🛡️ 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

1,183,321 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1520.01%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 IPv610,6870.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,79364.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,3377.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-03 22:50).

📋 One autonomous system

757,793 domains
DomainNameservers and addresses
aalborgsalsa.dkandy.ns.cloudflare.com 108.162.193.101 AS13335, 172.64.33.101 AS13335, 173.245.59.101 AS13335, 2606:4700:58::adf5:3b65 AS13335, 2803:f800:50::6ca2:c165 AS13335, 2a06:98c1:50::ac40:2165 AS13335
tess.ns.cloudflare.com 108.162.192.227 AS13335, 172.64.32.227 AS13335, 173.245.58.227 AS13335, 2606:4700:50::adf5:3ae3 AS13335, 2803:f800:50::6ca2:c0e3 AS13335, 2a06:98c1:50::ac40:20e3 AS13335
aalborgsamarbejdet.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
aalborgsatellites.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
aalborgscanning.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
aalborgscanningoggraviditet.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
aalborgscanningshus.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
aalborgscanningsklinik.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
aalborgsejlklub.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
aalborgseminarium.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
aalborgskakforening.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
aalborgskanning.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
aalborgskolefoto.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
aalborgskolen.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
aalborgskoler.dkjervis.skole.cloud 194.239.103.170 AS3292
oswald.skole.cloud 194.239.103.171 AS3292
aalborgskolevognsudstyr.dkns1.ideal.shop 178.105.97.213 AS24940, 2a01:4f8:c014:3bb2::1 AS24940
ns2.ideal.shop 2a01:4f8:c012:70b2::1 AS24940, 46.224.133.227 AS24940
ns3.ideal.shop 2a01:4f8:c015:f1ad::1 AS24940, 49.12.110.155 AS24940
aalborgskyline.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
aalborgslotsteater.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
aalborgslushice.dkns1.aveo.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.aveo.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
aalborgslystbådehavn.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
aalborgsmedelaug.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
aalborgsmertefys.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
aalborgsmerteklinik.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
aalborgsmerteogidræt.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
aalborgsmerteogsport.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
aalborgsmertesportsfysio.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
aalborgsmertesportspecialist.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
aalborgsnak.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
aalborgspace.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
aalborgspand.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
aalborgspillet.dkhattie.ns.cloudflare.com 108.162.194.172 AS13335, 162.159.38.172 AS13335, 172.64.34.172 AS13335, 2606:4700:50::a29f:26ac AS13335, 2803:f800:50::6ca2:c2ac AS13335, 2a06:98c1:50::ac40:22ac AS13335
keaton.ns.cloudflare.com 108.162.195.181 AS13335, 162.159.44.181 AS13335, 172.64.35.181 AS13335, 2606:4700:58::a29f:2cb5 AS13335, 2803:f800:50::6ca2:c3b5 AS13335, 2a06:98c1:50::ac40:23b5 AS13335
aalborgsportogsmerte.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
aalborgsportsklinik.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
aalborgstadion.dkarvind.ns.cloudflare.com 108.162.195.227 AS13335, 162.159.44.227 AS13335, 172.64.35.227 AS13335, 2606:4700:58::a29f:2ce3 AS13335, 2803:f800:50::6ca2:c3e3 AS13335, 2a06:98c1:50::ac40:23e3 AS13335
tessa.ns.cloudflare.com 108.162.194.229 AS13335, 162.159.38.229 AS13335, 172.64.34.229 AS13335, 2606:4700:50::a29f:26e5 AS13335, 2803:f800:50::6ca2:c2e5 AS13335, 2a06:98c1:50::ac40:22e5 AS13335
aalborgstadsarkiv.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
aalborgstafetten.dkns3.webhot.dk 178.72.21.249 AS3342
ns4.webhot.dk 178.72.21.250 AS3342
aalborgstandlæger.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
aalborgstay.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
aalborgsteinerskole.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
aalborgstift.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
aalborgstiftstidendesfond.dkns1-04.azure-dns.com 13.107.236.4 AS8075, 2603:1061:0:700::4 AS8075
ns2-04.azure-dns.net 150.171.21.4 AS8075, 2620:1ec:8ec:700::4 AS8075
ns3-04.azure-dns.org 204.14.183.4 AS8075, 2a01:111:4000:700::4 AS8075
ns4-04.azure-dns.info 208.84.5.4 AS8075, 2620:1ec:bda:700::4 AS8075
aalborgstorcenter.dkns1.parkingcrew.net 13.248.158.159 AS16509
ns2.parkingcrew.net 76.223.21.9 AS16509
aalborgstreetfood.dkmckinley.ns.cloudflare.com 108.162.194.73 AS13335, 162.159.38.73 AS13335, 172.64.34.73 AS13335, 2606:4700:50::a29f:2649 AS13335, 2803:f800:50::6ca2:c249 AS13335, 2a06:98c1:50::ac40:2249 AS13335
tate.ns.cloudflare.com 108.162.195.191 AS13335, 162.159.44.191 AS13335, 172.64.35.191 AS13335, 2606:4700:58::a29f:2cbf AS13335, 2803:f800:50::6ca2:c3bf AS13335, 2a06:98c1:50::ac40:23bf AS13335
aalborgstreetwalkers.dkns1.ppi.dk 52.30.62.50 AS16509
ns2.ppi.dk 35.156.158.113 AS16509
aalborgstudenterterapi.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
aalborgstudioapartments.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
aalborgstx.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
aalborgstyrkeloefterklub.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
aalborgsurreal.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
aalborgsurvey.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
aalborgsvinbar.dkns4.wixdns.net 216.239.36.101 AS15169
ns5.wixdns.net 216.239.38.101 AS15169
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