AS3371 — MCI-ASN

AS3371 announces 131 IPv4 prefixes covering 1,154,304 addresses and 3 IPv6 prefixes.

About this network

A legacy MCI autonomous system (MCI-ASN) now held by Verizon Business, and the largest of the group by address count: it originates well over a million IPv4 addresses of Verizon's inherited space.

What it's used for

• Announcing large Verizon Business allocations, the blocks from which customer and service addressing is drawn.

Notable

• Carrier-held address space. Its size means the ranges behind it cover a broad mix of Verizon Business services rather than one organisation's network.
• Part of the MCI-ASN family registered in 1994 and carried into Verizon with the 2006 MCI acquisition, alongside AS3369, AS3372, AS3373 and AS3374.

Interesting

• MCI's own network absorbed UUNET, one of the first commercial internet backbones, which is why registry records under these ASNs still show UUNET-era block names decades later.

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

Announced prefixes

• 63.39.0.0/17
• 63.39.128.0/19
• 63.39.208.0/20
• 63.39.224.0/20
• 63.91.192.0/18
• 69.96.0.0/20
• 69.103.0.0/16
• 100.5.64.0/18
• 108.37.128.0/17
• 142.77.8.0/22
• 142.77.72.0/21
• 142.77.80.0/20
• 153.39.96.0/19
• 153.39.128.0/17
• 159.98.0.0/18
• 159.98.64.0/21
• 159.98.80.0/20
• 159.98.96.0/21
• 159.98.116.0/22
• 159.98.120.0/21
• 159.98.128.0/17
• 162.47.152.0/22
• 165.122.48.0/20
• 166.32.32.0/20
• 166.32.64.0/18
• 166.32.176.0/20
• 166.32.192.0/19
• 166.32.224.0/20
• 166.33.128.0/19
• 166.33.208.0/20
• 166.33.224.0/19
• 166.34.0.0/18
• 166.35.0.0/17
• 166.36.32.0/19
• 166.36.64.0/20
• 166.36.96.0/19
• 166.36.128.0/17
• 166.37.64.0/19
• 166.37.128.0/18
• 166.37.192.0/23
• 166.37.196.0/22
• 166.37.224.0/21
• 166.38.0.0/19
• 166.38.32.0/23
• 166.38.35.0/24
• 166.38.36.0/23
• 166.38.39.0/24
• 166.38.40.0/21
• 166.38.48.0/22
• 166.38.54.0/23
• 166.38.56.0/21
• 166.38.64.0/21
• 166.38.72.0/22
• 166.38.80.0/20
• 166.38.128.0/22
• 166.38.134.0/23
• 166.38.138.0/23
• 166.38.140.0/22
• 166.38.144.0/20
• 166.38.177.0/24
• 166.38.184.0/22
• 166.38.240.0/20
• 166.39.16.0/20
• 166.39.32.0/19
• 166.39.96.0/20
• 166.39.112.0/22
• 166.39.160.0/19
• 166.39.192.0/20
• 166.39.224.0/19
• 166.40.0.0/18
• 166.40.64.0/19
• 166.40.96.0/20
• 166.40.128.0/19
• 166.40.160.0/24
• 166.40.168.0/24
• 166.40.170.0/23
• 166.40.174.0/23
• 166.40.176.0/20
• 166.40.192.0/20
• 166.40.208.0/21
• 166.40.224.0/19
• 166.41.0.0/20
• 166.41.64.0/18
• 166.41.128.0/20
• 166.41.208.0/20
• 166.41.224.0/19
• 166.42.0.0/16
• 166.43.0.0/17
• 166.43.128.0/20
• 166.43.192.0/18
• 166.44.0.0/17
• 166.44.128.0/18
• 166.44.192.0/19
• 166.44.224.0/20
• 166.44.242.0/23
• 166.44.244.0/22
• 166.44.248.0/21
• 166.45.0.0/16
• 166.46.0.0/18
• 166.46.64.0/19

and 34 more.

Upstream networks

• AS3378 Verizon Business
• AS3372 Verizon Business

Downstream networks

• AS3376 Verizon Business
• AS3377 Verizon Business
• AS3374 Verizon Business
• AS3373 Verizon Business

Adjacent networks

• AS3378 Verizon Business
• AS3376 Verizon Business
• AS3374 Verizon Business
• AS3377 Verizon Business
• AS3373 Verizon Business
• AS3372 Verizon Business