🛡️ 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

1,183,325 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 address1,3110.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6890.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,85464.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,3487.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-04 05:03).

📋 One autonomous system

757,854 domains
DomainNameservers and addresses
aarhusjulemarked.dkprimary.infoserv.dk 139.162.157.8, 2a01:7e01::f03c:91ff:fe59:943d
secondary.infoserv.dk 139.162.227.162 AS63949, 2a01:7e00::f03c:92ff:fe07:7dc2
aarhusjuleskib.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
aarhusjuristen.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
aarhuskalender.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
aarhuskalenderen.dkjoselyn.ns.cloudflare.com 108.162.194.43 AS13335, 162.159.38.43 AS13335, 172.64.34.43 AS13335, 2606:4700:50::a29f:262b AS13335, 2803:f800:50::6ca2:c22b AS13335, 2a06:98c1:50::ac40:222b AS13335
skip.ns.cloudflare.com 108.162.193.233 AS13335, 172.64.33.233 AS13335, 173.245.59.233 AS13335, 2606:4700:58::adf5:3be9 AS13335, 2803:f800:50::6ca2:c1e9 AS13335, 2a06:98c1:50::ac40:21e9 AS13335
aarhuskammerkor.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
aarhuskampsport.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
aarhuskanalen.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
aarhuskanoudlejning.dkmario.ns.cloudflare.com 108.162.193.203 AS13335, 172.64.33.203 AS13335, 173.245.59.203 AS13335, 2606:4700:58::adf5:3bcb AS13335, 2803:f800:50::6ca2:c1cb AS13335, 2a06:98c1:50::ac40:21cb AS13335
sima.ns.cloudflare.com 108.162.192.222 AS13335, 172.64.32.222 AS13335, 173.245.58.222 AS13335, 2606:4700:50::adf5:3ade AS13335, 2803:f800:50::6ca2:c0de AS13335, 2a06:98c1:50::ac40:20de AS13335
aarhuskat-gym.dkns3.supportcenter.dk 87.54.32.150 AS3292
ns4.supportcenter.dk 2.106.7.200 AS3292
aarhuskinball.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
aarhuskirurgi.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
aarhusklaverskole.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
aarhuskleinsmedie.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
aarhusklinik.dktreasure.ns.cloudflare.com 108.162.194.116 AS13335, 162.159.38.116 AS13335, 172.64.34.116 AS13335, 2606:4700:50::a29f:2674 AS13335, 2803:f800:50::6ca2:c274 AS13335, 2a06:98c1:50::ac40:2274 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
aarhuskloakservice.dkns1.gnrx.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.gnrx.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
aarhuskodengros.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
aarhuskoereskole.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
aarhuskollegiet.dkns12.wixdns.net 216.239.36.101 AS15169
ns13.wixdns.net 216.239.38.101 AS15169
aarhuskom.dkns1-06.azure-dns.com 13.107.236.6 AS8075, 2603:1061:0:700::6 AS8075
ns2-06.azure-dns.net 150.171.21.6 AS8075, 2620:1ec:8ec:700::6 AS8075
ns3-06.azure-dns.org 204.14.183.6 AS8075, 2a01:111:4000:700::6 AS8075
ns4-06.azure-dns.info 208.84.5.6 AS8075, 2620:1ec:bda:700::6 AS8075
aarhuskommune.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
aarhuskommuneerhverv.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
aarhuskommunesferiefond.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
aarhuskomune.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
aarhuskoncert.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
aarhuskoncerter.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
aarhuskonference.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
aarhuskonferencen.dkns7.bricksite.net 35.246.226.10 AS396982
ns8.bricksite.net 35.242.190.82 AS396982
aarhuskonservative.dkgracie.ns.cloudflare.com 108.162.194.144 AS13335, 162.159.38.144 AS13335, 172.64.34.144 AS13335, 2606:4700:50::a29f:2690 AS13335, 2803:f800:50::6ca2:c290 AS13335, 2a06:98c1:50::ac40:2290 AS13335
greg.ns.cloudflare.com 108.162.193.115 AS13335, 172.64.33.115 AS13335, 173.245.59.115 AS13335, 2606:4700:58::adf5:3b73 AS13335, 2803:f800:50::6ca2:c173 AS13335, 2a06:98c1:50::ac40:2173 AS13335
aarhuskontorhotel.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
aarhuskor.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
aarhuskort.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
aarhuskortet.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
aarhuskraftvarme.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
aarhuskrisecenter.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
aarhuskropsterapi.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
aarhuskrudtlager.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
aarhuskrypto.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
aarhuskultur.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
aarhuskunstakademi.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
aarhuskunstbygning.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
aarhuskunsthal.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
aarhuskunstskole.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
aarhuskøbenhavn.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
aarhuskøleteknik.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
aarhuskøreskole.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
aarhuskøretekniskanlæg.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
aarhuslaan.dkns1-09.azure-dns.com 13.107.236.9 AS8075, 2603:1061:0:700::9 AS8075
ns2-09.azure-dns.net 150.171.21.9 AS8075, 2620:1ec:8ec:700::9 AS8075
ns3-09.azure-dns.org 204.14.183.9 AS8075, 2a01:111:4000:700::9 AS8075
ns4-09.azure-dns.info 208.84.5.9 AS8075, 2620:1ec:bda:700::9 AS8075
aarhuslaaseservice.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
aarhuslabyrint.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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