AS2856 BT-UK-AS British Telecommunications Limited

BT-UK-AS British Telecommunications Limited · registered in the United Kingdom

IPv4 addresses13,859,584548 prefixes · 0.442% of announced IPv4

Rank in United Kingdom#1largest network in GB by IPv4 space, of 2,074 · 20.41% of GB

Rank worldwide#29of 79,396 networks with IPv4

IPv6136 x /32 (8,912,900 x /48)5 prefixes

CountryUnited Kingdom2,261 ASNs registered there

Open AS2856 in ASN lookup Look up an IP in this network (5.35.192.1) All networks in United Kingdom

IPv4 prefixes

First 500 of 548 prefixes, in address order.

5.35.192.0/21
5.80.0.0/15
5.181.136.0/24
9.151.0.0/19
9.151.208.0/20
9.151.248.0/21
9.232.192.0/18
9.233.48.0/20
9.237.96.0/19
9.237.128.0/18
9.237.192.0/19
15.145.20.0/22
23.26.70.0/24
23.26.108.0/24
23.26.117.0/24
23.26.131.0/24
23.26.192.0/24
23.27.32.0/21
23.27.40.0/24
23.27.102.0/23
23.27.104.0/22
23.27.108.0/24
23.230.82.0/23
23.230.242.0/24
23.230.252.0/24
31.48.0.0/13
31.90.0.0/15
31.92.0.0/15
31.94.0.0/16
31.96.0.0/16
31.100.0.0/14
31.104.0.0/16
31.106.0.0/15
31.112.0.0/13
31.120.0.0/14
31.124.0.0/16
31.126.0.0/15
31.130.240.0/23
37.44.229.0/24
37.44.230.0/23
37.97.112.0/22
37.143.3.0/24
37.230.61.0/24
40.27.28.0/24
40.27.72.0/24
45.39.116.0/24
45.39.188.0/24
45.149.7.0/24
45.149.168.0/22
46.68.0.0/18
46.68.64.0/23
46.68.66.0/24
46.68.67.0/24
46.68.68.0/22
46.68.72.0/21
46.68.80.0/20
46.68.96.0/19
46.68.128.0/17
46.69.0.0/16
46.248.96.0/22
46.248.102.0/23
46.248.104.0/23
46.248.120.0/22
50.117.7.0/24
50.117.51.0/24
50.118.154.0/23
51.14.0.0/16
51.64.32.0/23
51.146.44.0/22
51.146.128.0/22
51.146.136.0/22
51.146.235.0/24
51.146.252.0/22
51.149.18.0/23
51.194.36.0/23
51.194.100.0/22
51.230.0.0/17
51.230.255.0/24
51.241.3.0/24
51.241.201.0/24
62.6.0.0/15
62.172.8.0/21
62.172.16.0/20
62.172.32.0/19
62.172.64.0/18
62.172.128.0/19
62.172.160.0/21
62.172.168.0/22
62.172.172.0/24
62.172.174.0/23
62.172.176.0/20
62.172.192.0/18
62.192.124.0/23
62.239.0.0/16
62.244.11.0/24
62.244.12.0/24
62.244.29.0/24
62.244.36.0/23
62.244.45.0/24
62.244.56.0/24
64.205.136.0/22
64.205.144.0/22
72.9.180.0/22
77.90.135.0/24
77.90.138.0/24
77.90.151.0/24
77.90.153.0/24
77.90.164.0/24
77.94.224.0/24
78.105.97.0/24
78.105.136.0/22
78.105.151.0/24
78.105.175.0/24
78.105.179.0/24
78.105.188.0/24
78.105.191.0/24
78.105.194.0/24
78.105.198.0/24
78.105.200.0/24
78.105.202.0/24
79.132.64.0/23
79.139.52.0/22
80.81.58.0/24
81.128.0.0/11
81.161.52.0/22
82.38.9.0/24
82.38.56.0/22
82.39.173.0/24
82.41.112.0/22
82.108.4.0/22
82.108.32.0/21
82.108.44.0/22
82.108.52.0/22
82.108.68.0/22
82.108.88.0/23
82.108.92.0/22
82.108.102.0/23
82.108.116.0/22
82.108.140.0/22
82.108.152.0/23
82.136.54.0/23
82.140.134.0/24
82.140.138.0/24
82.140.143.0/24
82.140.170.0/24
82.153.33.0/24
82.153.85.0/24
82.153.88.0/24
82.153.179.0/24
82.153.181.0/24
82.153.190.0/24
82.153.238.0/24
