DNS should never hang on one server. This page counts the .dk domains whose nameservers share a single host, address, network or autonomous system, the single points of failure that turn one outage into a dead domain. Data comes from our own scanners, which re-resolve every .dk domain in the zone roughly once a week.
| Every nameserver is on… | Domains | Share | Why it matters |
|---|---|---|---|
| A single nameserver host | 493 | 0.04% | Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two. |
| A single nameserver address | 3,290 | 0.26% | Several NS names, but they all resolve to one IP, so they are really one server. |
| One IPv4 /24 and no IPv6 | 17,634 | 1.37% | All nameservers share one network: a routing problem there takes them all down. |
| One autonomous system | 814,545 | 63.4% | Common and usually fine with a large provider, but one network outage still takes all nameservers down. |
| No IPv6 nameserver | 103,987 | 8.1% | IPv6-only resolvers cannot reach the zone. |