All IP Ranges
81.0.0.0/8
AS2856 | 81.128.0.0/11

81.128.0.0/11

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
Registry	RIPE
ID	UK-BT-20020725

WHOIS Details

inetnum:        81.128.0.0 - 81.159.255.255
org:            ORG-BPIS1-RIPE
netname:        UK-BT-20020725
country:        GB
admin-c:        FLS15-RIPE
tech-c:         FLS15-RIPE
status:         ALLOCATED PA
mnt-by:         RIPE-NCC-HM-MNT
mnt-by:         BTNET-INFRA-MNT
mnt-routes:     BTNET-INFRA-MNT
created:        2002-09-10T14:35:54Z
last-modified:  2024-03-11T16:17:01Z
source:         RIPE
abuse-email:    abuse@bt.com
abuse-c:        AR13878-RIPE
abuse-org:      ORG-BPIS1-RIPE

organisation:   ORG-BPIS1-RIPE
org-name:       British Telecommunications PLC
country:        GB
org-type:       LIR
address:        PP1, Floor1, Orion, Adastral Park, Martlesham Heath
address:        IP5 3RE
address:        Ipswich
address:        UNITED KINGDOM
phone:          +44 (0)20 7356 5000
abuse-c:        AR13878-RIPE
mnt-ref:        BTNET-MNT
mnt-ref:        BTNET-INFRA-MNT
mnt-ref:        RIPE-NCC-HM-MNT
mnt-by:         RIPE-NCC-HM-MNT
mnt-by:         BTNET-INFRA-MNT
admin-c:        FLS15-RIPE
admin-c:        MS35380-RIPE
admin-c:        GF1231-RIPE
created:        2004-04-17T12:11:50Z
last-modified:  2025-03-24T17:20:04Z
source:         RIPE
e-mail:         ipaddman@bt.com
abuse-email:    abuse@bt.com
abuse-c:        AR13878-RIPE
abuse-org:      undefined

role:           BT IP Address Admin
address:        PP 1, Floor 1
address:        Orion Building
address:        Adastral Park
address:        Martlesham Heath
address:        Ipswich
address:        IP5 3RE
address:        UK
e-mail:         ipaddman@bt.com
e-mail:         abuse@bt.com
remarks:        
remarks:        
nic-hdl:        FLS15-RIPE
mnt-by:         BTNET-INFRA-MNT
created:        2002-08-29T06:26:48Z
last-modified:  2023-06-21T11:23:36Z
source:         RIPE

route:          81.128.0.0/11
descr:          BT Public Internet Service
origin:         AS2856
mnt-by:         BTNET-INFRA-MNT
notify:         ip.address.admin@bt.com
created:        2002-10-22T13:45:17Z
last-modified:  2014-07-31T07:51:30Z
source:         RIPE

Overlapping Ranges

BGP prefixes that are contained by 81.128.0.0/11

Range	ASN	Company	Num of IPs
81.128.0.0/12	AS2856	BT Infrastructure Layer	1,048,576

