AS3377 — MCI-ASN

AS3377 announces 4 IPv4 prefixes covering 78,336 addresses and 0 IPv6 prefixes.

About this network

A legacy MCI autonomous system (MCI-ASN) now operated by Verizon Business. It is one of several adjacent MCI ASNs that survived the MCI → MCI WorldCom → Verizon Business chain of acquisitions.

What it's used for

• Announcing MCI-era address space for Verizon Business, mostly customer and managed-service networks.
• It complements, rather than replaces, Verizon's main backbone ASN AS701.

Notable

• The ARIN registration dates to 1994 — a genuine early-internet allocation from MCI's backbone build-out, not a modern reissue.
• Carrier-assigned addressing: IPs here normally sit inside customer organizations that buy connectivity from Verizon Business.

Interesting

• AS3375, AS3376 and AS3378 share the same handle and the same history — MCI took a consecutive run of AS numbers and kept them.

This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy.

Announced prefixes

• 131.146.0.0/16
• 166.44.240.0/23
• 166.58.0.0/19
• 166.58.32.0/20

Upstream networks

• AS3378 Verizon Business
• AS3371 Verizon Business
• AS3372 Verizon Business

Adjacent networks

• AS3378 Verizon Business
• AS3371 Verizon Business
• AS3372 Verizon Business