AS5400 — BT

AS5400 announces 73 IPv4 prefixes covering 713,728 addresses and 12 IPv6 prefixes.

About this network

AS5400 is BT's international IP backbone, the network behind BT.net and BT's global network services business. It is the carrier-side network, distinct from BT's UK consumer and broadband ASNs.

What it's used for

• IP transit and global connectivity for BT's enterprise, wholesale and carrier customers across Europe, North America and Asia.
• Peering with thousands of other networks at major exchanges; the ASN sits near the top of transit-ranking tables.
• Backbone for BT's managed WAN, MPLS and internet products sold outside the UK consumer market.

Notable

• Carrier address, not eyeball address: hosts on AS5400 are far more likely to be enterprise sites, corporate edge routers and infrastructure than home broadband subscribers. BT's UK retail broadband is announced from a separate ASN.
• BT's internet capability is deliberately split by role — a European/global backbone (this ASN), a UK network, and in-country networks in several other European markets. Attributing traffic on AS5400 to "BT home users" is a common mistake.

Interesting

• The network grew out of BT's late-1990s/2000s continental fibre build and the IP business that was branded BT Ignite before becoming BT Global Services.

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

Announced prefixes

• 31.95.0.0/21
• 31.95.14.0/23
• 31.95.16.0/20
• 31.95.48.0/21
• 31.95.56.0/24
• 31.95.64.0/21
• 31.95.96.0/19
• 31.95.160.0/20
• 31.95.184.0/21
• 31.95.208.0/21
• 31.95.218.0/23
• 31.95.220.0/22
• 31.95.240.0/22
• 31.95.246.0/23
• 31.95.248.0/22
• 31.95.254.0/23
• 46.248.8.0/22
• 62.5.0.0/17
• 62.102.0.0/17
• 62.134.0.0/16
• 62.172.0.0/21
• 62.173.192.0/18
• 62.180.0.0/16
• 80.255.160.0/20
• 82.138.160.0/19
• 82.150.0.0/19
• 132.244.64.0/21
• 132.244.72.0/22
• 132.244.76.0/23
• 132.244.78.0/24
• 132.244.240.0/24
• 136.238.84.0/23
• 136.238.224.0/24
• 166.49.128.0/17
• 185.94.0.0/22
• 185.249.4.0/24
• 192.109.52.0/24
• 194.33.53.0/24
• 194.33.54.0/23
• 194.50.160.0/24
• 194.74.80.0/21
• 194.76.40.0/24
• 194.107.114.0/24
• 194.213.64.0/19
• 195.36.82.0/24
• 195.36.104.0/24
• 195.60.182.0/23
• 195.66.70.0/24
• 195.90.64.0/19
• 195.99.64.0/20
• 195.100.0.0/16
• 195.163.0.0/16
• 195.171.36.0/22
• 195.182.96.0/19
• 198.178.236.0/24
• 203.158.68.0/23
• 203.158.72.0/23
• 203.158.76.0/23
• 203.158.88.0/23
• 204.52.188.0/24
• 204.231.112.0/24
• 206.73.0.0/16
• 212.8.160.0/19
• 212.21.192.0/19
• 212.31.192.0/19
• 212.41.128.0/19
• 212.108.0.0/19
• 212.127.0.0/19
• 212.162.192.0/18
• 213.15.0.0/16
• 213.137.160.0/19
• 213.194.0.0/18
• 213.236.64.0/18
• 2001:740::/32
• 2402:fb00:8000::/39
• 2402:fb00:8400::/39
• 2402:fb00:8800::/40
• 2402:fb00:c000::/38
• 2606:f100:d000::/39
• 2606:f100:d400::/38
• 2606:f100:d800::/37
• 2606:f100:e400::/39
• 2a00:2000::/22
• 2a0c:7c80::/29
• 2a0c:8480::/30

Upstream networks

• AS1299 Arelion Sweden AB
• AS6939 Hurricane Electric LLC
• AS3356 Level 3 Parent, LLC
• AS174 Cogent Communications, LLC
• AS9002 RETN Limited
• AS3257 GTT Communications Inc.
• AS50304 Blix Solutions AS
• AS577 Bell Canada
• AS3491 PCCW Global (HK) Ltd.
• AS4637 Telstra Global
• AS6762 TELECOM ITALIA SPARKLE S.p.A.
• AS3333 Reseaux IP Europeens Network Coordination Centre (RIPE NCC)
• AS1836 green.ch AG
• AS6453 TATA COMMUNICATIONS (AMERICA) INC
• AS3303 Swisscom (Schweiz) AG
• AS2914 NTT America, Inc.
• AS12552 GlobalConnect AB
• AS20485 Joint Stock Company TransTeleCom
• AS11164 Internet2
• AS2497 Internet Initiative Japan Inc.
• AS37100 SEACOM Limited
• AS1273 IDDQD-AS
• AS5511 Orange S.A.
• AS13030 Init7 (Switzerland) Ltd.
• AS7195 EDGEUNO S.A.S

