🛡️ 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

1,183,573 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1450.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3060.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6800.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,94464.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,2767.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-05 18:29).

📋 One autonomous system

757,944 domains
DomainNameservers and addresses
web4rent.dkbrad.ns.cloudflare.com 108.162.193.105 AS13335, 172.64.33.105 AS13335, 173.245.59.105 AS13335, 2606:4700:58::adf5:3b69 AS13335, 2803:f800:50::6ca2:c169 AS13335, 2a06:98c1:50::ac40:2169 AS13335
raquel.ns.cloudflare.com 108.162.194.210 AS13335, 162.159.38.210 AS13335, 172.64.34.210 AS13335, 2606:4700:50::a29f:26d2 AS13335, 2803:f800:50::6ca2:c2d2 AS13335, 2a06:98c1:50::ac40:22d2 AS13335
web4sailors.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
web4test.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
web4u.dkns.scannet2.dk 185.25.141.9 AS48854, 2a02:2339:4006:10d::4171:4171 AS48854
ns2.scannet2.dk 2a02:2339:1:112:0:5:1:b11 AS48854, 91.197.248.72 AS48854
web4u2.dkachiel.ns.cloudflare.com 108.162.195.123 AS13335, 162.159.44.123 AS13335, 172.64.35.123 AS13335, 2606:4700:58::a29f:2c7b AS13335, 2803:f800:50::6ca2:c37b AS13335, 2a06:98c1:50::ac40:237b AS13335
nola.ns.cloudflare.com 108.162.192.212 AS13335, 172.64.32.212 AS13335, 173.245.58.212 AS13335, 2606:4700:50::adf5:3ad4 AS13335, 2803:f800:50::6ca2:c0d4 AS13335, 2a06:98c1:50::ac40:20d4 AS13335
web4us.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
web500.dkns1.curanet.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.curanet.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
web7.dkns3.nordicway.dk 2a01:4f8:c2c:d3c0::1 AS24940, 78.47.45.64 AS24940
ns4.nordicway.dk 2a01:4f8:c010:24a2::1 AS24940, 78.47.56.84 AS24940
web9.dkns1.curanet.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.curanet.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
web99.dkns1.123host.dk 75.2.86.204 AS16509
ns2.123host.dk 166.117.220.151 AS16509
webability.dkmillie.ns.cloudflare.com 108.162.194.181 AS13335, 162.159.38.181 AS13335, 172.64.34.181 AS13335, 2606:4700:50::a29f:26b5 AS13335, 2803:f800:50::6ca2:c2b5 AS13335, 2a06:98c1:50::ac40:22b5 AS13335
zac.ns.cloudflare.com 108.162.195.178 AS13335, 162.159.44.178 AS13335, 172.64.35.178 AS13335, 2606:4700:58::a29f:2cb2 AS13335, 2803:f800:50::6ca2:c3b2 AS13335, 2a06:98c1:50::ac40:23b2 AS13335
webaboteket.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
webacademy.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
webaccess.dkns1.dreamhost.com 162.159.26.14 AS13335
ns2.dreamhost.com 162.159.26.81 AS13335
ns3.dreamhost.com 162.159.27.84 AS13335
webaccessibility.dkaspen.ns.cloudflare.com 108.162.194.109 AS13335, 162.159.38.109 AS13335, 172.64.34.109 AS13335, 2606:4700:50::a29f:266d AS13335, 2803:f800:50::6ca2:c26d AS13335, 2a06:98c1:50::ac40:226d AS13335
titan.ns.cloudflare.com 108.162.195.93 AS13335, 162.159.44.93 AS13335, 172.64.35.93 AS13335, 2606:4700:58::a29f:2c5d AS13335, 2803:f800:50::6ca2:c35d AS13335, 2a06:98c1:50::ac40:235d AS13335
