Autonomous system
AS4 ISI-AS
Unclassified ARIN
Summary
USC Information Sciences Institute (ISI)
education research legacy
One of the oldest allocations on the internet (ISI-AS), belonging to the Information Sciences Institute of the University of Southern California.
What it's used for
- Research networking for ISI, a computer science and networking research institute.
Notable
- A single-digit AS number reflects how early ISI connected. ISI was central to the early internet: home of Jon Postel and the original IANA 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.
Transit providers
7 upstream, 3 downstream and 15 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 2026-10-15, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 27 prefixes · 65.54K addresses IPv6 6 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 33 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS4- Registry name
- ISI-AS
- Registrant
- University of Southern California
- Abuse contact
- action@isi.edu
- Registered
- 1984-02-22
- Last changed
- 2023-09-29
- Allocation
- assigned
Routing security
RPKI and IRR
- RPKI
- 2% valid · 1 valid, 51 with no ROA
- ROAs
- 4 authorising AS4
- ASPA
- no ASPA record
- IRR
- 71% registered · 37 of 52 announcements 5 other origin
- Route objects
- 28 naming AS4
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 1,782 prefixes, as published 2026-10-16. 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