🛡️ Nameserver Resilience

Domains whose DNS hangs on a single nameserver, address, network or AS · all insights

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.

🛡️ Single points of failure

1,185,870 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1460.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3100.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,8270.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system754,02263.6%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver86,0427.3%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-09-29 17:57).

📋 A single nameserver address

1,310 domains
dhd.dk [/] search Domains, Hosts & DNS — .dk zone