83.148.168.0/22
83.148.180.0/22
83.223.153.0/24
83.223.154.0/24
83.245.16.0/21
83.245.24.0/22
84.23.0.0/19
84.46.177.0/24
84.46.181.0/24
84.46.183.0/24
84.46.188.0/24
84.46.190.0/23
84.46.194.0/24
84.55.17.0/24
84.55.22.0/24
85.88.224.0/22
85.88.232.0/23
85.88.240.0/23
85.189.72.0/21
85.189.132.0/23
85.189.153.0/24
85.189.154.0/23
85.189.156.0/24
85.189.159.0/24
85.189.160.0/24
85.189.162.0/24
85.189.164.0/23
85.189.167.0/24
85.189.174.0/23
85.189.178.0/24
85.189.181.0/24
85.189.183.0/24
85.189.189.0/24
85.189.190.0/23
85.204.160.0/22
85.235.123.0/24
86.38.56.0/24
86.38.63.0/24
86.38.65.0/24
86.38.67.0/24
86.38.68.0/24
86.38.86.0/24
86.38.93.0/24
86.38.118.0/24
86.38.123.0/24
86.38.148.0/24
86.38.193.0/24
86.38.233.0/24
86.38.244.0/24
86.54.81.0/24
86.110.57.0/24
86.128.0.0/10
87.76.183.0/24
87.81.112.0/20
87.86.24.0/23
87.86.248.0/22
87.232.114.0/24
87.237.16.0/21
89.39.172.0/23
89.117.183.0/24
89.117.198.0/24
89.117.203.0/24
89.117.235.0/24
89.145.172.0/23
91.90.125.0/24
91.90.127.0/24
91.102.189.0/24
91.102.190.0/23
91.111.0.0/16
91.142.128.0/24
91.227.78.0/24
91.230.16.0/24
91.230.40.0/24
91.236.216.0/23
94.26.64.0/23
94.72.248.0/21
94.125.16.0/22
94.192.96.0/20
94.193.112.0/20
94.194.188.0/22
94.194.200.0/21
94.194.240.0/22
94.232.100.0/22
95.144.0.0/13
95.173.59.0/24
109.144.0.0/12
109.180.0.0/15
109.205.158.0/24
109.249.0.0/16
132.146.0.0/16
132.153.3.0/24
132.153.244.0/22
132.153.248.0/22
132.153.252.0/23
132.153.254.0/24
132.244.79.0/24
138.108.94.0/24
142.205.162.0/23
143.223.132.0/24
144.87.0.0/19
144.87.128.0/17
144.177.74.0/23
145.79.172.0/22
147.78.68.0/22
147.90.32.0/24
147.90.36.0/24
147.90.55.0/24
147.90.115.0/24
147.90.127.0/24
147.148.0.0/14
147.152.0.0/16
147.189.68.0/22
147.189.76.0/22
148.252.3.0/24
148.252.7.0/24
148.253.220.0/23
149.117.130.0/24
149.254.0.0/23
149.254.2.0/23
149.254.4.0/22
149.254.8.0/21
149.254.16.0/20
149.254.32.0/19
149.254.64.0/18
149.254.128.0/17
151.240.180.0/22
151.240.184.0/21
151.240.192.0/21
151.240.200.0/22
151.241.52.0/22
151.241.56.0/21
151.241.180.0/22
151.241.184.0/21
151.241.192.0/21
151.241.200.0/22
151.242.24.0/24
151.242.42.0/24
151.243.254.0/24
151.244.80.0/22
151.244.204.0/22
151.244.208.0/22
151.245.80.0/22
151.245.204.0/22
151.245.208.0/22
151.246.145.0/24
151.246.239.0/24
151.247.220.0/24
151.247.231.0/24
151.247.245.0/24
152.114.196.0/24
152.114.220.0/22
156.146.3.0/24
157.236.254.0/23
159.180.96.0/19
159.197.13.0/24
159.197.44.0/23
159.253.66.0/23
161.104.0.0/21
163.5.37.0/24
163.5.67.0/24
163.5.98.0/24
163.5.115.0/24
163.5.122.0/24
163.5.208.0/24
163.5.217.0/24
163.5.222.0/24
163.5.249.0/24
164.38.2.0/24
164.38.12.0/24
164.38.16.0/22
164.38.31.0/24
164.38.32.0/23
164.38.34.0/24
164.38.120.0/22
164.38.134.0/24
164.38.148.0/23
164.38.156.0/24
164.38.184.0/22
164.38.196.0/23
164.134.1.0/24
164.134.134.0/23
164.134.136.0/23
164.134.138.0/24
