1. All IP Ranges
  2. 81.0.0.0/8
  3. AS2856  | 81.128.0.0/12

81.128.0.0/12

AS2856  ·  British Telecommunications PLC

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Summary

Country United Kingdom
Domain bt.com
ASN AS2856
Parent Range 81.128.0.0/11
Registry RIPE
ID BT-INFRA

WHOIS Details

inetnum:        81.128.0.0 - 81.143.255.255
netname:        BT-INFRA
descr:          BT Infrastructure Layer
country:        GB
admin-c:        BS1474-RIPE
tech-c:         BS1474-RIPE
status:         LIR-PARTITIONED PA
mnt-by:         BTNET-INFRA-MNT
mnt-lower:      BTNET-MNT
mnt-routes:     BTNET-MNT
created:        2014-08-01T07:43:40Z
last-modified:  2014-08-01T07:43:40Z
source:         RIPE
abuse-email:    abuse@bt.com
abuse-c:        AR13878-RIPE
abuse-org:      ORG-BPIS1-RIPE

role:           BTnet Support
address:        Adhara
address:        Adastral Park
address:        Martlesham Heath
address:        Ipswich
address:        SUFFLK IP5 3RE
address:        GB
phone:          +44 800 0858963 5
phone:          +44 1473 336231
e-mail:         as2856peering@bt.com
e-mail:         btnetdns@bt.com
admin-c:        FLS15-RIPE
tech-c:         FLS15-RIPE
nic-hdl:        BS1474-RIPE
remarks:        For all queries contact as2856peering@bt.com
remarks:        Please send delisting issues to btnetdns@bt.com
mnt-by:         BTNET-MNT
created:        2002-04-30T07:54:10Z
last-modified:  2025-07-18T13:07:21Z
source:         RIPE

route:          81.128.0.0/12
descr:          BT Public Internet Service
origin:         AS2856
mnt-by:         BTNET-INFRA-MNT
notify:         ip.address.admin@bt.com
created:        2005-06-16T14:11:53Z
last-modified:  2014-07-31T07:47:16Z
source:         RIPE

Overlapping Ranges

BGP prefixes that contain 81.128.0.0/12

Range ASN Company Num of IPs
81.128.0.0/11 AS2856 British Telecommunications PLC 2,097,152

Nearby Ranges

BGP prefixes that overlap with 81.0.0.0/8

Range ASN Company Num of IPs
81.128.0.0/11 AS2856 British Telecommunications PLC 2,097,152
81.96.0.0/12 AS5089 Virgin Media Limited 1,048,576
81.76.0.0/14 AS5378 Vodafone Limited 262,144
81.68.0.0/14 AS45090 Tencent Cloud Computing (Beijing) Co., Ltd 262,144
81.204.0.0/14 AS1136 KPN B.V. 262,144
81.64.0.0/14 AS15557 Societe Francaise Du Radiotelephone - SFR SA 262,144
81.212.0.0/14 AS9121 Turk Telekomunikasyon Anonim Sirketi 262,144
81.182.0.0/15 AS5483 Magyar Telekom Plc. 131,072
81.82.0.0/15 AS6848 Telenet BV 131,072
81.164.0.0/15 AS6848 Telenet BV 131,072
81.62.0.0/15 AS3303 Swisscom (Schweiz) AG 131,072
81.178.0.0/15 AS13285 TalkTalk Communications Limited 131,072
81.166.0.0/15 AS29695 Lyse Tele AS 131,072
81.60.0.0/15 AS12430 VODAFONE ONO, S.A. 131,072
81.56.0.0/15 AS29447 Free SAS 131,072
81.220.0.0/16 AS15557 Societe Francaise Du Radiotelephone - SFR SA 65,536
81.39.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.38.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.36.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.40.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.219.0.0/16 AS12741 Netia SA 65,536
81.198.0.0/16 AS12578 SIA Tet 65,536
81.198.0.0/16 AS24921 SIA Tet 65,536
81.32.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.223.0.0/16 AS8412 T-Mobile Austria GmbH 65,536
81.84.0.0/16 AS2860 NOS COMUNICACOES, S.A. 65,536
81.37.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.192.0.0/16 AS6713 Office National des Postes et Telecommunications ONPT (Maroc Telecom) / IAM 65,536
81.35.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.185.0.0/16 AS15557 Societe Francaise Du Radiotelephone - SFR SA 65,536
81.197.0.0/16 AS719 Elisa Oyj 65,536
81.218.0.0/16 AS8551 Bezeq International Ltd. 65,536
81.187.0.0/16 AS41489 Andrews & Arnold Ltd 65,536
81.56.0.0/16 AS29447 Iliad / Free SAS 65,536
81.44.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.86.0.0/16 AS13285 TalkTalk Communications Limited 65,536
81.190.0.0/16 AS21021 Multimedia Polska Sp. z o.o. 65,536
81.216.0.0/16 AS1257 Tele2 Sverige AB 65,536
81.34.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.81.0.0/16 AS1267 WIND TRE S.P.A. 65,536
81.57.0.0/16 AS29447 Iliad / Free SAS 65,536
81.196.0.0/16 AS8708 DIGI ROMANIA S.A. 65,536
81.33.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.194.0.0/16 AS2200 Renater 65,536
81.221.0.0/16 AS1836 green.ch AG 65,536
81.80.0.0/16 AS3215 Orange S.A. 65,536
81.193.0.0/16 AS3243 MEO - SERVICOS DE COMUNICACOES E MULTIMEDIA S.A. 65,536
81.184.0.0/16 AS6739 VODAFONE ONO, S.A. 65,536
81.189.0.0/16 AS8437 Network of Hutchison Drei Austria GmbH 65,536

