AS3356 — LEVEL3

Network type: transit

AS3356 announces 4,495 IPv4 prefixes covering 27,343,488 addresses and 143 IPv6 prefixes.

About this network

AS3356 is the former Level 3 Communications backbone, now operated by Lumen Technologies. It is one of the largest Tier 1 networks on the internet.

What it's used for

• Global IP transit — carrying traffic between networks that pay Lumen for reachability, and settlement-free peering with other Tier 1s.
• Long-haul fiber and wholesale backbone services underpinning many other providers.

Notable

• As a Tier 1, AS3356 reaches the entire internet without buying transit from anyone; it appears in a huge fraction of internet routing paths.
• After Level 3 merged with CenturyLink (later rebranded Lumen), 3356 remained the dominant backbone ASN, absorbing much of the old CenturyLink footprint.

Interesting

• The Level 3 backbone traces its lineage to some of the earliest commercial long-haul IP networks built during the late-1990s fiber boom.

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

Announced prefixes

• 4.0.0.0/12
• 4.16.0.0/15
• 4.18.0.0/16
• 4.19.0.0/21
• 4.19.8.0/22
• 4.19.14.0/23
• 4.19.16.0/20
• 4.19.32.0/19
• 4.19.64.0/18
• 4.19.128.0/17
• 4.20.0.0/14
• 4.24.0.0/14
• 4.28.0.0/15
• 4.30.0.0/16
• 4.31.0.0/17
• 4.31.128.0/18
• 4.31.192.0/19
• 4.31.224.0/21
• 4.31.232.0/22
• 4.31.236.0/26
• 4.31.236.72/29
• 4.31.236.80/28
• 4.31.236.96/27
• 4.31.236.128/25
• 4.31.237.0/24
• 4.31.238.0/23
• 4.31.240.0/20
• 4.32.0.0/15
• 4.34.0.0/21
• 4.34.8.0/22
• 4.34.14.0/23
• 4.34.16.0/20
• 4.34.32.0/19
• 4.34.64.0/18
• 4.34.128.0/17
• 4.35.0.0/18
• 4.35.64.0/22
• 4.35.68.0/24
• 4.35.70.0/23
• 4.35.72.0/21
• 4.35.80.0/20
• 4.35.96.0/19
• 4.35.128.0/17
• 4.36.0.0/15
• 4.38.0.0/16
• 4.39.0.0/18
• 4.39.64.0/19
• 4.39.96.0/23
• 4.39.98.0/24
• 4.39.100.0/22
• 4.39.104.0/21
• 4.39.112.0/20
• 4.39.128.0/17
• 4.40.0.0/13
• 4.48.0.0/12
• 4.64.0.0/13
• 4.72.0.0/15
• 4.74.0.0/16
• 4.75.0.0/17
• 4.75.128.0/22
• 4.75.133.0/24
• 4.75.134.0/23
• 4.75.136.0/21
• 4.75.144.0/20
• 4.75.160.0/19
• 4.75.192.0/18
• 4.76.0.0/14
• 4.80.0.0/12
• 4.96.0.0/11
• 5.252.72.0/24
• 8.0.0.0/15
• 8.2.0.0/20
• 8.2.16.0/24
• 8.2.19.0/24
• 8.2.20.0/22
• 8.2.24.0/21
• 8.2.32.0/19
• 8.2.64.0/22
• 8.2.73.0/24
• 8.2.74.0/23
• 8.2.76.0/23
• 8.2.78.0/24
• 8.2.80.0/20
• 8.2.97.0/24
• 8.2.98.0/23
• 8.2.100.0/22
• 8.2.106.0/23
• 8.2.112.0/22
• 8.2.116.0/23
• 8.2.120.0/21
• 8.2.128.0/23
• 8.2.136.0/21
• 8.2.148.0/22
• 8.2.152.0/21
• 8.2.160.0/20
• 8.2.178.0/23
• 8.2.180.0/22
• 8.2.188.0/22
• 8.2.196.0/24
• 8.2.198.0/23

and 4,538 more.

