`construct.cz`

DNSSEC	⚠️ Not signed
A	2606:4700:3030::6815:94f^{🇺🇸 Cloudflare2606:4700:3030::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	2606:4700:3035::ac43:bd2e^{🇺🇸 Cloudflare2606:4700:3035::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	104.21.9.79^{Cloudflare104.21.0.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	172.67.189.46^{🇺🇸 Cloudflare172.67.176.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
NS	`kara.ns.cloudflare.com` ⭐
		A	2606:4700:50::adf5:3a7b^{🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`kara.ns.cloudflare.com`
		A	2803:f800:50::6ca2:c07b^{🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L}
			PTR	`kara.ns.cloudflare.com`
		A	2a06:98c1:50::ac40:207b^{🇺🇸 Cloudflare2a06:98c1:50::/45}
			PTR	`kara.ns.cloudflare.com`
		A	108.162.192.123^{🇺🇸 Cloudflare108.162.192.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`kara.ns.cloudflare.com`
		A	172.64.32.123^{🇺🇸 Cloudflare172.64.32.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`kara.ns.cloudflare.com`
		A	173.245.58.123^{🇺🇸 Cloudflare173.245.58.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`kara.ns.cloudflare.com`
NS	`lars.ns.cloudflare.com`
		A	2606:4700:58::adf5:3bc3^{🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`lars.ns.cloudflare.com`
		A	2803:f800:50::6ca2:c1c3^{🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L}
			PTR	`lars.ns.cloudflare.com`
		A	2a06:98c1:50::ac40:21c3^{🇺🇸 Cloudflare2a06:98c1:50::/45}
			PTR	`lars.ns.cloudflare.com`
		A	108.162.193.195^{🇺🇸 Cloudflare108.162.193.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`lars.ns.cloudflare.com`
		A	172.64.33.195^{🇺🇸 Cloudflare172.64.33.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`lars.ns.cloudflare.com`
		A	173.245.59.195^{🇺🇸 Cloudflare173.245.59.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`lars.ns.cloudflare.com`
MX	`mx2.construct.cz` ⭐
		A	81.0.254.169^{🇨🇿 CASABLANCA-AS81.0.254.0/23 Casablanca INT}
			PTR	`unassigned-81-0-254-169.casablanca.cz`
MX	`mail.comacomp.cz`⁽³⁰⁰⁾
		A	2a03:6e80:0:ff02::2^{🇨🇿 COMA2a03:6e80::/32 Aggregate for CZ-COMA}
			PTR	`mail.comacomp.cz`
		A	84.16.96.6^{🇨🇿 COMA84.16.96.0/19 Aggregate for CZ-COMA-20040714}
			PTR	`mail.comacomp.cz`
MX	`mx.construct.cz`⁽⁵⁰⁰⁾
		A	84.21.115.50^{🇨🇿 COMA84.21.96.0/19 Aggregate for CZ-COMA-20040913}
			PTR	`cl084021115050.unet.cz`
MX	`mail.construct.cz`^(10000)
		A	84.21.115.46^{🇨🇿 COMA84.21.96.0/19 Aggregate for CZ-COMA-20040913}
			PTR	`mail.construct.cz`
TXT	`v=spf1 ip4:85.163.104.2 ip4:83.167.250.161 ip4:84.16.96.6 ip4:84.21.115.50 ip...`
HTTPS	HTTP/3, HTTP/2 ✓ hints match
		IPv4 hints	104.21.9.79, 172.67.189.46
		IPv6 hints	2606:4700:3030::6815:94f, 2606:4700:3035::ac43:bd2e
		ECH	X25519, HKDF-SHA256 + AES-128-GCM draft, id=14, name=cloudflare-ech.com
SOA	`kara.ns.cloudflare.com`dns@cloudflare.com serial=2402134434

`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=1778334436

WOT: SAFE (76/100)

