81.91.80.0/21

AS39790 · Web4U s.r.o.

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

Summary

Country	Czechia
Domain	web4u.cz
ASN	AS39790
Parent Range	81.91.80.0/20
Registry	RIPE
ID	CZ-WEB4USRO-20060425

WHOIS Details

inetnum:        81.91.80.0 - 81.91.95.255
netname:        CZ-WEB4USRO-20060425
country:        CZ
org:            ORG-WS296-RIPE
admin-c:        WM3536-RIPE
tech-c:         WM3536-RIPE
status:         ALLOCATED PA
mnt-by:         MNT-WEB4U
mnt-by:         RIPE-NCC-HM-MNT
created:        2022-09-28T14:32:39Z
last-modified:  2022-09-28T14:32:39Z
source:         RIPE
abuse-email:    abuse@web4u.cz
abuse-c:        AR68991-RIPE
abuse-org:      ORG-WS296-RIPE

organisation:   ORG-WS296-RIPE
org-name:       Web4U s.r.o.
country:        CZ
org-type:       LIR
address:        Mahlerovy sady 1
address:        13000
address:        Praha 3
address:        CZECH REPUBLIC
phone:          +420270001456
e-mail:         ripe@web4u.cz
admin-c:        WM3536-RIPE
tech-c:         WM3536-RIPE
abuse-c:        AR68991-RIPE
mnt-ref:        MNT-WEB4U
mnt-by:         RIPE-NCC-HM-MNT
mnt-by:         MNT-WEB4U
created:        2022-09-20T07:29:12Z
last-modified:  2022-09-20T07:29:13Z
source:         RIPE
abuse-email:    abuse@web4u.cz
abuse-c:        AR68991-RIPE
abuse-org:      undefined

role:           WEB4U network operations
address:        CZECH REPUBLIC
address:        Praha 3
address:        13000
address:        Mahlerovy sady 1
phone:          +420270001456
e-mail:         praha@web4u.cz
admin-c:        FP15631-RIPE
tech-c:         FP15631-RIPE
abuse-mailbox:  abuse@web4u.cz
nic-hdl:        WM3536-RIPE
mnt-by:         MNT-WEB4U
created:        2022-09-20T07:29:12Z
last-modified:  2022-10-17T12:21:14Z
source:         RIPE

route:          81.91.80.0/21
origin:         AS39790
mnt-by:         MNT-WEB4U
created:        2024-05-16T12:05:41Z
last-modified:  2024-05-16T12:05:41Z
source:         RIPE

