dot4u.cz - robtex.com

dot4u.cz

DNSSEC🔒 Signed (DS record present)
A185.58.40.20🇨🇿 MASTER-AS185.58.40.0/22 CZ-MASTER-20140519
PTRxiphos.dot4u.cz
NSns2.web4u.cz ⭐
A2a02:a40:100:28ff::12🇨🇿 BlueTone-AS2a02:a40::/32 Ceske Radiokomunikace, a.s.
PTRns2.web4u.cz
A85.207.53.12🇨🇿 BlueTone-AS85.207.0.0/16 BlueTone-CRa-CZ Fourth address block
PTRns2.web4u.cz
NSns.web4u.cz
A2001:1568:fd::241🇨🇿 WEB4U2001:1568::/33
PTRns.web4u.cz
A185.14.224.241🇨🇿 WEB4U185.14.224.0/23
PTRns.web4u.cz
MX6146904674b37b9a.mx2.emailprofi.seznam.cz ⭐
A2a02:598:2::1146🇨🇿 SEZNAM-CZ2a02:598:2::/48
PTRwildcard.mx2.emailprofi.seznam.cz
A77.75.77.146🇨🇿 SEZNAM-CZ77.75.76.0/23 SEZNAM - III
PTRwildcard.mx2.emailprofi.seznam.cz
MX6146904674b37b9a.mx1.emailprofi.seznam.cz(20)
A2a02:598:2::1056🇨🇿 SEZNAM-CZ2a02:598:2::/48
PTRwildcard.mx1.emailprofi.seznam.cz
A77.75.77.56🇨🇿 SEZNAM-CZ77.75.76.0/23 SEZNAM - III
PTRwildcard.mx1.emailprofi.seznam.cz
TXTv=spf1 a:mail.dot4u.cz include:_spf.google.com include:spf.seznam.cz ~all
SOAns.web4u.czadmin@web4u.cz 2026-04-22 #0

cz

DNSSEC🔒 Signed (DS record present)
NSa.ns.nic.cz ⭐
NSb.ns.nic.cz
NSc.ns.nic.cz
NSd.ns.nic.cz
SOAa.ns.nic.czhostmaster@nic.cz serial=1780876036

Subdomains

xiphos.dot4u.cz
www.dot4u.cz
mysql.dot4u.cz
webadmin.dot4u.cz

Same first word

dot4u.org
dot4u.be
dot4u.cz
dot4u.com
dot4u.net

Similar names

4tudo.com

DNS History

6 records (5 active, 1 former)

20162017201820192020202120222023202420252026NSns.web4u.czns2.web4u.czMX6146904674b37b9a.mx1.emailprofi.seznam.cz6146904674b37b9a.mx2.emailprofi.seznam.czxiphos.dot4u.czA185.58.40.20
●NSns.web4u.cz2015-08-29 → 2026-06-08 · 2 obs
● 2015-08-29 00:34:28
● 2026-06-08 00:19:00
●NSns2.web4u.cz2015-08-29 → 2026-06-08 · 2 obs
● 2015-08-29 00:34:28
● 2026-06-08 00:19:00
●MX6146904674b37b9a.mx1.emailprofi.seznam.cz2026-04-08 → 2026-06-08 · 3 obs
○ 2026-04-05 11:44:58
● 2026-04-08 19:31:04
● 2026-06-08 00:19:00
●MX6146904674b37b9a.mx2.emailprofi.seznam.cz2026-04-08 → 2026-06-08 · 3 obs
○ 2026-04-05 11:44:58
● 2026-04-08 19:31:04
● 2026-06-08 00:19:00
○MXxiphos.dot4u.cz2015-08-29 → 2026-04-05 · 4 obs
● 2015-08-29 00:34:28
● 2026-04-05 11:44:58
○ 2026-04-08 19:31:04
○ 2026-06-08 00:19:00
●A185.58.40.202015-08-29 → 2026-06-08 · 2 obs
● 2015-08-29 00:34:28
● 2026-06-08 00:19:00

🔍 DNS Trace

📋 Delegation Chain

ZoneNameserversGlue
cza.ns.nic.cz, b.ns.nic.cz, c.ns.nic.cz, d.ns.nic.cz-
dot4u.czns.web4u.cz, ns2.web4u.cz4 records

✅ Authoritative Response

Server:85.207.53.12

NS records: ns.web4u.cz, ns2.web4u.cz

🔒 DNSSEC Status

🔐 Secure (DNSSEC validated)

Chain of trust verified from root to domain

⏱️ Timing

Total: 947ms | Queries: -

📄 Records

TypeCountSample Data
A1185.58.40.20
NS2ns.web4u.cz, ns2.web4u.cz
MX26146904674b37b9a.mx2.emailprofi.seznam.c, 6146904674b37b9a.mx1.emailprofi.seznam.c
TXT1v=spf1 a:mail.dot4u.cz include:_spf.goog
SOA1ns.web4u.cz admin.web4u.cz

📌 Glue Records Collected

Total: 4

Out-of-bailiwick: 4 (ns2.web4u.cz, ns.web4u.cz, ns2.web4u.cz...)

Analysis

Hierarchy

dot4u.cz has four subdomains: xiphos.dot4u.cz, www.dot4u.cz, mysql.dot4u.cz and webadmin.dot4u.cz.

IP Addresses

dot4u.cz points to a single IP number: 185.58.40.20.

Additional host names — ingdrak.cz, falton.cz, ekochem-ppu.cz and two others — share IP numbers with dot4u.cz.

Name Servers

Two name servers handle the delegation for dot4u.cz: ns2.web4u.cz and ns.web4u.cz.

dot4u.cz shares its name server setup with other domains, including dodamevamvejce.cz, ispis.com, mwardmanufacturing.com and two others.

dot4u.cz is at least partially co-delegated on name servers with other domains, such as gasstorage.cz.

ns2.web4u.cz and ns.web4u.cz both carry two IP addresses. The A records for ns2.web4u.cz are 85.207.53.12 and 2a02:a40:100:28ff::12; the A records for ns.web4u.cz are 185.14.224.241 and 2001:1568:fd::241.

Mail Servers

dot4u.cz has two mail servers: 6146904674b37b9a.mx1.emailprofi.seznam.cz and 6146904674b37b9a.mx2.emailprofi.seznam.cz.

6146904674b37b9a.mx1.emailprofi.seznam.cz and 6146904674b37b9a.mx2.emailprofi.seznam.cz both carry two IP addresses. The A records for 6146904674b37b9a.mx1.emailprofi.seznam.cz are 77.75.77.56 and 2a02:598:2::1056; the A records for 6146904674b37b9a.mx2.emailprofi.seznam.cz are 77.75.77.146 and 2a02:598:2::1146.