.1 Background

In 1999, the first provisional IPv6 policy was published in all regions.

This document was replaced in 2002 by a joint policy document. At the time it was considered important to have one policy for all regions to prevent RIR shopping. Over time, regional policies started diverging from each other from 2004 onwards.

9.2 Acknowledgment

The following people contributed to the initial version of this document: Akihiro Inomata, Akinori Maemura, Kosuke Ito, Kuniaki Kondo, Takashi Arano, Tomohiro Fujisaki, and Toshiyuki Yamasaki, Thomas Narten, David Kessens, John Crain, Steve Deering, Gert Doering, Richard Jimmerson, Mirjam Kuehne, Anne Lord, Jun Murai, Paul Mylotte, Ray Plzak, Dave Pratt, Stuart Prevost, Barbara Roseman, Gerard Ross, Paul Wilson, Cathy Wittbrodt and Wilfried Woeber.

10.0 Attribution

This document is compiled from policies developed by the RIPE community.

The following people actively contributed by making proposals through the RIPE Policy Development Process (PDP):

Brett Carr, Ondrej Sury, Jordi Palet Martinez, Andy Davidson, Rob Evans, Kurtis Lindqvist, Geoff Huston, Elvis Daniel Velea, Daniel Stolpe, Olaf Sonderegger.