`open-course.com`

DNSSEC	⚠️ Not signed
NS	`ns1.flippa.com` ⚠️ Not in zone NS records
		A	18.233.141.236^{🇺🇸 Amazon18.232.0.0/14 EC2 IAD prefix}
			PTR	`ec2-18-233-141-236.compute-1.amazonaws.com`
NS	`ns2.flippa.com` ⚠️ Not in zone NS records
		A	18.233.141.236^{🇺🇸 Amazon18.232.0.0/14 EC2 IAD prefix}
			PTR	`ec2-18-233-141-236.compute-1.amazonaws.com`

`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=1784694067

WOT: UNKNOWN (60/100)

Same first word

open-course.com

open-course.net

Similar names

DNS History

4 records (2 active, 2 former)

●NSns1.flippa.com2026-07-12 → 2026-07-22 · 2 obs

● 2026-07-12 08:19:20
● 2026-07-22 04:38:10

●NSns2.flippa.com2026-07-12 → 2026-07-22 · 2 obs

● 2026-07-12 08:19:20
● 2026-07-22 04:38:10

○A54.175.122.1942017-03-22 → 2017-03-22 · 3 obs

● 2017-03-22 03:25:56
○ 2026-07-12 08:19:20
○ 2026-07-22 04:38:10

○CNAMEwebapp.parkingpage.production.flippa.com2017-03-22 → 2017-03-22 · 3 obs

● 2017-03-22 03:25:56
○ 2026-07-12 08:19:20
○ 2026-07-22 04:38:10

🔍 DNS Trace

Analysis

Name Servers

open-course.com is served by two delegated name servers, ns1.flippa.com and ns2.flippa.com.

open-course.com shares its NS records with other domains, for example tophi.net, fnbmagazine.com, sellcarbot.com and two others.

The name servers of open-course.com overlap at least partially with those of other domains — among them shops.us, lateenos.com, aquientequejas.com and two more.

ns1.flippa.com and ns2.flippa.com share one IP address between them — 18.233.141.236.

These two host names — ns1.flippa.com and ns2.flippa.com — each point to 18.233.141.236 IP addresses.

open-course.com - robtex.com

open-course.com

com