offcourse.co - dns.ninja

`offcourse.co`

DNSSEC	⚠️ Not signed
A	2606:4700:3031::ac43:9283^{🇺🇸 Cloudflare2606:4700:3031::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	2606:4700:3035::6815:2967^{🇺🇸 Cloudflare2606:4700:3035::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	104.21.41.103^{Cloudflare104.21.32.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	172.67.146.131^{🇺🇸 Cloudflare172.67.144.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
NS	`kai.ns.cloudflare.com` ⭐
		A	2606:4700:58::adf5:3bbc^{🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`kai.ns.cloudflare.com`
		A	2803:f800:50::6ca2:c1bc^{🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L}
			PTR	`kai.ns.cloudflare.com`
		A	2a06:98c1:50::ac40:21bc^{🇺🇸 Cloudflare2a06:98c1:50::/45}
			PTR	`kai.ns.cloudflare.com`
		A	108.162.193.188^{🇺🇸 Cloudflare108.162.193.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`kai.ns.cloudflare.com`
		A	172.64.33.188^{🇺🇸 Cloudflare172.64.33.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`kai.ns.cloudflare.com`
		A	173.245.59.188^{🇺🇸 Cloudflare173.245.59.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`kai.ns.cloudflare.com`
NS	`meg.ns.cloudflare.com`
		A	2606:4700:50::adf5:3ac4^{🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`meg.ns.cloudflare.com`
		A	2803:f800:50::6ca2:c0c4^{🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L}
			PTR	`meg.ns.cloudflare.com`
		A	2a06:98c1:50::ac40:20c4^{🇺🇸 Cloudflare2a06:98c1:50::/45}
			PTR	`meg.ns.cloudflare.com`
		A	108.162.192.196^{🇺🇸 Cloudflare108.162.192.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`meg.ns.cloudflare.com`
		A	172.64.32.196^{🇺🇸 Cloudflare172.64.32.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`meg.ns.cloudflare.com`
		A	173.245.58.196^{🇺🇸 Cloudflare173.245.58.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`meg.ns.cloudflare.com`
MX	`aspmx.l.google.com` ⭐
		A	2607:f8b0:4004:c09::1a^{🇺🇸 Google2607:f8b0:4004::/48}
			PTR	`bh-in-f26.1e100.net`
		A	64.233.180.27^{🇺🇸 Google64.233.180.0/24}
			PTR	`on-in-f27.1e100.net`
			PTR	`pe-in-f27.1e100.net`
MX	`alt1.aspmx.l.google.com`⁽²⁰⁾
		A	2800:3f0:4003:c0f::1a^{🇨🇱 Google2800:3f0:4003::/48}
		A	108.177.123.26^{🇺🇸 Google108.177.123.0/24}
			PTR	`lcscld-in-f26.1e100.net`
MX	`alt2.aspmx.l.google.com`⁽²⁰⁾
		A	2a00:1450:400b:c02::1b^{🇮🇪 Google2a00:1450:400b::/48}
			PTR	`dj-in-f27.1e100.net`
		A	172.253.116.27^{🇺🇸 Google172.253.116.0/24}
			PTR	`dj-in-f27.1e100.net`
MX	`aspmx2.googlemail.com`⁽³⁰⁾
		A	2800:3f0:4003:c0f::1b^{🇨🇱 Google2800:3f0:4003::/48}
		A	108.177.123.26^{🇺🇸 Google108.177.123.0/24}
			PTR	`lcscld-in-f26.1e100.net`
MX	`aspmx3.googlemail.com`⁽³⁰⁾
		A	2a00:1450:400b:c02::1b^{🇮🇪 Google2a00:1450:400b::/48}
			PTR	`dj-in-f27.1e100.net`
		A	172.253.116.26^{🇺🇸 Google172.253.116.0/24}
			PTR	`dj-in-f26.1e100.net`
MX	`aspmx4.googlemail.com`⁽³⁰⁾
		A	2a00:1450:4009:c0f::1a^{🇬🇧 Google2a00:1450:4009::/48}
			PTR	`yulhrs-in-f26.1e100.net`
		A	192.178.223.27^{🇺🇸 Google192.178.223.0/24}
			PTR	`yulhrs-in-f27.1e100.net`
MX	`aspmx5.googlemail.com`⁽³⁰⁾
		A	2a00:1450:400c:c23::1a^{🇧🇪 Google2a00:1450:400c::/48}
			PTR	`yubrupd-in-f26.1e100.net`
		A	172.253.157.26^{🇺🇸 Google172.253.0.0/16}
			PTR	`yubrupd-in-f26.1e100.net`
TXT	`DZC`
TXT	`mailerlite-domain-verification=f2f4ab5d3c5648bc8d67737c60b28a44aed6bb93`
TXT	`v=spf1 a mx include:_spf.mlsend.com ~all`
HTTPS	HTTP/3, HTTP/2 ✓ hints match
		IPv4 hints	104.21.41.103, 172.67.146.131
		IPv6 hints	2606:4700:3031::ac43:9283, 2606:4700:3035::6815:2967
		ECH	X25519, HKDF-SHA256 + AES-128-GCM draft, id=157, name=cloudflare-ech.com
SOA	`kai.ns.cloudflare.com`dns@cloudflare.com serial=2407521023