webackpack.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
webadgang.dkns.scannet2.dk 185.25.141.9 AS48854, 2a02:2339:4006:10d::4171:4171 AS48854
ns2.scannet2.dk 2a02:2339:1:112:0:5:1:b11 AS48854, 91.197.248.72 AS48854
webadministrate.dkleah.ns.cloudflare.com 108.162.192.129 AS13335, 172.64.32.129 AS13335, 173.245.58.129 AS13335, 2606:4700:50::adf5:3a81 AS13335, 2803:f800:50::6ca2:c081 AS13335, 2a06:98c1:50::ac40:2081 AS13335
sid.ns.cloudflare.com 108.162.193.143 AS13335, 172.64.33.143 AS13335, 173.245.59.143 AS13335, 2606:4700:58::adf5:3b8f AS13335, 2803:f800:50::6ca2:c18f AS13335, 2a06:98c1:50::ac40:218f AS13335
webador.dkns-cloud-b1.googledomains.com 2001:4860:4802:32::6b AS15169, 216.239.32.107 AS15169
ns-cloud-b2.googledomains.com 2001:4860:4802:34::6b AS15169, 216.239.34.107 AS15169
ns-cloud-b3.googledomains.com 2001:4860:4802:36::6b AS15169, 216.239.36.107 AS15169
ns-cloud-b4.googledomains.com 2001:4860:4802:38::6b AS15169, 216.239.38.107 AS15169
webadore.dkns1.openprovider.nl 162.159.26.10 AS13335, 2400:cb00:2049:1::a29f:1a0a AS13335
ns2.openprovider.be 162.159.27.96 AS13335, 2400:cb00:2049:1::a29f:1b60 AS13335
ns3.openprovider.eu 162.159.48.89 AS13335, 2400:cb00:2049:1::a29f:3059 AS13335
webadresse.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
webadvise.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
webadviser.dkbryce.ns.cloudflare.com 108.162.195.137 AS13335, 162.159.44.137 AS13335, 172.64.35.137 AS13335, 2606:4700:58::a29f:2c89 AS13335, 2803:f800:50::6ca2:c389 AS13335, 2a06:98c1:50::ac40:2389 AS13335
kayleigh.ns.cloudflare.com 108.162.194.92 AS13335, 162.159.38.92 AS13335, 172.64.34.92 AS13335, 2606:4700:50::a29f:265c AS13335, 2803:f800:50::6ca2:c25c AS13335, 2a06:98c1:50::ac40:225c AS13335
webadvokater.dkns1.nhl-data.dk 185.136.96.11 AS203391, 2a06:fb00:1::1:11 AS203391
ns2.nhl-data.dk 185.136.97.11 AS203391, 2a06:fb00:1::2:11 AS203391
ns3.nhl-data.dk 185.136.98.11 AS203391, 2a06:fb00:1::3:11 AS203391
ns4.nhl-data.dk 185.136.99.11 AS203391, 2a06:fb00:1::4:11 AS203391
webadvokaterne.dkns1.nhl-data.dk 185.136.96.11 AS203391, 2a06:fb00:1::1:11 AS203391
ns2.nhl-data.dk 185.136.97.11 AS203391, 2a06:fb00:1::2:11 AS203391
ns3.nhl-data.dk 185.136.98.11 AS203391, 2a06:fb00:1::3:11 AS203391
ns4.nhl-data.dk 185.136.99.11 AS203391, 2a06:fb00:1::4:11 AS203391
webafdeling.dkns1.curanet.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.curanet.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
webagency.dkns1.dns-parking.com 162.159.24.201 AS13335, 2400:cb00:2049:1::a29f:18c9 AS13335
ns2.dns-parking.com 162.159.25.42 AS13335, 2400:cb00:2049:1::a29f:192a AS13335
webagenda.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
webagent.dkstan.ns.cloudflare.com 108.162.193.235 AS13335, 172.64.33.235 AS13335, 173.245.59.235 AS13335, 2606:4700:58::adf5:3beb AS13335, 2803:f800:50::6ca2:c1eb AS13335, 2a06:98c1:50::ac40:21eb AS13335
ullis.ns.cloudflare.com 108.162.194.127 AS13335, 162.159.38.127 AS13335, 172.64.34.127 AS13335, 2606:4700:50::a29f:267f AS13335, 2803:f800:50::6ca2:c27f AS13335, 2a06:98c1:50::ac40:227f AS13335
webagenten.dkjonah.ns.cloudflare.com 108.162.193.186 AS13335, 172.64.33.186 AS13335, 173.245.59.186 AS13335, 2606:4700:58::adf5:3bba AS13335, 2803:f800:50::6ca2:c1ba AS13335, 2a06:98c1:50::ac40:21ba AS13335
