courses - robtex.com
courses
(root)
| DNSSEC | 🔒 Signed (DS record present) | ||||||
| NS | a.root-servers.net ⭐ ⚠️ Not in parent delegation | ||||||
| NS | b.root-servers.net ⚠️ Not in parent delegation | ||||||
| NS | c.root-servers.net ⚠️ Not in parent delegation | ||||||
| NS | d.root-servers.net ⚠️ Not in parent delegation | ||||||
| NS | e.root-servers.net ⚠️ Not in parent delegation | ||||||
| NS | f.root-servers.net ⚠️ Not in parent delegation | ||||||
| NS | g.root-servers.net ⚠️ Not in parent delegation | ||||||
| NS | h.root-servers.net ⚠️ Not in parent delegation | ||||||
| NS | i.root-servers.net ⚠️ Not in parent delegation | ||||||
| NS | j.root-servers.net ⚠️ Not in parent delegation | ||||||
| NS | k.root-servers.net ⚠️ Not in parent delegation | ||||||
| NS | l.root-servers.net ⚠️ Not in parent delegation | ||||||
| NS | m.root-servers.net ⚠️ Not in parent delegation | ||||||
| SOA | a.root-servers.netnstld@verisign-grs.com 2026-06-02 #0 | ||||||
Subdomains
Same first word
Similar names
DNS History
7 records (6 active, 1 former)
●NSa.nic.courses2015-08-21 → 2026-06-02 · 2 obs
● 2026-06-02 15:16:06
●NSb.nic.courses2015-08-21 → 2026-06-02 · 2 obs
● 2026-06-02 15:16:06
●NSc.nic.courses2015-08-21 → 2026-06-02 · 2 obs
● 2026-06-02 15:16:06
○NSd.nic.courses2015-08-21 → 2017-06-04 · 4 obs
● 2017-06-04 20:57:56
○ 2026-02-14 18:29:46
○ 2026-06-02 15:16:06
●NSx.nic.courses2026-02-14 → 2026-06-02 · 3 obs
● 2026-02-14 18:29:46
● 2026-06-02 15:16:06
●NSy.nic.courses2026-02-14 → 2026-06-02 · 3 obs
● 2026-02-14 18:29:46
● 2026-06-02 15:16:06
●NSz.nic.courses2026-02-14 → 2026-06-02 · 3 obs
● 2026-02-14 18:29:46
● 2026-06-02 15:16:06
🔍 DNS Trace
📋 Delegation Chain
| Zone | Nameservers | Glue |
|---|---|---|
| courses | a.nic.courses, b.nic.courses, c.nic.courses, x.nic.courses... | 12 records |
✅ Authoritative Response
Server:156.154.174.82
NS records: a.nic.courses, b.nic.courses, c.nic.courses, x.nic.courses, y.nic.courses, z.nic.courses
🔒 DNSSEC Status
🔐 Secure (DNSSEC validated)
Chain of trust verified from root to domain
⏱️ Timing
Total: 272ms | Queries: -
📄 Records
| Type | Count | Sample Data |
|---|---|---|
| NS | 6 | a.nic.courses, b.nic.courses... |
| SOA | 1 | a.nic.courses admin.tldns.godaddy |
📌 Glue Records Collected
Total: 12
In-bailiwick: 12 (a.nic.courses, b.nic.courses, c.nic.courses...)
Analysis
Hierarchy
courses is the parent domain for pbtkhdu.courses, instagram.courses, unamensagens.courses, auricpp.courses, yetells-essim.courses and several hundred additional host names.
Name Servers
courses is delegated to 6 name servers: a.nic.courses, b.nic.courses, c.nic.courses and three others.
The DNS delegation for courses at least partly coincides with that of other domains, nic.courses being one example.
It is common for these name servers to be used in conjunction with the name servers x.nic.courses, y.nic.courses and z.nic.courses.
Host names with two IP numbers:
a.nic.courses maps to two IP addresses — 37.209.192.9 and 2001:dcd:1::9.
b.nic.courses maps to two IP addresses — 37.209.194.9 and 2001:dcd:2::9.
c.nic.courses maps to two IP addresses — 37.209.196.9 and 2001:dcd:3::9.
x.nic.courses maps to two IP addresses — 156.154.172.82 and 2610:a1:1074::1:82.
y.nic.courses maps to two IP addresses — 156.154.173.82 and 2610:a1:1075::1:82.
z.nic.courses maps to two IP addresses — 156.154.174.82 and 2610:a1:1076::1:82.