`courself.co`

DNSSEC	⚠️ Not signed
A	2606:4700:3032::6815:4ae7^{🇺🇸 Cloudflare2606:4700:3032::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	2606:4700:3037::ac43:a450^{🇺🇸 Cloudflare2606:4700:3037::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	104.21.74.231^{Cloudflare104.21.64.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	172.67.164.80^{🇺🇸 Cloudflare172.67.160.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
NS	`leif.ns.cloudflare.com` ⭐
		A	2606:4700:58::a29f:2cde^{🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`leif.ns.cloudflare.com`
		A	2803:f800:50::6ca2:c3de^{🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L}
			PTR	`leif.ns.cloudflare.com`
		A	2a06:98c1:50::ac40:23de^{🇺🇸 Cloudflare2a06:98c1:50::/45}
			PTR	`leif.ns.cloudflare.com`
		A	108.162.195.222^{🇺🇸 Cloudflare108.162.195.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`leif.ns.cloudflare.com`
		A	162.159.44.222^{Cloudflare162.159.32.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`leif.ns.cloudflare.com`
		A	172.64.35.222^{🇺🇸 Cloudflare172.64.35.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`leif.ns.cloudflare.com`
NS	`naomi.ns.cloudflare.com`
		A	2606:4700:50::adf5:3ad0^{🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`naomi.ns.cloudflare.com`
		A	2803:f800:50::6ca2:c0d0^{🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L}
			PTR	`naomi.ns.cloudflare.com`
		A	2a06:98c1:50::ac40:20d0^{🇺🇸 Cloudflare2a06:98c1:50::/45}
			PTR	`naomi.ns.cloudflare.com`
		A	108.162.192.208^{🇺🇸 Cloudflare108.162.192.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`naomi.ns.cloudflare.com`
		A	172.64.32.208^{🇺🇸 Cloudflare172.64.32.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`naomi.ns.cloudflare.com`
		A	173.245.58.208^{🇺🇸 Cloudflare173.245.58.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`naomi.ns.cloudflare.com`
MX	`smtp.google.com` ⭐
		A	2607:f8b0:4023:c06::1a^{🇺🇸 Google2607:f8b0::/32}
			PTR	`dz-in-f26.1e100.net`
		A	2607:f8b0:4023:c06::1b^{🇺🇸 Google2607:f8b0::/32}
			PTR	`dz-in-f27.1e100.net`
		A	2607:f8b0:4023:c0b::1a^{🇺🇸 Google2607:f8b0::/32}
			PTR	`dd-in-f26.1e100.net`
		A	2607:f8b0:4023:c0b::1b^{🇺🇸 Google2607:f8b0::/32}
			PTR	`dd-in-f27.1e100.net`
		A	142.250.101.26^{🇺🇸 Google142.250.101.0/24}
			PTR	`dz-in-f26.1e100.net`
		A	142.250.101.27^{🇺🇸 Google142.250.101.0/24}
			PTR	`dz-in-f27.1e100.net`
		A	142.250.141.26^{🇺🇸 Google142.250.141.0/24}
			PTR	`dd-in-f26.1e100.net`
		A	142.250.141.27^{🇺🇸 Google142.250.141.0/24}
			PTR	`dd-in-f27.1e100.net`
		A	142.251.2.26^{🇺🇸 Google142.251.2.0/24}
			PTR	`dl-in-f26.1e100.net`
TXT	`google-site-verification=Qmlzvk4e_xOv2dkosGp5J8LOB37X1fPoJFxAg-NdE4o`
TXT	`google-site-verification=ZDkIvPsC-PWddnRM29cY5XZv8-WhS7O8HBpMhrLaJ0E`
HTTPS	HTTP/3, HTTP/2 ✓ hints match
		IPv4	104.21.74.231, 172.67.164.80
		IPv6	2606:4700:3032::6815:4ae7, 2606:4700:3037::ac43:a450
SOA	`leif.ns.cloudflare.com`dns@cloudflare.com serial=2396809876

