linux101.dk is a .dk domain served by 2 nameservers (curt.ns.cloudflare.com, marge.ns.cloudflare.com). It was registered on 31 May 2025 (WHOIS) and was already in the .dk zone when our tracking began on 16 June 2026. Its website address 104.21.26.63 is hosted by Cloudflare, Inc. (AS13335). The zone is not DNSSEC-signed, has no DMARC policy and is reachable over IPv6. Below are all of its DNS records from our latest scan: nameservers, A/AAAA, MX, TXT, SPF, DMARC, CAA, TLSA/DANE, MTA-STS, SRV and more.
| IP | TTL | PTR | ASN | ISP / Org | CIDR | Country | City |
|---|---|---|---|---|---|---|---|
| 104.21.26.63 | 300s | — | AS13335 | Cloudflare, Inc. | 104.21.0.0/17 | — | — |
| 172.67.135.147 | 300s | — | AS13335 | Cloudflare, Inc. | 172.67.128.0/17 | — | — |
| IPv6 Address | TTL | PTR | ASN | ISP / Org | CIDR | Country | City |
|---|---|---|---|---|---|---|---|
| 2606:4700:3030::6815:1a3f | 300s | — | AS13335 | Cloudflare, Inc. | 2606:4700:3000:0:0:0:0:0/42 | — | — |
| 2606:4700:3031::ac43:8793 | 300s | — | AS13335 | Cloudflare, Inc. | 2606:4700:3000:0:0:0:0:0/42 | — | — |
| Priority | Target | SvcParams |
|---|---|---|
| 1 service | . | alpn="h3,h2" ipv4hint=104.21.26.63,172.67.135.147 ech=AEX+DQBBlAAgACAm5CoMZdsR3bia/zyD99Ta3UGuAYW+x62dnLAOq+7AJAAEAAEAAQASY2xvdWRmbGFyZS1lY2guY29tAAA= ipv6hint=2606:4700:3030::6815:1a3f,2606:4700:3031::ac43:8793 |
| www | 104.21.26.63 172.67.135.147 2606:4700:3030::6815:1a3f 2606:4700:3031::ac43:8793 (AS13335) (address records, no CNAME) |
| www vs bare domain | Same network linux101.dk: 104.21.26.63 172.67.135.147 2606:4700:3030::6815:1a3f 2606:4700:3031::ac43:8793 (AS13335) www.linux101.dk: 104.21.26.63 172.67.135.147 2606:4700:3030::6815:1a3f 2606:4700:3031::ac43:8793 (AS13335) |
| Wildcard | No |
| Type | Name | Value |
|---|---|---|
| TXT | _acme-challenge.linux101.dk | GOhPZxG7X2S6Ql22F8RYMsRhhxGvLl4yIuvMMgtrTY0 |
| TXT | _acme-challenge.linux101.dk | W_rIm_NtFt4OcYZUYiZb_Sm69D7PEtItu6nKJ10s9_Q |
| Check | Result |
|---|---|
| Validation Status | 🔓 Insecure |
| AD Flag (resolver validates) | ✗ Not set |
| DS Record | ✗ Not found |
| DNSKEY Record | ✗ Not found |
| Flags | unsigned answer |
| Field | Value |
|---|---|
| Serial | 2417579135 |
| Primary NS (MNAME) | curt.ns.cloudflare.com |
| Responsible (RNAME) | dns@cloudflare.com |
| Refresh | 10000s |
| Retry | 2400s |
| Expire | 604800s |
| Minimum (neg-cache TTL) | 1800s |
| Field | Value |
|---|---|
| Registrar | Key-Systems GmbH |
| Registered | 2025-05-31 |
| Expires | 2027-05-30 (221d) |
| Scanned At | Duration | Records | DNSSEC |
|---|---|---|---|
| 2026-10-16 06:37:11 shown | 672ms | 2 NS 2 A 0 MX | 🔓 Insecure |
| 2026-09-17 17:58:29 | 1347ms | 2 NS 2 A 0 MX | 🔓 Insecure |
| 2026-08-28 09:46:46 | 1090ms | 2 NS 2 A 0 MX | 🔓 Insecure |
| 2026-08-19 17:02:19 | 4141ms | 2 NS 2 A 0 MX | 🔓 Insecure |
| 2026-08-17 11:47:50 | 1593ms | 2 NS 2 A 0 MX | 🔓 Insecure |
| 2026-07-19 08:00:19 | 2745ms | 2 NS 2 A 0 MX | 🔓 Insecure |
| 2026-06-18 03:38:07 | 23461ms | 2 NS 2 A 0 MX | 🔓 Insecure |
| 2026-06-18 00:06:44 | 3283ms | 2 NS 2 A 0 MX | 🔓 Insecure |