Autonomous system
AS20252 JSIWMC
Unclassified ARIN
Summary
Weill Cornell Medicine
education medical research business
JSIWMC is the autonomous system for Weill Cornell Medicine, the medical school of Cornell University.
What it's used for
- The address space carries institutional infrastructure for a major medical research and education center, with netnames including
JSIWMC,CUMC, andWCMCQ-NET(Weill Cornell Medical College in Qatar). - The AS announces 98,816 IPv4 addresses across 4 prefixes while maintaining only 5 observed neighbours, a ratio that indicates an internal corporate estate with site-by-site segmentation rather than a transit or access network.
Notable
- Registrants for the two largest prefixes (
157.139.0.0/16and140.251.0.0/17) align with the announcer, identified as Joan and Sanford I. Weill Medical College and Graduate School of Medical Sciences of Cornell University. - The inventory includes a
/24prefix (38.146.193.0/24) registered to Cogent Communications, LLC, and another/24(207.162.253.0/24) registered to Weill Cornell Medical College in Qatar, indicating a mix of owned and potentially leased or affiliated space. - The address inventory is dominated by two large blocks (a
/16and a/17) with two smaller/24allocations, reflecting a consolidated internal network with specific sub-allocations for distinct sites or functions.
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 2026-10-21, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 4 prefixes · 98.82K addresses IPv6 0 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 4 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS20252- Registry name
- JSIWMC
- Registrant
- Joan and Sanford I. Weill Medical College and Graduate School of Medical Sciences of Cornell University
- Abuse contact
- abuse@med.cornell.edu
- Registered
- 2001-04-12
- Last changed
- 2012-02-24
- Allocation
- assigned
Declared
PeeringDB profile
- Name
- JSIWMC
- Scope
- Not Disclosed
- Traffic ratio
- Not Disclosed
PeeringDB records are maintained by the network operator and are not independently verified. Treat them as a statement of intent rather than of fact. For the observed and recorded view, see peering, which lists the exchanges Packet Clearing House has a port on file for.
Routing security
RPKI and IRR
- RPKI
- 0% valid · 0 valid, 4 with no ROA
- ROAs
- 0 authorising AS20252
- ASPA
- no ASPA record
- IRR
- 100% registered · 4 of 4 announcements
- Route objects
- 9 naming AS20252
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: 442 networks and 1,779 prefixes, as published 2026-10-22. 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