🛡️ 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

1,183,327 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1530.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3090.11%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 system757,76764.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,3247.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-03 16:39).

📋 One autonomous system

757,767 domains
DomainNameservers and addresses
aalborg-polterabend.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
aalborg-portland.dkns1.eurodns.com 199.167.66.107 AS23393, 2610:1c8:b002::107 AS23393
ns2.eurodns.com 104.37.178.107 AS23393, 2610:1c8:b001::107 AS23393
ns3.eurodns.com 199.167.66.108 AS23393, 2610:1c8:b002::108 AS23393
ns4.eurodns.com 104.37.178.108 AS23393, 2610:1c8:b001::108 AS23393
aalborg-print-skilte.dkalexia.ns.cloudflare.com 108.162.194.175 AS13335, 162.159.38.175 AS13335, 172.64.34.175 AS13335, 2606:4700:50::a29f:26af AS13335, 2803:f800:50::6ca2:c2af AS13335, 2a06:98c1:50::ac40:22af AS13335
trevor.ns.cloudflare.com 108.162.195.154 AS13335, 162.159.44.154 AS13335, 172.64.35.154 AS13335, 2606:4700:58::a29f:2c9a AS13335, 2803:f800:50::6ca2:c39a AS13335, 2a06:98c1:50::ac40:239a AS13335
aalborg-print.dkns1.siteground.net 75.2.77.104 AS16509
ns2.siteground.net 99.83.229.113 AS16509
aalborg-psykolog.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
aalborg-psykoterapeut.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
aalborg-psykoterapi.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
aalborg-q.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
aalborg-rammegalleri.dkns1.dnshotel.dk 2a01:4f8:1c17:4999::2 AS24940, 88.99.120.238 AS24940
ns2.dnshotel.dk 2a01:4f8:c0c:4051::2 AS24940, 94.130.170.39 AS24940
aalborg-recycling.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
aalborg-roadrunners.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
aalborg-scanning.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
aalborg-sejlklub.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
aalborg-siden.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
aalborg-skanning.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
aalborg-skiklub.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
aalborg-smedelaug.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
aalborg-smeden.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
aalborg-smertefys.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
aalborg-smerteklinik.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
aalborg-smerteogidræt.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
aalborg-smerteogsport.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
aalborg-specialistcenter.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
aalborg-sportogsmerte.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
aalborg-sportsklinik.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
aalborg-spritfabrik.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
aalborg-steiner.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
aalborg-stenhuggeri.dkns1.wwi.dk 208.94.148.4 AS16552, 2600:1800:10::1 AS16552
ns2.wwi.dk 208.80.124.4 AS16552, 2600:1801:11::1 AS16552
ns3.wwi.as 208.80.126.4 AS16552, 2600:1802:12::1 AS16552
ns4.wwi.eu 208.80.125.4 AS16552, 2600:1801:13::1 AS16552
aalborg-streetfood.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
aalborg-stressklinik.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
aalborg-sundhedsklinik.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
aalborg-sygehus.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
aalborg-tandpleje.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
aalborg-tandplejeteam.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
aalborg-taxa.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
aalborg-taxi.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
aalborg-teambuilding.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
aalborg-teater.dkns.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
aalborg-teltudlejning.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
aalborg-tourist.dkamir.ns.cloudflare.com 108.162.193.62 AS13335, 172.64.33.62 AS13335, 173.245.59.62 AS13335, 2606:4700:58::adf5:3b3e AS13335, 2803:f800:50::6ca2:c13e AS13335, 2a06:98c1:50::ac40:213e AS13335
lola.ns.cloudflare.com 108.162.192.132 AS13335, 172.64.32.132 AS13335, 173.245.58.132 AS13335, 2606:4700:50::adf5:3a84 AS13335, 2803:f800:50::6ca2:c084 AS13335, 2a06:98c1:50::ac40:2084 AS13335
aalborg-tours.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
aalborg-trafikinfo.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
aalborg-trappevask.dkjohnny.ns.cloudflare.com 108.162.195.186 AS13335, 162.159.44.186 AS13335, 172.64.35.186 AS13335, 2606:4700:58::a29f:2cba AS13335, 2803:f800:50::6ca2:c3ba AS13335, 2a06:98c1:50::ac40:23ba AS13335
nelci.ns.cloudflare.com 108.162.194.152 AS13335, 162.159.38.152 AS13335, 172.64.34.152 AS13335, 2606:4700:50::a29f:2698 AS13335, 2803:f800:50::6ca2:c298 AS13335, 2a06:98c1:50::ac40:2298 AS13335
aalborg-triton.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
aalborg-tryk.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
aalborg-trykkeri.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
aalborg-turistfart.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
aalborg-udlejning.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
aalborg-uni.dkns1.aau.dk 130.225.52.5 AS1835, 2001:878:300:1::5 AS1835
ns2.aau.dk 130.225.54.5 AS1835, 2001:878:300:100::5 AS1835
aalborg-universitet.dkns1.aau.dk 130.225.52.5 AS1835, 2001:878:300:1::5 AS1835
ns2.aau.dk 130.225.54.5 AS1835, 2001:878:300:100::5 AS1835
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