`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=1759688088

rank #28849 globally
rank #137 in the tld
📈 Tranco rank: #109,001

Same first word

offcourse.in

offcourse.co

offcourse.nl

offcourse.org

offcourse.golf

offcourse.com.tr

offcourse.io

offcourse.dk

offcourse.bike

offcourse.se

offcourse.no

offcourse.biz

offcourse.be

offcourse.com

offcourse.ca

offcourse.de

offcourse.jp

Similar names

courseoff.com

freofocus.com.au

forefocus.com

offsource.com

freofocus.com

DNS History

19 records (13 active, 6 former)

●NSkai.ns.cloudflare.com2026-03-22 → 2026-06-22 · 3 obs

○ 2018-07-31 12:44:24
● 2026-03-22 16:19:10
● 2026-06-22 11:57:10

●NSmeg.ns.cloudflare.com2026-03-22 → 2026-06-22 · 3 obs

○ 2018-07-31 12:44:24
● 2026-03-22 16:19:10
● 2026-06-22 11:57:10

○NSns1.dreamhost.com2015-07-11 → 2018-07-31 · 4 obs

● 2015-07-11 15:36:34
● 2018-07-31 12:44:24
○ 2026-03-22 16:19:10
○ 2026-06-22 11:57:10

○NSns2.dreamhost.com2015-07-11 → 2018-07-31 · 4 obs

● 2015-07-11 15:36:34
● 2018-07-31 12:44:24
○ 2026-03-22 16:19:10
○ 2026-06-22 11:57:10

○NSns3.dreamhost.com2015-07-11 → 2018-07-31 · 4 obs

● 2015-07-11 15:36:34
● 2018-07-31 12:44:24
○ 2026-03-22 16:19:10
○ 2026-06-22 11:57:10

●MXalt1.aspmx.l.google.com2015-07-11 → 2026-06-22 · 2 obs

● 2015-07-11 15:36:34
● 2026-06-22 11:57:10

●MXalt2.aspmx.l.google.com2015-07-11 → 2026-06-22 · 2 obs

● 2015-07-11 15:36:34
● 2026-06-22 11:57:10

●MXaspmx.l.google.com2015-07-11 → 2026-06-22 · 2 obs

● 2015-07-11 15:36:34
● 2026-06-22 11:57:10

●MXaspmx2.googlemail.com2015-07-11 → 2026-06-22 · 2 obs

● 2015-07-11 15:36:34
● 2026-06-22 11:57:10

●MXaspmx3.googlemail.com2015-07-11 → 2026-06-22 · 2 obs

● 2015-07-11 15:36:34
● 2026-06-22 11:57:10

●MXaspmx4.googlemail.com2015-07-11 → 2026-06-22 · 2 obs

● 2015-07-11 15:36:34
● 2026-06-22 11:57:10

●MXaspmx5.googlemail.com2015-07-11 → 2026-06-22 · 2 obs

● 2015-07-11 15:36:34
● 2026-06-22 11:57:10

●A104.21.41.1032026-03-22 → 2026-06-22 · 3 obs

○ 2018-07-31 12:44:24
● 2026-03-22 16:19:10
● 2026-06-22 11:57:10

○A162.243.56.782015-07-11 → 2015-07-11 · 3 obs

● 2015-07-11 15:36:34
○ 2015-11-15 01:45:56
○ 2026-06-22 11:57:10

●A172.67.146.1312026-03-22 → 2026-06-22 · 3 obs

○ 2018-07-31 12:44:24
● 2026-03-22 16:19:10
● 2026-06-22 11:57:10

○A2604:a880:0:1010::f7c:60012017-02-03 → 2018-07-31 · 5 obs

○ 2015-11-15 01:45:56
● 2017-02-03 20:12:48
● 2018-07-31 12:44:24
○ 2026-03-22 16:19:10
○ 2026-06-22 11:57:10