Hosted domains

There are 3,709 domain names hosted across 1,655 IP addresses on this ASN. Checkout our API to access full domain hosting information.

IP Address Domain Domains on this IP
81.142.113.81 kendallgroup.net 88
81.128.239.117 worldcognacawards.com 62
81.136.181.36 sapws.net 59
81.130.171.229 closepromote.com 30
81.133.74.88 cornerstone.systems 29
81.128.250.13 actonaccessscaffolding.co.uk 26
81.128.216.75 enableflow.co.uk 25
81.133.105.103 pick-up.soccer 22
81.142.49.6 njmaden.com 21
81.143.221.131 kemr.co.uk 20
81.128.160.188 priceengines.co.uk 19
81.128.245.172 hollandsmacniven.co.uk 16
81.128.195.220 obis-uk.co.uk 16
81.128.173.172 prestigefireandsecurity.co 16
81.130.165.202 shoempire.co.uk 16
81.130.179.42 pro-plastics.co.uk 15
81.134.37.149 cloudfibre.net 14
81.128.245.171 turnerlittle.es 14
81.139.49.72 visitscotland.com 14
81.130.234.236 stonewillys.co.uk 13

Hosted domains API

Our Hosted Domains API, or Reverse IP API returns a full list of domains that are hosted on a single IP address.
Useful for Cybersecurity
Read more

Pingable IPs

388,795 IPs in this range replied to an ICMP ping during our most recent internet scan. Learn more.

IP Address ASN Details
81.130.153.17 AS2856 British Telecommunications PLC 2.80ms from London, GB
81.130.173.53 AS2856 British Telecommunications PLC 1.87ms from London, GB
81.129.225.90 AS2856 British Telecommunications PLC 5.61ms from London, GB
81.130.74.108 AS2856 British Telecommunications PLC 3.97ms from London, GB
81.130.165.209 AS2856 British Telecommunications PLC 4.46ms from London, GB
81.130.99.52 AS2856 British Telecommunications PLC 1.72ms from London, GB
81.130.76.252 AS2856 British Telecommunications PLC 3.29ms from London, GB
81.130.69.230 AS2856 British Telecommunications PLC 4.97ms from London, GB
81.129.243.250 AS2856 British Telecommunications PLC 5.80ms from London, GB
81.130.240.19 AS2856 British Telecommunications PLC 23.62ms from London, GB
81.130.228.68 AS2856 British Telecommunications PLC 2.89ms from London, GB
81.130.116.207 AS2856 British Telecommunications PLC 8.34ms from London, GB
81.130.128.111 AS2856 British Telecommunications PLC 2.44ms from London, GB
81.129.237.155 AS2856 British Telecommunications PLC 5.63ms from London, GB
81.130.193.135 AS2856 British Telecommunications PLC 2.44ms from London, GB
81.130.154.251 AS2856 British Telecommunications PLC 2.46ms from London, GB
81.130.111.251 AS2856 British Telecommunications PLC 0.66ms from London, GB
81.129.236.49 AS2856 British Telecommunications PLC 7.87ms from London, GB
81.130.106.17 AS2856 British Telecommunications PLC 10.36ms from London, GB
81.129.240.48 AS2856 British Telecommunications PLC 4.63ms from London, GB
81.130.211.249 AS2856 British Telecommunications PLC 2.94ms from London, GB
81.129.233.100 AS2856 British Telecommunications PLC 5.94ms from London, GB
81.129.200.58 AS2856 British Telecommunications PLC 7.09ms from London, GB
81.129.249.175 AS2856 British Telecommunications PLC 4.78ms from London, GB
81.130.75.57 AS2856 British Telecommunications PLC 8.84ms from London, GB

