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Data Accuracy Update#

ARIN 58 Public Policy and Members Meeting digest Program Core pick 22–23 October 2026

Slides Recording

John Sweeting (ARIN, Chief Experience Officer)

Play the recording: Data Accuracy Update

  • Why: Registry accuracy is network security infrastructure — the stated objectives are preventing resource hijacking and supporting law enforcement. For anyone building systems that consume WHOIS/RDAP data or dealing with hijacked/legacy space, the mechanics of how ARIN is cleaning up non-agreement holdings are directly relevant.
  • What: Progress report on driving the remaining "not under agreement" space to zero: 372,877 /24-equivalents remain outside agreements (Q3 2026), down 26,313 quarter-over-quarter and down 81% since Q1 2024; 16,212 legacy CIDR blocks; 2,195 /24-equivalents already returned to the IPv4 waitlist. A Q4 2025 step change brought 1.28M /24-equivalents under RSAs in one quarter. The remaining center of gravity: 715 /16-sized blocks hold 49.1% of the outstanding space, and just 23 blocks of /15 or larger hold 38% of it.
  • How: A cohort model. Cohort 1 (2,660 orgs with zero usable contact info) gets services stopped, a 12-month quarantine hold, then release via the waitlist with rights extinguished. Cohort 2 (10,218 orgs with contacts pending verification) gets targeted outreach and DAP contact validation; organizations whose contacts prove inaccurate fall back to Cohort 1. The /16 population is managed as a named list with account-level engagement.
  • Where applicable: ARIN-registry-specific, but the quarantine-then-rights-extinguishment pattern for unreachable holders is a notable operational model for any registry-like system. The 49%-in-/16s concentration means most remaining work is a small number of very large legacy accounts.