`courses123.com`

DNSSEC	⚠️ Not signed
A	2606:4700:3031::ac43:ad19^{🇺🇸 Cloudflare2606:4700:3031::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	2606:4700:3034::6815:3fec^{🇺🇸 Cloudflare2606:4700:3034::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	104.21.63.236^{Cloudflare104.21.48.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	172.67.173.25^{🇺🇸 Cloudflare172.67.160.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
NS	`isaac.ns.cloudflare.com` ⭐
		A	2606:4700:58::adf5:3bb1^{🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`isaac.ns.cloudflare.com`
		A	2803:f800:50::6ca2:c1b1^{🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L}
			PTR	`isaac.ns.cloudflare.com`
		A	2a06:98c1:50::ac40:21b1^{🇺🇸 Cloudflare2a06:98c1:50::/45}
			PTR	`isaac.ns.cloudflare.com`
		A	108.162.193.177^{🇺🇸 Cloudflare108.162.193.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`isaac.ns.cloudflare.com`
		A	172.64.33.177^{🇺🇸 Cloudflare172.64.33.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`isaac.ns.cloudflare.com`
		A	173.245.59.177^{🇺🇸 Cloudflare173.245.59.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`isaac.ns.cloudflare.com`
NS	`lana.ns.cloudflare.com`
		A	2606:4700:50::adf5:3ab6^{🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`lana.ns.cloudflare.com`
		A	2803:f800:50::6ca2:c0b6^{🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L}
			PTR	`lana.ns.cloudflare.com`
		A	2a06:98c1:50::ac40:20b6^{🇺🇸 Cloudflare2a06:98c1:50::/45}
			PTR	`lana.ns.cloudflare.com`
		A	108.162.192.182^{🇺🇸 Cloudflare108.162.192.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`lana.ns.cloudflare.com`
		A	172.64.32.182^{🇺🇸 Cloudflare172.64.32.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`lana.ns.cloudflare.com`
		A	173.245.58.182^{🇺🇸 Cloudflare173.245.58.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`lana.ns.cloudflare.com`
MX	`courses123-com.mail.protection.outlook.com` ⭐
		A	2a01:111:f403:ca04::1^{🇮🇪 Microsoft2a01:111:f000::/36}
			PTR	`mail-db7pr03cu00401.inbound.protection.outlook.com`
		A	2a01:111:f403:ca04::6^{🇮🇪 Microsoft2a01:111:f000::/36}
			PTR	`mail-db4pr02cu00406.inbound.protection.outlook.com`
		A	2a01:111:f403:ca04::f^{🇮🇪 Microsoft2a01:111:f000::/36}
			PTR	`mail-db7pr03cu00507.inbound.protection.outlook.com`
		A	2a01:111:f403:ca09::20^{🇳🇱 Microsoft2a01:111:f000::/36}
			PTR	`mail-as8pr05cu00400.inbound.protection.outlook.com`
		A	52.101.68.3^{🇮🇪 Microsoft52.96.0.0/12 MICROSOFT}
			PTR	`mail-db7pr03cu00403.inbound.protection.outlook.com`
		A	52.101.68.5^{🇮🇪 Microsoft52.96.0.0/12 MICROSOFT}
			PTR	`mail-du2pr03cu00105.inbound.protection.outlook.com`
		A	52.101.68.8^{🇮🇪 Microsoft52.96.0.0/12 MICROSOFT}
			PTR	`mail-du0pr03cu00100.inbound.protection.outlook.com`
		A	52.101.73.6^{🇳🇱 Microsoft52.96.0.0/12 MICROSOFT}
			PTR	`mail-am6pr04cu00306.inbound.protection.outlook.com`
TXT	`MS=ms13263856`
TXT	`MS=ms99584475`
TXT	`google-site-verification=PO68CNR41-M5Jibo61M34v1uV7Zizl7AVl5lX5bgJDU`
TXT	`v=spf1 include:_spf.google.com include:spf.protection.outlook.com ~all`
HTTPS	HTTP/3, HTTP/2 ✓ hints match
		IPv4	104.21.63.236, 172.67.173.25
		IPv6	2606:4700:3031::ac43:ad19, 2606:4700:3034::6815:3fec
SOA	`isaac.ns.cloudflare.com`dns@cloudflare.com serial=2399439906