Subdomains

mx2.construct.cz

mail.construct.cz

mx.construct.cz

www.construct.cz

Same first word

Similar names

cscottrun.com

cntrustco.com

structcon.ca

structcon.org

tconstruc.com

structcon.net

structcon.in

trustconc.com

structcon.com

DNS History

19 records (10 active, 9 former)

○NSdns.alm.cz2015-07-03 → 2017-01-02 · 4 obs

● 2015-07-03 19:16:06
● 2017-01-02 17:51:14
○ 2026-02-20 13:41:32
○ 2026-05-09 14:00:16

○NSjs.alm.cz2015-07-03 → 2017-01-02 · 4 obs

● 2015-07-03 19:16:06
● 2017-01-02 17:51:14
○ 2026-02-20 13:41:32
○ 2026-05-09 14:00:16

●NSkara.ns.cloudflare.com2026-02-20 → 2026-05-09 · 3 obs

○ 2017-01-02 17:51:14
● 2026-02-20 13:41:32
● 2026-05-09 14:00:16

●NSlars.ns.cloudflare.com2026-02-20 → 2026-05-09 · 3 obs

○ 2017-01-02 17:51:14
● 2026-02-20 13:41:32
● 2026-05-09 14:00:16

●MXmail.comacomp.cz2015-07-03 → 2026-05-09 · 2 obs

● 2015-07-03 19:16:06
● 2026-05-09 14:00:16

●MXmail.construct.cz2015-07-03 → 2026-05-09 · 2 obs

● 2015-07-03 19:16:06
● 2026-05-09 14:00:16

●MXmx.construct.cz2015-07-03 → 2026-05-09 · 2 obs

● 2015-07-03 19:16:06
● 2026-05-09 14:00:16

●MXmx2.construct.cz2015-07-03 → 2026-05-09 · 2 obs

● 2015-07-03 19:16:06
● 2026-05-09 14:00:16

●A104.21.9.792026-02-20 → 2026-05-09 · 12 obs

○ 2017-01-02 17:51:14
● 2026-02-20 13:41:32
● 2026-02-24 16:35:34
○ 2026-03-07 02:10:04
● 2026-03-11 04:53:44
● 2026-03-14 09:30:10
○ 2026-03-24 00:35:26
● 2026-03-29 11:43:38
● 2026-04-01 22:35:38
○ 2026-04-04 11:42:50
● 2026-04-07 04:33:42
● 2026-05-09 14:00:16

○A109.123.208.432015-11-09 → 2016-04-30 · 5 obs

○ 2015-07-03 19:16:06
● 2015-11-09 19:16:40
● 2016-04-30 03:27:46
○ 2017-01-02 17:51:14
○ 2026-05-09 14:00:16

○A109.123.209.1912015-07-03 → 2015-07-03 · 3 obs

● 2015-07-03 19:16:06
○ 2015-11-09 19:16:40
○ 2026-05-09 14:00:16

●A172.67.189.462026-02-20 → 2026-05-09 · 12 obs

○A188.114.96.02026-03-07 → 2026-04-04 · 10 obs

○ 2026-02-24 16:35:34
● 2026-03-07 02:10:04
○ 2026-03-11 04:53:44
○ 2026-03-14 09:30:10
● 2026-03-24 00:35:26
○ 2026-03-29 11:43:38
○ 2026-04-01 22:35:38
● 2026-04-04 11:42:50
○ 2026-04-07 04:33:42
○ 2026-05-09 14:00:16

○A188.114.97.02026-03-07 → 2026-04-04 · 10 obs

●A2606:4700:3030::6815:94f2026-02-20 → 2026-05-09 · 12 obs

●A2606:4700:3035::ac43:bd2e2026-02-20 → 2026-05-09 · 12 obs

○A2a06:98c1:3120::2026-03-07 → 2026-04-04 · 10 obs

○A2a06:98c1:3121::2026-03-07 → 2026-04-04 · 10 obs

○A88.86.113.1612017-01-02 → 2017-01-02 · 4 obs

○ 2016-04-30 03:27:46
● 2017-01-02 17:51:14
○ 2026-02-20 13:41:32
○ 2026-05-09 14:00:16

