🛡️ 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
aarhus-fitness.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
aarhus-fliserens.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
aarhus-flyttefirma.dkaurora.ns.cloudflare.com 108.162.194.110 AS13335, 162.159.38.110 AS13335, 172.64.34.110 AS13335, 2606:4700:50::a29f:266e AS13335, 2803:f800:50::6ca2:c26e AS13335, 2a06:98c1:50::ac40:226e 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
aarhus-flytteservice.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
aarhus-friplejehjem.dkns-auth03.kmd.dk 131.165.64.5 AS6834
ns-auth04.kmd.dk 131.165.4.5 AS6834
aarhus-friskole.dkbella.ns.cloudflare.com 108.162.192.74 AS13335, 172.64.32.74 AS13335, 173.245.58.74 AS13335, 2606:4700:50::adf5:3a4a AS13335, 2803:f800:50::6ca2:c04a AS13335, 2a06:98c1:50::ac40:204a AS13335
mark.ns.cloudflare.com 108.162.193.130 AS13335, 172.64.33.130 AS13335, 173.245.59.130 AS13335, 2606:4700:58::adf5:3b82 AS13335, 2803:f800:50::6ca2:c182 AS13335, 2a06:98c1:50::ac40:2182 AS13335
aarhus-fysioterapicenter.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
aarhus-gardiner.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
aarhus-gartner.dkns1.telanco.dk 84.246.245.104 AS34165
ns2.telanco.dk 84.246.247.29 AS34165
aarhus-gf.dkdonovan.ns.cloudflare.com 108.162.195.114 AS13335, 162.159.44.114 AS13335, 172.64.35.114 AS13335, 2606:4700:58::a29f:2c72 AS13335, 2803:f800:50::6ca2:c372 AS13335, 2a06:98c1:50::ac40:2372 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
aarhus-glarmester.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
aarhus-gulvcenter.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
aarhus-gulvservice.dksterling.ns.cloudflare.com 108.162.195.143 AS13335, 162.159.44.143 AS13335, 172.64.35.143 AS13335, 2606:4700:58::a29f:2c8f AS13335, 2803:f800:50::6ca2:c38f AS13335, 2a06:98c1:50::ac40:238f AS13335
vivienne.ns.cloudflare.com 108.162.194.50 AS13335, 162.159.38.50 AS13335, 172.64.34.50 AS13335, 2606:4700:50::a29f:2632 AS13335, 2803:f800:50::6ca2:c232 AS13335, 2a06:98c1:50::ac40:2232 AS13335
aarhus-gymnasierne.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
aarhus-haandbold.dkns1.it-kons.dk 217.63.112.130 AS42525
ns2.it-kons.dk 217.63.112.118 AS42525
aarhus-hallen.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
aarhus-handywoman.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
aarhus-haveservice.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
aarhus-havn.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
aarhus-hc.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
aarhus-hostel.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
aarhus-hotel.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
aarhus-hunde.dkns1.mono.net 185.58.212.1 AS201595
ns2.mono.net 185.130.160.1 AS201595
ns3.mono.net 185.130.160.2 AS201595
ns4.mono.net 185.58.212.2 AS201595
aarhus-it.dkns1.site4now.net 204.188.197.246 AS46844, 204.188.197.84 AS46844, 70.39.73.45 AS46844
ns2.site4now.net 208.98.36.41 AS46844, 45.58.159.232 AS46844, 45.58.159.233 AS46844
ns3.site4now.net 208.98.36.42 AS46844, 45.58.159.230 AS46844, 45.58.159.231 AS46844
aarhus-kaffe-repair.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
aarhus-kaffe.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
aarhus-kiropraktor.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
aarhus-klunserne.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
aarhus-kobenhavn.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
aarhus-koereskole.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
aarhus-kommune.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
aarhus-kommuneatlas.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
aarhus-koncert.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
aarhus-koncerter.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
aarhus-kontor.dkns1.siteground.net 75.2.77.104 AS16509
ns2.siteground.net 99.83.229.113 AS16509
aarhus-kreativ.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
aarhus-krisecenter.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
aarhus-ku.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
aarhus-københavn.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
aarhus-køreskole.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
aarhus-laase.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
aarhus-laasesmed.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
aarhus-laasesmeden.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
aarhus-lagerhotel.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
aarhus-lagerrum.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
aarhus-landrover.dkelsa.ns.cloudflare.com 108.162.192.111 AS13335, 172.64.32.111 AS13335, 173.245.58.111 AS13335, 2606:4700:50::adf5:3a6f AS13335, 2803:f800:50::6ca2:c06f AS13335, 2a06:98c1:50::ac40:206f AS13335
roan.ns.cloudflare.com 108.162.193.226 AS13335, 172.64.33.226 AS13335, 173.245.59.226 AS13335, 2606:4700:58::adf5:3be2 AS13335, 2803:f800:50::6ca2:c1e2 AS13335, 2a06:98c1:50::ac40:21e2 AS13335
aarhus-leje.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
aarhus-loeve.dkns.pharmakon.dk 81.27.217.6 AS42525
ns2.pharmakon.dk 81.27.217.7 AS42525
aarhus-m1.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
aarhus-maler.dkns1.dnsserver.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.dnsserver.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
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