AS2856

AS2856 is BT’s network.

Short answer

AS2856 belongs to British Telecommunications PLC. DB-IP Lite attributes 13,860,608 IPv4 addresses in 422 ranges and 5 IPv6 ranges to it, all or nearly all of the IPv4 space in United Kingdom. The number is registered with RIPE NCC in United Kingdom on 22 Dec 1993.

Facts for AS2856
Operator (DB-IP)British Telecommunications PLC
KindHome broadband (curated)
IPv4 addresses13,860,608
IPv4 ranges422
IPv6 ranges5
RegistryRIPE NCC
Registered22 Dec 1993
Registry countryUnited Kingdom (GB)

Does it publish a geofeed?

Not for the range we sampled (31.112.0.0 – 31.124.255.255): its registry record, and the record above it, link no RFC 8805 geofeed (checked 2 Nov 2026). Without one, location databases have to estimate where these addresses are used, which is a common reason customers of BT see the wrong city. Customers can ask BT to publish one; the evidence report drafts that request.

Shared addresses (CGNAT)

BT hasn’t been documented as using carrier-grade NAT in a source we could check. To see whether your own connection is behind it, compare your router’s address on the CGNAT check.

IPv6

DB-IP lists 5 IPv6 ranges for AS2856, so customers can get IPv6 addresses, which databases place separately from IPv4.

Where its IPv4 space is used, according to DB-IP

GB100%
US0.05%
DE0.02%
IM0.02%
NL0.01%
ES0.01%
RO0.00%
BE0.00%

Share of the network’s IPv4 addresses by DB-IP Country Lite. IP Geolocation by DB-IP.

IP ranges

RangeAs CIDRAddresses
5.35.192.0 – 5.35.199.2555.35.192.0/212,048
5.80.0.0 – 5.81.255.2555.80.0.0/15131,072
5.181.136.0 – 5.181.136.2555.181.136.0/24256
9.151.0.0 – 9.151.31.2559.151.0.0/198,192
9.151.208.0 – 9.151.223.2559.151.208.0/204,096
9.151.248.0 – 9.151.255.2559.151.248.0/212,048
9.232.192.0 – 9.232.255.2559.232.192.0/1816,384
9.233.48.0 – 9.233.63.2559.233.48.0/204,096
9.237.96.0 – 9.237.223.2559.237.96.0/19, 9.237.128.0/18 …32,768
15.145.20.0 – 15.145.23.25515.145.20.0/221,024
23.26.70.0 – 23.26.70.25523.26.70.0/24256
23.26.108.0 – 23.26.108.25523.26.108.0/24256
23.26.117.0 – 23.26.117.25523.26.117.0/24256
23.26.131.0 – 23.26.131.25523.26.131.0/24256
23.26.192.0 – 23.26.192.25523.26.192.0/24256
23.27.32.0 – 23.27.40.25523.27.32.0/21, 23.27.40.0/242,304
23.27.102.0 – 23.27.108.25523.27.102.0/23, 23.27.104.0/22 …1,792
23.230.82.0 – 23.230.83.25523.230.82.0/23512
23.230.242.0 – 23.230.242.25523.230.242.0/24256
23.230.252.0 – 23.230.252.25523.230.252.0/24256
31.48.0.0 – 31.55.255.25531.48.0.0/13524,288
31.90.0.0 – 31.94.255.25531.90.0.0/15, 31.92.0.0/15 …327,680
31.96.0.0 – 31.96.255.25531.96.0.0/1665,536
31.100.0.0 – 31.104.255.25531.100.0.0/14, 31.104.0.0/16327,680
31.106.0.0 – 31.107.255.25531.106.0.0/15131,072
31.112.0.0 – 31.124.255.25531.112.0.0/13, 31.120.0.0/14 …851,968
31.126.0.0 – 31.127.255.25531.126.0.0/15131,072
31.130.240.0 – 31.130.241.25531.130.240.0/23512
37.44.229.0 – 37.44.231.25537.44.229.0/24, 37.44.230.0/23768
37.97.112.0 – 37.97.115.25537.97.112.0/221,024
37.143.3.0 – 37.143.3.25537.143.3.0/24256
37.230.61.0 – 37.230.61.25537.230.61.0/24256
40.27.28.0 – 40.27.28.25540.27.28.0/24256
40.27.72.0 – 40.27.72.25540.27.72.0/24256
45.39.116.0 – 45.39.116.25545.39.116.0/24256
45.39.188.0 – 45.39.188.25545.39.188.0/24256
45.149.7.0 – 45.149.7.25545.149.7.0/24256
45.149.168.0 – 45.149.171.25545.149.168.0/221,024
46.68.0.0 – 46.69.255.25546.68.0.0/15131,072
46.248.96.0 – 46.248.99.25546.248.96.0/221,024
46.248.102.0 – 46.248.105.25546.248.102.0/23, 46.248.104.0/231,024
46.248.120.0 – 46.248.123.25546.248.120.0/221,024
50.117.7.0 – 50.117.7.25550.117.7.0/24256
50.117.51.0 – 50.117.51.25550.117.51.0/24256
50.118.154.0 – 50.118.155.25550.118.154.0/23512
51.14.0.0 – 51.14.255.25551.14.0.0/1665,536
51.64.32.0 – 51.64.33.25551.64.32.0/23512
51.146.44.0 – 51.146.47.25551.146.44.0/221,024
51.146.128.0 – 51.146.131.25551.146.128.0/221,024
51.146.136.0 – 51.146.139.25551.146.136.0/221,024
2001:4878:c259:: – 2001:4878:c259:ffff:ffff:ffff:ffff:ffff2001:4878:c259::/48IPv6
2a00:2380:: – 2a00:23ff:ffff:ffff:ffff:ffff:ffff:ffff2a00:2380::/25IPv6
2a01:4c8:: – 2a01:4cf:ffff:ffff:ffff:ffff:ffff:ffff2a01:4c8::/29IPv6
2a02:ee80:4176:: – 2a02:ee80:4177:ffff:ffff:ffff:ffff:ffff2a02:ee80:4176::/47IPv6
2a03:1e82:90ff:: – 2a03:1e82:90ff:ffff:ffff:ffff:ffff:ffff2a03:1e82:90ff::/48IPv6
Showing 50 of 422 IPv4 and 5 of 5 IPv6 ranges All ranges (CSV)

IP Geolocation by DB-IP, ASN Lite, CC BY 4.0.

Using an address from this network? See which sources agree on where it is.

Sources

  1. DB-IP IP to ASN Lite (CC BY 4.0) · checked 3 Nov 2026
  2. NRO RIR delegated-extended statistics · checked 5 Nov 2026