Autonomous system
AS33503 MCW-1-AS - Medical College of Wisconsin
Unclassified ARIN
Summary
Medical College of Wisconsin
education business research healthcare
The AS handle MCW-1-AS is held by Medical College of Wisconsin.
What it's used for
- The address space carries internal corporate and academic infrastructure, evidenced by the consistent netname
MCW-NETand registrant "Medical College of Wisconsin Information Services" across all listed prefixes. - The AS announces 65,536 IPv4 addresses across 19 prefixes and 1 IPv6 prefix, while maintaining only 1 observed neighbour. This high address-to-neighbour ratio indicates a self-contained internal estate rather than a transit or access network.
Notable
- All registrants align with the announcer, consistently listing "Medical College of Wisconsin" and its Information Services department.
- The address inventory is finely subdivided into 19 distinct IPv4 prefixes, ranging from a /17 down to /24s, reflecting site-by-site segmentation typical of a large institutional campus.
- The AS was first seen in RIS on 2010-11-24, indicating it has been an active autonomous system for over a decade.
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
1 upstream, 0 downstream and 2 adjacent networks observed; most-used upstreams first.
| AS | Network | Paths seen |
|---|---|---|
| AS2381 | WiscNet | 431 |
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-11-08, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 19 prefixes · 65.54K addresses IPv6 1 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 20 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS33503- Registry name
- MCW-1-AS
- Registrant
- Medical College of Wisconsin
- Abuse contact
- hostmaster@mcw.edu
- Registered
- 2005-01-05
- Last changed
- 2012-03-20
- Allocation
- assigned
Routing security
RPKI and IRR
- RPKI
- 100% valid · 7 valid, 0 with no ROA
- ROAs
- 7 authorising AS33503
- ASPA
- no ASPA record
- IRR
- 100% registered · 7 of 7 announcements
- Route objects
- 9 naming AS33503
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: 455 networks and 1,854 prefixes, as published 2026-11-09. 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