courses4.ru - robtex.com
courses4.ru
| DNSSEC | ⚠️ Not signed | ||||||
| A | 213.136.85.7🇩🇪 CONTABO213.136.84.0/23 | ||||||
| PTR | m31607.contaboserver.net | ||||||
| NS | a.ns.selectel.ru ⭐ | ||||||
| A | 2a00:ab00:800::2:53🇷🇺 SELECTEL2a00:ab00::/32 Selectel IPv6 | ||||||
| A | 188.68.203.1🇷🇺 SELECTEL188.68.203.0/24 Selectel Route Object | ||||||
| PTR | a.ns.selectel.ru | ||||||
| NS | b.ns.selectel.ru | ||||||
| A | 2a00:ab00:801::2:53🇷🇺 SELECTEL2a00:ab00::/32 Selectel IPv6 | ||||||
| A | 77.223.114.2🇷🇺 SELECTEL77.223.114.0/24 Selectel Route Object | ||||||
| PTR | b.ns.selectel.ru | ||||||
| NS | c.ns.selectel.ru | ||||||
| A | 2a00:ab00:802::2:53🇷🇺 SELECTEL2a00:ab00::/32 Selectel IPv6 | ||||||
| A | 188.68.203.3🇷🇺 SELECTEL188.68.203.0/24 Selectel Route Object | ||||||
| PTR | c.ns.selectel.ru | ||||||
| NS | d.ns.selectel.ru | ||||||
| A | 2a00:ab00:803::2:53🇷🇺 SELECTEL2a00:ab00::/32 Selectel IPv6 | ||||||
| A | 77.223.114.4🇷🇺 SELECTEL77.223.114.0/24 Selectel Route Object | ||||||
| PTR | d.ns.selectel.ru | ||||||
| SOA | a.ns.selectel.rusupport@selectel.ru 2026-04-05 #3 | ||||||
ru
| DNSSEC | 🔒 Signed (DS record present) | ||||||
| NS | a.dns.ripn.net ⭐ | ||||||
| NS | b.dns.ripn.net | ||||||
| NS | d.dns.ripn.net | ||||||
| NS | e.dns.ripn.net | ||||||
| NS | f.dns.ripn.net | ||||||
| SOA | a.dns.ripn.nethostmaster@ripn.net serial=4068485 | ||||||
Subdomains
komsomolsk.courses4.ru |
kizel.courses4.ru |
bogorodsk.courses4.ru |
abdulino.courses4.ru |
abaza.courses4.ru |
pavlovsk.courses4.ru |
Same first word
DNS History
15 records (5 active, 10 former)
●NSa.ns.selectel.ru2026-04-12 → 2026-04-12 · 2 obs
● 2026-04-12 08:15:16
●NSb.ns.selectel.ru2026-04-12 → 2026-04-12 · 2 obs
● 2026-04-12 08:15:16
●NSc.ns.selectel.ru2026-04-12 → 2026-04-12 · 2 obs
● 2026-04-12 08:15:16
●NSd.ns.selectel.ru2026-04-12 → 2026-04-12 · 2 obs
● 2026-04-12 08:15:16
○NSns1.peterhost.ru2015-07-14 → 2016-11-27 · 4 obs
● 2016-11-27 18:19:14
○ 2017-09-22 16:25:46
○ 2026-04-12 08:15:16
○NSns1.snparking.ru2017-09-22 → 2017-09-22 · 3 obs
● 2017-09-22 16:25:46
○ 2026-04-12 08:15:16
○NSns2.peterhost.ru2015-07-14 → 2016-11-27 · 4 obs
● 2016-11-27 18:19:14
○ 2017-09-22 16:25:46
○ 2026-04-12 08:15:16
○NSns3.salenames.ru2017-09-22 → 2017-09-22 · 3 obs
● 2017-09-22 16:25:46
○ 2026-04-12 08:15:16
○NSns4.salenames.ru2017-09-22 → 2017-09-22 · 3 obs
● 2017-09-22 16:25:46
○ 2026-04-12 08:15:16
○MXmx2.peterhost.ru2015-07-14 → 2016-11-27 · 4 obs