Downstream networks

• AS2856 British Telecommunications Limited
• AS199541 EUROCONTROL, the European Organisation for the Safety of Air Navigation
• AS13205 Telecommunications Limited
• AS2110 Enet Communications LIMITED
• AS7246 Bristol-Myers Squibb Company
• AS33873 Arvato Systems GmbH
• AS21489 The North Atlantic Treaty Organization
• AS15442 Procter & Gamble Service GmbH
• AS8968 RETELIT-X S.R.L.
• AS21000 Atos France SAS
• AS30614 Dell, Inc.
• AS29063 Eviden Netherlands B.V.
• AS72 Schlumberger Limited
• AS25049 Shell Information Technology International B.V.
• AS15518 Circular Informationssysteme GmbH
• AS212565 Specsavers Optical Group Limited
• AS40126 Molson Coors Beverage Company
• AS22683 Koninklijke Philips N.V.
• AS51046 Bringo Limited
• AS12440 Hughes Network Systems GmbH
• AS34311 LG CNS Europe B.V
• AS16839 SERVICENOW, INC.
• AS59724 Elsevier Limited
• AS51466 Bridgestone Europe NV
• AS40934 Fortinet Inc.

Adjacent networks

• AS2856 British Telecommunications Limited
• AS1299 Arelion Sweden AB
• AS3356 Level 3 Parent, LLC
• AS6939 Hurricane Electric LLC
• AS174 Cogent Communications, LLC
• AS3257 GTT Communications Inc.
• AS199541 EUROCONTROL, the European Organisation for the Safety of Air Navigation
• AS11164 Internet2
• AS1836 green.ch AG
• AS12552 GlobalConnect AB
• AS37100 SEACOM Limited
• AS3333 Reseaux IP Europeens Network Coordination Centre (RIPE NCC)
• AS6762 TELECOM ITALIA SPARKLE S.p.A.
• AS2110 Enet Communications LIMITED
• AS20485 Joint Stock Company TransTeleCom
• AS4637 Telstra Global
• AS2497 Internet Initiative Japan Inc.
• AS8968 RETELIT-X S.R.L.
• AS6453 TATA COMMUNICATIONS (AMERICA) INC
• AS9002 RETN Limited
• AS50304 Blix Solutions AS
• AS577 Bell Canada
• AS13205 Telecommunications Limited
• AS33873 Arvato Systems GmbH
• AS7246 Bristol-Myers Squibb Company

Internet exchanges

• IX.br (PTT.br) São Paulo — São Paulo, Brazil
• DE-CIX Frankfurt — Frankfurt, Germany
• LINX LON1 — London, United Kingdom
• AMS-IX Amsterdam — Amsterdam, Netherlands
• Neutral Internet Exchange — Amsterdam, Netherlands
• France-IX Paris — Paris, France
• Equinix Internet Exchange Singapore — Singapore, Singapore
• Milan Internet Exchange — Milan, Italy
• Equinix Internet Exchange Ashburn — Ashburn, United States
• BroadBand Internet eXchange Tokyo — Tokyo, Japan
• Seattle Internet Exchange — Seattle, United States
• Coresite - Any2 West — Los Angeles, United States
• Any2 California — Los Angeles, United States
• Equinix Internet Exchange Warsaw — Warsaw, Poland
• Toronto Internet Exchange — Toronto, Canada
• Equinix Internet Exchange Chicago — Chicago, United States
• SwissIX — Zurich, Switzerland
• Equinix Internet Exchange Paris — Paris, France
• Equinix Internet Exchange Hong Kong — Hong Kong, China
• Equinix Internet Exchange Dallas — Dallas, United States
• DE-CIX Madrid — Madrid, Spain
• DE-CIX Dusseldorf — Düsseldorf, Germany
• New York International Internet Exchange — New York, United States
• DE-CIX Munich — Munich, Germany
• NIX.CZ - Neutral Internet eXchange for the Czech Republic — Prague, Czech Republic
• Equinix Internet Exchange San Jose (Bay Area) — San Jose, United States
• Vienna Internet Exchange — Vienna, Austria
• Equinix Internet Exchange Miami — Miami, United States
• ESpanix Madrid Lower LAN — Madrid, Spain
• Digital Realty Atlanta Internet Exchange — Atlanta, United States
• Berlin Commercial Internet Exchange — Berlin, Germany
• Megaport IX Melbourne — Melbourne, Australia
• BroadBand Internet eXchange Osaka — Osaka, Japan
• Equinix Internet Exchange Tokyo — Tokyo, Japan
• France-IX Marseille — Marseille, France
• Equinix Internet Exchange New York — New York, United States
• Budapest Internet Exchange — Budapest, Hungary
• Internet Neutral Exchange Association CLG - LAN1 — Dublin, Ireland
• DE-CIX Marseille — Marseille, France
• JPIX Osaka — Osaka, Japan
• Luxembourg Internet Exchange — Luxembourg, Luxembourg
• France-IX Lyon — Lyon, France
• CANIX Internet Exchange - Montreal — Montreal, Canada
• Belgian National Internet Exchange — Brussels, Belgium
• Equinix Internet Exchange Los Angeles — Los Angeles, United States
• Vancouver Internet Exchange — Vancouver, Canada
• Equinix Los Angeles IBX — Los Angeles, United States
• Norwegian Internet Exchange Oslo 1 — Oslo, Norway
• DE-CIX Lisbon — Lisbon, Portugal
• Catalunya Neutral Internet Exchange Point — Barcelona, Spain
• Danish Internet Exchange — Copenhagen, Denmark
• Netnod Sundsvall- Gävle — Sundsvall, Sweden
• Equinix-LA(former Paix) — Los Angeles, United States