🛡️ 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

1,183,542 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1470.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3040.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6770.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system758,00864.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,4057.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-05 05:55).

📋 One autonomous system

758,008 domains
DomainNameservers and addresses
acsicampings.dkns1.domaindiscount24.net 193.227.117.34 AS1921, 2a04:2b00:14cc::34 AS1921
ns2.domaindiscount24.net 194.50.187.34 AS1921, 2a04:2b00:14dd::34 AS1921
ns3.domaindiscount24.net 194.0.182.34 AS1921, 2a04:2b00:14ee::34 AS1921
acsieurolodges.dkns1.domaindiscount24.net 193.227.117.34 AS1921, 2a04:2b00:14cc::34 AS1921
ns2.domaindiscount24.net 194.50.187.34 AS1921, 2a04:2b00:14dd::34 AS1921
ns3.domaindiscount24.net 194.0.182.34 AS1921, 2a04:2b00:14ee::34 AS1921
acsit.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
acskagehus.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
acskive.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
acskodder.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
acsnet.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
acsoulflow.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
acspeak.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
acspire.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
acspireadvisory.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
acsports.dkcurns01.dnsadmin.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
curns02.dnsadmin.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
acsr.dkns1.dataspecialisten.dk 2a01:4f8:13b:3146::1 AS24940, 94.130.138.185 AS24940
ns2.dataspecialisten.dk 2a01:4f8:c17:5f0a::2 AS24940, 88.99.15.5 AS24940
acstevens.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
acstilladser.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
acstudiocph.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
acstudios.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
acsupport.dkapollo.dns-parking.com 172.64.53.7 AS13335, 2606:4700:5a::ac40:3507 AS13335
athena.dns-parking.com 172.64.52.164 AS13335, 2606:4700:52::ac40:34a4 AS13335
act-a.dkbrit.ns.cloudflare.com 108.162.192.78 AS13335, 172.64.32.78 AS13335, 173.245.58.78 AS13335, 2606:4700:50::adf5:3a4e AS13335, 2803:f800:50::6ca2:c04e AS13335, 2a06:98c1:50::ac40:204e AS13335
drake.ns.cloudflare.com 108.162.195.14 AS13335, 162.159.44.14 AS13335, 172.64.35.14 AS13335, 2606:4700:58::a29f:2c0e AS13335, 2803:f800:50::6ca2:c30e AS13335, 2a06:98c1:50::ac40:230e AS13335
act-aarhus.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
act-breeding.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
act-dk.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
act-fact.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
act-gruppen.dkns1.misspark.com 162.159.24.173 AS13335, 2400:cb00:2049:1::a29f:18ad AS13335
ns2.misspark.com 162.159.25.99 AS13335, 2400:cb00:2049:1::a29f:1963 AS13335
ns3.misspark.com 162.159.25.16 AS13335, 2400:cb00:2049:1::a29f:1910 AS13335
ns4.misspark.com 162.159.24.87 AS13335, 2400:cb00:2049:1::a29f:1857 AS13335
act-heartful.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
act-it.dkelias.ns.cloudflare.com 108.162.195.29 AS13335, 162.159.44.29 AS13335, 172.64.35.29 AS13335, 2606:4700:58::a29f:2c1d AS13335, 2803:f800:50::6ca2:c31d AS13335, 2a06:98c1:50::ac40:231d AS13335
perla.ns.cloudflare.com 108.162.194.203 AS13335, 162.159.38.203 AS13335, 172.64.34.203 AS13335, 2606:4700:50::a29f:26cb AS13335, 2803:f800:50::6ca2:c2cb AS13335, 2a06:98c1:50::ac40:22cb AS13335