165.120.0.0/16
166.88.17.0/24
166.88.18.0/24
166.88.32.0/24
166.88.200.0/24
167.148.60.0/22
178.78.106.0/23
178.78.108.0/22
178.78.112.0/20
178.92.112.0/22
178.92.180.0/22
178.93.104.0/22
178.94.244.0/22
178.95.60.0/22
178.212.56.0/23
185.58.165.0/24
185.68.200.0/22
185.90.32.0/22
185.128.205.0/24
185.149.6.0/24
185.177.64.0/23
185.230.13.0/24
185.230.15.0/24
188.172.160.0/20
188.220.122.0/24
188.220.151.0/24
188.220.157.0/24
188.220.167.0/24
188.220.194.0/24
188.220.212.0/24
188.220.229.0/24
188.221.168.0/24
188.221.177.0/24
188.221.184.0/24
188.221.188.0/24
188.221.210.0/24
192.8.112.0/24
192.8.149.0/24
192.12.73.0/24
192.53.46.0/24
192.65.219.0/24
192.65.221.0/24
192.65.222.0/23
192.65.224.0/22
192.65.228.0/24
192.152.14.0/24
192.177.94.0/23
193.9.26.0/24
193.23.32.0/24
193.32.46.0/24
193.32.48.0/24
193.33.199.0/24
193.35.128.0/20
193.35.158.0/23
193.35.160.0/23
193.35.197.0/24
193.35.220.0/22
193.36.78.0/23
193.36.80.0/24
193.36.81.0/24
193.36.82.0/23
193.36.240.0/24
193.36.243.0/24
193.36.253.0/24
193.37.142.0/24
193.37.160.0/20
193.38.192.0/22
193.38.196.0/22
193.38.201.0/24
193.38.202.0/23
193.38.204.0/22
193.38.208.0/20
193.39.141.0/24
193.84.142.0/24
193.111.18.0/23
193.113.0.0/16
193.138.107.0/24
193.187.140.0/22
193.195.138.0/24
194.32.20.0/22
194.32.29.0/24
194.32.31.0/24
194.32.207.0/24
194.35.183.0/24
194.36.68.0/24
194.36.135.0/24
194.59.188.0/24
194.60.136.0/22
194.72.0.0/15
194.74.0.0/18
194.74.64.0/20
194.74.88.0/21
194.74.96.0/19
194.74.128.0/17
194.75.32.0/19
194.75.64.0/20
194.75.96.0/19
194.75.128.0/18
194.75.192.0/20
194.75.208.0/21
194.75.216.0/22
194.75.224.0/19
194.101.69.0/24
194.102.0.0/19
194.132.24.0/23
194.155.58.0/24
194.169.32.0/21
194.189.44.0/24
194.189.186.0/23
194.227.72.0/23
194.227.120.0/24
195.35.123.0/24
195.36.106.0/24
195.88.20.0/24
195.99.0.0/21
195.99.16.0/20
195.99.80.0/21
195.99.96.0/19
195.99.128.0/18
195.99.192.0/19
195.99.240.0/20
195.104.240.0/24
195.130.3.0/24
195.130.6.0/24
195.130.11.0/24
195.130.12.0/22
195.171.0.0/19
195.171.32.0/22
195.171.40.0/21
195.171.48.0/20
195.171.64.0/18
195.171.128.0/17
195.182.62.0/24
195.218.32.0/19
198.178.235.0/24
198.232.43.0/24
205.239.40.0/23
205.239.42.0/24
207.180.43.0/24
209.101.8.0/23
212.82.0.0/19
212.134.46.0/24
212.134.52.0/24
212.134.54.0/24
212.134.124.0/22
212.134.164.0/22
212.134.208.0/22
212.134.224.0/22
212.140.56.0/21
212.140.64.0/18
212.140.128.0/17
212.148.1.0/24
212.212.16.0/22
213.1.0.0/16
213.120.0.0/14
213.169.196.0/23
213.169.202.0/23
213.190.16.0/24
213.190.18.0/24
213.205.192.0/19
213.205.224.0/19
213.209.146.0/24
213.209.149.0/24
213.209.150.0/24
213.249.188.0/22

IPv6 prefixes

All 5 prefixes.

2001:4878:c259::/48
2a00:2380::/25
2a01:4c8::/29
2a02:ee80:4176::/47
2a03:1e82:90ff::/48

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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