The nameserver ns1.openprovider.nl appears in the delegation of 1,826 .dk domains in our dataset — 0.14% of every scanned .dk domain. The full list is below — here is how those domains look under the hood.

On the DNSSEC side, 3 (0.2%) validate as secure — below the zone-wide average of 62.6%, while 1,733 (94.9%) are unsigned, with none failing validation outright — a further 90 come back indeterminate.

One thing worth flagging: 71 of these domains (3.9%) look like lame delegations — the .dk registry still points them here, but this nameserver doesn't answer authoritatively for the zone, which usually means the hosting was cancelled and the delegation was left dangling.