3f.dk is a .dk domain served by 2 nameservers (lisa.ns.cloudflare.com, max.ns.cloudflare.com). It was registered on 1 November 2002 (WHOIS) and was already in the .dk zone when our tracking began on 16 June 2026. Its website address 172.66.40.249 is hosted by Cloudflare, Inc. (AS13335). Mail is handled by 3f-dk.f-v1.mx.microsoft. 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 |
|---|---|---|---|---|---|---|---|
| 172.66.40.249 | 300s | — | AS13335 | Cloudflare, Inc. | 172.66.40.0/21 | — | — |
| 172.66.43.7 | 300s | — | AS13335 | Cloudflare, Inc. | 172.66.40.0/21 | — | — |
| Service | CNAME / IP |
|---|---|
| 🔷 Autodiscover | autodiscover.outlook.com → 52.98.154.152 |
| IPv6 Address | TTL | PTR | ASN | ISP / Org | CIDR | Country | City |
|---|---|---|---|---|---|---|---|
| 2606:4700:3108::ac42:28f9 | 300s | — | AS13335 | Cloudflare, Inc. | 2606:4700:3108:0:0:0:0:0/48 | — | — |
| 2606:4700:3108::ac42:2b07 | 300s | — | AS13335 | Cloudflare, Inc. | 2606:4700:3108:0:0:0:0:0/48 | — | — |
| Priority | Target | SvcParams |
|---|---|---|
| 1 service | . | alpn="h2" ipv4hint=172.66.40.249,172.66.43.7 ipv6hint=2606:4700:3108::ac42:28f9,2606:4700:3108::ac42:2b07 |
| Service | Priority | Weight | Port | Target |
|---|---|---|---|---|
| _sipfederationtls._tcp | 0 | 0 | 5061 | sipfed.online.lync.com |
| TXT Record |
|---|
| _kfi60qo31fwon3pfl52rufqghuku2s4 |
| _nn3od9bbc7n791yym1ek0m8rat2giko |
| 9b57k4tmyw99cxyd647lkst0bb5yl9nt |
| apple-domain-verification=I7NcqCXHmBPnQvA3 |
| facebook-domain-verification=cx1i1lglcowp198g4bgigvaes4baeo |
| google-site-verification=H1dyJKnjA-UgTyLq-I0XYAE3oTlg-syy-_vdRs7IbnM |
| google-site-verification=ZT0IrlPw0Or4SHyagAvP5ye8oJGI4c2PPuDBVrluaAo |
| mindmanager-verification=79b0e23d95d2d253211befb91a68fa41f6edbf5a8bbe869976831f0fddb0cff4 |
| MS=ms12157205 |
| v=spf1 ip4:52.232.5.115 ip4:77.66.57.123 ip4:168.245.61.203 ip4:168.245.67.108 ip4:193.163.134.0/24 ip4:159.183.35.2 include:spf.protection.outlook.com include:dedicated.mysmtp.com include:spf.mph1.com include:spf.hatteland.com -all |
| Policy | Record (3f.dk) |
|---|---|
| -all (hard fail) | v=spf1 ip4:52.232.5.115 ip4:77.66.57.123 ip4:168.245.61.203 ip4:168.245.67.108 ip4:193.163.134.0/24 ip4:159.183.35.2 include:spf.protection.outlook.com include:dedicated.mysmtp.com include:spf.mph1.com include:spf.hatteland.com -all |
| Policy | Record (_dmarc.3f.dk) |
|---|---|
| p=reject | v=DMARC1; p=reject; rua=mailto:7lrymkqp@ag.eu.dmarcian.com; ruf=mailto:7lrymkqp@fr.eu.dmarcian.com; |
| www | 172.66.40.249 172.66.43.7 2606:4700:3108::ac42:28f9 2606:4700:3108::ac42:2b07 (AS13335) (address records, no CNAME) |
| www vs bare domain | Same network |
| Wildcard | No |
| Denial of existence | Compact NSEC (RFC 9824, "black lies") not walkable |
| CDS / CDNSKEY | Published: key rollovers can be automated with the registry (RFC 7344/8078) 1 CDS, 1 CDNSKEY |
| Selector | CNAME | Key |
|---|---|---|
| default | — | RSA · ~1024 bit below 2048 bit |
| s1 | s1.domainkey.u7959841.wl092.sendgrid.net | RSA · ~2048 bit |
| s2 | s2.domainkey.u7959841.wl092.sendgrid.net | RSA · ~2048 bit |
DKIM selectors can't be listed, so we check the common ones (Microsoft 365, Google, Mailchimp, SendGrid, generic). Keys under other selectors aren't shown.
DNS lookups: 7/10 · policy: -all
No problems found| Service / Owner | Type | Cert association |
|---|---|---|
| SMTP _25._tcp.3f-dk.f-v1.mx.microsoft | DANE-EE · SPKI · SHA-256 | 803F7447CC75B208DBCA042346F5D8DF… |
| SMTP _25._tcp.3f-dk.f-v1.mx.microsoft | DANE-TA · Full cert · SHA-256 | C1AD7778796D20BCA65C889A26550211… |
| SMTP _25._tcp.3f-dk.f-v1.mx.microsoft | DANE-EE · SPKI · SHA-256 | 54883CC5F1849331E6BF5002C3129D20… |
| SMTP _25._tcp.3f-dk.f-v1.mx.microsoft | DANE-TA · Full cert · SHA-256 | EA7A25255D111FC3CE4CB8FABE3ADF9C… |
| Check | Result |
|---|---|
| Validation Status | 🔒 Secure |
| AD Flag (resolver validates) | ✓ Set |
| DS Record | ✓ Found |
| DNSKEY Record | ✓ Found |
| Flags | fully validated |
| Field | Value |
|---|---|
| Serial | 2415529817 |
| Primary NS (MNAME) | lisa.ns.cloudflare.com |
| Responsible (RNAME) | dns@cloudflare.com |
| Refresh | 10000s |
| Retry | 2400s |
| Expire | 604800s |
| Minimum (neg-cache TTL) | 1800s |
| Field | Value |
|---|---|
| Registrar | Simply.com A/S |
| Registered | 2002-11-01 |
| Expires | 2026-12-31 (75d) |
Other .dk domains whose WHOIS registrant has the same name and postal address. Matched on a keyed hash: the registrant's details are not stored or shown. Covers only domains whose WHOIS we have fetched (refreshed about monthly).
| Scanned At | Duration | Records | DNSSEC |
|---|---|---|---|
| 2026-10-09 10:18:57 | 1038ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-10-04 04:05:34 | 634ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-10-01 07:36:48 | 654ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-09-30 12:21:29 | 939ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-09-27 11:49:17 shown | 787ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-09-23 03:50:46 | 1418ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-09-03 23:27:29 | 742ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-08-29 14:16:11 | 1384ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-08-28 05:24:24 | 1079ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-08-17 21:11:08 | 4767ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-08-12 17:46:35 | 5117ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-08-08 03:08:11 | 1604ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-08-04 05:33:33 | 1401ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-07-21 04:25:15 | 1409ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-07-17 20:04:27 | 2072ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-07-12 06:57:47 | 1473ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-07-07 03:23:16 | 1546ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-07-03 06:17:10 | 1006ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-06-26 08:28:27 | 774ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-06-20 11:26:01 | 827ms | 2 NS 2 A 1 MX | 🔒 Secure |
| 2026-06-16 12:47:59 | 2952ms | 2 NS 2 A 1 MX | 🔓 Insecure |