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This policy proposal has been accepted

Proposal to Amend the IPv6 Assignment and Utilisation Requirement Policy

Summary of Proposal:

To amend the RIPE IPv6 address allocation policies regarding the definition of the default size of End Site assignments, the threshold value for End Site allocation efficiency, and the method of calculation of the End Site allocation efficiency metric.

These measures, if undertaken generally by all RIRs, would increase the anticipated useful lifetime of IPv6 to encompass a period in excess of 100 years in which no further allocation policy changes are anticipated.

  1. To alter the existing policy regarding LIR and ISP assignments to End Sites to allow the unit of assignment to be an LIR or ISP decision.
  2. To alter the definition of an End Site for the purposes of the calculation of ISP or LIR End Site allocation efficiency to a /56 size.
  3. To amend the IPv6 threshold End Site allocation utilisation level relating to assessment of utilisation of End Site allocation efficiency to that matching an HD Ratio value of 0.94.


The current IPv6 Address Allocation and Assignment Policy (ripe-267) suggests that most IPv6 subscribers should be assigned a /48 "in the general case, except for very large subscribers". The policy also asks the RIPE NCC to evaluate requests for additional allocations "in units of /48 assignments."

This has the effect of encouraging the assignment of much more address space than is ever likely to be needed by most subscribers. As a consequence of that, LIRs will need far more address space, depleting the available pool of addresses at an accelerated rate and reducing the lifetime of the IPv6 protocol.

A more detailed rationale is available in Geoff Huston's presentation on the subject, at RIPE 50.

Appendix A. References

This material is not formally part of the Policy Proposal. It is included here for informational purposes.

1. The IPv6 Address Plan - Geoff Huston

2. Internet Draft: Issues Related to the Management of IPv6 Address Space - Thomas Narten

3. Internet Draft: IPv6 Address Allocation to End Sites - Thomas Narten, Geoff Huston & Lea Roberts

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The Address Policy Working Group develops policies relating to the allocation and registration of Internet number resources (IPv4 and IPv6 addresses and ASNs) by the RIPE NCC and its members. Anyone with an interest in Internet numbering issues is welcome to observe, participate and contribute to the WG. To post a message to the list, send an email to Please note that only subscribers can post messages.

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