`instructor.cz`

DNSSEC	🔒 Signed (DS record present)
A	149.62.148.12^{🇨🇿 MASTER-AS}
		PTR	`d8106.masterinter.net`
NS	`ns1.ignum.com` ⭐
		A	2a00:1e40:a:53::5^{🇸🇰 IGNUM-AS}
			PTR	`ns1-bra.core.webglobe.com`
		A	185.65.223.35^{🇸🇰 IGNUM-AS}
			PTR	`ns1-bra.core.webglobe.com`
NS	`ns2.ignum.cz`
		A	2001:1ab0:7e1e:2::5^{🇨🇿 IGNUM-AS}
			PTR	`ns2-prg.core.webglobe.com`
		A	217.31.48.201^{🇨🇿 IGNUM-AS}
			PTR	`ns2-prg.core.webglobe.com`
MX	`mx0.fortion.net` ⭐
		A	185.175.87.39^{🇨🇿 Fortion}
MX	`mx1.fortion.net`⁽¹⁰⁾
		A	185.175.87.53^{🇨🇿 Fortion}
MX	`mx2.fortion.net`⁽²⁰⁾
		A	185.175.87.53^{🇨🇿 Fortion}
TXT	`google-site-verification=RtlPen05mKshhhaQGcDiBWpjBtzDUi-ELO6J27h7npw`
TXT	`v=spf1 ip4:217.11.236.98/32 include:spf.nethost.cz include:_spf.fortion.net -all`
TXT	`v=DMARC1; p=reject; rua=mailto:report@preventonline.cz; ruf=mailto:report@pre...`
SOA	`ns1.ignum.com`hostmaster@ignum.cz 2026-02-19 #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.cz`hostmaster@nic.cz serial=1771291036

Up

lms.instructor.cz

mail.instructor.cz

Same first word

instructor.info

instructor.nl

instructor.su

instructor.us

instructor.com.mx

instructor.in

instructor.be

instructor.company

instructor.net

instructor.in.ua

instructor.cc

instructor.ca

instructor.se

instructor.es

instructor.cz

instructor.at

instructor.sk

instructor.co.il

instructor.ru

instructor.solutions

Similar names

trutronics.org

trutronics.us

trustronic.com

trutronics.com

DNS History

15 records (6 active, 9 former)

○NSns1.casablanca.cz2008-04-15 → 2008-04-15 · 3 obs

● 2008-04-15 23:18:02
○ 2015-07-18 20:36:26
○ 2026-02-23 04:27:42

●NSns1.ignum.com2015-07-18 → 2026-02-23 · 3 obs

○ 2008-04-15 23:18:02
● 2015-07-18 20:36:26
● 2026-02-23 04:27:42

●NSns2.ignum.cz2015-07-18 → 2026-02-23 · 3 obs

○ 2008-04-15 23:18:02
● 2015-07-18 20:36:26
● 2026-02-23 04:27:42

○NSslave.casablanca.cz2008-04-15 → 2008-04-15 · 3 obs

● 2008-04-15 23:18:02
○ 2015-07-18 20:36:26
○ 2026-02-23 04:27:42

○MXmail.instructor.cz2008-04-15 → 2008-04-15 · 3 obs

● 2008-04-15 23:18:02
○ 2015-07-18 20:36:26
○ 2026-02-23 04:27:42

●MXmx0.fortion.net2020-02-25 → 2026-02-23 · 3 obs

○ 2017-01-02 16:35:10
● 2020-02-25 11:27:42
● 2026-02-23 04:27:42

●MXmx1.fortion.net2020-02-25 → 2026-02-23 · 3 obs

○ 2017-01-02 16:35:10
● 2020-02-25 11:27:42
● 2026-02-23 04:27:42

○MXmx1.savana.cz2015-07-18 → 2017-01-02 · 5 obs

○ 2008-04-15 23:18:02
● 2015-07-18 20:36:26
● 2017-01-02 16:35:10
○ 2020-02-25 11:27:42
○ 2026-02-23 04:27:42

