Summary

  • ARIN-2020-5 names Kat Hunter and Rob Seastrom as shepherds of a correction to the rules for an ISP’s downstream IPv4 customers. The old text pointed to RFC 2050, already superseded by RFC 7020; the newer RFC did not supply the customer utilization percentages.
  • The amendment referred instead to ARIN’s own section 4.3.3: a new-space plan with 50% utilization within 24 months. Earlier assignments had to show 80% use before more space was issued. The Board adopted the change in December 2020, and the current NRPM retains both tests.

A customer asks an ISP for more IPv4. The operator opens the rulebook and finds an instruction to consult an old document. That document has been superseded; its successor no longer states the numerical customer test the operator is supposed to apply. The paperwork resembles a measuring tape with the numbers rubbed off. ARIN-2020-5, shepherded by Kat Hunter and Rob Seastrom, put the numbers back in the local policy.

The proposal’s problem statement identifies the culprit: downstream-customer rules in sections 4.2.3.4.1 and 4.2.3.6 still referenced RFC 2050. RFC 7020 had superseded it without carrying those utilization requirements. The two documents were doing different jobs. A rule for deciding whether a customer needed scarce IPv4 could not rely on a historical pointer to tell an ISP what evidence to collect.

The repair separated two moments in a customer’s address life. For a new request, the customer gives its allocating ISP a plan consistent with ARIN section 4.3.3, whose basic test is 50% utilization within 24 months. When that customer asks for additional space, the prior assignment or reallocation records must show 80% utilization. Those records have to be available through SWIP or a qualifying distributed service. One figure measures a future plan; the other tests what happened to blocks already handed over.

The policy also kept a practical multihoming route. A downstream customer that needs to connect through multiple upstream providers can justify one /24 from one of them on that basis, while providing the upstream contacts and using a border routing protocol. The ISP may demonstrate the assignment to ARIN with the customer information it gathered or by identifying the customer’s AS number. This section is a good reminder that proof can be a record or a verifiable network identity, not a citation to a retired document.

The Board adopted ARIN-2020-5 on 16 December 2020; ARIN’s policy history dates implementation to 16 March 2021. The current NRPM still places the 50%-within-24-month criterion in 4.3.3 and the 80% prior-use requirement in 4.2.3.4.1. It also retains the multihomed /24 route in 4.2.3.6. The rulebook now sends the operator to the page that actually holds the test.

Hunter was one of two named policy shepherds. The change does not come with a published count of customer approvals or routing outcomes, but its mechanism is concrete. For the person at the ISP desk, the next IPv4 request now has a local answer: bring the plan for new space, and bring the record for the space already used. The old RFC can enjoy retirement without grading anyone’s homework.