`crystal-course.com`

DNSSEC	⚠️ Not signed
A	2606:4700:3034::6815:46eb^{🇺🇸 Cloudflare2606:4700:3034::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	2606:4700:3034::ac43:a8c0^{🇺🇸 Cloudflare2606:4700:3034::/48 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	104.21.70.235^{Cloudflare104.21.64.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
A	172.67.168.192^{🇺🇸 Cloudflare172.67.160.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US} ✓ In HTTPS hints
NS	`jo.ns.cloudflare.com` ⭐
		A	2606:4700:50::adf5:3aac^{🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`jo.ns.cloudflare.com`
		A	2803:f800:50::6ca2:c0ac^{🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L}
			PTR	`jo.ns.cloudflare.com`
		A	2a06:98c1:50::ac40:20ac^{🇺🇸 Cloudflare2a06:98c1:50::/45}
			PTR	`jo.ns.cloudflare.com`
		A	108.162.192.172^{🇺🇸 Cloudflare108.162.192.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`jo.ns.cloudflare.com`
		A	172.64.32.172^{🇺🇸 Cloudflare172.64.32.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`jo.ns.cloudflare.com`
		A	173.245.58.172^{🇺🇸 Cloudflare173.245.58.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`jo.ns.cloudflare.com`
NS	`milan.ns.cloudflare.com`
		A	2606:4700:58::a29f:2c15^{🇺🇸 Cloudflare2606:4700:50::/44 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`milan.ns.cloudflare.com`
		A	2803:f800:50::6ca2:c315^{🇨🇷 Cloudflare2803:f800:50::/45 LACNIC generated route6 for CloudFlare Latin America S.R.L}
			PTR	`milan.ns.cloudflare.com`
		A	2a06:98c1:50::ac40:2315^{🇺🇸 Cloudflare2a06:98c1:50::/45}
			PTR	`milan.ns.cloudflare.com`
		A	108.162.195.21^{🇺🇸 Cloudflare108.162.195.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`milan.ns.cloudflare.com`
		A	162.159.44.21^{Cloudflare162.159.32.0/20 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`milan.ns.cloudflare.com`
		A	172.64.35.21^{🇺🇸 Cloudflare172.64.35.0/24 , Inc. 101 Townsend Street, San Francisco, California 94107, US}
			PTR	`milan.ns.cloudflare.com`
HTTPS	HTTP/3, HTTP/2 ✓ hints match
		IPv4 hints	104.21.70.235, 172.67.168.192
		IPv6 hints	2606:4700:3034::6815:46eb, 2606:4700:3034::ac43:a8c0
SOA	`jo.ns.cloudflare.com`dns@cloudflare.com serial=2402414908

`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=1777272471

⚠️ On DNS blocklist: tif

Same first word

crystal-course.com

DNS History

6 records (6 active, 0 former)

●NSjo.ns.cloudflare.com2026-04-12 → 2026-04-27 · 2 obs

● 2026-04-12 21:48:02
● 2026-04-27 07:04:08

●NSmilan.ns.cloudflare.com2026-04-12 → 2026-04-27 · 2 obs

● 2026-04-12 21:48:02
● 2026-04-27 07:04:08

●A104.21.70.2352026-04-12 → 2026-04-27 · 2 obs

● 2026-04-12 21:48:02
● 2026-04-27 07:04:08

●A172.67.168.1922026-04-12 → 2026-04-27 · 2 obs

● 2026-04-12 21:48:02
● 2026-04-27 07:04:08

●A2606:4700:3034::6815:46eb2026-04-12 → 2026-04-27 · 2 obs

● 2026-04-12 21:48:02
● 2026-04-27 07:04:08

●A2606:4700:3034::ac43:a8c02026-04-12 → 2026-04-27 · 2 obs

● 2026-04-12 21:48:02
● 2026-04-27 07:04:08

🔍 DNS Trace

📋 Delegation Chain

Zone	Nameservers	Glue
com	a.gtld-servers.net, b.gtld-servers.net, c.gtld-servers.net, d.gtld-servers.net...	-
crystal-course.com	jo.ns.cloudflare.com, milan.ns.cloudflare.com	12 records

✅ Authoritative Response

Server:108.162.195.21

NS records: jo.ns.cloudflare.com, milan.ns.cloudflare.com

🔒 DNSSEC Status

⚠️ Insecure (no DNSSEC)

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

⏱️ Timing

Total: 123ms | Queries: -

📄 Records

Type	Count	Sample Data
A	2	`104.21.70.235, 172.67.168.192`
AAAA	2	`2606:4700:3034::6815:46eb, 2606:4700:3034::ac43:a8c0`
NS	2	`jo.ns.cloudflare.com, milan.ns.cloudflare.com`
HTTPS	1	`{"priority":1,"target":".","alpn":["h3",`
SOA	1	`jo.ns.cloudflare.com dns.cloudflare.com`

📌 Glue Records Collected

Total: 12

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

Analysis

IP Addresses

crystal-course.com points to four IP numbers: 2606:4700:3034::6815:46eb, 2606:4700:3034::ac43:a8c0, 104.21.70.235 and 172.67.168.192.

Other host names, for instance geometra.es, lunachan.net, www.alsoouq.com, asafship.com and www.nacknaija.com share IP numbers with crystal-course.com.

Name Servers

crystal-course.com is delegated to two name servers: jo.ns.cloudflare.com and milan.ns.cloudflare.com.

crystal-course.com uses the same name server setup as other domains, for instance ptpanama.com, gojiberry.ai, 4u-media.de, cedok.cz and saadsalman.com.

crystal-course.com shares name servers with other domains at least partially, for instance ytmp4.plus, upnines.com, narture.eu, councilonaging.net and choaq.com.

these name servers are commonly used together with logan.ns.cloudflare.com and carla.ns.cloudflare.com.

Host names with six IP numbers: jo.ns.cloudflare.com points to 2606:4700:50::adf5:3aac, 2803:f800:50::6ca2:c0ac, 2a06:98c1:50::ac40:20ac, 108.162.192.172, 172.64.32.172 and 173.245.58.172; milan.ns.cloudflare.com points to 2606:4700:58::a29f:2c15, 2803:f800:50::6ca2:c315, 2a06:98c1:50::ac40:2315, 108.162.195.21, 162.159.44.21 and 172.64.35.21.

crystal-course.com - robtex.com