Summary

  • ARIN-2020-3 names Amy Potter and Andrew Dul as co-shepherds. Its 2020 problem statement says the then-minimum /36 IPv6 allocation could move a 3X-Small ISP from $250 to $500 a year in ARIN fees. ARIN staff reported that a substantial fraction of the affected applicants had declined IPv6 after hearing the price.
  • The adopted policy let eligible small ISPs request a /40: no more than a /24 in direct IPv4 allocations and no more than a /22 in IPv4 reassignments or reallocations. It preserved expansion up to /32 without renumbering and required a /40 to become at least /36 if direct IPv4 holdings crossed /24. The Board adopted it in December 2020, and the current NRPM retains the route.

The tiniest ISP in ARIN’s 2020 fee schedule had an awkward choice. Ask for the smallest available IPv6 allocation and watch the annual registry charge jump from $250 to $500, or put the request back in the drawer. The network had not doubled. The address block was simply big enough to push the provider into the next billing bracket. Amy Potter and Andrew Dul co-shepherded ARIN-2020-3, which changed the size of the doorway.

The proposal’s problem statement gives the price example plainly. A 3X-Small ISP holding a /24 or less of direct IPv4 allocations would, under the fee schedule then in force, pay $500 rather than $250 a year if it received the old /36 minimum IPv6 allocation. ARIN Registration Services had reported to the Advisory Council that a substantial fraction of applicants in that position said no thanks when told about the fee. The file supplies no exact fraction, so the useful story is the mechanism: a technical minimum had become a commercial veto at the smallest end of the market.

The repair was deliberately narrow. An ISP could ask for /40 only if its direct IPv4 allocations totaled no more than /24, including zero, and its IPv4 reassignments or reallocations totaled no more than /22, also including zero. Both tests matter. An operator cannot claim to be tiny by pointing to one bucket while carrying a larger load in the other. The ordinary allocation floor remained /32 unless the applicant specifically asked for /36 or this new /40.

Small at entry did not mean trapped at entry. The same policy let a holder expand a /36 or /40 along nibble boundaries up to /32 without renumbering or additional justification. If a /40 holder’s direct IPv4 allocations later exceeded /24, the IPv6 allocation would automatically rise to /36. Potter and Dul’s package paired a cheaper first step with a staircase. The provider could grow its IPv6 footprint without tearing up customer numbering, while the special small-size lane closed as its old IPv4 footprint grew.

The Board adopted the policy on 16 December 2020; ARIN records implementation on 16 March 2021. The current NRPM, section 6.5.2.1, still lists the /40 eligibility tests, the expansion right and the automatic upgrade. Those are current rules. The $250 and $500 figures belong to the 2020 problem statement, when the policy was argued and adopted.

Potter was one of two named shepherds, and the public record gives no post-adoption count of new IPv6 takers. The rule itself shows the decision that mattered. A provider asking for IPv6 should be sized for its network, not accidentally priced out because the smallest envelope on the shelf was one size too large. ARIN gave the smallest operators an envelope marked /40; it also wrote down when they had to move to a bigger one.