`course-on.com`

DNSSEC	⚠️ Not signed
A	2606:4700:3031::ac43:91ee^{🇺🇸 Cloudflare2606:4700:3031::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	2606:4700:3035::6815:5fa2^{🇺🇸 Cloudflare2606:4700:3035::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	104.21.95.162^{Cloudflare104.21.80.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	172.67.145.238^{🇺🇸 Cloudflare172.67.144.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
NS	`brynne.ns.cloudflare.com` ⭐
		A	2606:4700:50::a29f:2641^{🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`brynne.ns.cloudflare.com`
		A	2803:f800:50::6ca2:c241^{🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L}
			PTR	`brynne.ns.cloudflare.com`
		A	2a06:98c1:50::ac40:2241^{🇺🇸 Cloudflare2a06:98c1:50::/45}
			PTR	`brynne.ns.cloudflare.com`
		A	108.162.194.65^{🇺🇸 Cloudflare108.162.194.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`brynne.ns.cloudflare.com`
		A	162.159.38.65^{Cloudflare162.159.32.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`brynne.ns.cloudflare.com`
		A	172.64.34.65^{🇺🇸 Cloudflare172.64.34.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`brynne.ns.cloudflare.com`
NS	`major.ns.cloudflare.com`
		A	2606:4700:58::adf5:3bf1^{🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`major.ns.cloudflare.com`
		A	2803:f800:50::6ca2:c1f1^{🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L}
			PTR	`major.ns.cloudflare.com`
		A	2a06:98c1:50::ac40:21f1^{🇺🇸 Cloudflare2a06:98c1:50::/45}
			PTR	`major.ns.cloudflare.com`
		A	108.162.193.241^{🇺🇸 Cloudflare108.162.193.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`major.ns.cloudflare.com`
		A	172.64.33.241^{🇺🇸 Cloudflare172.64.33.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`major.ns.cloudflare.com`
		A	173.245.59.241^{🇺🇸 Cloudflare173.245.59.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`major.ns.cloudflare.com`
MX	`_dc-mx.28f3d30d809e.course-on.com` ⭐
		A	95.217.117.236^{🇫🇮 Hetzner95.217.0.0/16 HETZNER-DC}
			PTR	`course-on.com`
TXT	`v=spf1 mx ~all`
HTTPS	HTTP/3, HTTP/2 ✓ hints match
		IPv4	104.21.95.162, 172.67.145.238
		IPv6	2606:4700:3031::ac43:91ee, 2606:4700:3035::6815:5fa2
SOA	`brynne.ns.cloudflare.com`dns@cloudflare.com serial=2398107636

`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

PTR for

236.117.217.95.in-addr.arpa

Same first word

course-on.com

Similar names

on-course.de

euro-cons.de

on-course.eu

DNS History

15 records (7 active, 8 former)

○NSalpha.freehost.com.ua2015-06-20 → 2017-03-14 · 4 obs

● 2015-06-20 04:58:50
● 2017-03-14 14:04:42
○ 2026-02-17 11:26:20
○ 2026-03-24 07:52:08

○NSbeta.freehost.com.ua2015-06-20 → 2017-03-14 · 4 obs

● 2015-06-20 04:58:50
● 2017-03-14 14:04:42
○ 2026-02-17 11:26:20
○ 2026-03-24 07:52:08

●NSbrynne.ns.cloudflare.com2026-02-17 → 2026-03-24 · 3 obs

○ 2017-03-14 14:04:42
● 2026-02-17 11:26:20
● 2026-03-24 07:52:08

○NSgamma.freehost.com.ua2015-06-20 → 2017-03-14 · 4 obs

● 2015-06-20 04:58:50
● 2017-03-14 14:04:42
○ 2026-02-17 11:26:20
○ 2026-03-24 07:52:08

●NSmajor.ns.cloudflare.com2026-02-17 → 2026-03-24 · 3 obs

○ 2017-03-14 14:04:42
● 2026-02-17 11:26:20
● 2026-03-24 07:52:08

●MX_dc-mx.28f3d30d809e.course-on.com2026-02-17 → 2026-03-24 · 3 obs

○ 2017-03-14 14:04:42
● 2026-02-17 11:26:20
● 2026-03-24 07:52:08

○MXmail0.freehost.com.ua2015-06-20 → 2017-03-14 · 4 obs

● 2015-06-20 04:58:50
● 2017-03-14 14:04:42
○ 2026-02-17 11:26:20
○ 2026-03-24 07:52:08

○MXmail1.freehost.com.ua2015-06-20 → 2017-03-14 · 4 obs

● 2015-06-20 04:58:50
● 2017-03-14 14:04:42
○ 2026-02-17 11:26:20
○ 2026-03-24 07:52:08

