4. IPv6 Address Allocation and Assignment Policies

4.1. Scope

This chapter describes policies for the allocation and assignment of the globally-unique IPv6 address space.

[RFC 4291] designate 2000::/3 to be the global unicast address space that IANA may allocate to RIRs. This chapter concerns initial and subsequent allocations of the 2000::/3 unicast address space, for which RIRs formulate allocation and assignment policies. Because end sites will generally be given /48 assignments
[RFC 3177], the particular emphasis of this document is on policies relating to the bits within 2000::/3 to the left of the /48 boundary.

4.2. Definitions

The following terms are specific to IPv6 allocation policies.

4.2.1. Utilization

Unlike IPv4, IPv6 is generally assigned to end sites in fixed amounts (/48). The actual utilization of addresses within each assignment will be quite low when compared to IPv4 assignments. In IPv6, "utilization" is only measured in terms of the bits to the left of the /48 boundary. In other words, utilization refers to the assignment of /48s to end sites, and not to the number of addresses assigned within individual /48s at those end sites.

Throughout this chapter, the term utilization refers to the assignment of /48s to end sites, and not to the number of addresses assigned within individual /48s at those end sites.

4.2.2. HD-Ratio

HD-Ratio is a way of measuring the efficiency of address assignment [RFC 3194]. It is an adaptation of the HD-Ratio originally defined in [RFC1715] and is expressed as follows:

where, in the case of this document, the objects are IPv6 site addresses (/48s) assigned from an IPv6 prefix of a given size (see Appendix 10.2).

4.3. IPv6 Address Space Management

4.3.1. 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.

4.3.2. 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.

4.3.3. 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.

4.3.4. 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 maximize the potential for subsequent allocations to be made contiguous with past allocations currently held. However, there can be no guarantee of contiguous allocation.

4.3.5. 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.

4.3.6. 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.

4.3.7. Minimized Overhead

It is desirable to minimize 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.

4.3.8. 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.

4.4. IPv6 Policy Principles

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

4.4.1. 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 chapter 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 organizations 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 organization 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.

4.4.2. 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.

4.4.3. Minimum allocation

RIRs will apply a minimum size for IPv6 allocations, to facilitate prefix-based filtering.

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

4.4.4. 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.

4.5. Policies for Allocations and Assignments

4.5.1. Initial Allocation

4.5.1.1. Distribución inicial

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

• Be an LIR or ISP.
• Document a detailed plan for the services and IPv6 connectivity to be offered to other organizations (clients) or self-owned/related departments/entities/sites to which it will assign /48s.
• Announce a single block on the Internet inter-domain routing system, aggregating the total IPv6 address allocation received, within a period not longer than 12 months.
• Offer IPv6 services to clients or self-owned/related entities (including departments and/or sites) physically located in the region covered by LACNIC within a period not longer than 24 months.

4.5.1.2. Initial Allocation Size

Organizations that meet the initial allocation criteria are eligible to receive a minimum allocation of /32.

Organizations may qualify for an initial allocation greater than /32 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 organization's infrastructure.

4.5.2. Subsequent Allocation

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

4.5.2.1. Subsequent Allocation Criteria

Subsequent allocation will be provided when an organization (ISP/LIR) satisfies the evaluation threshold of past address utilization in terms of the number of sites in units of /48 assignments. The HD-Ratio [RFC 3194] is used to determine the utilization thresholds that justify the allocation of additional address as described below.

4.5.2.2. Applied HD-Ratio

The HD-Ratio value of 0.94 is adopted as indicating an acceptable address utilization for justifying the allocation of additional address space. Appendix 10.2 provides a table showing the number of assignments that are necessary to achieve an acceptable utilization value for a given address block size.

4.5.2.3. Subsequent Allocation Size

When an organization has achieved an acceptable utilization 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 organization 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.

4.5.2.4. Returning the First Allocation for the Second Allocation

If an organization holds only one IPv6 allocation, a differentiated analysis shall be performed on a one-time-only basis.
If an organization that satisfies these conditions is willing to return to LACNIC, within a period of 6 months, the block it was initially allocated, the new allocation shall be studied as if it were an initial allocation, applying the criteria described in Section 4.5.1. Thus, in this case only, the criteria described in Sections 4.5.2.1 (criteria), 4.5.2.2 (HD-ratio), and 4.5.2.3 (size) shall not be applicable.

4.5.2.5. LIR-to-ISP Allocation

There is no specific policy for an organization (LIR) to allocate address space to subordinate ISPs. Each LIR organization may develop its own policy for subordinate ISPs to encourage optimum utilization 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.

4.5.3. Assignments by ISPs

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

4.5.3.1. Assignment address space size

Assignments are to be made in accordance with the existing guidelines [RFC3177,RIRs-on-48], which are summarized here as:

/48 in the general case, except for very large subscribers.

