Autonomous system
AS11941 PWLLP-AS001
Unclassified ARIN
Summary
Pillsbury Winthrop Shaw Pittman LLP
enterprise legacy
PWLLP-AS001 belongs to the international law firm Pillsbury Winthrop Shaw Pittman LLP. ARIN still carries the org under its predecessor name, Pillsbury Madison & Sutro, Inc., but the contacts all sit at pillsburylaw.com, and the listed address is the firm's Nashville operations office.
What it's used for
RIS shows 22 IPv4 prefixes totalling 5,632 addresses, no IPv6, and 12 observed BGP neighbours. Every prefix is a /24 drawn from one contiguous legacy range around 204.227.224.0–204.227.255.0, and every one is registered in ARIN as PMSNET, org Pillsbury Madison & Sutro, Inc. That is a single self-registered block sliced into /24s, not scattered space from unrelated registrants: entirely first-party inventory, with no leasing or brokerage pattern anywhere in it.
The shape fits a large multi-office law firm. Announcing the block as individual /24s rather than one aggregate lets the firm steer or fail over office ranges independently across a dozen upstreams, and a firm with offices across the US, London and Asia has good reason to do that. Twelve neighbours is still enterprise territory, well short of the hundreds a transit carrier would show against this much address space.
Notable
The name is a trap worth flagging. This is not the Pillsbury of flour and the Doughboy. Pillsbury Madison & Sutro was a San Francisco law firm, which merged with Winthrop Stimson Putnam & Roberts and later Shaw Pittman to become today's Pillsbury Winthrop Shaw Pittman, and the registry simply never caught up with the rebrand.
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.
Transit providers
10 upstream, 0 downstream and 10 adjacent networks observed; most-used upstreams first.
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-18, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 11 prefixes · 5.63K addresses IPv6 0 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 11 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS11941- Registry name
- PWLLP-AS001
- Registrant
- Pillsbury Madison & Sutro, Inc.
- Abuse contact
- jacob.hipes@pillsburylaw.com
- Registered
- 2005-05-09
- Last changed
- 2012-02-24
- Allocation
- assigned
Routing security
RPKI and IRR
- RPKI
- 100% valid · 22 valid, 0 with no ROA
- ROAs
- 1 authorising AS11941
- ASPA
- no ASPA record
- IRR
- 100% registered · 22 of 22 announcements
- Route objects
- 37 naming AS11941
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: 443 networks and 1,784 prefixes, as published 2026-10-19. 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