`co`

	DNSSEC	🔒 Signed (DS record present)
	NS	`ns0.centralnic.net` ⭐
	NS	`a.registrydns.co`
	NS	`b.registrydns.co`
	NS	`c.registrydns.co`
	NS	`d.registrydns.co`
	SOA	`ns0.centralnic.net`hostmaster@centralnic.net serial=1759615358

Subdomains

www.courself.co

Same first word

courself.com

courself.co

Similar names

DNS History

17 records (7 active, 10 former)

●NSleif.ns.cloudflare.com2020-04-06 → 2026-03-23 · 2 obs

● 2020-04-06 08:07:16
● 2026-03-23 19:11:54

●NSnaomi.ns.cloudflare.com2020-04-06 → 2026-03-23 · 2 obs

● 2020-04-06 08:07:16
● 2026-03-23 19:11:54

●MXsmtp.google.com2026-02-24 → 2026-03-23 · 2 obs

● 2026-02-24 03:24:08
● 2026-03-23 19:11:54

○A104.19.238.1172020-04-06 → 2020-04-06 · 3 obs

● 2020-04-06 08:07:16
○ 2026-02-24 03:24:08
○ 2026-03-23 19:11:54

○A104.19.239.1172020-04-06 → 2020-04-06 · 3 obs

● 2020-04-06 08:07:16
○ 2026-02-24 03:24:08
○ 2026-03-23 19:11:54

●A104.21.74.2312026-02-24 → 2026-03-23 · 9 obs

○ 2020-04-06 08:07:16
● 2026-02-24 03:24:08
● 2026-02-27 09:47:48
○ 2026-03-07 01:33:54
● 2026-03-08 19:43:42
○ 2026-03-14 14:01:02
○ 2026-03-15 18:27:42
● 2026-03-19 01:12:56
● 2026-03-23 19:11:54

○A172.64.80.12026-03-07 → 2026-03-15 · 7 obs

○ 2026-02-27 09:47:48
● 2026-03-07 01:33:54
○ 2026-03-08 19:43:42
○ 2026-03-14 14:01:02
● 2026-03-15 18:27:42
○ 2026-03-19 01:12:56
○ 2026-03-23 19:11:54

●A172.67.164.802026-02-24 → 2026-03-23 · 9 obs

○A188.114.96.02026-03-14 → 2026-03-14 · 4 obs

○ 2026-03-08 19:43:42
● 2026-03-14 14:01:02
○ 2026-03-15 18:27:42
○ 2026-03-23 19:11:54

○A188.114.97.02026-03-14 → 2026-03-14 · 4 obs

○ 2026-03-08 19:43:42
● 2026-03-14 14:01:02
○ 2026-03-15 18:27:42
○ 2026-03-23 19:11:54

○A2606:4700::6813:ee752020-04-06 → 2020-04-06 · 3 obs

● 2020-04-06 08:07:16
○ 2026-02-24 03:24:08
○ 2026-03-23 19:11:54

○A2606:4700::6813:ef752020-04-06 → 2020-04-06 · 3 obs

● 2020-04-06 08:07:16
○ 2026-02-24 03:24:08
○ 2026-03-23 19:11:54

○A2606:4700:130:436c:6f75:6466:6c61:72652026-03-15 → 2026-03-15 · 4 obs

○ 2026-03-14 14:01:02
● 2026-03-15 18:27:42
○ 2026-03-19 01:12:56
○ 2026-03-23 19:11:54

●A2606:4700:3032::6815:4ae72026-02-24 → 2026-03-23 · 6 obs

○ 2020-04-06 08:07:16
● 2026-02-24 03:24:08
● 2026-03-14 14:01:02
○ 2026-03-15 18:27:42
○ 2026-03-19 01:12:56
● 2026-03-23 19:11:54

●A2606:4700:3037::ac43:a4502026-02-24 → 2026-03-23 · 6 obs

○ 2020-04-06 08:07:16
● 2026-02-24 03:24:08
● 2026-03-14 14:01:02
○ 2026-03-15 18:27:42
○ 2026-03-19 01:12:56
● 2026-03-23 19:11:54

