contek.cz - robtex.com
contek.cz
| DNSSEC | ⚠️ Not signed | ||||||
| A | 81.91.86.10🇨🇿 AS3979081.91.80.0/21 | ||||||
| PTR | php4.web4u.cz | ||||||
| NS | ns2.web4u.cz ⭐ | ||||||
| A | 2a02:a40:100:28ff::12 | ||||||
| A | 85.207.53.12 | ||||||
| NS | ns.web4u.cz | ||||||
| A | 2001:1568:fd::241 | ||||||
| A | 185.14.224.241 | ||||||
| MX | mx1.mailchannels.net ⭐ | ||||||
| A | 54.187.177.89🇺🇸 Amazon54.186.0.0/15 EC2 PDX prefix | ||||||
| PTR | ec2-54-187-177-89.us-west-2.compute.amazonaws.com | ||||||
| MX | mx2.mailchannels.net ⭐ | ||||||
| A | 54.187.177.89🇺🇸 Amazon54.186.0.0/15 EC2 PDX prefix | ||||||
| PTR | ec2-54-187-177-89.us-west-2.compute.amazonaws.com | ||||||
| TXT | v=spf1 include:_spf.web4u.cz ~all | ||||||
| SOA | ns.web4u.czadmin@web4u.cz 2025-04-30 #0 | ||||||
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=1783383438 | ||||||
Same first word
Similar names
DNS History
6 records (5 active, 1 former)
○MXmail.contek.cz2015-07-25 → 2016-12-20 · 4 obs
● 2016-12-20 12:09:40
○ 2026-06-13 01:23:04
○ 2026-07-07 00:28:36
●MXmx1.mailchannels.net2026-06-13 → 2026-07-07 · 3 obs
● 2026-06-13 01:23:04
● 2026-07-07 00:28:36
●MXmx2.mailchannels.net2026-06-13 → 2026-07-07 · 3 obs
● 2026-06-13 01:23:04
● 2026-07-07 00:28:36
●A81.91.86.102015-07-25 → 2026-07-07 · 2 obs
● 2026-07-07 00:28:36
🔍 DNS Trace
📋 Delegation Chain
| Zone | Nameservers | Glue |
|---|---|---|
| cz | a.ns.nic.cz, b.ns.nic.cz, c.ns.nic.cz, d.ns.nic.cz | - |
| contek.cz | ns.web4u.cz, ns2.web4u.cz | 4 records |
✅ Authoritative Response
Server:185.14.224.241
NS records: ns.web4u.cz, ns2.web4u.cz
🔒 DNSSEC Status
🔐 Secure (DNSSEC validated)
Chain of trust verified from root to domain
⏱️ Timing
Total: 1875ms | Queries: -
📄 Records
| Type | Count | Sample Data |
|---|---|---|
| A | 1 | 81.91.86.10 |
| NS | 2 | ns.web4u.cz, ns2.web4u.cz |
| MX | 2 | mx1.mailchannels.net (pri: 10), mx2.mailchannels.net (pri: 10) |
| TXT | 1 | v=spf1 include:_spf.web4u.cz ~all |
| 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
IP Addresses
contek.cz resolves to one IP address: 81.91.86.10.
siringa.cz, vostrak.cz, brenston.cz and two other host names share IP numbers with contek.cz.
Name Servers
Two name servers handle the delegation for contek.cz: ns2.web4u.cz and ns.web4u.cz.
contek.cz uses the same name servers as several other domains — among them ltprojekt.cz, daj.cz, kindred.cz and two more.
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
Mail for contek.cz is handled by two mail servers — mx1.mailchannels.net and mx2.mailchannels.net.
contek.cz uses an identical mail server configuration to several other domains — among them bbstudiomanila.com, ardour.org, elanlimousines.com and two more.
contek.cz shares at least some of its mail servers with other domains, such as glashusen.se.
mx1.mailchannels.net directs to 54.187.177.89, as does mx2.mailchannels.net — both hostnames resolve to that one IP address.
mx1.mailchannels.net along with mx2.mailchannels.net each resolve to 54.187.177.89 IP addresses.