A reverse ASN lookup lists the .dk domains hosted on an autonomous system (a hosting company's or ISP's network), with its IPv6 and DNSSEC adoption. Enter an AS number without the AS prefix. Data comes from our own scanners, which re-resolve every .dk domain in the zone roughly once a week.
Every result on this page comes from our own scans of the .dk zone — not a third-party feed. The scanner continuously walks the zone and geolocates every address it finds; so far 1,308,661 of the 1,308,664 .dk domains in the zone have been scanned, 1,054,270 of them with a web address (A record) we could map, built from 16,155,048 scans and counting.
On the network side we have observed 113,153 unique IPv4 addresses inside 7,838 CIDR blocks — together spanning roughly 338.6 million addresses of IPv4 space — announced by 2,514 distinct autonomous systems from 2,305 providers across 86 countries. IPv6 adds another 171,037 unique addresses in 669 prefixes (about 7.3 trillion /64 networks of space), published by 228,090 domains (17.4% of the scanned zone).
Security-wise, 837,000 domains (64.0%) currently validate as DNSSEC-secure, while 23,873 fail validation outright (bogus). The full breakdown lives on the zone statistics page.
Beyond raw addresses, the dataset tracks 20,437 distinct nameservers and 216,425 mail hosts, plus TXT/SPF, CAA, TLSA/DANE, MTA-STS, SOA and PTR details for every domain — all cross-referenced, so a single ASN, CIDR or nameserver unfolds into its full hosting footprint through the reverse-lookup tools.