●MXmx2.fortion.net2020-02-25 → 2026-02-23 · 3 obs

○ 2017-01-02 16:35:10
● 2020-02-25 11:27:42
● 2026-02-23 04:27:42

○MXmx2.savana.cz2015-07-18 → 2017-01-02 · 5 obs

○ 2008-04-15 23:18:02
● 2015-07-18 20:36:26
● 2017-01-02 16:35:10
○ 2020-02-25 11:27:42
○ 2026-02-23 04:27:42

○MXrelay.casablanca.cz2008-04-15 → 2008-04-15 · 3 obs

● 2008-04-15 23:18:02
○ 2015-07-18 20:36:26
○ 2026-02-23 04:27:42

○A109.123.208.1012015-07-18 → 2017-01-02 · 5 obs

○ 2008-04-15 23:18:02
● 2015-07-18 20:36:26
● 2017-01-02 16:35:10
○ 2020-02-25 11:27:42
○ 2026-02-23 04:27:42

●A149.62.148.122026-02-23 → 2026-02-23 · 3 obs

○ 2020-02-25 11:27:42
● 2026-02-23 04:27:40
● 2026-02-23 04:27:42

○A185.175.84.1332020-02-25 → 2020-02-25 · 4 obs

○ 2017-01-02 16:35:10
● 2020-02-25 11:27:42
○ 2026-02-23 04:27:40
○ 2026-02-23 04:27:42

○A217.11.236.982008-04-15 → 2008-04-15 · 3 obs

● 2008-04-15 23:18:02
○ 2015-07-18 20:36:26
○ 2026-02-23 04:27:42

🔍 DNS Trace

📋 Delegation Chain

Zone	Nameservers	Glue
cz	a.ns.nic.cz, b.ns.nic.cz, c.ns.nic.cz, d.ns.nic.cz	-
instructor.cz	ns1.ignum.com, ns2.ignum.cz	2 records

✅ Authoritative Response

Server: 185.65.223.35

NS records: ns1.ignum.com, ns2.ignum.cz

🔒 DNSSEC Status

🔐 Secure (DNSSEC validated)

Chain of trust verified from root to domain

⏱️ Timing

Total: 2489ms | Queries: -

📄 Records

Type	Count	Sample Data
A	1	`149.62.148.12`
NS	2	`ns1.ignum.com, ns2.ignum.cz`
MX	3	`mx0.fortion.net (pri: 5), mx1.fortion.net (pri: 10)...`
TXT	3	`google-site-verification=RtlPen05mKshhha, v=spf1 ip4:217.11.236.98/32 include:spf....`
SOA	1	`ns1.ignum.com hostmaster.ignum.cz`

📌 Glue Records Collected

Total: 2

Out-of-bailiwick: 2 (ns2.ignum.cz, ns2.ignum.cz)

AI analysis

instructor.cz is a parent of lms.instructor.cz and mail.instructor.cz.

instructor.cz points to IP number: 149.62.148.12.

Other host names such as ares-group.cz, medbook.cz, prevent.cz, notix.cz and complus.cz share IPs with instructor.cz.

instructor.cz is delegated to two name servers: ns1.ignum.com and ns2.ignum.cz.

instructor.cz shares the same name server setup as vodarna.cz, sorm.biz, centrolat.sk, km-color.cz and emmacapital.ru.

instructor.cz at least partially shares name servers with other domains, for instance f2.cz, vsprednasky.cz, gameexpress.cz, liberatrix.cz and sotio.cz.

these name servers are commonly used with ns1.webcloud.cz, ns1.ignum.eu, ns2.ignum.eu and ns3.ignum.eu.

Host names with two IP numbers: ns1.ignum.com points to: 2a00:1e40:a:53::5 and 185.65.223.35; ns2.ignum.cz points to: 2001:1ab0:7e1e:2::5 and 217.31.48.201.

Three mail servers handle instructor.cz: mx0.fortion.net, mx1.fortion.net and mx2.fortion.net.

instructor.cz shares at least partially some mail servers with other domains, including dovolenavcr.cz, fortion.eu, e-jidelnicek.cz, wilens.cz and kampanila.cz.