○MXmail2.freehost.com.ua2015-06-20 → 2017-03-14 · 4 obs

● 2015-06-20 04:58:50
● 2017-03-14 14:04:42
○ 2026-02-17 11:26:20
○ 2026-03-24 07:52:08

●A104.21.95.1622026-02-17 → 2026-03-24 · 3 obs

○ 2017-03-14 14:04:42
● 2026-02-17 11:26:20
● 2026-03-24 07:52:08

●A172.67.145.2382026-02-17 → 2026-03-24 · 3 obs

○ 2017-03-14 14:04:42
● 2026-02-17 11:26:20
● 2026-03-24 07:52:08

○A178.20.153.1112016-01-22 → 2017-03-14 · 5 obs

○ 2015-11-22 07:37:46
● 2016-01-22 18:46:56
● 2017-03-14 14:04:42
○ 2026-02-17 11:26:20
○ 2026-03-24 07:52:08

○A178.20.153.662015-06-20 → 2015-11-22 · 4 obs

● 2015-06-20 04:58:50
● 2015-11-22 07:37:46
○ 2016-01-22 18:46:56
○ 2026-03-24 07:52:08

●A2606:4700:3031::ac43:91ee2026-02-17 → 2026-03-24 · 3 obs

○ 2017-03-14 14:04:42
● 2026-02-17 11:26:20
● 2026-03-24 07:52:08

●A2606:4700:3035::6815:5fa22026-02-17 → 2026-03-24 · 3 obs

○ 2017-03-14 14:04:42
● 2026-02-17 11:26:20
● 2026-03-24 07:52:08

🔍 DNS Trace

📋 Delegation Chain

Zone	Nameservers	Glue
com	a.gtld-servers.net, b.gtld-servers.net, c.gtld-servers.net, d.gtld-servers.net...	-
course-on.com	major.ns.cloudflare.com, brynne.ns.cloudflare.com	12 records

✅ Authoritative Response

Server:108.162.194.65

NS records: major.ns.cloudflare.com, brynne.ns.cloudflare.com

🔒 DNSSEC Status

⚠️ Insecure (no DNSSEC)

No DS record for course-on.com (unsigned zone)

⏱️ Timing

Total: 151ms | Queries: -

📄 Records

Type	Count	Sample Data
A	2	`104.21.95.162, 172.67.145.238`
AAAA	2	`2606:4700:3031::ac43:91ee, 2606:4700:3035::6815:5fa2`
NS	2	`brynne.ns.cloudflare.com, major.ns.cloudflare.com`
MX	1	`_dc-mx.28f3d30d809e.course-on.com (pri:`
TXT	1	`v=spf1 mx ~all`
HTTPS	1	`{"priority":1,"target":".","alpn":["h3",`
SOA	1	`brynne.ns.cloudflare.com dns.cloudflare.`

📌 Glue Records Collected

Total: 12

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

Analysis

IP Addresses

course-on.com points to four IP numbers: 2606:4700:3031::ac43:91ee, 2606:4700:3035::6815:5fa2, 104.21.95.162 and 172.67.145.238.

Other host names, for instance hotelscombined.lv, webpro-it.co.uk, www.diaryofaquilter.com, diaryofaquilter.com and 594s.com share IP numbers with course-on.com.

Name Servers

course-on.com's delegation is to two name servers brynne.ns.cloudflare.com and major.ns.cloudflare.com.

course-on.com shares the same name server configuration as other domains, such as chaosheroesonline.jp, dot39.com, joingrouper.com, brasilmetropole.com.br and catespark.com.

course-on.com at least partially shares its name servers with other domains, for instance deepwater-valves.com, optelvision.com, encontreoportunidades.com.br, brickimobiliaria.com.br and kbitconsultants.com.au.

These name servers are commonly used with dora.ns.cloudflare.com, lex.ns.cloudflare.com and carl.ns.cloudflare.com.

Host names with six IP numbers:

brynne.ns.cloudflare.com points to: 2606:4700:50::a29f:2641, 2803:f800:50::6ca2:c241, 2a06:98c1:50::ac40:2241, 108.162.194.65, 162.159.38.65 and 172.64.34.65.

major.ns.cloudflare.com points to: 2606:4700:58::adf5:3bf1, 2803:f800:50::6ca2:c1f1, 2a06:98c1:50::ac40:21f1, 108.162.193.241, 172.64.33.241 and 173.245.59.241.

Mail Servers

course-on.com is served by a single mail server, _dc-mx.28f3d30d809e.course-on.com.

_dc-mx.28f3d30d809e.course-on.com points to IP number 95.217.117.236.

course-on.com - robtex.com

course-on.com

com

PTR for

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

`course-on.com`

`com`