act-logimark.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
act-parrots.dkns5.kasserver.com 85.13.128.3 AS34788
ns6.kasserver.com 85.13.159.101 AS34788
act-partner.dkns1.azehosting.net 2a01:4f8:13b:3146::1 AS24940, 94.130.138.185 AS24940
ns2.azehosting.net 2a01:4f8:c17:5f0a::2 AS24940, 88.99.15.5 AS24940
ns3.azehosting.net 2a01:4f8:c17:6a6e::2 AS24940, 88.99.39.181 AS24940
act-praxis.dkns4.dns-123.net 35.198.132.83 AS396982
ns5.dns-123.net 35.187.184.173 AS396982
ns6.dns-123.net 35.228.54.1 AS396982
act-psykologerne.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
act-shop.dkns1.misspark.com 162.159.24.173 AS13335, 2400:cb00:2049:1::a29f:18ad AS13335
ns2.misspark.com 162.159.25.99 AS13335, 2400:cb00:2049:1::a29f:1963 AS13335
ns3.misspark.com 162.159.25.16 AS13335, 2400:cb00:2049:1::a29f:1910 AS13335
ns4.misspark.com 162.159.24.87 AS13335, 2400:cb00:2049:1::a29f:1857 AS13335
act-team.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
act-to.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
act-zone.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
act.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
act2change.dkns1.bdm.microsoftonline.com 13.107.236.208 AS8075, 2603:1061:0:700::d0 AS8075
ns2.bdm.microsoftonline.com 150.171.21.208 AS8075, 2620:1ec:8ec:700::d0 AS8075
ns3.bdm.microsoftonline.com 204.14.183.208 AS8075, 2a01:111:4000:700::d0 AS8075
ns4.bdm.microsoftonline.com 208.84.5.208 AS8075, 2620:1ec:bda:700::d0 AS8075
act2learn.dkchristina.ns.cloudflare.com 108.162.194.193 AS13335, 162.159.38.193 AS13335, 172.64.34.193 AS13335, 2606:4700:50::a29f:26c1 AS13335, 2803:f800:50::6ca2:c2c1 AS13335, 2a06:98c1:50::ac40:22c1 AS13335
reese.ns.cloudflare.com 108.162.195.117 AS13335, 162.159.44.117 AS13335, 172.64.35.117 AS13335, 2606:4700:58::a29f:2c75 AS13335, 2803:f800:50::6ca2:c375 AS13335, 2a06:98c1:50::ac40:2375 AS13335
acta-anaesth.dkkeira.ns.cloudflare.com 108.162.194.206 AS13335, 162.159.38.206 AS13335, 172.64.34.206 AS13335, 2606:4700:50::a29f:26ce AS13335, 2803:f800:50::6ca2:c2ce AS13335, 2a06:98c1:50::ac40:22ce AS13335
ram.ns.cloudflare.com 108.162.193.225 AS13335, 172.64.33.225 AS13335, 173.245.59.225 AS13335, 2606:4700:58::adf5:3be1 AS13335, 2803:f800:50::6ca2:c1e1 AS13335, 2a06:98c1:50::ac40:21e1 AS13335
acta-recycling.dkns1.wannafind.dk 185.25.141.6 AS48854, 2a02:2339:4006:103:1c:3f6d:daba:dee AS48854
ns2.wannafind.dk 2a02:2339:1:104::daba:daa AS48854, 91.197.248.69 AS48854
acta.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
actaadvokater.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
actabio.dkns7.bricksite.net 35.246.226.10 AS396982
ns8.bricksite.net 35.242.190.82 AS396982
actachemscand.dkns1.parkingcrew.net 13.248.158.159 AS16509
ns2.parkingcrew.net 76.223.21.9 AS16509
actaconsult.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
actacultura.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
actag.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
actagroup.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
actai.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
actakademiet.dkadi.ns.cloudflare.com 108.162.192.56 AS13335, 172.64.32.56 AS13335, 173.245.58.56 AS13335, 2606:4700:50::adf5:3a38 AS13335, 2803:f800:50::6ca2:c038 AS13335, 2a06:98c1:50::ac40:2038 AS13335
yadiel.ns.cloudflare.com 108.162.195.4 AS13335, 162.159.44.4 AS13335, 172.64.35.4 AS13335, 2606:4700:58::a29f:2c04 AS13335, 2803:f800:50::6ca2:c304 AS13335, 2a06:98c1:50::ac40:2304 AS13335
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