🛡️ 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
aalborgcity.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
aalborgcitygaven.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
aalborgcitygaver.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
aalborgcitykiropraktik.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
aalborgcomedyclub.dkns6.wixdns.net 216.239.32.100 AS15169
ns7.wixdns.net 216.239.34.100 AS15169
aalborgcup.dkns3.webhot.dk 178.72.21.249 AS3342
ns4.webhot.dk 178.72.21.250 AS3342
aalborgcurlingklub.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
aalborgcvb.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
aalborgcykelby.dkashton.ns.cloudflare.com 108.162.195.173 AS13335, 162.159.44.173 AS13335, 172.64.35.173 AS13335, 2606:4700:58::a29f:2cad AS13335, 2803:f800:50::6ca2:c3ad AS13335, 2a06:98c1:50::ac40:23ad AS13335
kiki.ns.cloudflare.com 108.162.192.180 AS13335, 172.64.32.180 AS13335, 173.245.58.180 AS13335, 2606:4700:50::adf5:3ab4 AS13335, 2803:f800:50::6ca2:c0b4 AS13335, 2a06:98c1:50::ac40:20b4 AS13335
aalborgdagblad.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
aalborgdamp.dkbarbara.ns.cloudflare.com 108.162.192.248 AS13335, 172.64.32.248 AS13335, 173.245.58.248 AS13335, 2606:4700:50::adf5:3af8 AS13335, 2803:f800:50::6ca2:c0f8 AS13335, 2a06:98c1:50::ac40:20f8 AS13335
justin.ns.cloudflare.com 108.162.193.187 AS13335, 172.64.33.187 AS13335, 173.245.59.187 AS13335, 2606:4700:58::adf5:3bbb AS13335, 2803:f800:50::6ca2:c1bb AS13335, 2a06:98c1:50::ac40:21bb AS13335
aalborgdata.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
aalborgdeaf.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
aalborgdental.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
aalborgdesign.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
aalborgdh.dkjarred.ns.cloudflare.com 108.162.195.126 AS13335, 162.159.44.126 AS13335, 172.64.35.126 AS13335, 2606:4700:58::a29f:2c7e AS13335, 2803:f800:50::6ca2:c37e AS13335, 2a06:98c1:50::ac40:237e AS13335
virginia.ns.cloudflare.com 108.162.194.37 AS13335, 162.159.38.37 AS13335, 172.64.34.37 AS13335, 2606:4700:50::a29f:2625 AS13335, 2803:f800:50::6ca2:c225 AS13335, 2a06:98c1:50::ac40:2225 AS13335
aalborgdiscountflyt.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
aalborgdivers.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
aalborgdiætist.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
aalborgdiætisten.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
aalborgdomkirke.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
aalborgdressageevent.dkkim.ns.cloudflare.com 108.162.192.126 AS13335, 172.64.32.126 AS13335, 173.245.58.126 AS13335, 2606:4700:50::adf5:3a7e AS13335, 2803:f800:50::6ca2:c07e AS13335, 2a06:98c1:50::ac40:207e AS13335
patryk.ns.cloudflare.com 108.162.195.122 AS13335, 162.159.44.122 AS13335, 172.64.35.122 AS13335, 2606:4700:58::a29f:2c7a AS13335, 2803:f800:50::6ca2:c37a AS13335, 2a06:98c1:50::ac40:237a AS13335
aalborgdrive.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
aalborgdronefoto.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
aalborgdronevideo.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
aalborgdyk.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
aalborgdykkerskole.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
aalborgdyrehospital.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
aalborgdødsborydning.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