Nearby Ranges

BGP prefixes that overlap with 81.0.0.0/8

Range	ASN	Company	Num of IPs
81.128.0.0/12	AS2856	BT Infrastructure Layer	1,048,576
81.96.0.0/12	AS5089	Virgin Media Limited	1,048,576
81.76.0.0/14	AS5378	Vodafone Limited	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
81.204.0.0/14	AS1136	KPN B.V.	262,144
81.64.0.0/14	AS15557	Societe Francaise Du Radiotelephone - SFR SA	262,144
81.182.0.0/15	AS5483	Magyar Telekom Plc.	131,072
81.62.0.0/15	AS3303	Swisscom (Schweiz) AG	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
81.178.0.0/15	AS13285	TalkTalk Communications Limited	131,072
81.82.0.0/15	AS6848	Telenet BV	131,072
81.164.0.0/15	AS6848	Telenet BV	131,072
81.221.0.0/16	AS1836	green.ch AG	65,536
81.184.0.0/16	AS6739	VODAFONE ONO, S.A.	65,536
81.61.0.0/16	AS6739	ONO_HFC	65,536
81.187.0.0/16	AS20712	Andrews & Arnold Ltd	65,536
81.196.0.0/16	AS8708	DIGI ROMANIA S.A.	65,536
81.223.0.0/16	AS8412	T-Mobile Austria GmbH	65,536
81.218.0.0/16	AS8551	Bezeq International Ltd.	65,536
81.202.0.0/16	AS6739	Cableuropa - ONO	65,536
81.198.0.0/16	AS24921	SIA Tet	65,536
81.87.0.0/16	AS786	Jisc Services Limited	65,536
81.189.0.0/16	AS8437	Network of Hutchison Drei Austria GmbH	65,536
81.198.0.0/16	AS12578	SIA Tet	65,536
81.44.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.39.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.190.0.0/16	AS21021	Multimedia Polska Sp. z o.o.	65,536
81.57.0.0/16	AS29447	Iliad / Free SAS	65,536
81.38.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.193.0.0/16	AS3243	MEO - SERVICOS DE COMUNICACOES E MULTIMEDIA S.A.	65,536
81.191.0.0/16	AS2116	GLOBALCONNECT AS	65,536
81.195.0.0/16	AS8359	MTS PJSC	65,536
81.185.0.0/16	AS15557	Societe Francaise Du Radiotelephone - SFR SA	65,536
81.33.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.32.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.34.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.56.0.0/16	AS29447	Iliad / Free SAS	65,536
81.37.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.36.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.219.0.0/16	AS12741	Netia SA	65,536
81.40.0.0/16	AS3352	Telefonica de Espana SAU	65,536
81.81.0.0/16	AS1267	WIND TRE S.P.A.	65,536
81.220.0.0/16	AS15557	Societe Francaise Du Radiotelephone - SFR SA	65,536
81.187.0.0/16	AS41489	Andrews & Arnold Ltd	65,536
81.192.0.0/16	AS6713	Office National des Postes et Telecommunications ONPT (Maroc Telecom) / IAM	65,536
81.86.0.0/16	AS13285	TalkTalk Communications Limited	65,536

Hosted domains

There are 8,281 domain names hosted across 3,044 IP addresses on this ASN. Checkout our API to access full domain hosting information.

IP Address	Domain	Domains on this IP
81.145.31.210	gdgreenock.co.uk	881
81.145.16.13	ipadserver.co.uk	260
81.145.31.217	gdfetchingham.co.uk	251
81.145.31.222	marketrasen-gdm.co.uk	159
81.134.40.54	bancroftleisure.co.uk	109
81.144.251.155	campingandcaravanningclub.co.uk	99
81.144.162.21	lubricantsales.co.uk	78
81.145.16.53	mustardpotvets.com	67
81.144.218.84	airconditioningrepairsliverpool.uk	60
81.128.160.145	vowsweddingvideos.co.uk	58
81.133.245.70	lockandsonsroofing.co.uk	50
81.145.58.165	screencontracts.co.uk	42
81.128.180.98	propertyprofile.co.uk	42
81.144.179.205	gardeningdiary.co.uk	41
81.133.252.110	fred-force.com	41
81.145.167.201	go-tcha-evolve.co.uk	36
81.144.224.25	brandontoolhire.eu	35
81.150.25.196	clearsoftwaresolutions.co.uk	29
81.150.7.16	bellait.support	29
81.139.48.154	legalindemnitynews.co.uk	25

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

980,761 IPs in this range replied to an ICMP ping during our most recent internet scan. Learn more.

