4. IPv6 ADDRESS ALLOCATION AND ASSIGNMENT POLICIES

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4.1. Scope

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

[RFC2373, RFC2373bis] 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 6177], the particular emphasis of this document is on recommendations to LIRs/ISPs regarding their assignments to connected users and customers.

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.

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 number of prefixes assigned to end users, not their size or the number of addresses actually used in those prefixes. This is how it should be understood throughout this document.

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:

         Log (number of assigned objects)

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

         Log (maximum number of assignable objects)

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 2).

4.3.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.

4.3.1.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.

4.3.2.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.

4.3.3.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.

4.4.Policies for Allocations and Assignments

4.4.1.Initial Allocation

4.4.1.1.IPv6 allocation to a LIR or ISP with a previous IPv4 allocation from LACNIC

LACNIC will allocate IPv6 address blocks to a LIR or ISP that has already received an IPv4 allocation from LACNIC. If the allocation would be announced in the Internet inter-domain routing system, the organization must announce the allocated block with the minimum possible level of disaggregation to the one that is publishing the IP blocks. LACNIC will allocate a single /32 when received a request from a LIR or ISP with a previous IPv4 allocation. In case that the organization request the allocation of an address block larger than a /32, the LIR or ISP must present the documentation required in section 4.4.1.3.

4.4.1.2.IPv6 allocation to a LIR or ISP without a previous IPv4 allocation from LACNIC.

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 the allocated block in the Internet inter-domain routing system, with the minimum possible level of disaggregation to the one that is publishing the IP blocks, within a period no 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.

4.4.1.3.Initial Allocation Size

Organizations may qualify for an initial allocation larger than a /32 by submitting documentation that justifies the request.

In this case, the initial allocation shall be based on the space needed to serve the organization's clients, number of users, extent of its infrastructure, hierarchical and/or geographic structure, infrastructure segmentation for security or other reasons, and the longevity anticipated for the initial allocation.


In order to comply with the requirements mentioned above, the prefix assigned to the ISP must be within the binary "boundaries" of the IP address.

4.4.1.4.Rectifying the size of initial allocations

During IPv6 deployment, if an organization finds that the size of the initial allocation it requested no longer satisfies its needs, the organization may submit a new addressing plan to LACNIC, without having to wait until it can fulfill the requirements for a subsequent allocation, and therefore the organization will not have to prove utilization thresholds, but, instead the desire to apply a different addressing plan that is better suited to the reality of the deployment.

The new size will be adjusted according to the new addressing plan as specified in section 4.4.1.3., and will thus qualify for extending the current prefix the necessary number of bits.

If it were not possible to provide this prefix length because the adjacent space is already being used by another organization, or if making the allocation would not leave sufficient space for subsequent allocations, LACNIC shall inform the applicant, who may choose to:

  1. a) receive a new prefix with the new requested size and renumber their network and return "original" initial allocation to LACNIC within 6 months, or
  2. b) receive a complementary prefix to complete their addressing plan, and announce both the "original" initial prefix and the new prefix resulting from the new allocation. For all effects and purposes, in the case of subsequent allocations, both allocations shall be considered as if they were a single allocation.

    Each organization may only use this procedure once, so for this "second opportunity" they should carefully study the final medium and long term network addressing plan.

4.4.2.Subsequent Allocation

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

4.4.2.1.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.

4.4.2.2.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 2 provides a table showing the number of assignments that are necessary to achieve an acceptable utilization value for a given address block size.

4.4.2.3.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 requires more address space, the organization shall provide documentation justifying the space it needs to serve its clients, number of users, extent of its infrastructure, hierarchical and/or geographic structure, infrastructure segmentation for security or other reasons, and the longevity anticipated for the initial allocation.

4.4.2.4.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 Users 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.

4.4.3. Assignments by ISPs

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

4.4.3.1.Assignment address space size

 Assignment of address space. Assignments are to be made in accordance with the need specified by the ISP's user as well as with existing recommendations [RIPE-690, https://www.ripe.net/publications/docs/ripe-690], highlights of which are summarized below:

* End sites or users must be assigned a prefix that is a multiple of "n" /64’s which must be enough to meet their current and planned needs, considering existing protocols and future possibilities and thus avoiding possible renumbering scenarios.

* The size of the prefix to be assigned is an operational decision of the LIR/ISP, although the selection of /48s is recommended for simpler and more functional infrastructure for all the endpoints of the network.

* Persistent prefix assignments are recommended to avoid undesired failures.

* Using a /64 prefix for point-to-point with GUAs is recommended.

The size of LIRs/ISPs assignments does not concern RIRs/NIRs.