Other Pingable IPs

Below is a random selection of 25 IPs that replied to an ICMP ping during our most recent internet scan.

IP Address ASN Details
77.168.146.60 AS1136 KPN B.V. 2.54ms from Amsterdam, NL
71.203.105.92 AS7922 Comcast Cable Communications, LLC 9.53ms from Atlanta, US
139.9.118.60 AS55990 Huawei Cloud Service data center 3.71ms from Beijing, CN
69.145.126.236 AS33588 Charter Communications LLC 8.43ms from Denver, US
93.229.172.252 AS3320 Deutsche Telekom AG 5.14ms from Frankfurt am Main, DE
217.81.229.204 AS3320 Deutsche Telekom AG 9.43ms from Frankfurt am Main, DE
195.135.189.252 AS8469 CANCOM Managed Services GmbH 8.35ms from Frankfurt am Main, DE
116.104.1.60 AS7552 Viettel Group 4.90ms from Hanoi, VN
66.25.33.12 AS11427 Charter Communications Inc 7.47ms from Houston, US
85.106.245.220 AS47331 TTNet A.S. 6.80ms from Istanbul, TR
121.242.1.12 AS4755 TATA Communications formerly VSNL is Leading ISP 0.87ms from Lohogaon, IN
199.48.122.172 AS7194 City of Burbank 0.62ms from Los Angeles, US
130.186.98.252 AS3275 CINECA CONSORZIO INTERUNIVERSITARIO 4.56ms from Milan, IT
188.14.113.76 AS3269 Telecom Italia S.p.A. 5.68ms from Naples, IT
189.15.180.172 AS53006 ALGAR TELECOM S/A 8.12ms from Osasco, BR
112.225.153.156 AS4837 CHINA UNICOM China169 Backbone 1.49ms from Qingdao, CN
151.241.153.156 AS984 OCTOPUS WEB SOLUTION INC 0.14ms from San Jose, US
81.191.200.44 AS2116 GLOBALCONNECT AS 1.88ms from Sandefjord, NO
183.107.79.12 AS4766 Korea Telecom 5.74ms from Seoul, KR
124.222.36.124 AS45090 Shenzhen Tencent Computer Systems Company Limited 0.73ms from Shanghai, CN
123.200.188.220 AS9723 iseek Communications Pty Ltd 0.42ms from Sydney, AU
183.86.103.124 AS10010 TOKAI Communications Corporation 6.63ms from Tokyo, JP
219.105.45.12 AS10013 FreeBit Co.,Ltd. 12.28ms from Tokyo, JP
145.108.73.220 AS1103 SURF B.V. 3.60ms from Amsterdam, NL
13.93.95.140 AS8075 Microsoft Corporation 0.27ms from Amsterdam, NL

Traceroute

Below is a recent traceroute taken from the IPinfo ProbeNet to an IP in this range. Learn more.

$
traceroute -a -n -q1 81.136.130.171
traceroute to 81.136.130.171 (81.136.130.171): 64 hops max, 52 byte packets
3 [AS2856] 62.6.201.160 10.247 ms
4 *
5 [AS2856] 217.32.26.89 9.569 ms
6 [AS2856] 81.136.130.171 20.728 ms
Measurement taken from IPinfo ProbeNet in Oudeschip, NL
On

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IP address ranges, or netblocks, are groups of related IP addresses. They are usually represented as a base IP address, followed by a slash, and then a netmask which represents how many IP addresses are contained within the netblock. This format is known as CIDR. You'll also sometimes see netblocks given as a start ip address, and an end ip address, or an ip address range.

Traffic works its way around the internet based on the routing table, which contains a list of networks and their associated netblocks.

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