🛡️ 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

1,186,156 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1470.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3070.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,8010.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,81663.9%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,8847.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-01 01:58).

📋 One autonomous system

757,816 domains
DomainNameservers and addresses
3f-kastrup.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
3f-kommunale.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
3f-nordsjælland.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
3f-nordøstsjælland.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
3f-post.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
3f-ungdom.dkjay.ns.cloudflare.com 108.162.193.123 AS13335, 172.64.33.123 AS13335, 173.245.59.123 AS13335, 2606:4700:58::adf5:3b7b AS13335, 2803:f800:50::6ca2:c17b AS13335, 2a06:98c1:50::ac40:217b AS13335
uma.ns.cloudflare.com 108.162.192.146 AS13335, 172.64.32.146 AS13335, 173.245.58.146 AS13335, 2606:4700:50::adf5:3a92 AS13335, 2803:f800:50::6ca2:c092 AS13335, 2a06:98c1:50::ac40:2092 AS13335
3f-øresundnord.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
3f.dklisa.ns.cloudflare.com 108.162.192.131 AS13335, 172.64.32.131 AS13335, 173.245.58.131 AS13335, 2606:4700:50::adf5:3a83 AS13335, 2803:f800:50::6ca2:c083 AS13335, 2a06:98c1:50::ac40:2083 AS13335
max.ns.cloudflare.com 108.162.193.132 AS13335, 172.64.33.132 AS13335, 173.245.59.132 AS13335, 2606:4700:58::adf5:3b84 AS13335, 2803:f800:50::6ca2:c184 AS13335, 2a06:98c1:50::ac40:2184 AS13335
3fa.dklisa.ns.cloudflare.com 108.162.192.131 AS13335, 172.64.32.131 AS13335, 173.245.58.131 AS13335, 2606:4700:50::adf5:3a83 AS13335, 2803:f800:50::6ca2:c083 AS13335, 2a06:98c1:50::ac40:2083 AS13335
max.ns.cloudflare.com 108.162.193.132 AS13335, 172.64.33.132 AS13335, 173.245.59.132 AS13335, 2606:4700:58::adf5:3b84 AS13335, 2803:f800:50::6ca2:c184 AS13335, 2a06:98c1:50::ac40:2184 AS13335
3fadder.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
3falke.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
3falkelaegerne.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
3fbold.dkjay.ns.cloudflare.com 108.162.193.123 AS13335, 172.64.33.123 AS13335, 173.245.59.123 AS13335, 2606:4700:58::adf5:3b7b AS13335, 2803:f800:50::6ca2:c17b AS13335, 2a06:98c1:50::ac40:217b AS13335
uma.ns.cloudflare.com 108.162.192.146 AS13335, 172.64.32.146 AS13335, 173.245.58.146 AS13335, 2606:4700:50::adf5:3a92 AS13335, 2803:f800:50::6ca2:c092 AS13335, 2a06:98c1:50::ac40:2092 AS13335
3fcm.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
3ferietilbud.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
3ff.dkjay.ns.cloudflare.com 108.162.193.123 AS13335, 172.64.33.123 AS13335, 173.245.59.123 AS13335, 2606:4700:58::adf5:3b7b AS13335, 2803:f800:50::6ca2:c17b AS13335, 2a06:98c1:50::ac40:217b AS13335
uma.ns.cloudflare.com 108.162.192.146 AS13335, 172.64.32.146 AS13335, 173.245.58.146 AS13335, 2606:4700:50::adf5:3a92 AS13335, 2803:f800:50::6ca2:c092 AS13335, 2a06:98c1:50::ac40:2092 AS13335
3ffemern.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
3fff.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
3fhorsens.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
3fhr-feriebolig.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
3fhrferiebolig.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
3fi.dklisa.ns.cloudflare.com 108.162.192.131 AS13335, 172.64.32.131 AS13335, 173.245.58.131 AS13335, 2606:4700:50::adf5:3a83 AS13335, 2803:f800:50::6ca2:c083 AS13335, 2a06:98c1:50::ac40:2083 AS13335
max.ns.cloudflare.com 108.162.193.132 AS13335, 172.64.33.132 AS13335, 173.245.59.132 AS13335, 2606:4700:58::adf5:3b84 AS13335, 2803:f800:50::6ca2:c184 AS13335, 2a06:98c1:50::ac40:2184 AS13335
3findustri.dkjay.ns.cloudflare.com 108.162.193.123 AS13335, 172.64.33.123 AS13335, 173.245.59.123 AS13335, 2606:4700:58::adf5:3b7b AS13335, 2803:f800:50::6ca2:c17b AS13335, 2a06:98c1:50::ac40:217b AS13335
uma.ns.cloudflare.com 108.162.192.146 AS13335, 172.64.32.146 AS13335, 173.245.58.146 AS13335, 2606:4700:50::adf5:3a92 AS13335, 2803:f800:50::6ca2:c092 AS13335, 2a06:98c1:50::ac40:2092 AS13335
3finger.dkns1.wedohosting.dk 77.247.73.93 AS31590