`com`

	DNSSEC	🔒 Signed (DS record present)
	NS	`a.gtld-servers.net` ⭐
	NS	`b.gtld-servers.net`
	NS	`c.gtld-servers.net`
	NS	`d.gtld-servers.net`
	NS	`e.gtld-servers.net`
	NS	`f.gtld-servers.net`
	NS	`g.gtld-servers.net`
	NS	`h.gtld-servers.net`
	NS	`i.gtld-servers.net`
	NS	`j.gtld-servers.net`
	NS	`k.gtld-servers.net`
	NS	`l.gtld-servers.net`
	NS	`m.gtld-servers.net`
	SOA	`a.gtld-servers.net`nstld@verisign-grs.com serial=1771291435

Same first word

courses123.com

Similar names

sources123.com

123courses.com

DNS History

15 records (7 active, 8 former)

●NSisaac.ns.cloudflare.com2016-09-18 → 2026-03-22 · 3 obs

○ 2016-04-02 00:54:28
● 2016-09-18 08:59:54
● 2026-03-22 17:03:16

●NSlana.ns.cloudflare.com2016-09-18 → 2026-03-22 · 3 obs

○ 2016-04-02 00:54:28
● 2016-09-18 08:59:54
● 2026-03-22 17:03:16

○NSns1.blacknight.com2015-12-24 → 2016-04-02 · 4 obs

● 2015-12-24 00:27:32
● 2016-04-02 00:54:28
○ 2016-09-18 08:59:54
○ 2026-03-22 17:03:16

○NSns2.blacknight.com2015-12-24 → 2016-04-02 · 4 obs

● 2015-12-24 00:27:32
● 2016-04-02 00:54:28
○ 2016-09-18 08:59:54
○ 2026-03-22 17:03:16

●MXcourses123-com.mail.protection.outlook.com2026-02-14 → 2026-03-22 · 3 obs

○ 2017-05-24 15:16:52
● 2026-02-14 23:57:34
● 2026-03-22 17:03:16

○MXmail.courses123.com2016-09-18 → 2017-05-24 · 4 obs

● 2016-09-18 08:59:54
● 2017-05-24 15:16:52
○ 2026-02-14 23:57:34
○ 2026-03-22 17:03:16

●A104.21.63.2362026-02-14 → 2026-03-22 · 3 obs

○ 2017-05-24 15:16:52
● 2026-02-14 23:57:34
● 2026-03-22 17:03:16

○A104.25.174.302016-09-18 → 2017-05-24 · 5 obs

○ 2016-04-02 00:54:28
● 2016-09-18 08:59:54
● 2017-05-24 15:16:52
○ 2026-02-14 23:57:34
○ 2026-03-22 17:03:16

○A104.25.175.302016-09-18 → 2017-05-24 · 5 obs

○ 2016-04-02 00:54:28
● 2016-09-18 08:59:54
● 2017-05-24 15:16:52
○ 2026-02-14 23:57:34
○ 2026-03-22 17:03:16

●A172.67.173.252026-02-14 → 2026-03-22 · 3 obs

○ 2017-05-24 15:16:52
● 2026-02-14 23:57:34
● 2026-03-22 17:03:16

○A2400:cb00:2048:1::6819:ae1e2016-09-18 → 2017-05-24 · 5 obs

○ 2016-04-02 00:54:28
● 2016-09-18 08:59:54
● 2017-05-24 15:16:52
○ 2026-02-14 23:57:34
○ 2026-03-22 17:03:16

○A2400:cb00:2048:1::6819:af1e2016-09-18 → 2017-05-24 · 5 obs

○ 2016-04-02 00:54:28
● 2016-09-18 08:59:54
● 2017-05-24 15:16:52
○ 2026-02-14 23:57:34
○ 2026-03-22 17:03:16