IP Address	ASN	Details
81.135.97.91	AS2856 British Telecommunications PLC	`2.01ms` from London, GB
81.135.170.50	AS2856 British Telecommunications PLC	`4.49ms` from London, GB
81.135.37.130	AS2856 British Telecommunications PLC	`12.12ms` from London, GB
81.135.66.48	AS2856 British Telecommunications PLC	`1.58ms` from London, GB
81.135.14.102	AS2856 British Telecommunications PLC	`2.79ms` from London, GB
81.135.165.146	AS2856 British Telecommunications PLC	`6.11ms` from London, GB
81.136.5.117	AS2856 British Telecommunications PLC	`6.50ms` from London, GB
81.135.252.30	AS2856 British Telecommunications PLC	`3.44ms` from London, GB
81.135.245.22	AS2856 British Telecommunications PLC	`5.17ms` from London, GB
81.136.4.11	AS2856 British Telecommunications PLC	`5.16ms` from London, GB
81.135.191.232	AS2856 British Telecommunications PLC	`5.58ms` from London, GB
81.135.9.173	AS2856 British Telecommunications PLC	`6.77ms` from London, GB
81.135.68.199	AS2856 British Telecommunications PLC	`5.57ms` from London, GB
81.135.247.244	AS2856 British Telecommunications PLC	`1.80ms` from London, GB
81.135.134.49	AS2856 British Telecommunications PLC	`4.53ms` from London, GB
81.135.129.169	AS2856 British Telecommunications PLC	`4.82ms` from London, GB
81.135.128.115	AS2856 British Telecommunications PLC	`1.75ms` from London, GB
81.135.102.72	AS2856 British Telecommunications PLC	`11.92ms` from London, GB
81.135.203.200	AS2856 British Telecommunications PLC	`6.45ms` from London, GB
81.135.113.120	AS2856 British Telecommunications PLC	`5.26ms` from London, GB
81.135.182.152	AS2856 British Telecommunications PLC	`5.54ms` from London, GB
81.135.52.181	AS2856 British Telecommunications PLC	`1.23ms` from London, GB
81.135.44.23	AS2856 British Telecommunications PLC	`3.79ms` from London, GB
81.135.226.166	AS2856 British Telecommunications PLC	`3.01ms` from London, GB
81.135.251.79	AS2856 British Telecommunications PLC	`3.04ms` 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
3.18.241.123	AS16509 Amazon.com, Inc.	`0.18ms` from Columbus, US
93.240.52.75	AS3320 Deutsche Telekom AG	`2.51ms` from Hamburg, DE
136.32.174.43	AS16591 Google Fiber Inc.	`0.87ms` from Kansas City, US
119.110.99.107	AS18206 TM TECHNOLOGY SERVICES SDN. BHD.	`2.46ms` from Kuala Lumpur, MY
98.152.17.123	AS20001 Charter Communications Inc	`2.20ms` from Los Angeles, US
131.239.213.187	AS46887 Crown Castle Fiber LLC	`0.28ms` from Miami, US
45.201.217.107	AS54801 Zillion Network Inc.	`0.58ms` from San Jose, US
182.222.120.91	AS17858 LG POWERCOMM	`1.88ms` from Seoul, KR
60.68.53.139	AS17676 SoftBank Corp.	`2.75ms` from Tokyo, JP
39.98.113.235	AS37963 Hangzhou Alibaba Advertising Co.,Ltd.	`0.65ms` from Zhangjiakou, CN
122.176.228.59	AS24560 Bharti Airtel Ltd., Telemedia Services	`2.87ms` from Ahmedabad, IN
89.210.32.139	AS3329 VODAFONE-PANAFON HELLENIC TELECOMMUNICATIONS COMPANY SA	`1.52ms` from Athens, GR
108.241.76.155	AS7018 AT&T Enterprises, LLC	`17.23ms` from Chicago, US
112.111.40.187	AS4837 CHINA UNICOM China169 Backbone	`7.02ms` from Fuzhou, CN
62.236.75.27	AS16086 DNA Oyj	`0.77ms` from Helsinki, FI
175.41.13.11	AS54994 Meteverse Limited.	`0.71ms` from Hong Kong, HK
194.190.83.123	AS50776 Joint Stock Company System Telecom	`3.25ms` from Kemerovo, RU
76.170.13.251	AS20001 Charter Communications Inc	`5.50ms` from Los Angeles, US
112.81.181.171	AS4837 CHINA UNICOM China169 Backbone	`6.85ms` from Nanjing, CN
171.37.251.91	AS4837 CHINA UNICOM China169 Backbone	`7.10ms` from Nanning, CN
45.253.225.187	AS45062 Netease-Network	`3.32ms` from Ningbo, CN
83.114.12.11	AS3215 Orange S.A.	`2.49ms` from Paris, FR
97.74.13.171	AS26496 GoDaddy.com, LLC	`0.94ms` from Phoenix, US
20.163.64.43	AS8075 Microsoft Corporation	`0.17ms` from Phoenix, US
83.11.169.27	AS5617 Orange Polska Spolka Akcyjna	`4.57ms` from Poznan, PL

Traceroute

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

traceroute -a -n -q1 -f5 -m9 81.128.48.108

traceroute to 81.128.48.108 (81.128.48.108): 9 hops max, 52 byte packets

5 [] 37.120.220.117 10.114 ms

6 [AS2856] 109.159.253.90 9.825 ms

7 *

8 *

9 *

Measurement taken from

IPinfo ProbeNet in Brussels, BE

On October 30th 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