rirtracker

IPv4 range · 65,536 addresses

153.61.0.0/16

Now

ARIN statistics
Allocated (dated 2026-06-17) on 2026-10-09 (US)
Registry
ARIN
Holder
Anthropic, PBC
From
ARIN's statistics for 2026-10-09 and the latest transfer record

Latest change

+ Add Intra-ARIN transfer

Reported
2026-06-17
Confidence
Confirmed
Inventory
No effect on ARIN applicant inventory

Timeline since 2026-01-01 (1)

2026-06-17 + Add Intra-ARIN transfer Confirmed
ARIN-Issued
Add 153.61.0.0-153.61.255.255
From
NCR Voyix Corporation ARIN
To
Anthropic, PBC ARIN
Piece of
153.60.0.0/15: the rest of the block stayed with the seller
Inventory
No effect on ARIN applicant inventory

ARIN's transfer log records a transfer from NCR Voyix Corporation (ARIN) to Anthropic, PBC (ARIN) on 2026-06-17 20:58 UTC. ARIN-Issued lists it as "Add" because the registration changed hands; it is not a new allocation from ARIN.

Evidence (4) · classifier 1.0.0,
  1. ARIN-Issued ARIN-Issued report for 2026-06-17: "Add 153.61.0.0-153.61.255.255" source · retrieved
  2. Transfer log Transfer log: RESOURCE_TRANSFER on 2026-06-17 20:58 UTC, NCR Voyix Corporation (ARIN) to Anthropic, PBC (ARIN); resources moved: 153.61.0.0/16 source · retrieved
  3. Before ARIN delegated statistics 2026-06-16 (produced 2026-06-16T09:00:20+00:00), before the report: allocated (dated 1991-09-23) source · retrieved
  4. After ARIN delegated statistics 2026-06-18 (produced 2026-06-18T09:00:20+00:00), after the report: allocated (dated 2026-06-17) source · retrieved

Transfer records (1)

Date (UTC)TypeRange movedFromTo
Resource transfer153.61.0.0/16 NCR Voyix Corporation ARINAnthropic, PBC ARIN

Every record in ARIN's transfer log that moved any part of this IPv4 range, back to 2009.

RDAP lookups

Not looked up. The tracker queries RDAP for changes as they're reported (on first sight, after 24 hours and after seven days); older changes aren't looked up because today's RDAP says nothing about the past.

This page as data: ip/153.61.0.0-153.61.255.255.json