opt.dk is a .dk domain served by 2 nameservers (nico.ns.cloudflare.com, stephane.ns.cloudflare.com). It was registered on 20 August 2018 (WHOIS) and was already in the .dk zone when our tracking began on 16 June 2026. Its website address 104.21.21.138 is hosted by Cloudflare, Inc. (AS13335). Mail is handled by .. 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 |
|---|---|---|---|---|---|---|---|
| 104.21.21.138 | 300s | — | AS13335 | Cloudflare, Inc. | 104.21.0.0/17 | — | — |
| 172.67.199.24 | 300s | — | AS13335 | Cloudflare, Inc. | 172.67.128.0/17 | — | — |
| Priority | TTL | Mail Server | IP addresses | PTR | ASN |
|---|---|---|---|---|---|
| 0 | 300s | . Null MX — domain accepts no email (RFC 7505) | |||
| Service | CNAME / IP |
|---|---|
| 🔷 Autodiscover | 104.21.21.138 |
| 🔶 Autoconfig | 172.67.199.24 |
| IPv6 Address | TTL | PTR | ASN | ISP / Org | CIDR | Country | City |
|---|---|---|---|---|---|---|---|
| 2606:4700:3033::6815:158a | 300s | — | AS13335 | Cloudflare, Inc. | 2606:4700:3000:0:0:0:0:0/42 | — | — |
| 2606:4700:3037::ac43:c718 | 300s | — | AS13335 | Cloudflare, Inc. | 2606:4700:3000:0:0:0:0:0/42 | — | — |
| Priority | Target | SvcParams |
|---|---|---|
| 1 service | . | alpn="h3,h2" ipv4hint=104.21.21.138,172.67.199.24 ech=AEX+DQBBrwAgACA/0UDqrNJK4rs+DYl4HRFRnCdJb6gUCBgiI2GOG49AAQAEAAEAAQASY2xvdWRmbGFyZS1lY2guY29tAAA= ipv6hint=2606:4700:3033::6815:158a,2606:4700:3037::ac43:c718 |
| www | 104.21.21.138 172.67.199.24 2606:4700:3033::6815:158a 2606:4700:3037::ac43:c718 (AS13335) (address records, no CNAME) |
| www vs bare domain | Same network |
| Wildcard | Yes: any name under the zone resolves |
| CDS / CDNSKEY | Published: key rollovers can be automated with the registry (RFC 7344/8078) 1 CDS, 1 CDNSKEY |
| Check | Result |
|---|---|
| Validation Status | 🔓 Insecure |
| AD Flag (resolver validates) | ✗ Not set |
| DS Record | ✗ Not found |
| DNSKEY Record | ✓ Found |
| Flags | unsigned answer |
| Field | Value |
|---|---|
| Serial | 2416847212 |
| Primary NS (MNAME) | nico.ns.cloudflare.com |
| Responsible (RNAME) | dns@cloudflare.com |
| Refresh | 10000s |
| Retry | 2400s |
| Expire | 604800s |
| Minimum (neg-cache TTL) | 1800s |
| Field | Value |
|---|---|
| Registrar | Punktum dk A/S (direct) |
| Registered | 2018-08-20 |
| Expires | 2027-08-31 (317d) |
| Scanned At | Duration | Records | DNSSEC |
|---|---|---|---|
| 2026-10-08 01:13:23 shown | 2462ms | 2 NS 2 A 1 MX | 🔓 Insecure |
| 2026-09-30 23:34:36 | 495ms | 2 NS 2 A 1 MX | 🔓 Insecure |
| 2026-09-30 06:03:01 | 692ms | 2 NS 2 A 1 MX | 🔓 Insecure |
| 2026-09-19 14:35:40 | 1262ms | 2 NS 2 A 1 MX | 🔓 Insecure |
| 2026-09-12 11:42:50 | 1342ms | 2 NS 2 A 1 MX | 🔓 Insecure |
| 2026-09-07 22:41:23 | 1894ms | 2 NS 2 A 1 MX | 🔓 Insecure |
| 2026-08-21 08:28:02 | 1722ms | 2 NS 2 A 1 MX | 🔓 Insecure |
| 2026-08-01 11:27:05 | 959ms | 2 NS 2 A 1 MX | 🔓 Insecure |
| 2026-07-27 13:09:12 | 9383ms | 2 NS 2 A 1 MX | 🔓 Insecure |
| 2026-07-11 05:43:49 | 8735ms | 2 NS 2 A 1 MX | 🔓 Insecure |
| 2026-07-03 19:51:10 | 1322ms | 2 NS 2 A 1 MX | 🔓 Insecure |
| 2026-07-02 07:20:51 | 1988ms | 2 NS 2 A 1 MX | 🔓 Insecure |
| 2026-06-18 03:52:28 | 2684ms | 2 NS 2 A 0 MX | 🔓 Insecure |