🛡️ 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

1,185,762 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1480.01%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 IPv610,8150.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system754,61263.6%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver86,0127.3%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-09-30 00:23).

📋 One autonomous system

754,612 domains
DomainNameservers and addresses
øxenbjerg.dkns.dandomain.dk 185.25.141.3 AS48854, 2a02:2339:4006:109::dd AS48854
ns2.dandomain.dk 2a02:2339:1:108::dd:dd AS48854, 91.197.248.66 AS48854
øxenhave.dkns7.bricksite.net 35.246.226.10 AS396982
ns8.bricksite.net 35.242.190.82 AS396982
øxenholm.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
ns4.simply.com 91.197.248.80 AS48854
øxenholtbiler.dkns1.curanet.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123
ns2.curanet.dk 2a02:2339:1:10f::123:123, 91.197.248.75
øyoga.dknucum.ns.cloudflare.com 108.162.194.145 AS13335, 162.159.38.145 AS13335, 172.64.34.145 AS13335, 2606:4700:50::a29f:2691 AS13335, 2803:f800:50::6ca2:c291 AS13335, 2a06:98c1:50::ac40:2291 AS13335
yichun.ns.cloudflare.com 108.162.193.248 AS13335, 172.64.33.248 AS13335, 173.245.59.248 AS13335, 2606:4700:58::adf5:3bf8 AS13335, 2803:f800:50::6ca2:c1f8 AS13335, 2a06:98c1:50::ac40:21f8 AS13335
øzcoiffure.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
ns4.simply.com 91.197.248.80 AS48854
øø.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
ü.dkchan.ns.cloudflare.com 108.162.192.82 AS13335, 172.64.32.82 AS13335, 173.245.58.82 AS13335, 2606:4700:50::adf5:3a52 AS13335, 2803:f800:50::6ca2:c052 AS13335, 2a06:98c1:50::ac40:2052 AS13335
hank.ns.cloudflare.com 108.162.193.116 AS13335, 172.64.33.116 AS13335, 173.245.59.116 AS13335, 2606:4700:58::adf5:3b74 AS13335, 2803:f800:50::6ca2:c174 AS13335, 2a06:98c1:50::ac40:2174 AS13335
über.dkns1.shellhost.dk 193.200.90.91 AS62121, 2001:67c:564::13 AS62121
ns2.shellhost.dk 193.200.91.90 AS62121, 2001:67c:564::12 AS62121
übique.dkns1.dnsserver.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.dnsserver.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
üniku.dkns.dandomain.dk 185.25.141.3 AS48854, 2a02:2339:4006:109::dd AS48854
ns2.dandomain.dk 2a02:2339:1:108::dd:dd AS48854, 91.197.248.66 AS48854
ünschwart.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78 AS48854
ns2.simply.com 185.25.141.15 AS48854, 2a02:2339:4006:101::4562:4562 AS48854
ns3.simply.com 91.197.248.79 AS48854
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