Draft Policy ARIN-2025-6

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Current Text (3 September 2025)

Problem Statement

Sections 6.5.2.1 explains the initial IPv6 ISP/LIR allocation in a way that is difficult to follow and the formula in section (c) does not match the remainder of the text.

Policy Statement

In 6.5.2.1c, replace:

“This calculation can be summarized as /N where N = P-(X+Y) and P is the organization’s Provider Allocation Unit X is a multiple of 4 greater than 4/3serving sites and Y is a multiple of 4 greater than 4/3end sites served by largest serving site.”

with:

“This calculation can be summarized as /N where N = P-(X+Y) and P is the organization’s Provider Allocation Unit, X is a multiple of 4 greater than 4/3log_2(serving sites) and Y is a multiple of 4 greater than 4/3log_2(end sites served by largest serving site).

In 2.15 and 2.16, replace “provider assignment unit"with “provider allocation unit.”

Comments

“Provider assignment unit” in section 2.15 was intended to match “Provider Allocation Unit“ in this policy section, but the words fell out of sync.

Timetable for Implementation

Immediate

Staff and Legal Review (16 March 2026)

Staff Understanding

NRPM section “6.5.2.1. Size” describes requirements for the size of IPv6 allocations to ISPs/LIRs. Sub-section “c” defines how to calculate the largest allocation justified by the requestor. Accompanying the text description is a mathematical formula that intends to summarize the calculation as “/N where N = P-(X+Y) and P is the organization’s Provider Allocation Unit X is a multiple of 4 greater than 4/3 serving sites and Y is a multiple of 4 greater than 4/3 end sites served by largest serving site.”

This draft policy indicates the formula does not match the text, and intends to correct it with, “This calculation can be summarized as /N where N = P-(X+Y) and P is the organization’s Provider Allocation Unit, X is a multiple of 4 greater than 4/3 log_2(serving sites) and Y is a multiple of 4 greater than 4/3 log_2(end sites served by largest serving site).”

ARIN staff currently implements NRPM 6.5.2.1.c based on the policy text rather than the summarized formula. The summarized formula is overly complex for many typical IPv6 requestors, while the policy text is more readily understood by customers and more consistently applied by ARIN staff.

In practice, staff evaluates initial allocation size by reviewing the number of serving sites in the ARIN region and the number of end sites served by the largest serving site and then applying the 75% utilization standard consistent with current implementation. This approach is also reflected in the training materials ARIN provides to assist organizations in calculating IPv6 address requirements. In addition, the applicable policy parameters are built into the workflow for IPv6 ISP address requests.

Removal of the summarized formula from the NRPM would have no impact on ARIN operations and would simplify the policy language for IPv6 requestors. Staff would continue to implement NRPM 6.5.2.1.c consistent with current practice.

NRPM section “6.5.2.1. Size” includes the text “Provider Allocation Unit”, while sections 2.15 and 2.16 reference the term, “Provider Assignment Unit “. This draft policy intends to update the text in sections 2.15 and 2.16 to “Provider Allocation Unit”. Modifying “Assignment” to “Allocation” aligns with the deprecation of Direct Assignment’s that occurred during ARIN’s fee harmonization. Staff agrees the terms should match between section 2 and section 6. Staff considers subnetted Direct Allocations, Reallocations, and Reassignments to be “Provider Assignment Units”. This modification aligns with staff’s current implementation.

Implementable as Written?

Yes

Impact on ARIN Registry Operations and Services

None

Legal Review

No material legal issue

Implementation Timeframe Estimate

3 Months

Implementation Requirements

• Staff Training
• Updates to public documentation

Proposal/Draft Policy Text Assessed

3 September 2025

History and Earlier Versions

Related Meetings