Autonomous system
AS3620 MCIASN-BLK
Unclassified ARIN
IPv4 addresses
256
1 prefixes
IPv6 prefixes
0
counted as prefixes, not addresses
Countries
1
mostly US
Flagged prefixes
0
none
Summary
Verizon Business (legacy MCI)
enterprise legacy
One of the legacy MCI autonomous system numbers (MCIASN-BLK) now held by
Verizon Business.
What it's used for
- Announcing a single small block of Verizon Business address space; the ASN originates one
/24rather than acting as a general-purpose backbone. - Retained from MCI's network as part of the address and ASN estate Verizon inherited.
Notable
MCIASN-BLKwas a block of AS numbers rather than a single assignment — MCI held a contiguous run of them, and several sit adjacent to this one in the low-3600s. The handle names the block, not the specific network behind it.- Carrier-held space. Public registry data does not identify a distinct end-network here, so the honest description is simply "Verizon Business".
Interesting
- The handle is a fossil: MCI was absorbed by Verizon in 2006, but the ARIN record still carries the MCI name. Handles routinely outlive the companies that earned them.
This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy. Source, and how to suggest an edit.
Address space
Summary
| Country | Name | Prefixes |
|---|---|---|
| US | United States of America | 1 |
Registry
Allocation record
- Registry
- ARIN
- Handle
AS3617- Registry name
- MCIASN-BLK
- Registrant
- Verizon Business
- Abuse contact
- abuse@verizon.com
- Registered
- 1994-05-24
- Last changed
- 2024-07-02
- Status
- active
Reputation
Classification and threat
Unclassified Not in the curated lists. Most of the ~80,000 allocated ASNs are not.
No IC3 indicators Nothing from the FBI IC3 feed.
Threat data is alpha. Absence of an indicator is not evidence of good behaviour, only of absence from this one feed.
Elsewhere