class.cz - robtex.com
class.cz
| DNSSEC | ⚠️ Not signed | ||||||
| NS | ns.grdns.cz ⚠️ Not in zone NS records | ||||||
| A | 2001:15e8:101:1::c268🇨🇿 INTERNET-CZ2001:15e8::/32 | ||||||
| PTR | ns.grdns.cz | ||||||
| A | 81.2.194.104🇨🇿 INTERNET-CZ81.2.192.0/18 INTERNET CZ, a.s. | ||||||
| PTR | ns.grdns.cz | ||||||
| NS | ns.grdns.it ⚠️ Not in zone NS records | ||||||
| A | 2a00:6d41:2:1::7🇮🇹 ARUBA-ASN2a00:6d41::/32 Aruba S.p.A. IPv6 Network | ||||||
| PTR | ns.grdns.it | ||||||
| A | 95.110.254.167🇮🇹 ARUBA-ASN95.110.192.0/18 Aruba S.p.A. Network | ||||||
| PTR | ns.grdns.it | ||||||
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=1778435235 | ||||||
Same first word
Similar names
DNS History
8 records (2 active, 6 former)
●NSns.grdns.cz2026-05-06 → 2026-05-10 · 3 obs
○ 2016-05-03 14:25:48
● 2026-05-06 18:54:48
● 2026-05-10 18:31:18
● 2026-05-06 18:54:48
● 2026-05-10 18:31:18
●NSns.grdns.it2026-05-06 → 2026-05-10 · 3 obs
○ 2016-05-03 14:25:48
● 2026-05-06 18:54:48
● 2026-05-10 18:31:18
● 2026-05-06 18:54:48
● 2026-05-10 18:31:18
○NSns1.regzone.cz2015-08-23 → 2016-05-03 · 4 obs
● 2015-08-23 06:14:36
● 2016-05-03 14:25:48
○ 2026-05-06 18:54:48
○ 2026-05-10 18:31:18
● 2016-05-03 14:25:48
○ 2026-05-06 18:54:48
○ 2026-05-10 18:31:18
○NSns1.regzone.de2015-08-23 → 2016-05-03 · 4 obs
● 2015-08-23 06:14:36
● 2016-05-03 14:25:48
○ 2026-05-06 18:54:48
○ 2026-05-10 18:31:18
● 2016-05-03 14:25:48
○ 2026-05-06 18:54:48
○ 2026-05-10 18:31:18
○NSns1.regzone.info2015-08-23 → 2016-05-03 · 4 obs
● 2015-08-23 06:14:36
● 2016-05-03 14:25:48
○ 2026-05-06 18:54:48
○ 2026-05-10 18:31:18
● 2016-05-03 14:25:48
○ 2026-05-06 18:54:48
○ 2026-05-10 18:31:18
○MXin.smtp.cz2015-08-23 → 2016-05-03 · 4 obs
● 2015-08-23 06:14:36
● 2016-05-03 14:25:48
○ 2026-05-06 18:54:48
○ 2026-05-10 18:31:18
● 2016-05-03 14:25:48
○ 2026-05-06 18:54:48
○ 2026-05-10 18:31:18
○MXmx.smtp.cz2015-08-23 → 2016-05-03 · 4 obs
● 2015-08-23 06:14:36
● 2016-05-03 14:25:48
○ 2026-05-06 18:54:48
○ 2026-05-10 18:31:18
● 2016-05-03 14:25:48
○ 2026-05-06 18:54:48
○ 2026-05-10 18:31:18
○A217.198.116.1882015-08-23 → 2016-05-03 · 4 obs
● 2015-08-23 06:14:36
● 2016-05-03 14:25:48
○ 2026-05-06 18:54:48
○ 2026-05-10 18:31:18
● 2016-05-03 14:25:48
○ 2026-05-06 18:54:48
○ 2026-05-10 18:31:18
🔍 DNS Trace
📋 Delegation Chain
| Zone | Nameservers | Glue |
|---|---|---|
| cz | a.ns.nic.cz, d.ns.nic.cz, c.ns.nic.cz, b.ns.nic.cz | - |
| class.cz | ns.grdns.cz, ns.grdns.it | 2 records |
✅ Authoritative Response
Server:81.2.194.104
NS records: ns.grdns.cz, ns.grdns.it
🔒 DNSSEC Status
⚠️ Insecure (no DNSSEC)
No DS record for class.cz (unsigned zone)
⏱️ Timing
Total: 1600ms | Queries: -
📄 Records
| Type | Count | Sample Data |
|---|
📌 Glue Records Collected
Total: 2
Out-of-bailiwick: 2 (ns.grdns.cz, ns.grdns.cz)
Analysis
Name Servers
class.cz's delegation uses two name servers, ns.grdns.cz and ns.grdns.it.
class.cz shares the same name server setup as other domains, for example auto-brejla.cz, steroid.cz, laurens.cz, biorep.cz and sport5.cz.
class.cz at least partially shares name servers with other domains; for instance gemerske-teplice.sk.
Host names with two IPs:
ns.grdns.cz points to: 2001:15e8:101:1::c268 and 81.2.194.104
ns.grdns.it points to: 2a00:6d41:2:1::7 and 95.110.254.167