○A2a06:98c1:3120::2026-03-19 → 2026-03-19 · 3 obs

○ 2026-03-15 18:27:42
● 2026-03-19 01:12:56
○ 2026-03-23 19:11:54

○A2a06:98c1:3121::2026-03-19 → 2026-03-19 · 3 obs

○ 2026-03-15 18:27:42
● 2026-03-19 01:12:56
○ 2026-03-23 19:11:54

🔍 DNS Trace

📋 Delegation Chain

Zone	Nameservers	Glue
co	a.registrydns.co, b.registrydns.co, c.registrydns.co, d.registrydns.co	-
courself.co	leif.ns.cloudflare.com, naomi.ns.cloudflare.com	-

✅ Authoritative Response

Server:172.64.35.222

NS records: leif.ns.cloudflare.com, naomi.ns.cloudflare.com

🔒 DNSSEC Status

⚠️ Insecure (no DNSSEC)

No DS record for courself.co (unsigned zone)

⏱️ Timing

Total: 582ms | Queries: -

📄 Records

Type	Count	Sample Data
A	2	`104.21.74.231, 172.67.164.80`
AAAA	2	`2606:4700:3037::ac43:a450, 2606:4700:3032::6815:4ae7`
NS	2	`leif.ns.cloudflare.com, naomi.ns.cloudflare.com`
MX	1	`smtp.google.com (pri: 0)`
TXT	2	`google-site-verification=Qmlzvk4e_xOv2dk, google-site-verification=ZDkIvPsC-PWddnR`
HTTPS	1	`{"priority":1,"target":".","alpn":["h3",`
SOA	1	`leif.ns.cloudflare.com dns.cloudflare.co`

Analysis

Hierarchy

courself.co is a parent of www.courself.co.

IP Addresses

courself.co points to four IP numbers: 2606:4700:3032::6815:4ae7, 2606:4700:3037::ac43:a450, 104.21.74.231 and 172.67.164.80.

Other host names, for instance yuloocrio.live, orusttorget.se, summermovieexpress.net, okcits.com and sonitech.co.uk share IP numbers with courself.co.

Name Servers

Delegation for courself.co rests with two name servers, leif.ns.cloudflare.com and naomi.ns.cloudflare.com.

courself.co shares the same name server setup as other domains, including altiplanominerals.com, elperiodicodecastillayleon.com, osrqhr.es, jeetway.me and jeetway.club.

courself.co at least partially shares name servers with other domains, for instance iucpuv.cn, journaldunumerique.com, scrample.com, danasia.cn and ianscarffe.com.

These name servers are commonly used with kim.ns.cloudflare.com and emma.ns.cloudflare.com.

Host names with six IP numbers: leif.ns.cloudflare.com points to: 2606:4700:58::a29f:2cde, 2803:f800:50::6ca2:c3de, 2a06:98c1:50::ac40:23de, 108.162.195.222, 162.159.44.222 and 172.64.35.222. naomi.ns.cloudflare.com points to: 2606:4700:50::adf5:3ad0, 2803:f800:50::6ca2:c0d0, 2a06:98c1:50::ac40:20d0, 108.162.192.208, 172.64.32.208 and 173.245.58.208.

Mail Servers

courself.co is handled by a single mail server, smtp.google.com.

courself.co uses the same mail server configuration as other domains, such as casmt.com, pisystems.net, ibksport.com, kdi.ie and infconsult.com.br.

courself.co shares mail servers with other domains at least in part, for instance aayouleagues.com, pandemonium.com, buonmecoffee.com, xmobile.co.il and fsts.org.

These mail servers are often used with 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.

Host smtp.google.com points to nine IP numbers: 2607:f8b0:4023:c06::1a, 2607:f8b0:4023:c06::1b, 2607:f8b0:4023:c0b::1a, 2607:f8b0:4023:c0b::1b, 142.250.101.26, 142.250.101.27, 142.250.141.26, 142.250.141.27 and 142.251.2.26.

courself.co - robtex.com

courself.co

co

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

`courself.co`

`co`