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
81.212.0.0/14 AS47331 Turk Telekomunikasyon Anonim Sirketi 262,144
81.212.0.0/14 AS9121 Turk Telekomunikasyon Anonim Sirketi 262,144
81.64.0.0/14 AS15557 Societe Francaise Du Radiotelephone - SFR SA 262,144
81.204.0.0/14 AS1136 KPN B.V. 262,144
81.68.0.0/14 AS45090 Tencent Cloud Computing (Beijing) Co., Ltd 262,144
81.76.0.0/14 AS5378 Vodafone Limited 262,144
81.166.0.0/15 AS29695 Lyse Tele AS 131,072
81.60.0.0/15 AS12430 VODAFONE ONO, S.A. 131,072
81.82.0.0/15 AS6848 Telenet BV 131,072
81.56.0.0/15 AS29447 Free SAS 131,072
81.178.0.0/15 AS13285 TalkTalk Communications Limited 131,072
81.164.0.0/15 AS6848 Telenet BV 131,072
81.182.0.0/15 AS5483 Magyar Telekom Plc. 131,072
81.62.0.0/15 AS3303 Swisscom (Schweiz) AG 131,072
81.202.0.0/16 AS6739 Cableuropa - ONO 65,536
81.195.0.0/16 AS8359 MTS PJSC 65,536
81.190.0.0/16 AS21021 Multimedia Polska Sp. z o.o. 65,536
81.87.0.0/16 AS786 Jisc Services Limited 65,536
81.84.0.0/16 AS2860 NOS COMUNICACOES, S.A. 65,536
81.44.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.33.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.184.0.0/16 AS6739 VODAFONE ONO, S.A. 65,536
81.35.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.34.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.197.0.0/16 AS719 Elisa Oyj 65,536
81.187.0.0/16 AS20712 Andrews & Arnold Ltd 65,536
81.39.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.32.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.191.0.0/16 AS2116 GLOBALCONNECT AS 65,536
81.194.0.0/16 AS2200 Renater 65,536
81.38.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.40.0.0/16 AS3352 Telefonica de Espana SAU 65,536
81.61.0.0/16 AS6739 ONO_HFC 65,536
81.36.0.0/16 AS3352 Telefonica de Espana SAU 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
81.80.0.0/16 AS3215 Orange S.A. 65,536
81.223.0.0/16 AS8412 T-Mobile Austria GmbH 65,536
81.188.0.0/16 AS3257 GTT Communications Belgium N.V. 65,536
81.185.0.0/16 AS15557 Societe Francaise Du Radiotelephone - SFR SA 65,536
81.81.0.0/16 AS1267 WIND TRE S.P.A. 65,536
81.56.0.0/16 AS29447 Iliad / Free SAS 65,536
81.193.0.0/16 AS3243 MEO - SERVICOS DE COMUNICACOES E MULTIMEDIA S.A. 65,536
81.219.0.0/16 AS12741 Netia SA 65,536
81.220.0.0/16 AS15557 Societe Francaise Du Radiotelephone - SFR SA 65,536
81.198.0.0/16 AS12578 SIA Tet 65,536
81.216.0.0/16 AS1257 Tele2 Sverige AB 65,536

Hosted domains

There are 3,692 domain names hosted across 1,659 IP addresses on this ASN. Checkout our API to access full domain hosting information.

IP Address Domain Domains on this IP
81.136.181.36 amail.uk 59
81.133.245.70 tmdstoragesolutions.co.uk 49
81.128.180.98 businessjet.co.uk 42
81.128.250.13 advancedentist.com 26
81.143.201.172 epos-web.co.uk 23
81.143.221.131 zaingrundy.com 20
81.128.167.213 hypertecstorage.eu 17
81.128.140.142 reparation-carte-mere-fujitsu-siemens.fr 17
81.128.195.220 motorandhomedirect.com 16
81.137.54.177 boatchandleronline.com 16
81.130.165.202 united-footwear.co.uk 15
81.134.37.149 redboxproductionsltd.co.uk 14
81.128.245.171 turnerlittleblog.co.uk 14
81.143.29.9 binaryphysics.com 14
81.133.105.103 playpickup.soccer 14
81.128.180.82 lintonhousecoffee.co.uk 13
81.130.208.151 lupusmateria.com 13
81.132.61.74 leakingdignity.games 13
81.137.202.197 architecturechester.co.uk 12
81.128.203.38 clogau.biz 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

404,996 IPs in this range replied to an ICMP ping during our most recent internet scan. Learn more.

