All IP Ranges
81.0.0.0/8
AS2856 | 81.128.0.0/12

81.128.0.0/12

AS2856 · British Telecommunications PLC

Need more data or want to access it via API or data downloads? Sign up to get free access

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
81.204.0.0/14	AS1136	KPN B.V.	262,144
81.212.0.0/14	AS9121	Turk Telekomunikasyon Anonim Sirketi	262,144
81.68.0.0/14	AS45090	Tencent Cloud Computing (Beijing) Co., Ltd	262,144
81.64.0.0/14	AS15557	Societe Francaise Du Radiotelephone - SFR SA	262,144
81.76.0.0/14	AS5378	Vodafone Limited	262,144
81.62.0.0/15	AS3303	Swisscom (Schweiz) AG	131,072
81.82.0.0/15	AS6848	Telenet BV	131,072
81.178.0.0/15	AS9105	TalkTalk Communications Limited	131,072
81.60.0.0/15	AS12430	VODAFONE ONO, S.A.	131,072
81.56.0.0/15	AS29447	Free SAS	131,072
81.166.0.0/15	AS29695	Lyse Tele AS	131,072
81.164.0.0/15	AS6848	Telenet BV	131,072
81.182.0.0/15	AS5483	Magyar Telekom Plc.	131,072
81.193.0.0/16	AS3243	MEO - SERVICOS DE COMUNICACOES E MULTIMEDIA S.A.	65,536
81.194.0.0/16	AS2200	Renater	65,536
81.218.0.0/16	AS8551	Bezeq International Ltd.	65,536
81.189.0.0/16	AS8437	Network of Hutchison Drei Austria GmbH	65,536
81.192.0.0/16	AS6713	Office National des Postes et Telecommunications ONPT (Maroc Telecom) / IAM	65,536
81.185.0.0/16	AS15557	Societe Francaise Du Radiotelephone - SFR SA	65,536
81.195.0.0/16	AS8359	MTS PJSC	65,536
81.87.0.0/16	AS786	Jisc Services Limited	65,536
81.44.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.197.0.0/16	AS719	Elisa Oyj	65,536
81.38.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.57.0.0/16	AS29447	Iliad / Free SAS	65,536
81.86.0.0/16	AS9105	TalkTalk Communications Limited	65,536
81.198.0.0/16	AS24921	SIA Tet	65,536
81.184.0.0/16	AS6739	VODAFONE ONO, S.A.	65,536
81.187.0.0/16	AS20712	Andrews & Arnold Ltd	65,536
81.187.0.0/16	AS41489	Andrews & Arnold Ltd	65,536
81.35.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.188.0.0/16	AS3257	GTT Communications Belgium N.V.	65,536
81.190.0.0/16	AS21021	Multimedia Polska Sp. z o.o.	65,536
81.191.0.0/16	AS2116	GLOBALCONNECT AS	65,536
81.34.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.36.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.220.0.0/16	AS15557	Societe Francaise Du Radiotelephone - SFR SA	65,536
81.219.0.0/16	AS12741	Netia SA	65,536
81.33.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.221.0.0/16	AS1836	green.ch AG	65,536
81.202.0.0/16	AS6739	Cableuropa - ONO	65,536
81.198.0.0/16	AS12578	SIA Tet	65,536
81.216.0.0/16	AS1257	Tele2 Sverige AB	65,536
81.32.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.39.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.40.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.56.0.0/16	AS29447	Iliad / Free SAS	65,536

Hosted domains

There are 3,687 domain names hosted across 1,654 IP addresses on this ASN. Checkout our API to access full domain hosting information.

IP Address	Domain	Domains on this IP
81.134.40.54	coachesconnect.org.uk	107
81.142.113.81	kevinfrostracing.co.uk	85
81.128.239.117	worldgrappaawards.com	67
81.133.245.70	micro-quiz.co.uk	52
81.128.180.98	firstimage.net	42
81.133.252.110	iaq-filtration.com	41
81.130.171.229	hartwell.tech	30
81.128.216.75	kesgravewills.co.uk	25
81.142.49.6	njmaden.com	21
81.128.140.142	depannage-portable-apple.fr	17
81.128.167.213	hypertecindustrial.co.uk	17
81.130.165.202	faulknersfootwear.co.uk	16
81.128.245.172	renrutconsultancy.co.uk	16
81.137.54.177	tufftechint.com	16
81.128.195.220	onebusinessinsurance.co.uk	16
81.130.179.42	ever-rosedesignco.co.uk	15
81.134.37.149	beardchops.com	14
81.130.234.236	reservation-highway.com	14
81.128.203.38	pet-television.co.uk	11
81.143.60.249	officialwebsitelist.co.uk	11

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

386,176 IPs in this range replied to an ICMP ping during our most recent internet scan. Learn more.