Overlapping Ranges

BGP prefixes that contain 81.91.80.0/21

Range	ASN	Company	Num of IPs
81.91.80.0/20	AS39790	Web4U s.r.o.	4,096

Nearby Ranges

BGP prefixes that overlap with 81.91.0.0/16

Range	ASN	Company	Num of IPs
81.91.32.0/19	AS8359	MTS PJSC	8,192
81.91.0.0/20	AS197308	Telia Cygate AB	4,096
81.91.112.0/20	AS12180	ALKIM BASIN YAYIN ILETISIM LTD. STI.	4,096
81.91.144.0/20	AS206065	Tose'h Fanavari Ertebabat Pasargad Arian Co. PJS	4,096
81.91.224.0/20	AS28683	SOCIETE BENINOISE D'INFRASTRUCTURES NUMERIQUES	4,096
81.91.192.0/20	AS29009	UK Broadband Ltd.	4,096
81.91.112.0/20	AS29060	ALKIM BASIN YAYIN ILETISIM LTD. STI.	4,096
81.91.80.0/20	AS39790	Web4U s.r.o.	4,096
81.91.208.0/20	AS39817	OvaNet, a.s.	4,096
81.91.160.0/20	AS8763	DENIC eG	4,096
81.91.96.0/21	AS60981	Associated Networks (UK) Limited	2,048
81.91.24.0/21	AS30873	Public Telecommunication Corporation	2,048
81.91.152.0/21	AS206065	Tose'h Fanavari Ertebabat Pasargad Arian Co. PJS	2,048
81.91.104.0/21	AS13101	Amtswerke Eggebek Verwaltungs GmbH trading as Amtswerke Eggebek GmbH & Co.KG.	2,048
81.91.16.0/21	AS199163	DATAGROUP Operations GmbH	2,048
81.91.248.0/22	AS29668	vXtream Ltd	1,024
81.91.242.0/24	AS29668	vXtream Ltd	256
81.91.244.0/24	AS29668	vXtream LTD	256
81.91.252.0/24	AS29668	vXtream - Switzerland /24 - # 2	256
81.91.253.0/24	AS29668	vXtream - Switzerland /24 - # 1	256
81.91.41.0/24	AS8359	MTS Ural branch, fixed Broadband access	256
81.91.189.0/24	AS44705	Obyedinennye Nakhabinskie seti LLC	256
81.91.180.0/24	AS48503	Tele2 Kazakhstan	256
81.91.181.0/24	AS48503	Tele2 Kazakhstan	256
81.91.182.0/24	AS48503	Tele2 Kazakhstan	256
81.91.183.0/24	AS48503	Tele2 Kazakhstan	256
81.91.184.0/24	AS48503	Tele2 Kazakhstan	256
81.91.185.0/24	AS48503	Tele2 Kazakhstan	256
81.91.190.0/24	AS202090	Aktivnie Tehnologii LLC	256
81.91.191.0/24	AS202090	Aktivnie Tehnologii LLC	256
81.91.186.0/24	AS48503	Tele2 Kazakhstan	256
81.91.187.0/24	AS48503	Tele2 Kazakhstan	256
81.91.225.0/24	AS28683	SOCIETE BENINOISE D'INFRASTRUCTURES NUMERIQUES	256
81.91.224.0/24	AS28683	SOCIETE BENINOISE D'INFRASTRUCTURES NUMERIQUES	256
81.91.228.0/24	AS28683	SOCIETE BENINOISE D'INFRASTRUCTURES NUMERIQUES	256
81.91.234.0/24	AS28683	SOCIETE BENINOISE D'INFRASTRUCTURES NUMERIQUES	256
81.91.235.0/24	AS28683	SOCIETE BENINOISE D'INFRASTRUCTURES NUMERIQUES	256
81.91.236.0/24	AS28683	SOCIETE BENINOISE D'INFRASTRUCTURES NUMERIQUES	256
81.91.188.0/24	AS48503	Tele2 Kazakhstan	256

Hosted domains

There are 44,238 domain names hosted across 275 IP addresses on this ASN. Checkout our API to access full domain hosting information.

IP Address	Domain	Domains on this IP
81.91.86.14	pregis.cz	27110
81.91.86.12	institutvk.cz	5312
81.91.86.13	tvarog.cz	3224
81.91.86.11	praguechess.cz	2625
81.91.86.10	isis.cz	675
81.91.84.215	netzsch.cz	471
81.91.84.107	penziondvorak.cz	366
81.91.84.51	skiresort.cz	346
81.91.82.42	hotel-signal.cz	268
81.91.84.138	levna-izolace.eu	223
81.91.82.209	odborne-konference.cz	182
81.91.84.210	brzdim.cz	181
81.91.85.211	izolacerovnan.cz	173
81.91.84.73	kostymy-praha.cz	141
81.91.84.131	info-bratislava.sk	135
81.91.85.97	csop5.cz	123
81.91.85.141	razitka-colop.eu	122
81.91.85.90	trailpoint.cz	113
81.91.84.168	stoll-lader.de	113
81.91.83.112	hakcs.cz	111

