The nameserver nsb.perf1.com appears in the delegation of 224 .dk domains in our dataset — 0.02% of every scanned .dk domain. The full list is below — here is how those domains look under the hood.

On the DNSSEC side, 27 (12.1%) validate as secure — below the zone-wide average of 62.8%, while 195 (87.1%) are unsigned, with none failing validation outright — a further 2 come back indeterminate.

One thing worth flagging: 1 of these domain (0.4%) 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.