Upstream networks

• AS6939 Hurricane Electric LLC
• AS174 Cogent Communications, LLC
• AS2914 NTT America, Inc.
• AS1299 Arelion Sweden AB
• AS3549 Level 3 Parent, LLC
• AS3257 GTT Communications Inc.
• AS9002 RETN Limited
• AS577 Bell Canada
• AS7018 AT&T Enterprises, LLC
• AS37721 Virtual Technologies & Solutions
• AS14907 Wikimedia Foundation Inc.
• AS50628 Leonix Telecom SAS
• AS50300 CustodianDC Limited
• AS17639 Converge ICT Solutions Inc.
• AS8280 SYNAPSECOM S.A. Provider of Telecommunications and Internet Services
• AS3491 PCCW Global (HK) Ltd.
• AS1836 green.ch AG
• AS1764 Next Layer Telekommunikationsdienstleistungs- und Beratungs GmbH
• AS48185 team.blue NV
• AS2497 Internet Initiative Japan Inc.
• AS3320 Deutsche Telekom AG
• AS57866 Fusix Networks B.V.
• AS2152 CENIC
• AS3216 PJSC "Vimpelcom"
• AS971 PureVoltage Hosting Inc.

Downstream networks

• AS749 United States Department of Defense (DoD)
• AS209 CenturyLink Communications, LLC
• AS11492 CABLE ONE, INC.
• AS19901 Brightspeed
• AS12479 Orange Espagne SA
• AS34984 Superonline Iletisim Hizmetleri A.S.
• AS36992 ETISALAT MISR
• AS10753 Level 3 Parent, LLC
• AS8151 UNINET
• AS6327 Shaw Communications
• AS11830 Instituto Costarricense de Electricidad y Telecom.
• AS7029 Windstream Communications LLC
• AS3561 CenturyLink Communications, LLC
• AS3549 Level 3 Parent, LLC
• AS6079 RCN
• AS31898 Oracle Corporation
• AS8103 Florida Department of Management Services - Division of Telecommunications
• AS7979 Servers.com, Inc.
• AS16509 Amazon.com, Inc.
• AS8452 IDDQD-AS
• AS9009 M247 Europe SRL
• AS13335 Cloudflare, Inc.
• AS13649 Flexential Colorado Corp.
• AS12322 Free SAS
• AS11404 Wave Broadband

Adjacent networks

• AS3549 Level 3 Parent, LLC
• AS174 Cogent Communications, LLC
• AS1299 Arelion Sweden AB
• AS2914 NTT America, Inc.
• AS721 United States Department of Defense (DoD)
• AS6939 Hurricane Electric LLC
• AS2152 CENIC
• AS14907 Wikimedia Foundation Inc.
• AS9002 RETN Limited
• AS58453 China Mobile International Limited
• AS3257 GTT Communications Inc.
• AS48185 team.blue NV
• AS577 Bell Canada
• AS971 PureVoltage Hosting Inc.
• AS7018 AT&T Enterprises, LLC
• AS293 ESnet
• AS6762 TELECOM ITALIA SPARKLE S.p.A.
• AS50300 CustodianDC Limited
• AS3741 Dimension Data
• AS1836 green.ch AG
• AS749 United States Department of Defense (DoD)
• AS6453 TATA COMMUNICATIONS (AMERICA) INC
• AS17639 Converge ICT Solutions Inc.
• AS2497 Internet Initiative Japan Inc.
• AS209 CenturyLink Communications, LLC

Internet exchanges

• NAPAfrica IX Johannesburg — Johannesburg, South Africa
• NAPAfrica IX Cape Town — Cape Town, South Africa
• IX.br (PTT.br) Belo Horizonte — Belo Horizonte, Brazil
• UAE-IX — Dubai, United Arab Emirates