The nameserver serena.ns.cloudflare.com appears in the delegation of 648 .dk domains in our dataset — 0.05% of every scanned .dk domain. The full list is below — here is how those domains look under the hood.

On the DNSSEC side, 404 (62.3%) validate as secure — right around the zone-wide average of 62.7%, while 235 (36.3%) are unsigned, with none failing validation outright — a further 9 come back indeterminate.

One thing worth flagging: 5 of these domains (0.8%) 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.