AS3620 — MCIASN-BLK

AS3620 announces 1 IPv4 prefixes covering 256 addresses and 0 IPv6 prefixes.

About this network

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 /24 rather than acting as a general-purpose backbone.
• Retained from MCI's network as part of the address and ASN estate Verizon inherited.

Notable

• MCIASN-BLK was 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.

Announced prefixes

• 198.160.128.0/24

Upstream networks

• AS703 Verizon Business

Adjacent networks

• AS703 Verizon Business

Routing security

• RPKI: 0 valid, 0 invalid and 1 not-found announcements; 0 ROAs.
• ASPA: none published.
• IRR: 100% of announcements registered; 1 route objects.
• Listed in as-sets: AS7545:AS-TPGN-CUSTOMERS.