PI Assignment Size

This policy proposal has been accepted

The new RIPE Document is: ripe-528

2006-05

State:: Accepted

Publication date

05 Jan 2011

Affects

ripe-527

Draft document

DRAFT: IPv4 Address Allocation and Assignment Policies for the RIPE NCC Service Region

Authors

Nick Hilliard [INEX]
Paul Hoogsteder [Breedband Delft]

Proposal Version

3.0 - 24 Jun 2011

All Versions

Accepted

20 Oct 2011

Working Group

Address Policy Working Group

Proposal type

Policy term

Indefinite

New RIPE Document

ripe-528

This proposal allows for End Users who request a Provider Independent IPv4 address assignment to be assigned limited additional address space to make the assignment size a multiple of /24. The End User must demonstrate the intent to multihome the assignment.

The scope of this proposal is twofold:

1. to allow some flexibility in terms of PI assignment so that there is less incentive for End Users to exaggerate or falsify information on their application forms, and

2. to provide a mechanism to prevent this policy proposal from being abused by End Users who wish to apply for arbitrarily large amounts of PI address space.

Policy Text

b. New policy text

[The following text is to appear in the RIPE policy document ripe-527, “IPv4 Address Allocation and Assignment Policies for the RIPE NCC Service Region”, if the proposal reaches consensus]

6.10 Provider Independent IPv4 Assignments for Multihoming

The RIPE NCC will assign additional contiguous IPv4 addresses to an End User in order to make the assignment size a multiple of a /24 if an End User demonstrates:

-the need for Provider Independent (PI) IPv4 address space; and

-the intent to announce this address space for the purpose of multihoming to two or more Autonomous Systems which the End User does not own or control.

Cumulatively, no more than 255 additional IPv4 addresses may be assigned to any particular End User for the purposes outlined above.

Rationale

a. Arguments supporting the proposal

It is generally understood that the minimum prefix size which is generally routable on the Internet is a /24. The first paragraph acknowledges this and ensures that if the End User needs address space, they will not be assigned prefixes which are effectively useless from a routing point of view.

Removal of discrimination: prefixes of /25 and longer are routinely filtered by many network service providers on the Internet. As many End Users who apply for PI assignments do so for the purposes of small-scale multi-homing, in practice the current assignment policies discriminate against these End Users.

Good stewardship: there is significant evidence that End User applications significantly exaggerate their IP addressing requirements when applying for PI assignments in order to make their application qualify for a small PI assignments. By removing the incentive for End Users to exaggerate on PI assignment application forms where that address space is required for multihoming, the RIPE NCC can perform better stewardship of IP number resources.

Precedent exists: /24-aligned PI assignment requests are accepted by other RIRs. This demonstrates that acceptance of this policy will not create any new or undesirable precedents for global IP address assignment policies.

Negligible effect: There is no evidence to suggest that implementation of this policy will have an appreciable effect on the IPv4 depletion rate, as the current policy requirements are routinely ignored due to exaggerated utilisation claims.

Discussion

The last suggested paragraph of 6.10 qualifies the first paragraph in the following ways:

1. It allows multihomed End Users with a requirement for one or more IPv4 PI addresses to qualify for a /24.

2. It allows multihomed End Users who can demonstrate a need for marginally more than a /24 to apply for two /24s, or in general to assign one more /24 to an End User who can justify at least a single /24 on the basis of the current policies.

3. It stops abuse by ensuring that an End User cannot repeatedly go back to the RIPE NCC to ask for more /24s on the same basis.

The wording used to describe a multihomed End User is inspired by the equivalent policy wording in ARIN, and was chosen to ensure that the global policy divergence is minimised if this policy is passed.

The current IPv4 PI assignment policies implemented by the RIPE NCC are based on the principal of justification by quantity of addresses. While this approach works reasonably well when the End User has a requirement for larger numbers of IPv4 address, it discriminates against organisations who use small quantities of PI addresses, typically for multihoming this address space on the Internet.

The RIPE NCC has previously published PI assignment figures which provide strong circumstantial evidence that many End Users exaggerate the quantities of addresses required on their PI application forms in order to adhere to the current policy guidelines. This is harmful to the RIPE NCC because it means that the organisation is not receiving accurate information on actual address space usage, but rather information based on what is likely to quality for a successful address application.

b. Arguments opposing the proposal

Timescales: it could be argued that on the basis that RIR IPv4 address depletion is likely to occur within less than a year, this policy is too late for there to be any point in implementing it.

Routing policy vs. addressing policy: it has been argued that this policy makes addressing policy contingent on Internet routing policies, and that the two should remain separate.

Impact Analysis

Note: In order to provide additional information related to the proposal, details of an impact analysis carried out by the RIPE NCC are documented below. The projections presented in this analysis are based on existing data and should be viewed only as an indication of the possible impact that the policy might have if the proposal is accepted and implemented.

A. RIPE NCC's Understanding of the Proposed Policy

This proposal directs the RIPE NCC to assign IPv4 PI space in multiples of a /24 when the end-user demonstrates the intent to multi-home the address space to at least two autonomous systems that the end-user does not control.

This may result in more address space being assigned than would otherwise be justified. Therefore the RIPE NCC shall ensure that the total amount of "extra" space held by the end-user will not exceed 255 IPs, even if the end-user receives multiple IPv4 PI assignments over the years.

B. Impact of Policy on Registry and Addressing System

Address/Internet Number Resource Consumption: