czechcourse.com - robtex.com

czechcourse.com

DNSSEC⚠️ Not signed
A2606:4700:3032::ac43:8cdc🇺🇸 Cloudflare2606:4700:3032::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US ✓ In HTTPS hints
A2606:4700:3033::6815:5ee1🇺🇸 Cloudflare2606:4700:3033::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US ✓ In HTTPS hints
A104.21.94.225Cloudflare104.21.80.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US ✓ In HTTPS hints
A172.67.140.220🇺🇸 Cloudflare172.67.128.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US ✓ In HTTPS hints
NSadam.ns.cloudflare.com ⭐
A2606:4700:58::adf5:3b36🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US
PTRadam.ns.cloudflare.com
A2803:f800:50::6ca2:c136🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L
PTRadam.ns.cloudflare.com
A2a06:98c1:50::ac40:2136🇺🇸 Cloudflare2a06:98c1:50::/45
PTRadam.ns.cloudflare.com
A108.162.193.54🇺🇸 Cloudflare108.162.193.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US
PTRadam.ns.cloudflare.com
A172.64.33.54🇺🇸 Cloudflare172.64.33.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US
PTRadam.ns.cloudflare.com
A173.245.59.54🇺🇸 Cloudflare173.245.59.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US
PTRadam.ns.cloudflare.com
NSrosemary.ns.cloudflare.com
A2606:4700:50::a29f:264d🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US
PTRrosemary.ns.cloudflare.com
A2803:f800:50::6ca2:c24d🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L
PTRrosemary.ns.cloudflare.com
A2a06:98c1:50::ac40:224d🇺🇸 Cloudflare2a06:98c1:50::/45
PTRrosemary.ns.cloudflare.com
A108.162.194.77🇺🇸 Cloudflare108.162.194.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US
PTRrosemary.ns.cloudflare.com
A162.159.38.77Cloudflare162.159.32.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US
PTRrosemary.ns.cloudflare.com
A172.64.34.77🇺🇸 Cloudflare172.64.34.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US
PTRrosemary.ns.cloudflare.com
MXaspmx.l.google.com ⭐
A2607:f8b0:4004:c07::1a🇺🇸 Google2607:f8b0:4004::/48
PTRbc-in-f26.1e100.net
A172.253.63.27🇺🇸 Google172.253.63.0/24
PTRbi-in-f27.1e100.net
MXalt1.aspmx.l.google.com(5)
A2607:f8b0:4023:2801::1b🇺🇸 Google2607:f8b0::/32
PTRlcausi-in-f27.1e100.net
A192.178.128.26🇺🇸 Google192.178.128.0/24
PTRlcausi-in-f26.1e100.net
MXalt2.aspmx.l.google.com(5)
A2a00:1450:4013:c1e::1b🇳🇱 Google2a00:1450:4013::/48
PTRyugrqzs-in-f27.1e100.net
A192.178.213.27🇺🇸 Google192.178.213.0/24
PTRyugrqzs-in-f27.1e100.net
MXalt3.aspmx.l.google.com(10)
A2a00:1450:4009:c0f::1b🇬🇧 Google2a00:1450:4009::/48
PTRyulhrs-in-f27.1e100.net
A192.178.223.27🇺🇸 Google192.178.223.0/24
PTRip-192-178-223-27.defastlink.net
MXalt4.aspmx.l.google.com(10)
A2607:f8b0:4003:c4a::1b🇺🇸 Google2607:f8b0:4003::/48
PTRyutulth-in-f27.1e100.net
A142.251.96.27🇺🇸 Google142.250.0.0/15
PTRyutulth-in-f27.1e100.net
TXTgoogle-site-verification=Uj-JnfI_wcEXPs7nRp-0S9gAaUlXN8aejR4pIzACZmU
TXTgoogle-site-verification=umg7a5Gv9C2_uIL7KXD6Jp6vcv22-gbyizCoDVBHMgI
TXTv=spf1 include:_spf.google.com -all
HTTPSHTTP/3, HTTP/2 ✓ hints match
IPv4104.21.94.225, 172.67.140.220
IPv62606:4700:3032::ac43:8cdc, 2606:4700:3033::6815:5ee1
SOAadam.ns.cloudflare.comdns@cloudflare.com serial=2397828127

com

DNSSEC🔒 Signed (DS record present)
NSa.gtld-servers.net ⭐
NSb.gtld-servers.net
NSc.gtld-servers.net
NSd.gtld-servers.net
NSe.gtld-servers.net
NSf.gtld-servers.net
NSg.gtld-servers.net
NSh.gtld-servers.net
NSi.gtld-servers.net
NSj.gtld-servers.net
NSk.gtld-servers.net
NSl.gtld-servers.net
NSm.gtld-servers.net
SOAa.gtld-servers.netnstld@verisign-grs.com serial=1774686097

