zero.cz - robtex.com
zero.cz
| DNSSEC | ⚠️ Not signed | ||||||
| A | 81.91.91.54🇨🇿 WEB4U81.91.88.0/21 | ||||||
| PTR | wm108.web-media.cz | ||||||
| NS | ns2.web4u.cz ⭐ | ||||||
| A | 2a02:a40:100:28ff::12🇨🇿 BlueTone-AS2a02:a40::/32 Ceske Radiokomunikace, a.s. | ||||||
| PTR | ns2.web4u.cz | ||||||
| A | 85.207.53.12🇨🇿 BlueTone-AS85.207.0.0/16 BlueTone-CRa-CZ Fourth address block | ||||||
| PTR | ns2.web4u.cz | ||||||
| NS | ns.web4u.cz | ||||||
| A | 2001:1568:fd::241🇨🇿 WEB4U2001:1568::/33 | ||||||
| PTR | ns.web4u.cz | ||||||
| A | 185.14.224.241🇨🇿 WEB4U185.14.224.0/23 | ||||||
| PTR | ns.web4u.cz | ||||||
| MX | mail.zero.cz ⭐ | ||||||
| A | 81.91.84.134🇨🇿 WEB4U81.91.80.0/21 | ||||||
| PTR | m105.server4u.cz | ||||||
| TXT | v=spf1 a mx ptr ip4:81.91.85.148 include:_emailing.heureka.cz ~all | ||||||
| SOA | ns.web4u.czadmin@web4u.cz 2008-09-30 #1 | ||||||
cz
| DNSSEC | 🔒 Signed (DS record present) | ||||||
| NS | a.ns.nic.cz ⭐ | ||||||
| NS | b.ns.nic.cz | ||||||
| NS | c.ns.nic.cz | ||||||
| NS | d.ns.nic.cz | ||||||
| SOA | a.ns.nic.czhostmaster@nic.cz serial=1783979240 | ||||||
Subdomains
mail.zero.cz |
Same first word
Similar names
DNS History
5 records (4 active, 1 former)
●MXmail.zero.cz2015-07-26 → 2026-07-13 · 2 obs
● 2026-07-13 23:07:00
○A81.91.84.1762015-07-26 → 2021-06-17 · 4 obs
● 2021-06-17 20:54:32
○ 2026-03-13 04:17:48
○ 2026-07-13 23:07:00
●A81.91.91.542026-03-13 → 2026-07-13 · 3 obs
● 2026-03-13 04:17:48
● 2026-07-13 23:07:00
🔍 DNS Trace
📋 Delegation Chain
| Zone | Nameservers | Glue |
|---|---|---|
| cz | a.ns.nic.cz, c.ns.nic.cz, b.ns.nic.cz, d.ns.nic.cz | - |
| zero.cz | ns2.web4u.cz, ns.web4u.cz | 4 records |
✅ Authoritative Response
Server:85.207.53.12
NS records: ns2.web4u.cz, ns.web4u.cz
🔒 DNSSEC Status
⚠️ Insecure (no DNSSEC)
No DS record for zero.cz (unsigned zone)
⏱️ Timing
Total: 1854ms | Queries: -
📄 Records
| Type | Count | Sample Data |
|---|---|---|
| A | 1 | 81.91.91.54 |
| NS | 2 | ns.web4u.cz, ns2.web4u.cz |
| MX | 1 | mail.zero.cz (pri: 10) |
| TXT | 1 | v=spf1 a mx ptr ip4:81.91.85.148 include |
| SOA | 1 | ns.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
mail.zero.cz is a subdomain of zero.cz.
IP Addresses
zero.cz directs to one IP number, which is 81.91.91.54.
Among the host names that share IP numbers with zero.cz are lamda.cz, wkk.cz, puttpd.cz and two others.
Name Servers
zero.cz has two authoritative name servers — ns2.web4u.cz and ns.web4u.cz.
zero.cz has the same name server delegation as a number of other domains, such as feset.cz, autograbl.cz, 90.91.81.in-addr.arpa and two more.
Both ns2.web4u.cz and ns.web4u.cz have two IP addresses each. ns2.web4u.cz resolves to 85.207.53.12 and 2a02:a40:100:28ff::12; ns.web4u.cz resolves to 185.14.224.241 and 2001:1568:fd::241.
Mail Servers
zero.cz routes its mail through a single mail server, mail.zero.cz.
mail.zero.cz points to one IP number — 81.91.84.134.