🔍 DNS Trace

📋 Delegation Chain

Zone	Nameservers	Glue
cz	a.ns.nic.cz, b.ns.nic.cz, c.ns.nic.cz, d.ns.nic.cz	-
construct.cz	kara.ns.cloudflare.com, lars.ns.cloudflare.com	-

✅ Authoritative Response

Server:173.245.59.195

NS records: kara.ns.cloudflare.com, lars.ns.cloudflare.com

🔒 DNSSEC Status

⚠️ Insecure (no DNSSEC)

No DS record for construct.cz (unsigned zone)

⏱️ Timing

Total: 1123ms | Queries: -

📄 Records

Type	Count	Sample Data
A	2	`172.67.189.46, 104.21.9.79`
AAAA	2	`2606:4700:3030::6815:94f, 2606:4700:3035::ac43:bd2e`
NS	2	`kara.ns.cloudflare.com, lars.ns.cloudflare.com`
MX	4	`mx.construct.cz (pri: 100), mail.construct.cz (pri: 10000)...`
TXT	1	`v=spf1 ip4:85.163.104.2 ip4:83.167.250.1`
HTTPS	1	`{"priority":1,"target":".","alpn":["h3",`
SOA	1	`kara.ns.cloudflare.com dns.cloudflare.co`

Analysis

Hierarchy

construct.cz is a parent of mx2.construct.cz, mail.construct.cz, mx.construct.cz and www.construct.cz.

IP Addresses

construct.cz resolves to four IP numbers: 2606:4700:3030::6815:94f, 2606:4700:3035::ac43:bd2e, 104.21.9.79 and 172.67.189.46.

other host names for instance vitovelyros.com, primewire.digital, mail.indianbanglanews.com, chicago-town.com and lacinka.org share IP numbers with construct.cz.

Name Servers

construct.cz is delegated to two name servers: kara.ns.cloudflare.com and lars.ns.cloudflare.com.

construct.cz shares the same name server setup as other domains, for example azhuge233.com, inf.org, froize.co.uk, jobcannon.io and ipswichcardinals.co.uk.

construct.cz at least partially shares name servers with other domains, for instance veterandefenders.org, sig-m.co.il, hendrey.com.au, elaianthos.gr and bayernmaiden.com.

These name servers are often used with bonnie.ns.cloudflare.com and ridge.ns.cloudflare.com.

Host names with six IP numbers:

kara.ns.cloudflare.com points to: 2606:4700:50::adf5:3a7b, 2803:f800:50::6ca2:c07b, 2a06:98c1:50::ac40:207b, 108.162.192.123, 172.64.32.123 and 173.245.58.123; lars.ns.cloudflare.com points to: 2606:4700:58::adf5:3bc3, 2803:f800:50::6ca2:c1c3, 2a06:98c1:50::ac40:21c3, 108.162.193.195, 172.64.33.195 and 173.245.59.195.

Mail Servers

Four mail servers handle construct.cz: mail.comacomp.cz, mail.construct.cz, mx2.construct.cz and mx.construct.cz.

construct.cz shares mail servers with other domains at least partially, including kelvin.cz, rajcha.cz, tdnet.cz, drevotvarbystre.cz and odber.unet.cz.

these mail servers are commonly used alongside smtpb-in-2.worldonline.cz.

Host names with two IP numbers:

mail.comacomp.cz points to: 2a03:6e80:0:ff02::2 and 84.16.96.6.

Host names with one IP number:

mail.construct.cz points to: 84.21.115.46; mx2.construct.cz points to: 81.0.254.169; mx.construct.cz points to: 84.21.115.50.

construct.cz - robtex.com

construct.cz

cz

Subdomains

Same first word

Similar names

DNS History

🔍 DNS Trace

📋 Delegation Chain

✅ Authoritative Response

🔒 DNSSEC Status

⏱️ Timing

📄 Records

Analysis

Hierarchy

IP Addresses

Name Servers

Mail Servers

`construct.cz`

`cz`