Autonomous system
AS4583 THOMSON-REUTERS
Unclassified ARIN
Summary
West Publishing Corporation (Thomson Reuters)
enterprise legacy
AS4583 (THOMSON-REUTERS) is registered to West Publishing Corporation, the legal-publishing business behind Westlaw and now part of Thomson Reuters. Its main campus is in Eagan, Minnesota.
What it's used for
Corporate and product infrastructure for Thomson Reuters' legal business: the systems and internet-facing services behind its research and publishing platforms, plus staff networks.
Notable
- Enterprise space belonging to a large information-services company, not a service provider network.
- The registry keeps the historic West Publishing corporate entity as the holder while the AS handle carries the modern parent's name, which is why lookups on this number can show either brand.
This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy. Source, and how to suggest an edit.
Interconnection
Peering at a glance
Internet exchanges
No exchange port on file. Many exchanges publish no participant list, so this is not proof of absence.
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-26, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 6 prefixes · 5.38K addresses IPv6 0 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 6 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS4583- Registry name
- THOMSON-REUTERS
- Registrant
- West Publishing Corporation
- Abuse contact
- TR.IP-ABUSE@thomsonreuters.com
- Registered
- 1995-05-01
- Last changed
- 2021-10-04
- Allocation
- assigned
Routing security
RPKI and IRR
- RPKI
- 0% valid · 0 valid, 7 with no ROA
- ROAs
- 0 authorising AS4583
- ASPA
- no ASPA record
- IRR
- 57% registered · 4 of 7 announcements
- Route objects
- 11 naming AS4583
Reputation
Classification and threat
Unclassified Not in the curated lists. Most of the ~80,000 allocated ASNs are not.
Spamhaus DROP
Not on ASN-DROP The network as a whole is not listed.
No DROP prefixes None of its announced space is on the DROP prefix list.
Spamhaus DROP ("Don't Route Or Peer") lists space and networks run by, or hijacked for, spam and cybercrime operations: 445 networks and 1,817 prefixes, as published 2026-10-27. A short, high-confidence list, so a match is worth taking seriously, and absence from it says little on its own.
FBI IC3
No IC3 indicators Nothing from the FBI IC3 feed.
IC3 threat data is alpha. Absence of an indicator is not evidence of good behaviour, only of absence from this one feed.
Elsewhere