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Autonomous System

AS5400 · British Telecommunications Limited

Overview

AS5400 is announced on the Internet: RIPE RIS route collectors currently see 85 IPv4 prefixes and 40 IPv6 prefixes originated by this network. Together, its IPv4 prefixes cover 714,240 addresses, with overlapping prefixes counted once. In the paths the collectors record, it has 52 upstream neighbours (transit providers or peers) and 115 downstream neighbours (customers or networks it carries). Its most visible upstreams are Arelion Sweden AB (AS1299), Level 3 Parent, LLC (AS3356), and Hurricane Electric LLC (AS6939). AS5400 was assigned by RIPE NCC, and its registration country is United Kingdom.

Source: RIPEstat (RIPE NCC), RIS route collectors. Read on October 16, 2026 at 8:58 PM UTC. This page is refreshed at most every 12 hours.

Go further

Trace a route to this networkOpen in the BGP viewerWHOIS of 62.134.0.1

The trace goes to 62.134.0.1, the first address of 62.134.0.0/16. An address picked inside a prefix may not answer (nothing listens there, or the network filters probes): the trace then shows the path up to the last network that replies.

Announced prefixes

IPv4 prefixes (85 prefixes)

PrefixAddresses
31.95.0.0/212,048
31.95.14.0/23512
31.95.16.0/204,096
31.95.48.0/212,048
31.95.56.0/24256
31.95.64.0/212,048
31.95.96.0/198,192
31.95.160.0/204,096
31.95.184.0/212,048
31.95.208.0/212,048
31.95.218.0/23512
31.95.220.0/221,024
31.95.240.0/221,024
31.95.246.0/23512
31.95.248.0/221,024
31.95.254.0/23512
46.248.8.0/23512
46.248.10.0/23512
62.5.0.0/1732,768
62.102.0.0/1732,768
62.134.0.0/1665,536
62.172.0.0/212,048
62.173.192.0/1816,384
62.180.0.0/1665,536
80.255.160.0/204,096
80.255.160.0/24256
80.255.161.0/24256
80.255.162.0/24256
82.138.160.0/198,192
82.150.0.0/198,192
132.244.64.0/212,048
132.244.72.0/212,048
132.244.240.0/24256
136.238.84.0/24256
136.238.85.0/24256
136.238.224.0/24256
166.49.128.0/1732,768
185.94.0.0/221,024
185.249.4.0/24256
192.109.52.0/24256
193.58.130.0/23512
194.33.53.0/24256
194.33.54.0/24256
194.33.55.0/24256
194.50.160.0/24256
194.74.80.0/212,048
194.76.40.0/24256
194.107.114.0/24256
194.213.64.0/198,192
195.36.82.0/24256
195.36.104.0/24256
195.60.182.0/24256
195.60.183.0/24256
195.66.70.0/24256
195.90.64.0/198,192
195.99.64.0/204,096
195.100.0.0/1665,536
195.163.0.0/1665,536
195.171.36.0/221,024
195.182.96.0/198,192
198.178.236.0/24256
203.158.68.0/23512
203.158.72.0/23512
203.158.76.0/23512
203.158.88.0/24256
203.158.89.0/24256
204.52.188.0/24256
206.73.0.0/1665,536
206.73.0.0/198,192
206.73.48.0/204,096
206.73.80.0/204,096
206.73.112.0/221,024
206.73.116.0/221,024
206.73.156.0/221,024
212.8.160.0/198,192
212.21.192.0/198,192
212.31.192.0/198,192
212.41.128.0/198,192
212.108.0.0/198,192
212.127.0.0/198,192
212.162.192.0/1816,384
213.15.0.0/1665,536
213.137.160.0/198,192
213.194.0.0/1816,384
213.236.64.0/1816,384

IPv6 prefixes (40 prefixes)

Prefix
2001:740::/32
2402:fb00:8000::/39
2402:fb00:8400::/39
2402:fb00:8800::/40
2402:fb00:c000::/39
2402:fb00:c200::/39
2606:f100:d000::/39
2606:f100:d400::/39
2606:f100:d600::/39
2606:f100:d800::/38
2606:f100:dc00::/38
2606:f100:e400::/39
2a00:2000::/23
2a00:2080::/32
2a00:2081::/32
2a00:2082::/32
2a00:2083::/32
2a00:2084::/32
2a00:2086::/32
2a00:2089::/32
2a00:208a::/32
2a00:208b::/32
2a00:208c::/32
2a00:208d::/32
2a00:2090::/32
2a00:2094::/32
2a00:2095::/32
2a00:2096::/32
2a00:2097::/32
2a00:2200::/25
2a00:2200:200::/40
2a00:2200:300::/40
2a00:2200:900::/40
2a00:2200:b00::/40
2a00:2200:d00::/40
2a00:2200:2000::/40
2a00:2200:5300::/40
2a00:2280::/25
2a00:2300::/25
2a0c:7c80::/29

Neighbours

Upstreams (transit or peers) (52)