●A2606:4700:3031::ac43:92832026-03-22 → 2026-06-22 · 3 obs

○ 2018-07-31 12:44:24
● 2026-03-22 16:19:10
● 2026-06-22 11:57:10

●A2606:4700:3035::6815:29672026-03-22 → 2026-06-22 · 3 obs

○ 2018-07-31 12:44:24
● 2026-03-22 16:19:10
● 2026-06-22 11:57:10

○A45.55.100.1182015-11-15 → 2018-07-31 · 5 obs

○ 2015-07-11 15:36:34
● 2015-11-15 01:45:56
● 2018-07-31 12:44:24
○ 2026-03-22 16:19:10
○ 2026-06-22 11:57:10

🔍 DNS Trace

📋 Delegation Chain

Zone	Nameservers	Glue
co	d.registrydns.co, b.registrydns.co, a.registrydns.co, c.registrydns.co	-
offcourse.co	meg.ns.cloudflare.com, kai.ns.cloudflare.com	-

✅ Authoritative Response

Server:172.64.32.196

NS records: meg.ns.cloudflare.com, kai.ns.cloudflare.com

🔒 DNSSEC Status

⚠️ Insecure (no DNSSEC)

No DS record for offcourse.co (unsigned zone)

⏱️ Timing

Total: 1647ms | Queries: -

📄 Records

Type	Count	Sample Data
A	2	`172.67.146.131, 104.21.41.103`
AAAA	2	`2606:4700:3031::ac43:9283, 2606:4700:3035::6815:2967`
NS	2	`kai.ns.cloudflare.com, meg.ns.cloudflare.com`
MX	7	`ASPMX.L.GOOGLE.COM (pri: 10), ALT1.ASPMX.L.GOOGLE.COM (pri: 20)...`
TXT	3	`DZC, mailerlite-domain-verification=f2f4ab5d3...`
HTTPS	1	`{"priority":1,"target":".","alpn":["h3",`
SOA	1	`kai.ns.cloudflare.com dns.cloudflare.com`

Analysis

IP Addresses

offcourse.co has four IP addresses: 104.21.41.103, 172.67.146.131, 2606:4700:3031::ac43:9283 and 2606:4700:3035::6815:2967.

pmb.poltekkes-tjk.ac.id, coolerpodcasts.com, saerang.com plus two other host names have IP numbers in common with offcourse.co.

Name Servers

offcourse.co is delegated to two name servers: kai.ns.cloudflare.com and meg.ns.cloudflare.com.

The name server configuration of offcourse.co is shared with other domains, for instance alcas.it, apgautorubber.com, singlepoint.com and two others.

offcourse.co has at least partial name server overlap with other domains, such as didgeridoo-network.com, burnetmyanmar.org, superhost.ir and two others.

These name servers tend to appear together with the name servers leah.ns.cloudflare.com, joan.ns.cloudflare.com and destiny.ns.cloudflare.com.

Hosts with 6 IP addresses each:

kai.ns.cloudflare.com resolves to 108.162.193.188, 172.64.33.188, 173.245.59.188 and 3 other IP addresses.

meg.ns.cloudflare.com resolves to 108.162.192.196, 172.64.32.196, 173.245.58.196 and 3 other IP addresses.

Mail Servers

Mail for offcourse.co is routed through 7 mail servers, including aspmx2.googlemail.com, aspmx3.googlemail.com, aspmx4.googlemail.com and 4 other.

At least some of the mail servers used by offcourse.co are shared with other domains: blueskyapparel.net, clear.ml, ns500742.ns500731.ns500742.ns500754.ns500754.ns500705.ns500704.ns500704.ns500705.ns500704.ns500688.ns500688.ns500649.ns500649.ns500666.ns500142.lusty(0x736c7574)z.com and two others among them.

These mail servers are often deployed together with alt1.aspmx.l.google.com, aspmx.l.google.com, alt2.aspmx.l.google.com and 3 other mail servers.

Host names pointing to two IP addresses:

aspmx2.googlemail.com points to 108.177.123.26 and 2800:3f0:4003:c0f::1b.

aspmx3.googlemail.com points to 172.253.116.26 and 2a00:1450:400b:c02::1b.

aspmx4.googlemail.com points to 192.178.223.27 and 2a00:1450:4009:c0f::1a.

aspmx5.googlemail.com points to 172.253.157.26 and 2a00:1450:400c:c23::1a.

aspmx.l.google.com points to 64.233.180.27 and 2607:f8b0:4004:c09::1a.

alt1.aspmx.l.google.com points to 108.177.123.26 and 2800:3f0:4003:c0f::1a.

alt2.aspmx.l.google.com points to 172.253.116.27 and 2a00:1450:400b:c02::1b.

aspmx2.googlemail.com and alt1.aspmx.l.google.com are host names that each point to 108.177.123.26 IP addresses.

aspmx3.googlemail.com and alt2.aspmx.l.google.com are host names that each point to 2a00:1450:400b:c02::1b IP addresses.