●A2606:4700:3031::ac43:ad192026-02-14 → 2026-03-22 · 3 obs

○ 2017-05-24 15:16:52
● 2026-02-14 23:57:34
● 2026-03-22 17:03:16

●A2606:4700:3034::6815:3fec2026-02-14 → 2026-03-22 · 3 obs

○ 2017-05-24 15:16:52
● 2026-02-14 23:57:34
● 2026-03-22 17:03:16

○A78.153.212.1732015-12-24 → 2016-04-02 · 4 obs

● 2015-12-24 00:27:32
● 2016-04-02 00:54:28
○ 2016-09-18 08:59:54
○ 2026-03-22 17:03:16

🔍 DNS Trace

📋 Delegation Chain

Zone	Nameservers	Glue
com	a.gtld-servers.net, b.gtld-servers.net, c.gtld-servers.net, d.gtld-servers.net...	-
courses123.com	isaac.ns.cloudflare.com, lana.ns.cloudflare.com	12 records

✅ Authoritative Response

Server: 108.162.193.177

NS records: isaac.ns.cloudflare.com, lana.ns.cloudflare.com

🔒 DNSSEC Status

⚠️ Insecure (no DNSSEC)

No DS record for courses123.com (unsigned zone)

⏱️ Timing

Total: 186ms | Queries: -

📄 Records

Type	Count	Sample Data
A	2	`172.67.173.25, 104.21.63.236`
AAAA	2	`2606:4700:3034::6815:3fec, 2606:4700:3031::ac43:ad19`
NS	2	`isaac.ns.cloudflare.com, lana.ns.cloudflare.com`
MX	1	`courses123-com.mail.protection.outlook.c`
TXT	4	`MS=ms13263856, MS=ms99584475...`
HTTPS	1	`{"priority":1,"target":".","alpn":["h3",`
SOA	1	`isaac.ns.cloudflare.com dns.cloudflare.c`

📌 Glue Records Collected

Total: 12

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

Analysis

IP Addresses

courses123.com maps to four IP numbers: 2606:4700:3031::ac43:ad19, 2606:4700:3034::6815:3fec, 104.21.63.236 and 172.67.173.25.

other host names include inhalerotc.com, tamalesmexicanos.net, kefirlab.com, electrosonic.co.il and spellassist.com; they share IP numbers with courses123.com.

Name Servers

Two name servers isaac.ns.cloudflare.com and lana.ns.cloudflare.com handle the delegation for courses123.com.

courses123.com shares the same name server setup as other domains, for instance nectar.id, webmurahbagus.com, historicaltextarchive.com, mymetala.com and zenithflow.life.

courses123.com at least partially shares name servers with other domains, for instance kolcraft.com, alliance.org.hk, codeshelper.com, mcpropvp.com and bellasmiles4all.com.

These name servers are commonly used with sevki.ns.cloudflare.com and dolly.ns.cloudflare.com.

Six IP addresses per host:

isaac.ns.cloudflare.com points to 2606:4700:58::adf5:3bb1, 2803:f800:50::6ca2:c1b1, 2a06:98c1:50::ac40:21b1, 108.162.193.177, 172.64.33.177 and 173.245.59.177; lana.ns.cloudflare.com points to 2606:4700:50::adf5:3ab6, 2803:f800:50::6ca2:c0b6, 2a06:98c1:50::ac40:20b6, 108.162.192.182, 172.64.32.182 and 173.245.58.182

Mail Servers

courses123.com is handled by a single mail server, courses123-com.mail.protection.outlook.com.

Hostname courses123-com.mail.protection.outlook.com resolves to eight IP numbers: 2a01:111:f403:ca04::1, 2a01:111:f403:ca04::6, 2a01:111:f403:ca04::f, 2a01:111:f403:ca09::20, 52.101.68.3, 52.101.68.5, 52.101.68.8 and 52.101.73.6.

courses123.com - robtex.com

courses123.com

com

Same first word

Similar names

DNS History

🔍 DNS Trace

📋 Delegation Chain

✅ Authoritative Response

🔒 DNSSEC Status

⏱️ Timing

📄 Records

📌 Glue Records Collected

Analysis

IP Addresses

Name Servers

Mail Servers

`courses123.com`

`com`