Autonomous system
AS3371 MCI-ASN
Unclassified ARIN
Summary
Verizon Business (MCI)
enterprise legacy
A legacy MCI autonomous system (MCI-ASN) now held by Verizon Business, and the largest of the group by address count: it originates well over a million IPv4 addresses of Verizon's inherited space.
What it's used for
- Announcing large Verizon Business allocations, the blocks from which customer and service addressing is drawn.
Notable
- Carrier-held address space. Its size means the ranges behind it cover a broad mix of Verizon Business services rather than one organisation's network.
- Part of the
MCI-ASNfamily registered in 1994 and carried into Verizon with the 2006 MCI acquisition, alongside AS3369, AS3372, AS3373 and AS3374.
Interesting
- MCI's own network absorbed UUNET, one of the first commercial internet backbones, which is why registry records under these ASNs still show UUNET-era block names decades later.
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 2026-10-27, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 131 prefixes · 1.15M addresses IPv6 3 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 134 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS3369- Registry name
- MCI-ASN
- Registrant
- Verizon Business
- Abuse contact
- abuse@verizon.com
- Registered
- 1994-01-06
- Last changed
- 2024-07-02
- Allocation
- assigned
Routing security
RPKI and IRR
- RPKI
- 10% valid · 3 valid, 28 with no ROA
- ROAs
- 6 authorising AS3371
- ASPA
- no ASPA record
- IRR
- 6% registered · 2 of 31 announcements
- Route objects
- 5 naming AS3371
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: 446 networks and 1,852 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