IP Address ASN Details
81.141.101.85 AS2856 British Telecommunications PLC 4.82ms from London, GB
81.141.106.51 AS2856 British Telecommunications PLC 2.02ms from London, GB
81.141.79.96 AS2856 British Telecommunications PLC 3.79ms from London, GB
81.141.225.117 AS2856 British Telecommunications PLC 3.44ms from London, GB
81.142.41.134 AS2856 British Telecommunications PLC 6.25ms from London, GB
81.141.244.25 AS2856 British Telecommunications PLC 6.93ms from London, GB
81.141.76.62 AS2856 British Telecommunications PLC 3.48ms from London, GB
81.141.110.216 AS2856 British Telecommunications PLC 2.05ms from London, GB
81.141.197.229 AS2856 British Telecommunications PLC 5.66ms from London, GB
81.142.53.149 AS2856 British Telecommunications PLC 6.79ms from London, GB
81.141.164.168 AS2856 British Telecommunications PLC 3.41ms from London, GB
81.141.165.143 AS2856 British Telecommunications PLC 5.24ms from London, GB
81.141.200.54 AS2856 British Telecommunications PLC 1.84ms from London, GB
81.141.75.53 AS2856 British Telecommunications PLC 3.19ms from London, GB
81.141.236.45 AS2856 British Telecommunications PLC 6.18ms from London, GB
81.141.127.222 AS2856 British Telecommunications PLC 1.85ms from London, GB
81.141.122.204 AS2856 British Telecommunications PLC 7.80ms from London, GB
81.141.124.50 AS2856 British Telecommunications PLC 5.38ms from London, GB
81.141.146.226 AS2856 British Telecommunications PLC 2.81ms from London, GB
81.142.93.222 AS2856 British Telecommunications PLC 5.86ms from London, GB
81.142.35.134 AS2856 British Telecommunications PLC 4.88ms from London, GB
81.141.208.172 AS2856 British Telecommunications PLC 1.66ms from London, GB
81.142.34.179 AS2856 British Telecommunications PLC 17.46ms from London, GB
81.142.71.26 AS2856 British Telecommunications PLC 6.67ms from London, GB
81.141.238.159 AS2856 British Telecommunications PLC 2.75ms 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
181.93.164.188 AS7303 Telecom Argentina S.A. 7.35ms from Asuncion, PY
34.209.81.12 AS16509 Amazon.com, Inc. 0.16ms from Boardman, US
181.24.55.76 AS22927 Telefonica de Argentina 12.80ms from Buenos Aires, AR
87.156.45.188 AS3320 Deutsche Telekom AG 5.00ms from Frankfurt am Main, DE
220.246.248.252 AS4760 HKT Limited 1.56ms from Hong Kong, HK
117.60.143.76 AS4134 CHINANET-BACKBONE 5.95ms from Huai'an, CN
86.13.41.76 AS5089 Virgin Media Limited 7.28ms from London, GB
217.31.61.12 AS29134 Webglobe, s.r.o. 0.19ms from Prague, CZ
201.252.186.12 AS7303 Telecom Argentina S.A. 16.41ms from Rosario, AR
46.147.224.44 AS42116 JSC "ER-Telecom Holding" 11.54ms from Samara, RU
20.253.149.44 AS8075 Microsoft Corporation 0.56ms from San Jose, US
118.36.48.44 AS4766 Korea Telecom 1.51ms from Seoul, KR
119.221.199.12 AS4766 Korea Telecom 6.09ms from Seoul, KR
115.1.225.140 AS4766 Korea Telecom 2.30ms from Seoul, KR
34.85.67.60 AS396982 Google LLC 0.16ms from Tokyo, JP
97.149.32.108 AS6167 Verizon Business 11.82ms from Chicago, US
174.98.175.204 AS10796 Charter Communications Inc 9.34ms from Columbus, US
92.216.52.156 AS3209 Vodafone GmbH 6.24ms from Frankfurt am Main, DE
188.37.123.188 AS12353 Vodafone Portugal 6.34ms from Lisbon, PT
188.37.6.140 AS12353 Vodafone Portugal 2.44ms from Lisbon, PT
82.44.69.156 AS5089 Virgin Media Limited 15.52ms from London, GB
172.167.185.92 AS8075 Microsoft Corporation 0.21ms from London, GB
217.18.224.252 AS29680 Gamma Operadora de Comunicaciones S.A. 3.98ms from Madrid, ES
49.188.73.76 AS4804 Microplex PTY LTD 6.96ms from Melbourne, AU
75.72.169.60 AS7922 Comcast Cable Communications, LLC 3.34ms from Minneapolis, US

Traceroute

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

$
traceroute -a -n -q1 -m5 81.139.116.203
traceroute to 81.139.116.203 (81.139.116.203): 5 hops max, 52 byte packets
2 [AS2856] 109.159.253.70 76.174 ms
3 *
4 *
5 *
Measurement taken from IPinfo ProbeNet in Ashburn, US
On

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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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