81.91.88.0/21

AS39790 · Web4U s.r.o.

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Summary

Country	Czechia
Domain	web4u.cz
ASN	AS39790
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

Hosted domains

There are 2,811 domain names hosted across 209 IP addresses on this ASN. Checkout our API to access full domain hosting information.

IP Address	Domain	Domains on this IP
81.91.92.221	mini-jeraby.cz	344
81.91.92.70	boatoutlet.eu	169
81.91.91.14	anavy.cz	108
81.91.91.54	altx.cz	90
81.91.91.22	tpvz.cz	84
81.91.91.138	eshoplanda.cz	66
81.91.92.215	pramat.cz	60
81.91.92.157	ablakok-most.hu	58
81.91.92.148	davidsport.sk	51
81.91.92.83	hayo.cz	39
81.91.93.19	e-chiptuning.cz	39
81.91.91.38	tonerpartner.ro	32
81.91.92.243	maturitni-plachta.cz	31
81.91.91.53	caterpillar-tools.cz	31
81.91.92.169	gummastic.cz	30
81.91.91.112	klecany.net	27
81.91.92.172	mudr-habova.cz	26
81.91.92.39	caraplasma.cz	24
81.91.92.236	osmistovky.cz	23
81.91.92.216	bagrtoms.cz	22

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

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

IP Address	ASN	Details
81.91.89.43	AS39790 Web4U s.r.o.	`0.70ms` from Prague, CZ
81.91.93.29	AS39790 Web4U s.r.o.	`0.54ms` from Prague, CZ
81.91.95.116	AS39790 Web4U s.r.o.	`0.51ms` from Prague, CZ
81.91.91.49	AS39790 Web4U s.r.o.	`0.37ms` from Prague, CZ
81.91.92.221	AS39790 Web4U s.r.o.	`0.41ms` 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
62.251.15.53	AS1136 KPN B.V.	`3.42ms` from Amsterdam, NL
73.216.149.133	AS7922 Comcast Cable Communications, LLC	`13.87ms` from Ashburn, US
207.5.75.229	AS53828 NETWORK INNOVATIONS, LLC	`0.62ms` from Atlanta, US
80.64.36.21	AS20815 GRN Network	`2.12ms` from Barcelona, ES
98.241.76.21	AS7922 Comcast Cable Communications, LLC	`1.22ms` from Boston, US
175.154.99.133	AS4837 CHINA UNICOM China169 Backbone	`10.02ms` from Chengdu, CN
194.47.159.21	AS8748 Blekinge Tekniska Hogskola	`6.34ms` from Copenhagen, DK
103.94.67.37	AS134013 Mass Computer	`1.71ms` from Delhi, IN
3.124.49.165	AS16509 Amazon.com, Inc.	`0.14ms` from Frankfurt am Main, DE
134.175.215.37	AS45090 Shenzhen Tencent Computer Systems Company Limited	`2.12ms` from Guangzhou, CN
98.200.25.53	AS7922 Comcast Cable Communications, LLC	`7.12ms` from Houston, US
81.214.6.85	AS9121 Turk Telekomunikasyon Anonim Sirketi	`10.10ms` from Istanbul, TR
68.175.83.85	AS12271 Charter Communications Inc	`4.07ms` from New York City, US
187.1.179.69	AS21574 Century Telecom Ltda	`7.43ms` from Osasco, BR
88.92.220.181	AS2119 Telenor Norge AS	`17.18ms` from Oslo, NO
27.196.3.165	AS4837 CHINA UNICOM China169 Backbone	`8.42ms` from Qingdao, CN
23.58.210.5	AS35994 Akamai Technologies, Inc.	`0.98ms` from San Jose, US
179.52.5.5	AS6400 Compañía Dominicana de Teléfonos S. A.	`2.27ms` from Santo Domingo, DO
71.183.255.117	AS701 Verizon Business	`2.68ms` from Secaucus, US
220.121.208.197	AS4766 Korea Telecom	`2.00ms` from Seoul, KR
119.31.236.85	AS38719 Dreamscape Networks Limited	`0.90ms` from Singapore, SG
61.62.185.53	AS18182 Sony Network Taiwan Limited	`2.14ms` from Taipei, TW
118.75.133.85	AS4837 CHINA UNICOM China169 Backbone	`7.67ms` from Taiyuan, CN
153.180.157.101	AS4713 NTT Communications Corporation	`2.50ms` from Tokyo, JP
67.71.16.197	AS577 Bell Canada	`8.06ms` from Toronto, CA

Traceroute

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

traceroute -a -n -q1 -f2 -m9 81.91.90.205

traceroute to 81.91.90.205 (81.91.90.205): 9 hops max, 52 byte packets

2 [AS30059] 70.36.35.1 1.343 ms

3 *

4 *

5 *

6 [AS3356] 212.133.51.18 121.633 ms

7 *

8 *

9 *

Measurement taken from

IPinfo ProbeNet in Cincinnati, US

On August 22nd 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.

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