ASNetworkVisibility
AS1299Arelion Sweden AB8,150
AS3356Level 3 Parent, LLC5,516
AS6939Hurricane Electric LLC2,698
AS174Cogent Communications, LLC2,159
AS6762TELECOM ITALIA SPARKLE S.p.A.1,741
AS3257GTT Communications Inc.1,647
AS6453TATA COMMUNICATIONS (AMERICA) INC1,101
AS3491PCCW Global (HK) Ltd.1,077
AS20485Joint Stock Company TransTeleCom647
AS33891Core-Backbone GmbH636
AS9002RETN Limited616
AS12956TELEFONICA GLOBAL SOLUTIONS SL564
AS3320Deutsche Telekom AG547
AS4637Telstra Global458
AS13030Init7 (Switzerland) Ltd.420
AS2856British Telecommunications Limited416
AS3935131173 Services AB416
AS5511Opentransit Orange S.A.369
AS2497Internet Initiative Japan Inc.359
AS24961WIIT AG357
AS8283Netwerkvereniging Coloclue298
AS35280F5 Networks SARL298
AS6830LibertyGlobal Liberty Global Europe Holding B.V.297
AS8218Zayo Infrastructure France SA284
AS37468Angola Cables235
AS1836green.ch AG227
AS30781Free Pro SAS211
AS6730-206
AS9121TTNet Turk Telekomunikasyon Anonim Sirketi200
AS1257Tele2 Sverige AB198

The 30 most visible of 52.

Downstreams (customers) (115)

ASNetworkVisibility
AS2856British Telecommunications Limited19,968
AS8968RETELIT-X S.R.L.2,216
AS2110Enet Communications LIMITED1,707
AS199541EUROCONTROL, the European Organisation for the Safety of Air Navigation532
AS29063Eviden Netherlands B.V.434
AS7246Bristol-Myers Squibb Company357
AS15499Computacenter Management GmbH trading as Computacenter AG & Co.oHG347
AS51046Bringo Limited305
AS40126Molson Coors Beverage Company304
AS21489The North Atlantic Treaty Organization282
AS21000-276
AS59724-270
AS13205-268
AS22683Koninklijke Philips N.V.265
AS25049-265
AS33873Arvato Systems GmbH265
AS3573Accenture LLP264
AS12298-262
AS212565Specsavers Optical Group Limited262
AS27311-261
AS34311-261
AS51466-260
AS202666-260
AS208053-260
AS48647-259
AS30864-258
AS72-256
AS7734-256
AS394805-256
AS21433AccentureFSSC Accenture UK Limited255

The 30 most visible of 115.

77 more neighbours appear on both sides of this network depending on the path, so they are counted in neither list.

Visibility is RIPEstat's count of how often the route collectors observed the link. It compares neighbours with each other; it is not a traffic volume.

How to read this page

An Autonomous System (AS) is a network run under one routing policy: an internet provider, a cloud, a content network, a university. Each one has a number, its ASN, assigned by a regional registry (ARIN, RIPE NCC, APNIC, LACNIC, AFRINIC), and uses BGP, the protocol networks use to tell each other where addresses are, to announce the blocks of addresses it delivers to.

A prefix such as 203.0.113.0/24 is a block of addresses: the number after the slash says how many bits are fixed, so a /24 holds 256 IPv4 addresses and a /16 holds 65,536. Networks often announce a large block and smaller pieces of it at the same time, which is why the address total counts each address once.

Neighbours come from the paths themselves. A network that appears just before this one in a path, on the collector's side, is an upstream: a transit provider or a peer. One that appears just after it is a downstream, usually a customer. Peering at an internet exchange also shows up as an upstream, so the upstream list is not a list of paid transit.

The data comes from RIPEstat, run by the RIPE NCC, which gathers the routing tables of hundreds of networks through its RIS route collectors. This page reads it when it is visited and keeps it for 12 hours at most; the BGP viewer reads it live.

Frequently asked questions

How do I find the ASN of an IP address?
Type the address in the BGP viewer: it shows the prefix that covers it, the AS that originates that prefix and the paths seen towards it. A traceroute also names the network of each hop, so you can see every AS a connection crosses.
Why does one company have several ASNs?
Large operators split their network by region, by activity or by history: a cloud may use one number for its backbone and another for a region, and every acquisition brings its own numbers. Each number has its own page, with its own prefixes and neighbours.
Why do prefix counts differ from one site to another?
Each source sees the routing table from different collectors, at a different time, and counts differently: some include prefixes withdrawn in recent weeks, some merge a block and its pieces. This page counts the prefixes RIPE RIS collectors see originated by the network at the end of the latest two-week window, and counts each IPv4 address once.
Is this the list of IP ranges of a cloud provider?
It is what its networks announce, which is what the Internet routes to them. Many providers also publish an official list of ranges per service and region; that list is the reference for firewall rules, because a range can be announced before it is used, or announced by another of their AS numbers.