Same first word

czechcourse.com

Similar names

courseczech.com

DNS History

19 records (11 active, 8 former)

2017201820192020202120222023202420252026NSadam.ns.cloudflare.comrosemary.ns.cloudflare.comns1.sedoparking.comns2.sedoparking.comMXalt1.aspmx.l.google.comalt2.aspmx.l.google.comalt3.aspmx.l.google.comalt4.aspmx.l.google.comaspmx.l.google.comlocalhostA104.21.94.225172.67.140.2202606:4700:3032::ac43:8cdc2606:4700:3033::6815:5ee1188.114.96.0188.114.97.02a06:98c1:3120::2a06:98c1:3121::72.52.4.119
●NSadam.ns.cloudflare.com2026-02-15 → 2026-03-28 · 3 obs
○ 2018-01-10 18:35:52
● 2026-02-15 00:58:04
● 2026-03-28 08:25:24
○NSns1.sedoparking.com2016-12-17 → 2016-12-17 · 3 obs
● 2016-12-17 07:07:02
○ 2018-01-10 18:35:52
○ 2026-03-28 08:25:24
○NSns2.sedoparking.com2016-12-17 → 2016-12-17 · 3 obs
● 2016-12-17 07:07:02
○ 2018-01-10 18:35:52
○ 2026-03-28 08:25:24
●NSrosemary.ns.cloudflare.com2026-02-15 → 2026-03-28 · 3 obs
○ 2018-01-10 18:35:52
● 2026-02-15 00:58:04
● 2026-03-28 08:25:24
●MXalt1.aspmx.l.google.com2026-02-15 → 2026-03-28 · 3 obs
○ 2018-01-10 18:35:52
● 2026-02-15 00:58:04
● 2026-03-28 08:25:24
●MXalt2.aspmx.l.google.com2026-02-15 → 2026-03-28 · 3 obs
○ 2018-01-10 18:35:52
● 2026-02-15 00:58:04
● 2026-03-28 08:25:24
●MXalt3.aspmx.l.google.com2026-02-15 → 2026-03-28 · 3 obs
○ 2018-01-10 18:35:52
● 2026-02-15 00:58:04
● 2026-03-28 08:25:24
●MXalt4.aspmx.l.google.com2026-02-15 → 2026-03-28 · 3 obs
○ 2018-01-10 18:35:52
● 2026-02-15 00:58:04
● 2026-03-28 08:25:24
●MXaspmx.l.google.com2026-02-15 → 2026-03-28 · 3 obs
○ 2018-01-10 18:35:52
● 2026-02-15 00:58:04
● 2026-03-28 08:25:24
○MXlocalhost2016-12-17 → 2016-12-17 · 3 obs
● 2016-12-17 07:07:02
○ 2018-01-10 18:35:52
○ 2026-03-28 08:25:24
●A104.21.94.2252026-02-15 → 2026-03-28 · 5 obs
○ 2018-01-10 18:35:52
● 2026-02-15 00:58:04
● 2026-02-15 23:14:00
○ 2026-03-28 01:24:36
● 2026-03-28 08:25:24
●A172.67.140.2202026-02-15 → 2026-03-28 · 5 obs
○ 2018-01-10 18:35:52
● 2026-02-15 00:58:04
● 2026-02-15 23:14:00
○ 2026-03-28 01:24:36
● 2026-03-28 08:25:24
○A188.114.96.02026-03-28 → 2026-03-28 · 3 obs
○ 2026-02-15 23:14:00
● 2026-03-28 01:24:36
○ 2026-03-28 08:25:24
○A188.114.97.02026-03-28 → 2026-03-28 · 3 obs
○ 2026-02-15 23:14:00
● 2026-03-28 01:24:36
○ 2026-03-28 08:25:24
●A2606:4700:3032::ac43:8cdc2026-02-15 → 2026-03-28 · 5 obs
○ 2018-01-10 18:35:52
● 2026-02-15 00:58:04
● 2026-02-15 23:14:00
○ 2026-03-28 01:24:36
● 2026-03-28 08:25:24
●A2606:4700:3033::6815:5ee12026-02-15 → 2026-03-28 · 5 obs
○ 2018-01-10 18:35:52
● 2026-02-15 00:58:04
● 2026-02-15 23:14:00
○ 2026-03-28 01:24:36
● 2026-03-28 08:25:24
○A2a06:98c1:3120::2026-03-28 → 2026-03-28 · 3 obs
○ 2026-02-15 23:14:00
● 2026-03-28 01:24:36
○ 2026-03-28 08:25:24
○A2a06:98c1:3121::2026-03-28 → 2026-03-28 · 3 obs
○ 2026-02-15 23:14:00
● 2026-03-28 01:24:36
○ 2026-03-28 08:25:24
○A72.52.4.1192016-12-17 → 2016-12-17 · 3 obs
● 2016-12-17 07:07:02
○ 2018-01-10 18:35:52
○ 2026-03-28 08:25:24