aalborgefterskole-virtuelt-aabent-hus.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
aalborgefterskole.dkashton.ns.cloudflare.com 108.162.195.173 AS13335, 162.159.44.173 AS13335, 172.64.35.173 AS13335, 2606:4700:58::a29f:2cad AS13335, 2803:f800:50::6ca2:c3ad AS13335, 2a06:98c1:50::ac40:23ad AS13335
serena.ns.cloudflare.com 108.162.192.220 AS13335, 172.64.32.220 AS13335, 173.245.58.220 AS13335, 2606:4700:50::adf5:3adc AS13335, 2803:f800:50::6ca2:c0dc AS13335, 2a06:98c1:50::ac40:20dc AS13335
aalborgejendomsservice.dkanahi.ns.cloudflare.com 108.162.194.24 AS13335, 162.159.38.24 AS13335, 172.64.34.24 AS13335, 2606:4700:50::a29f:2618 AS13335, 2803:f800:50::6ca2:c218 AS13335, 2a06:98c1:50::ac40:2218 AS13335
steven.ns.cloudflare.com 108.162.195.17 AS13335, 162.159.44.17 AS13335, 172.64.35.17 AS13335, 2606:4700:58::a29f:2c11 AS13335, 2803:f800:50::6ca2:c311 AS13335, 2a06:98c1:50::ac40:2311 AS13335
aalborgelektriker.dkclay.ns.cloudflare.com 108.162.193.88 AS13335, 172.64.33.88 AS13335, 173.245.59.88 AS13335, 2606:4700:58::adf5:3b58 AS13335, 2803:f800:50::6ca2:c158 AS13335, 2a06:98c1:50::ac40:2158 AS13335
desi.ns.cloudflare.com 108.162.192.96 AS13335, 172.64.32.96 AS13335, 173.245.58.96 AS13335, 2606:4700:50::adf5:3a60 AS13335, 2803:f800:50::6ca2:c060 AS13335, 2a06:98c1:50::ac40:2060 AS13335
aalborgenser.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
aalborgensere.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
aalborgenseren.dkbayan.ns.cloudflare.com 108.162.193.72 AS13335, 172.64.33.72 AS13335, 173.245.59.72 AS13335, 2606:4700:58::adf5:3b48 AS13335, 2803:f800:50::6ca2:c148 AS13335, 2a06:98c1:50::ac40:2148 AS13335
cora.ns.cloudflare.com 108.162.194.195 AS13335, 162.159.38.195 AS13335, 172.64.34.195 AS13335, 2606:4700:50::a29f:26c3 AS13335, 2803:f800:50::6ca2:c2c3 AS13335, 2a06:98c1:50::ac40:22c3 AS13335
aalborgenserne.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
aalborgensisk.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
aalborgepoxy.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
aalborger.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
aalborgerhvervscenter.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
aalborges.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
aalborgevent.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
aalborgevents.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
aalborgfarveoglak.dkns1.dnsservers.dk 2001:1448:0:a800::53 AS47292, 217.30.38.181 AS47292
ns2.dnsservers.dk 2001:1448:0:a500::53 AS47292, 217.30.38.27 AS47292
ns3.dnsservers.dk 2001:1448:0:a600::53 AS47292, 217.30.38.30 AS47292
aalborgfdk.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
aalborgfestfyrværkeri.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
aalborgfestival.dkbeth.ns.cloudflare.com 108.162.192.103 AS13335, 172.64.32.103 AS13335, 173.245.58.103 AS13335, 2606:4700:50::adf5:3a67 AS13335, 2803:f800:50::6ca2:c067 AS13335, 2a06:98c1:50::ac40:2067 AS13335
jim.ns.cloudflare.com 108.162.193.125 AS13335, 172.64.33.125 AS13335, 173.245.59.125 AS13335, 2606:4700:58::adf5:3b7d AS13335, 2803:f800:50::6ca2:c17d AS13335, 2a06:98c1:50::ac40:217d AS13335
aalborgfestivals.dkns1.namesystem.se 195.238.76.18 AS42708, 2a02:750:aaaa::1 AS42708
ns2.namesystem.se 195.238.77.18 AS42708, 2a02:750:aaaa::2 AS42708
ns3.namesystem.se 195.20.206.18 AS42708, 2a02:750:aaaa::3 AS42708
aalborgfestudlejning.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
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