linux4u.jp - dns.ninja
linux4u.jp
| DNSSEC | ⚠️ Not signed | ||||||
| A | 153.121.40.37🇯🇵 SAKURA-B153.121.32.0/19 (TOKYO) SAKURA Internet // EAST JAPAN BACKBONE 1-8-14 Minami Honmachi, Chuo-ku, Osaka 541-0054, Japan | ||||||
| PTR | sakura1.pocketstudio.net | ||||||
| NS | ns.linux4u.jp ⭐ | ||||||
| A | 153.121.40.37🇯🇵 SAKURA-B153.121.32.0/19 (TOKYO) SAKURA Internet // EAST JAPAN BACKBONE 1-8-14 Minami Honmachi, Chuo-ku, Osaka 541-0054, Japan | ||||||
| PTR | sakura1.pocketstudio.net | ||||||
| NS | sakura1.pocketstudio.net | ||||||
| A | 153.121.40.37🇯🇵 SAKURA-B153.121.32.0/19 (TOKYO) SAKURA Internet // EAST JAPAN BACKBONE 1-8-14 Minami Honmachi, Chuo-ku, Osaka 541-0054, Japan | ||||||
| PTR | sakura1.pocketstudio.net | ||||||
| NS | sakura3.pocketstudio.net | ||||||
| A | 153.121.46.159🇯🇵 SAKURA-B153.121.32.0/19 (TOKYO) SAKURA Internet // EAST JAPAN BACKBONE 1-8-14 Minami Honmachi, Chuo-ku, Osaka 541-0054, Japan | ||||||
| PTR | sakura3.pocketstudio.net | ||||||
| MX | ns.linux4u.jp ⭐ | ||||||
| A | 153.121.40.37🇯🇵 SAKURA-B153.121.32.0/19 (TOKYO) SAKURA Internet // EAST JAPAN BACKBONE 1-8-14 Minami Honmachi, Chuo-ku, Osaka 541-0054, Japan | ||||||
| PTR | sakura1.pocketstudio.net | ||||||
| SOA | ns.linux4u.jppostmaster@linux4u.jp 2014-12-31 #1 | ||||||
jp
| DNSSEC | 🔒 Signed (DS record present) | ||||||
| NS | z.dns.jp ⭐ | ||||||
| NS | a.dns.jp | ||||||
| NS | b.dns.jp | ||||||
| NS | c.dns.jp | ||||||
| NS | d.dns.jp | ||||||
| NS | e.dns.jp | ||||||
| NS | f.dns.jp | ||||||
| NS | g.dns.jp | ||||||
| NS | h.dns.jp | ||||||
| SOA | z.dns.jproot@dns.jp serial=1785429903 | ||||||
Subdomains
ns.linux4u.jp |
Same first word
DNS History
5 records (5 active, 0 former)
●NSns.linux4u.jp2015-07-07 → 2026-07-30 · 2 obs
● 2026-07-30 17:18:54
●NSsakura1.pocketstudio.net2015-07-07 → 2026-07-30 · 2 obs
● 2026-07-30 17:18:54
●NSsakura3.pocketstudio.net2015-07-07 → 2026-07-30 · 2 obs
● 2026-07-30 17:18:54
●MXns.linux4u.jp2015-07-07 → 2026-07-30 · 2 obs
● 2026-07-30 17:18:54
●A153.121.40.372015-07-07 → 2026-07-30 · 2 obs
● 2026-07-30 17:18:54
🔍 DNS Trace
📋 Delegation Chain
| Zone | Nameservers | Glue |
|---|---|---|
| jp | a.dns.jp, b.dns.jp, c.dns.jp, d.dns.jp... | - |
| linux4u.jp | sakura1.pocketstudio.net, sakura3.pocketstudio.net | - |
✅ Authoritative Response
Server:153.121.40.37
NS records: sakura1.pocketstudio.net, sakura3.pocketstudio.net
🔒 DNSSEC Status
⚠️ Insecure (no DNSSEC)
No DS record for linux4u.jp (unsigned zone)
⏱️ Timing
Total: 1246ms | Queries: -
📄 Records
| Type | Count | Sample Data |
|---|---|---|
| A | 1 | 153.121.40.37 |
| NS | 2 | sakura3.pocketstudio.net, sakura1.pocketstudio.net |
| MX | 1 | ns.linux4u.jp (pri: 10) |
| SOA | 1 | ns.linux4u.jp postmaster.linux4u.jp |
Analysis
Hierarchy
ns.linux4u.jp is a subdomain of linux4u.jp.
IP Addresses
linux4u.jp resolves to one IP address: 153.121.40.37.
ns.docker.jp, spten.jp, ns.cloudstack.jp and two other host names share IP numbers with linux4u.jp.
Name Servers
linux4u.jp carries NS records delegating to ns.linux4u.jp, sakura1.pocketstudio.net and sakura3.pocketstudio.net.
The name servers of linux4u.jp overlap at least partially with those of other domains — among them x29.jp, dkbk.jp, icqdojo.jp and two more.
These name servers commonly co-occur with the name servers ns.dkbk.jp, ns.icqdojo.jp, ns.spten.jp and ns.cloudcomputing.jp.
Each of the three hostnames — ns.linux4u.jp, sakura1.pocketstudio.net and sakura3.pocketstudio.net — has a single IP address. ns.linux4u.jp and sakura1.pocketstudio.net resolve to 153.121.40.37; sakura3.pocketstudio.net resolves to 153.121.46.159.
ns.linux4u.jp along with sakura1.pocketstudio.net each resolve to 153.121.40.37 IP addresses.
Mail Servers
Mail for linux4u.jp is handled by a single mail server, ns.linux4u.jp.
The mail server configuration of linux4u.jp is identical to that of other domains — ns.linux4u.jp being one example.