Accordingly, RIRs/NIRs will not request detailed information on IPv6 user networks as they did in IPv4, except for the cases described in Section 4.4.2 and for the purpose of measuring utilization as defined in this chapter.

4.4.3.2.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.

4.4.4.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 4.4.4.1 and 4.4.4.2, depending on whether or not the organization holds portable IPv4 addresses previously assigned by LACNIC.

4.4.4.1.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 the block maintaining de-aggregation to a minimum in accordance with the announcing organization's needs.

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

Subsequent assignments must be duly documented and justified. Where possible, such assignments will be made from a contiguous address block (i.e., extending the existing assignment "n" bits to the left).

4.4.4.2.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 the block maintaining de-aggregation to a minimum in accordance with the announcing organization's needs.
  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.

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


Subsequent assignments must be duly documented and justified. Where possible, such assignments will be made from a contiguous address block (i.e., extending the existing assignment "n" bits to the left).

4.4.4.3. Rectifying the size of an initial assignment

An End User organization may submit a new addressing plan to LACNIC if the plan initially submitted and used to justify the initial assignment no longer satisfies their current needs. This applies on a one-time basis.

The new prefix will be consistent with the new plan and shall comply with Sections 4.4.4.1 or 4.4.4.2.

If it were not possible to provide a prefix of that size, either because the adjacent prefixes are already being used by other organizations or because such an assignment would leave insufficient space for subsequent assignments, LACNIC shall inform this to the requesting organization, which will have the following options:

- receiving a new block with the requested prefix that fully covers the need justified by the user in the new plan, with the commitment to renumber its network and return the original block to LACNIC within a period of 6 months;

- receiving a new block which, together with the block that has already been assigned, covers the need justified by the user in the new plan, and maintaining both blocks.

Each organization may use this procedure only once.

4.4.5.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.

4.4.6.Registration assignments

All IPv6 address block assignments of a /48 or larger block made by an ISP to customers connected to their network and users of services provided must be registered on LACNIC's WHOIS database no more than 7 days after the assignment.

The information available in the WHOIS database will also be used by LACNIC when analyzing additional IPv4 address block requests made by the ISP.

The information available in the WHOIS database will be used by LACNIC to calculate the HD-Ratio when analyzing additional IPv4 address block requests made by the ISP.

Assignment registration is also necessary for the following reasons:

. To ensure that the IR has completed or is close to completing address space allocation such that the allocation of additional space is justified.

. To inform the Internet community which organization is using the IPv6 address space, including the point of contact in case of operation problems, security issues, etc.

. To assist in the study of IPv6 address allocation within the region.

4.4.6.1.Required Information

Assignments registered on LACNIC's WHOIS database must include the organization's name; address; administrative contact, technical contact, and contact in case of abuse, with their updated telephone numbers and email addresses.

4.4.6.1.1.Residential Customers

ISPs that provide services to residential customers may register on LACNIC's WHOIS database address blocks that are being used by equipment or customer service areas, by service.

Registered information must specify the service area, address of the ISP's main offices, its administrative contact, technical contact, and contact in case of abuse, including their updated telephone numbers and email addresses.

Assignments must be made in address blocks totalizing the number of customers served in the area or by the equipment.

4.4.6.1.2.Residential Customer Privacy

Residential customers receiving /48 and smaller IPv6 block assignments do not need to have their data registered on LACNIC's WHOIS database.

The ISP whose residential customer receives an IPv6 assignment of a /48 or larger block may choose to register the assignment on LACNIC's WHOIS database by entering its own data or a code used as internal reference. The administrative contact, technical contact, and contact in case of abuse must be those of the ISP.

4.4.7.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.

4.4.8.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 4.4.1.1. 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.

4.5. Mergers, Acquisitions, Reorganizations or Relocations

Because LACNIC's policies do not recognize the non-authorized sale or transfer of assigned or allocated resources, such transfers will be considered invalid.

Nevertheless, LACNIC will process and register any IPv6 resource transfer that occurs as a result of a partial or complete merger, acquisition, business reorganization or relocation, regardless of whether the resources are held by an ISP or an end-user.

To initiate this change and proceed with the registration, legal documentation must be submitted which, at the discretion of LACNIC, supports the operation. Examples of such documentation include:

  • A copy of the legal document validating the transfer of assets.
  • A detailed inventory of all the assets used by the applicant for maintaining the resources in use.
  • A list of the applicant's clients using the resources.

The need to maintain all the resources must also be justified, forcing the return of the surplus resources if applicable or, alternatively, the transfer of such surplus resources to third parties under the policies in force (4.4.1., 4.4.2., 4.4.3. y 4.4.4). When resources are to be returned, LACNIC will determine the corresponding conditions and deadline.