🛡️ 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

1,185,870 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1460.01%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 IPv610,8270.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system754,02263.6%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver86,0427.3%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-09-29 17:57).

📋 One autonomous system

754,022 domains
DomainNameservers and addresses
123bazar.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
123bearing.dkdns13.ovh.net 2001:41d0:d00:f200::2 AS16276, 5.135.98.29 AS16276
ns13.ovh.net 2001:41d0:b00:ec00::2 AS16276, 5.39.112.241 AS16276
123bedemand.dkmariah.ns.cloudflare.com 108.162.194.200 AS13335, 162.159.38.200 AS13335, 172.64.34.200 AS13335, 2606:4700:50::a29f:26c8 AS13335, 2803:f800:50::6ca2:c2c8 AS13335, 2a06:98c1:50::ac40:22c8 AS13335
phil.ns.cloudflare.com 108.162.193.137 AS13335, 172.64.33.137 AS13335, 173.245.59.137 AS13335, 2606:4700:58::adf5:3b89 AS13335, 2803:f800:50::6ca2:c189 AS13335, 2a06:98c1:50::ac40:2189 AS13335
123beregner.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
123bet.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
123bil.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
123biludlejning.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
123bilvask.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
123bolig.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
123booking.dkkimora.ns.cloudflare.com 108.162.194.243 AS13335, 162.159.38.243 AS13335, 172.64.34.243 AS13335, 2606:4700:50::a29f:26f3 AS13335, 2803:f800:50::6ca2:c2f3 AS13335, 2a06:98c1:50::ac40:22f3 AS13335
toby.ns.cloudflare.com 108.162.193.239 AS13335, 172.64.33.239 AS13335, 173.245.59.239 AS13335, 2606:4700:58::adf5:3bef AS13335, 2803:f800:50::6ca2:c1ef AS13335, 2a06:98c1:50::ac40:21ef AS13335
123bryllup.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
123business.dkns1.openprovider.nl 162.159.26.10 AS13335, 2400:cb00:2049:1::a29f:1a0a AS13335
ns2.openprovider.be 162.159.27.96 AS13335, 2400:cb00:2049:1::a29f:1b60 AS13335
ns3.openprovider.eu 162.159.48.89 AS13335, 2400:cb00:2049:1::a29f:3059 AS13335
123byd.dkseth.ns.cloudflare.com 108.162.193.142 AS13335, 172.64.33.142 AS13335, 173.245.59.142 AS13335, 2606:4700:58::adf5:3b8e AS13335, 2803:f800:50::6ca2:c18e AS13335, 2a06:98c1:50::ac40:218e AS13335
ulla.ns.cloudflare.com 108.162.192.233 AS13335, 172.64.32.233 AS13335, 173.245.58.233 AS13335, 2606:4700:50::adf5:3ae9 AS13335, 2803:f800:50::6ca2:c0e9 AS13335, 2a06:98c1:50::ac40:20e9 AS13335
123byg.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
123byggetilladelse.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
123card.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
123cards.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
123cloud.dktom.ns.cloudflare.com 108.162.193.147 AS13335, 172.64.33.147 AS13335, 173.245.59.147 AS13335, 2606:4700:58::adf5:3b93 AS13335, 2803:f800:50::6ca2:c193 AS13335, 2a06:98c1:50::ac40:2193 AS13335
vera.ns.cloudflare.com 108.162.192.147 AS13335, 172.64.32.147 AS13335, 173.245.58.147 AS13335, 2606:4700:50::adf5:3a93 AS13335, 2803:f800:50::6ca2:c093 AS13335, 2a06:98c1:50::ac40:2093 AS13335
123coach.dkns61.domaincontrol.com 2603:5:2153::20 AS44273, 97.74.101.32 AS44273
ns62.domaincontrol.com 173.201.69.32 AS44273, 2603:5:2253::20 AS44273
123coaching.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
123cv.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
123cykel.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
123daek.dkcandy.ns.cloudflare.com 108.162.192.79 AS13335, 172.64.32.79 AS13335, 173.245.58.79 AS13335, 2606:4700:50::adf5:3a4f AS13335, 2803:f800:50::6ca2:c04f AS13335, 2a06:98c1:50::ac40:204f AS13335
cullen.ns.cloudflare.com 108.162.195.91 AS13335, 162.159.44.91 AS13335, 172.64.35.91 AS13335, 2606:4700:58::a29f:2c5b AS13335, 2803:f800:50::6ca2:c35b AS13335, 2a06:98c1:50::ac40:235b AS13335
