AS3375 — MCI-ASN

AS3375 announces 7 IPv4 prefixes covering 33,280 addresses and 0 IPv6 prefixes.

About this network

A legacy MCI autonomous system (MCI-ASN), now held by Verizon Business after Verizon's acquisition of MCI. It is one of a run of adjacent MCI ASNs that Verizon still announces alongside its main backbone, AS701.

What it's used for

• Announcing Verizon Business / MCI-era address space, largely customer and managed-service networks rather than backbone transit itself.
• Registered under Verizon Business's Ashburn, Virginia address, the same registrant as the rest of the Verizon Business ASN family.

Notable

• The ARIN record dates to 1994, so this is a genuine early allocation from the era when MCI was building out one of the internet's first commercial backbones.
• Carrier-assigned space: addresses here generally belong to organizations buying connectivity from Verizon, not to Verizon's own offices.

Interesting

• MCI ASNs cluster tightly in this range — AS3376, AS3377 and AS3378 share the same MCI-ASN handle and the same corporate lineage.

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

Announced prefixes

• 165.122.32.0/20
• 165.122.192.0/18
• 166.37.194.0/23
• 166.37.200.0/21
• 166.37.208.0/20
• 166.37.232.0/21
• 166.37.240.0/20

Upstream networks

• AS3372 Verizon Business

Adjacent networks

• AS3372 Verizon Business

Routing security

• RPKI: 0 valid, 0 invalid and 8 not-found announcements; 0 ROAs.
• ASPA: none published.
• IRR: 0% of announcements registered; 0 route objects.