duc.dk is a .dk domain served by 2 nameservers (dee.ns.cloudflare.com, marty.ns.cloudflare.com). It was already in the .dk zone when our tracking began on 16 June 2026. Its website address 104.21.24.161 is hosted by Cloudflare, Inc. (AS13335). Mail is handled by route1.mx.cloudflare.net, route2.mx.cloudflare.net and 1 more. The zone is DNSSEC-signed and validates, publishes a DMARC policy and is reachable over IPv6. Below are all of its DNS records from this 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 |
|---|---|---|---|---|---|---|---|
| 104.21.24.161 | 300s | — | AS13335 | Cloudflare, Inc. | 104.21.0.0/17 | — | — |
| 172.67.219.152 | 300s | — | AS13335 | Cloudflare, Inc. | 172.67.128.0/17 | — | — |
| Service | CNAME / IP |
|---|---|
| 🔷 Autodiscover | 172.67.219.152 |
| 🔶 Autoconfig | 104.21.24.161 |
| IPv6 Address | TTL | PTR | ASN | ISP / Org | CIDR | Country | City |
|---|---|---|---|---|---|---|---|
| 2606:4700:3037::6815:18a1 | 300s | — | AS13335 | Cloudflare, Inc. | 2606:4700:3000:0:0:0:0:0/42 | — | — |
| 2606:4700:3037::ac43:db98 | 300s | — | AS13335 | Cloudflare, Inc. | 2606:4700:3000:0:0:0:0:0/42 | — | — |
| Priority | Target | SvcParams |
|---|---|---|
| 1 service | . | alpn="h3,h2" ipv4hint=104.21.24.161,172.67.219.152 ech=AEX+DQBBUQAgACAgvpA9jtAmAp0qHihscSSN8GZk44bsTnw2cYliSkAZGAAEAAEAAQASY2xvdWRmbGFyZS1lY2guY29tAAA= ipv6hint=2606:4700:3037::6815:18a1,2606:4700:3037::ac43:db98 |
| TXT Record |
|---|
| v=spf1 include:_spf.mx.cloudflare.net ~all |
| Policy | Record (duc.dk) |
|---|---|
| ~all (soft fail) | v=spf1 include:_spf.mx.cloudflare.net ~all |
| Policy | Record (_dmarc.duc.dk) |
|---|---|
| p=reject | v=DMARC1; p=reject; rua=mailto:info@duc.dk |
| www | 104.21.24.161 172.67.219.152 2606:4700:3037::6815:18a1 2606:4700:3037::ac43:db98 (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 |
DNS lookups: 1/10 · policy: ~all
No problems found| Service / Owner | Type | Cert association |
|---|---|---|
| SMTP _25._tcp.route1.mx.cloudflare.net | DANE-TA · SPKI · SHA-256 | 59E738E674221702AF1EDB87C5200C1A… |
| SMTP _25._tcp.route1.mx.cloudflare.net | DANE-EE · SPKI · SHA-256 | 0F0C6C164A36F97E7B4C5A5B69D6F4F2… |
| SMTP _25._tcp.route1.mx.cloudflare.net | DANE-EE · SPKI · SHA-256 | 9BE5B7D47F9EFF930C11EB04D27CAE6B… |
| SMTP _25._tcp.route2.mx.cloudflare.net | DANE-TA · SPKI · SHA-256 | 59E738E674221702AF1EDB87C5200C1A… |
| SMTP _25._tcp.route2.mx.cloudflare.net | DANE-EE · SPKI · SHA-256 | 0F0C6C164A36F97E7B4C5A5B69D6F4F2… |
| SMTP _25._tcp.route2.mx.cloudflare.net | DANE-EE · SPKI · SHA-256 | 9BE5B7D47F9EFF930C11EB04D27CAE6B… |
| SMTP _25._tcp.route3.mx.cloudflare.net | DANE-TA · SPKI · SHA-256 | 59E738E674221702AF1EDB87C5200C1A… |
| SMTP _25._tcp.route3.mx.cloudflare.net | DANE-EE · SPKI · SHA-256 | 0F0C6C164A36F97E7B4C5A5B69D6F4F2… |
| SMTP _25._tcp.route3.mx.cloudflare.net | DANE-EE · SPKI · SHA-256 | 9BE5B7D47F9EFF930C11EB04D27CAE6B… |
| Check | Result |
|---|---|
| Validation Status | 🔒 Secure |
| AD Flag (resolver validates) | ✓ Set |
| DS Record | ✓ Found |
| DNSKEY Record | ✓ Found |
| Flags | fully validated |
| Field | Value |
|---|---|
| Serial | 2407557880 |
| Primary NS (MNAME) | dee.ns.cloudflare.com |
| Responsible (RNAME) | dns@cloudflare.com |
| Refresh | 10000s |
| Retry | 2400s |
| Expire | 604800s |
| Minimum (neg-cache TTL) | 1800s |
| Scanned At | Duration | Records | DNSSEC |
|---|---|---|---|
| 2026-10-13 10:03:09 | 1221ms | 2 NS 2 A 3 MX | 🔒 Secure |
| 2026-10-12 09:41:53 | 2006ms | 2 NS 2 A 3 MX | 🔒 Secure |
| 2026-09-30 21:40:15 | 971ms | 2 NS 2 A 3 MX | 🔒 Secure |
| 2026-09-26 00:47:57 | 1076ms | 2 NS 2 A 3 MX | 🔒 Secure |
| 2026-09-25 00:24:29 | 927ms | 2 NS 2 A 3 MX | 🔒 Secure |
| 2026-09-24 05:48:27 | 1090ms | 2 NS 2 A 3 MX | 🔒 Secure |
| 2026-09-08 13:36:55 | 1490ms | 2 NS 2 A 3 MX | 🔒 Secure |
| 2026-09-01 12:43:06 | 5530ms | 2 NS 2 A 3 MX | 🔒 Secure |
| 2026-08-14 10:03:39 | 3189ms | 2 NS 2 A 3 MX | 🔒 Secure |
| 2026-08-09 09:30:48 | 2246ms | 2 NS 2 A 3 MX | 🔒 Secure |
| 2026-07-24 01:36:29 | 1750ms | 2 NS 2 A 3 MX | 🔒 Secure |
| 2026-07-16 04:16:05 | 10121ms | 2 NS 2 A 3 MX | 🔒 Secure |
| 2026-06-30 05:07:00 shown | 1875ms | 2 NS 2 A 3 MX | 🔒 Secure |
| 2026-06-19 23:01:28 | 1066ms | 2 NS 2 A 3 MX | 🔒 Secure |
| 2026-06-17 04:55:49 | 2928ms | 2 NS 2 A 3 MX | 🔒 Secure |