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

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

IP Address	ASN	Details
81.91.84.51	AS39790 Web4U s.r.o.	`0.38ms` from Prague, CZ
81.91.80.33	AS39790 Web4U s.r.o.	`0.43ms` from Prague, CZ
81.91.87.90	AS39790 Web4U s.r.o.	`0.41ms` from Prague, CZ
81.91.82.19	AS39790 Web4U s.r.o.	`0.39ms` from Prague, CZ
81.91.85.11	AS39790 Web4U s.r.o.	`0.41ms` from Prague, CZ
81.91.81.12	AS39790 Web4U s.r.o.	`0.43ms` from Prague, CZ
81.91.86.23	AS39790 Web4U s.r.o.	`0.41ms` from Prague, CZ
81.91.83.168	AS39790 Web4U s.r.o.	`0.39ms` from Prague, CZ

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
76.151.56.85	AS7922 Comcast Cable Communications, LLC	`6.74ms` from Ashburn, US
172.178.125.213	AS8075 Microsoft Corporation	`0.67ms` from Ashburn, US
67.137.183.21	AS7385 Allstream Business US, LLC	`8.46ms` from Chicago, US
169.151.13.5	AS2386 AT&T Enterprises, LLC	`1.68ms` from Dallas, US
4.38.76.85	AS3356 Level 3 Parent, LLC	`0.40ms` from Dallas, US
73.95.140.245	AS7922 Comcast Cable Communications, LLC	`3.37ms` from Denver, US
93.92.228.5	AS202636 Invermae Solutions SL	`0.49ms` from Madrid, ES
82.18.107.21	AS5089 Virgin Media Limited	`7.60ms` from Maidenhead, GB
190.248.135.245	AS13489 UNE EPM TELECOMUNICACIONES S.A.	`6.43ms` from Medellin, CO
87.13.35.53	AS3269 Telecom Italia S.p.A.	`9.24ms` from Milan, IT
80.117.53.213	AS3269 Telecom Italia S.p.A.	`7.87ms` from Milan, IT
126.159.114.149	AS17676 SoftBank Corp.	`3.51ms` from Osaka, JP
190.140.127.181	AS18809 Cable Onda	`8.59ms` from Panama, PA
186.121.104.117	AS3816 COLOMBIA TELECOMUNICACIONES S.A. ESP BIC	`18.68ms` from Panama, PA
13.37.78.165	AS16509 Amazon.com, Inc.	`0.12ms` from Paris, FR
121.22.54.21	AS4837 CHINA UNICOM China169 Backbone	`13.33ms` from Qingdao, CN
179.106.157.101	AS52537 microplan informatica ltda.	`8.28ms` from Rio de Janeiro, BR
34.146.137.101	AS396982 Google LLC	`0.15ms` from Tokyo, JP
195.116.232.85	AS5617 Orange Polska Spolka Akcyjna	`5.00ms` from Warsaw, PL
209.40.231.53	AS20340 CallTower, Inc.	`0.46ms` from Atlanta, US
91.126.96.5	AS35699 Adamo Telecom Iberia S.A.	`2.20ms` from Barcelona, ES
107.12.118.21	AS11426 Charter Communications Inc	`8.57ms` from Charlotte, US
43.102.132.21	AS24429 Zhejiang Taobao Network Co.,Ltd	`0.52ms` from Hong Kong, HK
70.123.245.5	AS11427 Charter Communications Inc	`7.82ms` from Houston, US
176.122.13.37	AS49588 SDS-Vostok Ltd.	`10.04ms` from Kharkiv, UA

Traceroute

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

traceroute -a -n -q1 -f4 81.91.83.228

traceroute to 81.91.83.228 (81.91.83.228): 64 hops max, 52 byte packets

4 [] 91.210.16.49 0.613 ms

5 *

6 [] 185.138.110.51 2.863 ms

7 [AS39790] 81.91.95.26 22.479 ms

8 [AS39790] 81.91.95.22 3.215 ms

9 [AS39790] 81.91.83.228 0.924 ms

Measurement taken from

IPinfo ProbeNet in Prague, CZ

On January 18th 2026

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