Autonomous System

AS3300 British Telecommunications PLC

ISPActiveUnited KingdomRIPE

AS3300 (BT) is an ISP network operated by British Telecommunications PLC in United Kingdom, registered with RIPE. It has 123 IPv4 prefixes with 604,416 addresses and 29 IPv6 prefixes, which makes it the 604th largest of 82,200 active autonomous systems by IPv4 space.

IPv4 addresses604,416in 123 prefixes
IPv6 prefixes29≈ 2.4 × 10²⁹ addresses
Size rank#604of 82,200 active ASNs
Abuser scoreVery Lowunder 0.01% of its addresses flagged · method

Details

OrganizationBritish Telecommunications PLC
AS nameBT
Websitebt.com
Country United Kingdom (GB)
Network typeISP
RegistryRIPE
Abuse contactabuse@eu.bt.net
Registered2002-09-19
Last updated2026-05-05

IPv4 prefixes

123 prefixes · 604,416 addresses
NetworkAddressesFirst – last address
205.248.0.0/1665,536205.248.0.0 – 205.248.255.255
206.182.0.0/1665,536206.182.0.0 – 206.182.255.255
207.117.0.0/1665,536207.117.0.0 – 207.117.255.255
207.209.0.0/1665,536207.209.0.0 – 207.209.255.255
209.28.0.0/1665,536209.28.0.0 – 209.28.255.255
204.231.0.0/1732,768204.231.0.0 – 204.231.127.255
61.14.0.0/1816,38461.14.0.0 – 61.14.63.255
63.250.128.0/1816,38463.250.128.0 – 63.250.191.255
192.237.64.0/1816,384192.237.64.0 – 192.237.127.255
198.207.64.0/1816,384198.207.64.0 – 198.207.127.255
199.6.64.0/1816,384199.6.64.0 – 199.6.127.255
204.140.64.0/1816,384204.140.64.0 – 204.140.127.255
204.231.128.0/1816,384204.231.128.0 – 204.231.191.255
206.182.128.0/1816,384206.182.128.0 – 206.182.191.255
206.182.192.0/1816,384206.182.192.0 – 206.182.255.255
192.92.32.0/198,192192.92.32.0 – 192.92.63.255
203.187.128.0/198,192203.187.128.0 – 203.187.159.255
207.209.0.0/198,192207.209.0.0 – 207.209.31.255
207.209.64.0/198,192207.209.64.0 – 207.209.95.255
72.29.128.0/204,09672.29.128.0 – 72.29.143.255
192.157.144.0/204,096192.157.144.0 – 192.157.159.255
192.92.24.0/212,048192.92.24.0 – 192.92.31.255
192.157.136.0/212,048192.157.136.0 – 192.157.143.255
61.14.4.0/221,02461.14.4.0 – 61.14.7.255
61.14.8.0/221,02461.14.8.0 – 61.14.11.255
The 25 largest of 123. The API and the database have all of them.

IPv6 prefixes

29 prefixes
  • 2402:fb00::/32
  • 2606:f100::/32
  • 2402:fb00::/36
  • 2402:fb00:1000::/36
  • 2402:fb00:2000::/36
  • 2402:fb00:3000::/36
  • 2606:f100::/36
  • 2606:f100:1000::/36
  • 2606:f100:2000::/36
  • 2606:f100:3000::/36
  • 2606:f100:4000::/36
  • 2606:f100:5000::/36
  • 2606:f100:6000::/36
  • 2606:f100:7000::/36
  • 2606:f100:8000::/36
  • 2606:f100:9000::/36
  • 2606:f100:c000::/36
  • 2402:fb00:f00::/40
  • 2402:fb00:1f00::/40
  • 2402:fb00:2f00::/40
  • 2402:fb00:3f00::/40
  • 2606:f100:f00::/40
  • 2606:f100:1f00::/40
  • 2606:f100:2f00::/40
  • 2606:f100:3f00::/40
The 25 largest of 29. The API and the database have all of them.

Query AS3300 with the API

The ASN lookup returns everything on this page as JSON, including every prefix. ASN lookups need an API key: a free account comes with 1,000 requests a day. 

curl "https://api.ipapi.is/?q=AS3300&key=YOUR_API_KEY"

Any address in its prefixes resolves to AS3300, with or without a key:

curl "https://api.ipapi.is/?q=205.248.0.1"

Other networks of British Telecommunications PLC

AS6871 British Telecommunications PLC2,130,944 IPv4 addressesAS5400 British Telecommunications PLC734,720 IPv4 addressesAS13205 British Telecommunications PLC20,224 IPv4 addresses

Largest networks in United Kingdom

AS285618,458,368 IPv4 addressesAS5089 Virgin Media Limited17,977,856 IPv4 addressesAS786 Jisc Services Limited6,972,160 IPv4 addressesAS5607 Sky UK Limited6,352,128 IPv4 addressesAS13285 TalkTalk Communications Limited3,956,736 IPv4 addressesAS5378 Vodafone Limited2,793,216 IPv4 addresses