🛡️ 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

1,185,859 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 address1,3060.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,7960.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system758,38264.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,8087.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-01 08:10).

📋 One autonomous system

758,382 domains
DomainNameservers and addresses
40965000.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
4097.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
40978787.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
40a.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
40aar.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
40dageforlivet.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
40fit.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
40g.dkns1-auth.enivest.net 2a02:1660:4101:0:62:50:163:254 AS35132, 62.50.163.254 AS35132
ns2-auth.enivest.net 217.149.115.2 AS35132
40iskyggen.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
40kroam.dkns.netc.dk 178.128.191.122 AS14061, 2604:a880:2:d0::1ce8:7001 AS14061
ns2.netc.dk 188.166.56.96 AS14061, 2a03:b0c0:2:d0::20:1001 AS14061
ns3.netc.dk 2400:6180:0:d0::16e6:2001 AS14061, 68.183.187.150 AS14061
40net.dkanton.ns.cloudflare.com 108.162.195.175 AS13335, 162.159.44.175 AS13335, 172.64.35.175 AS13335, 2606:4700:58::a29f:2caf AS13335, 2803:f800:50::6ca2:c3af AS13335, 2a06:98c1:50::ac40:23af AS13335
sofia.ns.cloudflare.com 108.162.192.223 AS13335, 172.64.32.223 AS13335, 173.245.58.223 AS13335, 2606:4700:50::adf5:3adf AS13335, 2803:f800:50::6ca2:c0df AS13335, 2a06:98c1:50::ac40:20df AS13335
40plus.dkollie.ns.cloudflare.com 108.162.194.71 AS13335, 162.159.38.71 AS13335, 172.64.34.71 AS13335, 2606:4700:50::a29f:2647 AS13335, 2803:f800:50::6ca2:c247 AS13335, 2a06:98c1:50::ac40:2247 AS13335
yoxall.ns.cloudflare.com 108.162.195.47 AS13335, 162.159.44.47 AS13335, 172.64.35.47 AS13335, 2606:4700:58::a29f:2c2f AS13335, 2803:f800:50::6ca2:c32f AS13335, 2a06:98c1:50::ac40:232f AS13335
40plusdating.dksharon.ns.cloudflare.com 108.162.192.221 AS13335, 172.64.32.221 AS13335, 173.245.58.221 AS13335, 2606:4700:50::adf5:3add AS13335, 2803:f800:50::6ca2:c0dd AS13335, 2a06:98c1:50::ac40:20dd 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
40tinet.dkanton.ns.cloudflare.com 108.162.195.175 AS13335, 162.159.44.175 AS13335, 172.64.35.175 AS13335, 2606:4700:58::a29f:2caf AS13335, 2803:f800:50::6ca2:c3af AS13335, 2a06:98c1:50::ac40:23af AS13335
sofia.ns.cloudflare.com 108.162.192.223 AS13335, 172.64.32.223 AS13335, 173.245.58.223 AS13335, 2606:4700:50::adf5:3adf AS13335, 2803:f800:50::6ca2:c0df AS13335, 2a06:98c1:50::ac40:20df AS13335
40two.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
40x20.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
40årsfødselsdagforandreasden5september2026.dkns1.dnsplatform.dk 94.130.53.176 AS24940
ns2.dnsplatform.dk 159.69.139.109 AS24940
4100.dkns7.bricksite.net 35.246.226.10 AS396982
ns8.bricksite.net 35.242.190.82 AS396982
4100anatolia.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
411.dkfrank.ns.cloudflare.com 108.162.193.166 AS13335, 172.64.33.166 AS13335, 173.245.59.166 AS13335, 2606:4700:58::adf5:3ba6 AS13335, 2803:f800:50::6ca2:c1a6 AS13335, 2a06:98c1:50::ac40:21a6 AS13335
mary.ns.cloudflare.com 108.162.192.134 AS13335, 172.64.32.134 AS13335, 173.245.58.134 AS13335, 2606:4700:50::adf5:3a86 AS13335, 2803:f800:50::6ca2:c086 AS13335, 2a06:98c1:50::ac40:2086 AS13335
41105307.dkns1.123hotel.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.123hotel.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
411313.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
4130-viby.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
4130.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
4140.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
41406360.dkamit.ns.cloudflare.com 108.162.193.63 AS13335, 172.64.33.63 AS13335, 173.245.59.63 AS13335, 2606:4700:58::adf5:3b3f AS13335, 2803:f800:50::6ca2:c13f AS13335, 2a06:98c1:50::ac40:213f AS13335
april.ns.cloudflare.com 108.162.192.66 AS13335, 172.64.32.66 AS13335, 173.245.58.66 AS13335, 2606:4700:50::adf5:3a42 AS13335, 2803:f800:50::6ca2:c042 AS13335, 2a06:98c1:50::ac40:2042 AS13335
4140borup.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
415.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
41599809.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
4160.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
416tatanka.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
417.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
4171.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
41712207.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
4173.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
417armyvarer.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
418.dkdemi.ns.cloudflare.com 108.162.192.95 AS13335, 172.64.32.95 AS13335, 173.245.58.95 AS13335, 2606:4700:50::adf5:3a5f AS13335, 2803:f800:50::6ca2:c05f AS13335, 2a06:98c1:50::ac40:205f AS13335
doug.ns.cloudflare.com 108.162.193.159 AS13335, 172.64.33.159 AS13335, 173.245.59.159 AS13335, 2606:4700:58::adf5:3b9f AS13335, 2803:f800:50::6ca2:c19f AS13335, 2a06:98c1:50::ac40:219f AS13335
4180.dkns.andersenit.dk 185.200.74.101 AS198614
ns1.andersenit.dk 87.238.248.10 AS198614
4180s.dkns.andersenit.dk 185.200.74.101 AS198614
ns1.andersenit.dk 87.238.248.10 AS198614
4184-denmark.dkdns1.cscdns.net 156.154.130.100 AS12008, 2610:a1:1022::100 AS12008
dns2.cscdns.net 156.154.131.100 AS12008, 2610:a1:1023::100 AS12008
4190.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
41club.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
4200.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
4200nu.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
4200retro.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
4200slagelse.dkns1.web24tech.com 85.215.129.49 AS8560
ns2.web24tech.com 85.215.133.5 AS8560
4202.dkmns01.domaincontrol.com 2603:5:2143::1f AS44273, 97.74.100.31 AS44273
mns02.domaincontrol.com 173.201.68.31 AS44273, 2603:5:2243::1f AS44273
420happiness.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
420north.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
42114211.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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