institutvk.cz - robtex.com
institutvk.cz
| DNSSEC | 🔒 Signed (DS record present) | ||||||
| A | 81.91.86.12🇨🇿 WEB4U81.91.80.0/21 | ||||||
| PTR | php53.web4u.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 | 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=1778698049 | ||||||
rank #4464 in the tld
Subdomains
www.institutvk.cz |
Same first word
institutvk.cz |
DNS History
6 records (5 active, 1 former)
○MXmail.institutvk.cz2015-05-14 → 2017-04-11 · 4 obs
● 2017-04-11 07:21:16
○ 2026-03-06 05:39:28
○ 2026-05-13 19:13:24
●MXmx1.mailchannels.net2026-03-06 → 2026-05-13 · 3 obs
● 2026-03-06 05:39:28
● 2026-05-13 19:13:24
●MXmx2.mailchannels.net2026-03-06 → 2026-05-13 · 3 obs
● 2026-03-06 05:39:28
● 2026-05-13 19:13:24
●A81.91.86.122015-05-14 → 2026-05-13 · 2 obs
● 2026-05-13 19:13:24
🔍 DNS Trace
📋 Delegation Chain
| Zone | Nameservers | Glue |
|---|---|---|
| cz | a.ns.nic.cz, b.ns.nic.cz, c.ns.nic.cz, d.ns.nic.cz | - |
| institutvk.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: 1382ms | Queries: -
📄 Records
| Type | Count | Sample Data |
|---|---|---|
| A | 1 | 81.91.86.12 |
| 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 (ns.web4u.cz, ns.web4u.cz, ns2.web4u.cz...)
Analysis
Hierarchy
institutvk.cz is the parent of www.institutvk.cz.
IP Addresses
institutvk.cz points to a single IP number: 81.91.86.12.
other host names for instance osin.cz, abaron.cz, euro1.zakarta.com, tezamo.cz and wixpad.eu share IP numbers with institutvk.cz.
Name Servers
institutvk.cz is delegated to two name servers: ns2.web4u.cz and ns.web4u.cz.
institutvk.cz shares the same name server setup as other domains, for example shoppin.sk, stavebniplasty.cz, cerafi.cz, levne-plachty.cz and modifio.com.
Host names with two IP numbers:
ns2.web4u.cz points to 2a02:a40:100:28ff::12 and 85.207.53.12
ns.web4u.cz points to 2001:1568:fd::241 and 185.14.224.241
Mail Servers
institutvk.cz is handled by two mail servers: mx1.mailchannels.net and mx2.mailchannels.net.
institutvk.cz shares the same mail server setup as other domains, for instance irainc.org, ctonemedia.net, wesselebersohn.com, matti.com and mojeanioly.com.
institutvk.cz shares some mail servers with other domains at least partially, for example keye.pl.
Host names with a single IP number:
mx1.mailchannels.net points to 54.187.177.89 and mx2.mailchannels.net points to 54.187.177.89.
Host names that point to 54.187.177.89: mx1.mailchannels.net and mx2.mailchannels.net.