123dbh.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
123disco.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
123disko.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
123dk.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
123domains.dkns1.bb-online.net 185.206.123.1 AS212217
ns2.bb-online.org 81.30.104.2 AS212217
ns3.bb-online.uk 46.253.129.1 AS212217
ns4.bb-online.biz 46.253.129.4 AS212217
123dprint.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
123duun.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
123ebike.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
123ebikes.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
123energi.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
123energiogvvs.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78
ns2.simply.com 185.25.141.15, 2a02:2339:4006:101::4562:4562
ns3.simply.com 91.197.248.79
123eventyr.dkdakota.ns.cloudflare.com 108.162.195.79 AS13335, 162.159.44.79 AS13335, 172.64.35.79 AS13335, 2606:4700:58::a29f:2c4f AS13335, 2803:f800:50::6ca2:c34f AS13335, 2a06:98c1:50::ac40:234f AS13335
jill.ns.cloudflare.com 108.162.192.122 AS13335, 172.64.32.122 AS13335, 173.245.58.122 AS13335, 2606:4700:50::adf5:3a7a AS13335, 2803:f800:50::6ca2:c07a AS13335, 2a06:98c1:50::ac40:207a AS13335
123faerdighaek.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
123fagforening.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
123fakta.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
123faktura.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
123festbands.dkbrad.ns.cloudflare.com 108.162.193.105 AS13335, 172.64.33.105 AS13335, 173.245.59.105 AS13335, 2606:4700:58::adf5:3b69 AS13335, 2803:f800:50::6ca2:c169 AS13335, 2a06:98c1:50::ac40:2169 AS13335
raquel.ns.cloudflare.com 108.162.194.210 AS13335, 162.159.38.210 AS13335, 172.64.34.210 AS13335, 2606:4700:50::a29f:26d2 AS13335, 2803:f800:50::6ca2:c2d2 AS13335, 2a06:98c1:50::ac40:22d2 AS13335
123festdjs.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
dan.ns.cloudflare.com 108.162.193.108 AS13335, 172.64.33.108 AS13335, 173.245.59.108 AS13335, 2606:4700:58::adf5:3b6c AS13335, 2803:f800:50::6ca2:c16c AS13335, 2a06:98c1:50::ac40:216c AS13335
123festmusik.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
123festunderholdning.dkhorizon.dns-parking.com 172.64.53.161 AS13335, 2606:4700:5a::ac40:35a1 AS13335
orbit.dns-parking.com 172.64.52.95 AS13335, 2606:4700:52::ac40:345f AS13335
123fiber.dkdom.ns.cloudflare.com 108.162.193.157 AS13335, 172.64.33.157 AS13335, 173.245.59.157 AS13335, 2606:4700:58::adf5:3b9d AS13335, 2803:f800:50::6ca2:c19d AS13335, 2a06:98c1:50::ac40:219d AS13335
isabel.ns.cloudflare.com 108.162.194.104 AS13335, 162.159.38.104 AS13335, 172.64.34.104 AS13335, 2606:4700:50::a29f:2668 AS13335, 2803:f800:50::6ca2:c268 AS13335, 2a06:98c1:50::ac40:2268 AS13335
123film.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
123find.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
123fisk.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
123fliserens.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
123flyt.dkelisabeth.ns.cloudflare.com 108.162.194.224 AS13335, 162.159.38.224 AS13335, 172.64.34.224 AS13335, 2606:4700:50::a29f:26e0 AS13335, 2803:f800:50::6ca2:c2e0 AS13335, 2a06:98c1:50::ac40:22e0 AS13335
gannon.ns.cloudflare.com 108.162.195.59 AS13335, 162.159.44.59 AS13335, 172.64.35.59 AS13335, 2606:4700:58::a29f:2c3b AS13335, 2803:f800:50::6ca2:c33b AS13335, 2a06:98c1:50::ac40:233b AS13335
123flyttefirma.dkjaime.ns.cloudflare.com 108.162.195.102 AS13335, 162.159.44.102 AS13335, 172.64.35.102 AS13335, 2606:4700:58::a29f:2c66 AS13335, 2803:f800:50::6ca2:c366 AS13335, 2a06:98c1:50::ac40:2366 AS13335
veda.ns.cloudflare.com 108.162.194.147 AS13335, 162.159.38.147 AS13335, 172.64.34.147 AS13335, 2606:4700:50::a29f:2693 AS13335, 2803:f800:50::6ca2:c293 AS13335, 2a06:98c1:50::ac40:2293 AS13335
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