/64 when it is known that one and only one subnet is needed by design.

/128 when it is absolutely known that one and only one device is connecting.

RIRs/NIRs are not concerned about which address size an LIR/ISP actually assigns. Accordingly, RIRs/NIRs will not request the detailed information on IPv6 user networks as they did in IPv4, except for the cases described in Section 4.5.2 and for the purposes of measuring utilization as defined in this chapter.

4.5.3.2. Assignment to Operator´s Infrastructure

An organization (ISP/LIR) may assign a /48 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.

4.5.4. Direct Assignments to End Sites

LACNIC will assign portable (provider-independent) IPv6 addresses directly to end sites in accordance with the two policies detailed in Sections 4.5.4.1 and 4.5.4.2, depending on whether or not the organization holds portable IPv4 addresses previously assigned by LACNIC.

4.5.4.1. Direct assignment of portable IPv6 addresses to End Sites having portable IPv4 addresses previously assigned by LACNIC

LACNIC will assign portable IPv6 address blocks directly to end sites if they hold portable IPv4 addresses previously assigned by LACNIC.

In case of announcing the assignment on the Internet inter-domain routing system, the receiving organization shall announce a single block, aggregating the total IPv6 address assignment received.

Assignments will be made in blocks smaller than or equal to a /32 but always greater than or equal to a /48.

Where possible, subsequent allocations will be made from an adjacent address block, but only if duly documented and justified.

4.5.4.2. Direct assignment of portable IPv6 addresses to End sites not having portable IPv4 addresses previously assigned by LACNIC

LACNIC will assign portable IPv6 address blocks directly to end sites that satisfy the following requirements:

1. Not be an LIR or ISP.
2. In case of announcing the assignment on the Internet inter-domain routing system, the receiving organization shall announce a single block aggregating the total IPv6 address assignment received.
3. Provide detailed information showing how the requested block will be used within the following three, six and twelve months.
4. Submit addressing plans for at least a year, and host numbers on each subnet.
5. Submit a detailed description of the network topology.
6. Prepare a detailed description of the network routing plans, including the routing protocols to be used as well as any existing limitations.

Assignments will be made in blocks smaller than or equal to a /32 but always greater than or equal to a /48.

Where possible, subsequent allocations will be made from an adjacent address block, but only if duly documented and justified.

4.5.5. IPv6 Micro-Assignments

LACNIC shall make micro-assignments in case of projects and network infrastructure that are key or critical for the operation and development of IPv6 within the region, such as, among others, IXPs (Internet Exchange Points), NAPs (Network Access Points), RIRs, DNS ccTLD providers. These assignments shall be made in prefixes longer than or equal to /32 but always shorter than or equal to /48.

In the case of IXPs or NAPs, in order to be eligible for this type of assignment, the organization must meet the following requirements:

1. Duly document the following aspects:
1. Prove by means of their bylaws their IXP or NAP capacity. The organization shall have at least three members and an open policy for the association of new members.
2. Submit a diagram of the organization’s network structure.
3. Document the numbering plan to be implemented.
2. Provide a utilization plan for the following three and six months.

The rest of the applications shall be studied based on the analysis of the documentation justifying the critical and/or key aspects of the project.
All micro-assignments shall be made from address blocks specifically reserved for this type of assignments. LACNIC shall publish the list of these blocks and those micro-assignments already awarded.

Organizations receiving micro-assignments shall not sub-assign these IP addresses.

4.5.6. Registration

When an organization holding an IPv6 address allocation makes IPv6 address assignments, it must register assignment information in a database, accessible by RIRs as appropriate (information registered by an RIR/NIR may be replaced by a distributed database for registering address management information in future). Information is registered in units of assigned /48 networks. When more than a /48 is assigned to an organization, the assigning organization is responsible for ensuring that the address space is registered in an RIR/NIR database.

RIR/NIRs will use registered data to calculate the HD-Ratio at the time of application for subsequent allocation and to check for changes in assignments over time.

IRs shall maintain systems and practices that protect the security of personal and commercial information that is used in request evaluation, but which is not required for public registration.

4.5.7. Reverse Lookup

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

4.5.8. Existing IPv6 Address Space Holders

Organizations that received /35 IPv6 allocations under the previous IPv6 address policy [RIRv6-Policies] are immediately entitled to have their allocation expanded to a /32 address block, without providing justification, so long as they satisfy the criteria in Section 4.5.1.1. The /32 address block will contain the already allocated smaller address block (one or multiple /35 address blocks in many cases) that was already reserved by the RIR for a subsequent allocation to the organization. Requests for additional space beyond the minimum /32 size will be evaluated as discussed elsewhere in the document.