● 2016-11-27 18:19:14
○ 2017-09-22 16:25:46
○ 2026-04-12 08:15:16
○MXmx3.peterhost.ru2015-07-14 → 2016-11-27 · 4 obs
● 2016-11-27 18:19:14
○ 2017-09-22 16:25:46
○ 2026-04-12 08:15:16
○MXmx4.peterhost.ru2015-07-14 → 2016-11-27 · 4 obs
● 2016-11-27 18:19:14
○ 2017-09-22 16:25:46
○ 2026-04-12 08:15:16
●A213.136.85.72026-04-12 → 2026-04-12 · 2 obs
● 2026-04-12 08:15:16
○A80.93.62.2462015-07-14 → 2016-11-27 · 4 obs
● 2016-11-27 18:19:14
○ 2017-09-22 16:25:46
○ 2026-04-12 08:15:16
○A91.195.240.1352017-09-22 → 2017-09-22 · 3 obs
● 2017-09-22 16:25:46
○ 2026-04-12 08:15:16
🔍 DNS Trace
📋 Delegation Chain
| Zone | Nameservers | Glue |
|---|---|---|
| ru | a.dns.ripn.net, d.dns.ripn.net, f.dns.ripn.net, b.dns.ripn.net... | - |
| courses4.ru | a.ns.selectel.ru, b.ns.selectel.ru, c.ns.selectel.ru, d.ns.selectel.ru | 4 records |
✅ Authoritative Response
Server:77.223.114.4
NS records: a.ns.selectel.ru, b.ns.selectel.ru, c.ns.selectel.ru, d.ns.selectel.ru
🔒 DNSSEC Status
⚠️ Insecure (no DNSSEC)
No DS record for courses4.ru (unsigned zone)
⏱️ Timing
Total: 785ms | Queries: -
📄 Records
| Type | Count | Sample Data |
|---|---|---|
| A | 1 | 213.136.85.7 |
| NS | 4 | c.ns.selectel.ru, b.ns.selectel.ru... |
| SOA | 1 | a.ns.selectel.ru support.selectel.ru |
📌 Glue Records Collected
Total: 4
Out-of-bailiwick: 4 (a.ns.selectel.ru, b.ns.selectel.ru, c.ns.selectel.ru...)
Analysis
Hierarchy
courses4.ru is the parent of komsomolsk.courses4.ru, kizel.courses4.ru, bogorodsk.courses4.ru, abdulino.courses4.ru, abaza.courses4.ru and a few other host names.
IP Addresses
courses4.ru resolves to one IP number: 213.136.85.7.
other host names including malaya-vishera.gvashev.ru, alushta.czstudy.ru, inza.traveltext.ru, konakovo.violori.ru and bui.hills2.ru share IP numbers with courses4.ru.
Name Servers
courses4.ru is delegated to four name servers: a.ns.selectel.ru, b.ns.selectel.ru, c.ns.selectel.ru and d.ns.selectel.ru.
courses4.ru at least partially shares name servers with other domains, for instance 52spravochka.ru, avtopahestamaser.am, colorshot.ru, jobcity.ru and ralzo.ru.
These name servers are commonly used alongside ns1.baz-on.ru and ns2.baz-on.ru.
Host names with two IP numbers:
a.ns.selectel.ru points to 2a00:ab00:800::2:53 and 188.68.203.1; b.ns.selectel.ru points to 2a00:ab00:801::2:53 and 77.223.114.2; c.ns.selectel.ru points to 2a00:ab00:802::2:53 and 188.68.203.3; d.ns.selectel.ru points to 2a00:ab00:803::2:53 and 77.223.114.4.