ns2.wedohosting.dk 77.247.73.93 AS31590
3finternational.dkjay.ns.cloudflare.com 108.162.193.123 AS13335, 172.64.33.123 AS13335, 173.245.59.123 AS13335, 2606:4700:58::adf5:3b7b AS13335, 2803:f800:50::6ca2:c17b AS13335, 2a06:98c1:50::ac40:217b AS13335
uma.ns.cloudflare.com 108.162.192.146 AS13335, 172.64.32.146 AS13335, 173.245.58.146 AS13335, 2606:4700:50::adf5:3a92 AS13335, 2803:f800:50::6ca2:c092 AS13335, 2a06:98c1:50::ac40:2092 AS13335
3fisk.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
3fitst.dklisa.ns.cloudflare.com 108.162.192.131 AS13335, 172.64.32.131 AS13335, 173.245.58.131 AS13335, 2606:4700:50::adf5:3a83 AS13335, 2803:f800:50::6ca2:c083 AS13335, 2a06:98c1:50::ac40:2083 AS13335
max.ns.cloudflare.com 108.162.193.132 AS13335, 172.64.33.132 AS13335, 173.245.59.132 AS13335, 2606:4700:58::adf5:3b84 AS13335, 2803:f800:50::6ca2:c184 AS13335, 2a06:98c1:50::ac40:2184 AS13335
3fiudv.dklisa.ns.cloudflare.com 108.162.192.131 AS13335, 172.64.32.131 AS13335, 173.245.58.131 AS13335, 2606:4700:50::adf5:3a83 AS13335, 2803:f800:50::6ca2:c083 AS13335, 2a06:98c1:50::ac40:2083 AS13335
max.ns.cloudflare.com 108.162.193.132 AS13335, 172.64.33.132 AS13335, 173.245.59.132 AS13335, 2606:4700:58::adf5:3b84 AS13335, 2803:f800:50::6ca2:c184 AS13335, 2a06:98c1:50::ac40:2184 AS13335
3fkastrup-tools.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
3fkastrup.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
3fkbh.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
3fklub.dkjay.ns.cloudflare.com 108.162.193.123 AS13335, 172.64.33.123 AS13335, 173.245.59.123 AS13335, 2606:4700:58::adf5:3b7b AS13335, 2803:f800:50::6ca2:c17b AS13335, 2a06:98c1:50::ac40:217b AS13335
uma.ns.cloudflare.com 108.162.192.146 AS13335, 172.64.32.146 AS13335, 173.245.58.146 AS13335, 2606:4700:50::adf5:3a92 AS13335, 2803:f800:50::6ca2:c092 AS13335, 2a06:98c1:50::ac40:2092 AS13335
3fklubben.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
3fkongres.dkjay.ns.cloudflare.com 108.162.193.123 AS13335, 172.64.33.123 AS13335, 173.245.59.123 AS13335, 2606:4700:58::adf5:3b7b AS13335, 2803:f800:50::6ca2:c17b AS13335, 2a06:98c1:50::ac40:217b AS13335
uma.ns.cloudflare.com 108.162.192.146 AS13335, 172.64.32.146 AS13335, 173.245.58.146 AS13335, 2606:4700:50::adf5:3a92 AS13335, 2803:f800:50::6ca2:c092 AS13335, 2a06:98c1:50::ac40:2092 AS13335
3fkurser.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
3floor.dkclark.ns.cloudflare.com 108.162.193.87 AS13335, 172.64.33.87 AS13335, 173.245.59.87 AS13335, 2606:4700:58::adf5:3b57 AS13335, 2803:f800:50::6ca2:c157 AS13335, 2a06:98c1:50::ac40:2157 AS13335
nicole.ns.cloudflare.com 108.162.192.211 AS13335, 172.64.32.211 AS13335, 173.245.58.211 AS13335, 2606:4700:50::adf5:3ad3 AS13335, 2803:f800:50::6ca2:c0d3 AS13335, 2a06:98c1:50::ac40:20d3 AS13335
3flyttepriser.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
3flyttetilbud.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
3fm.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
3fnet.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
3fnordsjaelland.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
3for1.dkns1.web24tech.com 85.215.129.49 AS8560
ns2.web24tech.com 85.215.133.5 AS8560
3for2.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
3for2vin.dkns1.linode.com 2600:14c0:6::2 AS21342, 92.123.94.2 AS21342
ns2.linode.com 2600:14c0:6::3 AS21342, 92.123.94.3 AS21342
ns3.linode.com 2600:14c0:7::3 AS21342, 92.123.95.3 AS21342
ns4.linode.com 2600:14c0:7::4 AS21342, 92.123.95.4 AS21342
ns5.linode.com 2600:14c0:7::2 AS21342, 92.123.95.2 AS21342
3forsendelsestilbud.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
3forsikring.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
3fpost.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
3fragttilbud.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
3frus.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
3fsuperliga.dkwally.ns.cloudflare.com 108.162.192.239 AS13335, 172.64.32.239 AS13335, 173.245.58.239 AS13335, 2606:4700:50::adf5:3aef AS13335, 2803:f800:50::6ca2:c0ef AS13335, 2a06:98c1:50::ac40:20ef AS13335
zac.ns.cloudflare.com 108.162.195.178 AS13335, 162.159.44.178 AS13335, 172.64.35.178 AS13335, 2606:4700:58::a29f:2cb2 AS13335, 2803:f800:50::6ca2:c3b2 AS13335, 2a06:98c1:50::ac40:23b2 AS13335
dhd.dk [/] search Domains, Hosts & DNS — .dk zone