IP Address	ASN	Details
81.133.37.76	AS2856 British Telecommunications PLC	`2.84ms` from London, GB
81.133.10.223	AS2856 British Telecommunications PLC	`2.34ms` from London, GB
81.132.222.124	AS2856 British Telecommunications PLC	`9.66ms` from London, GB
81.132.193.36	AS2856 British Telecommunications PLC	`1.95ms` from London, GB
81.132.72.161	AS2856 British Telecommunications PLC	`3.99ms` from London, GB
81.132.176.147	AS2856 British Telecommunications PLC	`2.60ms` from London, GB
81.132.172.48	AS2856 British Telecommunications PLC	`6.06ms` from London, GB
81.133.1.104	AS2856 British Telecommunications PLC	`2.00ms` from London, GB
81.133.21.230	AS2856 British Telecommunications PLC	`3.07ms` from London, GB
81.132.250.100	AS2856 British Telecommunications PLC	`3.28ms` from London, GB
81.132.148.13	AS2856 British Telecommunications PLC	`8.17ms` from London, GB
81.132.66.219	AS2856 British Telecommunications PLC	`5.77ms` from London, GB
81.132.187.65	AS2856 British Telecommunications PLC	`2.19ms` from London, GB
81.132.163.91	AS2856 British Telecommunications PLC	`1.96ms` from London, GB
81.132.96.53	AS2856 British Telecommunications PLC	`2.97ms` from London, GB
81.132.88.234	AS2856 British Telecommunications PLC	`1.85ms` from London, GB
81.132.198.225	AS2856 British Telecommunications PLC	`9.20ms` from London, GB
81.133.2.230	AS2856 British Telecommunications PLC	`2.24ms` from London, GB
81.132.122.226	AS2856 British Telecommunications PLC	`6.84ms` from London, GB
81.132.69.3	AS2856 British Telecommunications PLC	`4.94ms` from London, GB
81.132.74.225	AS2856 British Telecommunications PLC	`3.67ms` from London, GB
81.132.78.117	AS2856 British Telecommunications PLC	`2.95ms` from London, GB
81.132.178.106	AS2856 British Telecommunications PLC	`6.30ms` from London, GB
81.133.47.232	AS2856 British Telecommunications PLC	`1.64ms` from London, GB
81.133.48.99	AS2856 British Telecommunications PLC	`3.13ms` 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
51.12.72.236	AS8075 Microsoft Corporation	`0.26ms` from Gaevle, SE
206.161.216.28	AS135357 HONG KONG KOWLOON TELECOMMUNICATIONS CO.,LIMITED	`1.04ms` from Hong Kong, HK
113.237.139.92	AS4837 CHINA UNICOM China169 Backbone	`11.78ms` from Liaoyang, CN
15.185.198.28	AS16509 Amazon.com, Inc.	`0.41ms` from Manama, BH
86.204.51.140	AS3215 Orange S.A.	`14.35ms` from Milan, IT
46.61.247.252	AS12389 PJSC Rostelecom	`0.75ms` from Moscow, RU
58.220.65.28	AS137697 CHINATELECOM JiangSu YangZhou IDC networkdescr: YangZhou , Jiangsu Province, P.R.China.	`7.63ms` from Nanjing, CN
76.117.222.156	AS7922 Comcast Cable Communications, LLC	`8.83ms` from New York City, US
90.1.188.12	AS3215 Orange S.A.	`16.40ms` from Paris, FR
116.41.230.204	AS17858 LG POWERCOMM	`6.24ms` from Seoul, KR
49.61.202.124	AS4766 Korea Telecom	`3.99ms` from Seoul, KR
222.121.239.124	AS4766 Korea Telecom	`6.46ms` from Seoul, KR
201.51.1.108	AS7738 V tal	`8.70ms` from São Paulo, BR
43.212.35.236	AS16509 Amazon.com, Inc.	`0.51ms` from Taipei, TW
159.117.70.140	AS18046 DongFong Technology Co. Ltd.	`9.22ms` from Taipei, TW
54.199.46.12	AS16509 Amazon.com, Inc.	`0.26ms` from Tokyo, JP
77.168.224.92	AS1136 KPN B.V.	`2.10ms` from Amsterdam, NL
36.78.45.12	AS7713 PT Telekomunikasi Indonesia	`6.38ms` from Jakarta, ID
185.221.96.124	AS212238 Datacamp Limited	`0.17ms` from London, GB
75.222.89.140	AS6167 Verizon Business	`14.88ms` from Los Angeles, US
23.124.41.188	AS7018 AT&T Enterprises, LLC	`4.06ms` from Miami, US
115.219.198.204	AS4134 CHINANET-BACKBONE	`8.55ms` from Ningbo, CN
44.231.26.140	AS16509 Amazon.com, Inc.	`4.46ms` from Portland, US
134.197.138.252	AS3851 Nevada System of Higher Education	`11.44ms` from San Jose, US
69.123.94.220	AS6128 Cablevision Systems Corp.	`7.12ms` from Secaucus, US

Traceroute

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

traceroute -a -n -q1 -f3 -m10 81.128.24.113

traceroute to 81.128.24.113 (81.128.24.113): 10 hops max, 52 byte packets

3 [AS9009] 193.27.15.198 0.669 ms

4 [] 146.70.1.222 10.302 ms

5 [] 89.44.212.116 8.906 ms

6 [] 37.120.220.119 8.525 ms

7 [AS2856] 109.159.253.90 10.054 ms

8 *

9 *

10 *

Measurement taken from

IPinfo ProbeNet in Brussels, BE

On September 11th 2025

What are IP address ranges?

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.

An API built with users in mind: reliable, accurate, and easy-to-use

Discover why industry-leading companies around the globe love our data. IPinfo's accurate insights fuel use cases from cybersecurity, data enrichment, web personalization, and much more.

Get Started for Free Contact Sales