Autonomous system
AS3378 MCI-ASN
Unclassified ARIN
Summary
Verizon Business (MCI)
transit isp legacy
The last of the four consecutive legacy MCI autonomous systems (MCI-ASN) held by Verizon Business, and the busiest of the group by prefix count.
What it's used for
- Announcing a broad scatter of MCI-era IPv4 blocks for Verizon Business, predominantly customer and managed-service address space.
- Backbone transit proper is carried by AS701; this ASN exists mainly to originate legacy prefixes.
Notable
- Registered to Verizon Business in Ashburn, Virginia, with an ARIN record reaching back to the mid-1990s.
- The prefixes are numerous but mostly small (many /22s and /24s) — the signature of address space handed out to individual customer sites over decades.
Interesting
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, 3 downstream and 7 adjacent networks observed; most-used upstreams first.
| AS | Network | Paths seen |
|---|---|---|
| AS701 | Verizon Business | 2,238 |
Exchange presence is recorded rather than inferred: the directory collected by Packet Clearing House (https://www.pch.net/ixp/data) on 2026-10-14, licensed CC BY-NC-SA 3.0. Transit is inferred from observed BGP paths, never declared by either party.
Address space
Summary
IPv4 31 prefixes · 64.26K addresses IPv6 0 prefixes
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 31 |
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
- 0% valid · 0 valid, 38 with no ROA
- ROAs
- 0 authorising AS3378
- ASPA
- no ASPA record
- IRR
- 0% registered · 0 of 38 announcements
- Route objects
- 0 naming AS3378
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 1,772 prefixes, as published 2026-10-15. 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