🔍 DNS Trace

📋 Delegation Chain

ZoneNameserversGlue
coml.gtld-servers.net, j.gtld-servers.net, h.gtld-servers.net, d.gtld-servers.net...-
czechcourse.comadam.ns.cloudflare.com, rosemary.ns.cloudflare.com12 records

✅ Authoritative Response

Server:108.162.194.77

NS records: adam.ns.cloudflare.com, rosemary.ns.cloudflare.com

🔒 DNSSEC Status

⚠️ Insecure (no DNSSEC)

No DS record for czechcourse.com (unsigned zone)

⏱️ Timing

Total: 184ms | Queries: -

📄 Records

TypeCountSample Data
A2172.67.140.220, 104.21.94.225
AAAA22606:4700:3033::6815:5ee1, 2606:4700:3032::ac43:8cdc
NS2adam.ns.cloudflare.com, rosemary.ns.cloudflare.com
MX5aspmx.l.google.com (pri: 1), alt3.aspmx.l.google.com (pri: 10)...
TXT3google-site-verification=Uj-JnfI_wcEXPs7, google-site-verification=umg7a5Gv9C2_uIL...
HTTPS1{"priority":1,"target":".","alpn":["h3",
SOA1adam.ns.cloudflare.com dns.cloudflare.co

📌 Glue Records Collected

Total: 12

Out-of-bailiwick: 12 (adam.ns.cloudflare.com, adam.ns.cloudflare.com, adam.ns.cloudflare.com...)

Analysis

IP Addresses

czechcourse.com maps to four IP numbers: 2606:4700:3032::ac43:8cdc, 2606:4700:3033::6815:5ee1, 104.21.94.225 and 172.67.140.220.

Other host names such as free(0x6d696c66)(0x706f726e).org, www.lesjam.fr, hexahost.com.br, swissbanking.org and drmentz.com share IPs with czechcourse.com.

Name Servers

Two name servers adam.ns.cloudflare.com and rosemary.ns.cloudflare.com handle the delegation for czechcourse.com.

czechcourse.com shares the same name server setup as other domains, for example fineicons.com, estore5s.com, gutesten.de, restguru.com and debadotell.com.

czechcourse.com at least partially shares name servers with other domains, for example kmce.tv, icecloud.asia, coirnapro.vip, assur-commune.com and ach-portal.com.

these name servers are commonly used alongside sonia.ns.cloudflare.com name servers.

Host names with six IP numbers:

adam.ns.cloudflare.com points to 2606:4700:58::adf5:3b36, 2803:f800:50::6ca2:c136, 2a06:98c1:50::ac40:2136, 108.162.193.54, 172.64.33.54 and 173.245.59.54.

rosemary.ns.cloudflare.com points to 2606:4700:50::a29f:264d, 2803:f800:50::6ca2:c24d, 2a06:98c1:50::ac40:224d, 108.162.194.77, 162.159.38.77 and 172.64.34.77.

Mail Servers

czechcourse.com is handled by five mail servers: aspmx.l.google.com, alt1.aspmx.l.google.com, alt2.aspmx.l.google.com, alt3.aspmx.l.google.com and alt4.aspmx.l.google.com.

czechcourse.com shares at least partially some mail servers with other domains, for instance ns500698.ns500698.ns500698.ns500759.ns500736.ns500735.ns500698.ns500698.ns500576.ns500708.ns500708.ns500686.ns500619.ns500576.trackreceptor.com, ns500698.ns500759.ns500759.ns500736.ns500698.ns500735.ns500735.ns500576.ns500698.ns500619.ns500686.ns500619.ns500619.ns500576.trackreceptor.com, ns500754.ns500754.ns500671.ns500754.ns500671.ns500671.ns500678.ns500291.ns500671.ns500649.ns500649.ns500666.tenderladiesbz.com, deltium.com and ns500671.ns500754.ns500742.ns500671.ns500688.ns500704.ns500704.ns500704.ns500678.ns500666.ns500291.ns500291.ns500131.lustychickser.com.

these mail servers are often used together with aspmx2.googlemail.com, aspmx3.googlemail.com, aspmx4.googlemail.com and aspmx5.googlemail.com.

Host names with two IP numbers

Each host name points to two IP numbers:

aspmx.l.google.com points to 2607:f8b0:4004:c07::1a and 172.253.63.27

alt1.aspmx.l.google.com points to 2607:f8b0:4023:2801::1b and 192.178.128.26

alt2.aspmx.l.google.com points to 2a00:1450:4013:c1e::1b and 192.178.213.27

alt3.aspmx.l.google.com points to 2a00:1450:4009:c0f::1b and 192.178.223.27

alt4.aspmx.l.google.com points to 2607:f8b0:4003:c4a::1b and 142.251.96.27