liv.ns.cloudflare.com 108.162.192.188 AS13335, 172.64.32.188 AS13335, 173.245.58.188 AS13335, 2606:4700:50::adf5:3abc AS13335, 2803:f800:50::6ca2:c0bc AS13335, 2a06:98c1:50::ac40:20bc AS13335
webahead.dkns1.dlx.dk 2a00:1b18:1337:1337::53 AS47527, 46.30.121.210 AS47527
ns2.dlx.dk 185.208.212.124 AS47527, 2a00:1b19:1337:1337::53 AS47527
webai.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
webair.dkns.scannet2.dk 185.25.141.9 AS48854, 2a02:2339:4006:10d::4171:4171 AS48854
ns2.scannet2.dk 2a02:2339:1:112:0:5:1:b11 AS48854, 91.197.248.72 AS48854
webaktiv.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
webal.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
webalance.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
webalger.dkandronicus.ns.cloudflare.com 108.162.195.113 AS13335, 162.159.44.113 AS13335, 172.64.35.113 AS13335, 2606:4700:58::a29f:2c71 AS13335, 2803:f800:50::6ca2:c371 AS13335, 2a06:98c1:50::ac40:2371 AS13335
iris.ns.cloudflare.com 108.162.192.118 AS13335, 172.64.32.118 AS13335, 173.245.58.118 AS13335, 2606:4700:50::adf5:3a76 AS13335, 2803:f800:50::6ca2:c076 AS13335, 2a06:98c1:50::ac40:2076 AS13335
webalive.dkns.scannet2.dk 185.25.141.9 AS48854, 2a02:2339:4006:10d::4171:4171 AS48854
ns2.scannet2.dk 2a02:2339:1:112:0:5:1:b11 AS48854, 91.197.248.72 AS48854
webalyze.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
webamp.dkns1.curanet.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.curanet.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
webamptest.dkns1.curanet.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.curanet.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
webanalyse-kurser.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
webanalyse.dkns1.nordicway.dk 2a01:4f8:1c1a:a1e7::1 AS24940, 91.98.140.195 AS24940
ns2.nordicway.dk 2a01:4f8:c012:4db6::1 AS24940, 49.13.80.249 AS24940
ns3.nordicway.dk 2a01:4f8:c2c:d3c0::1 AS24940, 78.47.45.64 AS24940
ns4.nordicway.dk 2a01:4f8:c010:24a2::1 AS24940, 78.47.56.84 AS24940
webanalysen.dkclint.ns.cloudflare.com 108.162.193.90 AS13335, 172.64.33.90 AS13335, 173.245.59.90 AS13335, 2606:4700:58::adf5:3b5a AS13335, 2803:f800:50::6ca2:c15a AS13335, 2a06:98c1:50::ac40:215a AS13335
dina.ns.cloudflare.com 108.162.192.107 AS13335, 172.64.32.107 AS13335, 173.245.58.107 AS13335, 2606:4700:50::adf5:3a6b AS13335, 2803:f800:50::6ca2:c06b AS13335, 2a06:98c1:50::ac40:206b AS13335
webanalytiker.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
webanders.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
webanker.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
webannonce.dkns1.mydomain.com 172.64.52.99 AS13335
ns2.mydomain.com 172.64.53.76 AS13335
webanywhere.dkdawn.ns.cloudflare.com 108.162.192.106 AS13335, 172.64.32.106 AS13335, 173.245.58.106 AS13335, 2606:4700:50::adf5:3a6a AS13335, 2803:f800:50::6ca2:c06a AS13335, 2a06:98c1:50::ac40:206a AS13335
mitch.ns.cloudflare.com 108.162.193.208 AS13335, 172.64.33.208 AS13335, 173.245.59.208 AS13335, 2606:4700:58::adf5:3bd0 AS13335, 2803:f800:50::6ca2:c1d0 AS13335, 2a06:98c1:50::ac40:21d0 AS13335
webapi.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
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