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AS5400 BT British Telecommunications Limited

BT British Telecommunications Limited · registered in the United Kingdom

IPv4 addresses713,47277 prefixes · 0.023% of announced IPv4
Rank in United Kingdom#12largest network in GB by IPv4 space, of 2,074 · 1.05% of GB
Rank worldwide#458of 79,396 networks with IPv4
IPv6905 x /32 (59,316,480 x /48)54 prefixes
CountryUnited Kingdom2,261 ASNs registered there
Open AS5400 in ASN lookup Look up an IP in this network (31.95.0.1) All networks in United Kingdom

IPv4 prefixes

All 77 prefixes, in address order.

  • 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
  • 206.73.0.0/18
  • 206.73.64.0/19
  • 206.73.96.0/19
  • 206.73.128.0/19
  • 206.73.160.0/19
  • 206.73.192.0/18
  • 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

IPv6 prefixes

All 54 prefixes.

  • 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::/25
  • 2a00:2080::/30
  • 2a00:2084::/32
  • 2a00:2085::/32
  • 2a00:2086::/32
  • 2a00:2087::/32
  • 2a00:2088::/30
  • 2a00:208c::/31
  • 2a00:208e::/31
  • 2a00:2090::/32
  • 2a00:2091::/32
  • 2a00:2092::/31
  • 2a00:2094::/30
  • 2a00:2098::/29
  • 2a00:20a0::/27
  • 2a00:20c0::/26
  • 2a00:2100::/24
  • 2a00:2200::/37
  • 2a00:2200:800::/39
  • 2a00:2200:a00::/39
  • 2a00:2200:c00::/39
  • 2a00:2200:e00::/39
  • 2a00:2200:1000::/36
  • 2a00:2200:2000::/40
  • 2a00:2200:2100::/40
  • 2a00:2200:2200::/39
  • 2a00:2200:2400::/38
  • 2a00:2200:2800::/37
  • 2a00:2200:3000::/36
  • 2a00:2200:4000::/36
  • 2a00:2200:5000::/38
  • 2a00:2200:5400::/38
  • 2a00:2200:5800::/37
  • 2a00:2200:6000::/35
  • 2a00:2200:8000::/33
  • 2a00:2201::/32
  • 2a00:2202::/31
  • 2a00:2204::/30
  • 2a00:2208::/29
  • 2a00:2210::/28
  • 2a00:2220::/27
  • 2a00:2240::/26
  • 2a00:2280::/25
  • 2a00:2300::/25
  • 2a0c:7c80::/29

Other ASNs named BT British Telecommunications Limited

1 other network uses the same organisation name; together with AS5400 they announce 1,226,752 IPv4 addresses.

ASNNameIPv4 addresses
AS3300BT British Telecommunications Limited GB513,280

Similar-sized networks in United Kingdom

ASNNameIPv4 addresses
AS212238#9 CDNEXT Datacamp Limited1,066,496
AS8426#10 CLARANET-AS Claranet Limited904,704
AS5413#11 Wavenet-AS5413 Wavenet Limited732,416
AS31655#13 ASN-GammaTelecom Gamma Telecom Holdings Ltd609,536
AS206067#14 H3GUK Hutchison 3G UK Limited529,152
AS13037#15 ZEN-AS Zen Internet Ltd527,616

IP-to-ASN data: iptoasn.com (public domain). Snapshot downloaded 2026-11-11, refreshed daily. Ranges are what each network announces in BGP, not registry allocations. Data sources