🛡️ 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
40202070.dkdawn.cloudip.dev 2a04:3542:1000:910:681a:4eff:feb6:10bd AS202053, 94.237.87.201 AS202053
dusk.cloudip.dev 2a04:3544:1000:1510:681a:4eff:feb6:275c AS202053, 5.22.208.62 AS202053
40204020.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
40219611.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
4022.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
40222740.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
40270077.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
40272915.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
40273926.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
40274027.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
402meter.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
4030.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
40301928.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
40302010.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
40312512.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
40316313.dkns1.gnrx.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.gnrx.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
40321833.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
40369162.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
40373041.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
404.dkbrenda.ns.cloudflare.com 108.162.192.77 AS13335, 172.64.32.77 AS13335, 173.245.58.77 AS13335, 2606:4700:50::adf5:3a4d AS13335, 2803:f800:50::6ca2:c04d AS13335, 2a06:98c1:50::ac40:204d AS13335
stan.ns.cloudflare.com 108.162.193.235 AS13335, 172.64.33.235 AS13335, 173.245.59.235 AS13335, 2606:4700:58::adf5:3beb AS13335, 2803:f800:50::6ca2:c1eb AS13335, 2a06:98c1:50::ac40:21eb AS13335
4040.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
40406141.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
40408787.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
4040crew.dkns1.he.net 2001:470:100::2 AS6939, 216.218.130.2 AS6939
ns2.he.net 2001:470:200::2 AS6939, 216.218.131.2 AS6939
ns3.he.net 2001:470:300::2 AS6939, 216.218.132.2 AS6939
40425632.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
4045.dkboyd.ns.cloudflare.com 108.162.193.75 AS13335, 172.64.33.75 AS13335, 173.245.59.75 AS13335, 2606:4700:58::adf5:3b4b AS13335, 2803:f800:50::6ca2:c14b AS13335, 2a06:98c1:50::ac40:214b AS13335
nova.ns.cloudflare.com 108.162.194.129 AS13335, 162.159.38.129 AS13335, 172.64.34.129 AS13335, 2606:4700:50::a29f:2681 AS13335, 2803:f800:50::6ca2:c281 AS13335, 2a06:98c1:50::ac40:2281 AS13335
404cph.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
404studio.dkgabriella.ns.cloudflare.com 108.162.194.134 AS13335, 162.159.38.134 AS13335, 172.64.34.134 AS13335, 2606:4700:50::a29f:2686 AS13335, 2803:f800:50::6ca2:c286 AS13335, 2a06:98c1:50::ac40:2286 AS13335
rob.ns.cloudflare.com 108.162.193.140 AS13335, 172.64.33.140 AS13335, 173.245.59.140 AS13335, 2606:4700:58::adf5:3b8c AS13335, 2803:f800:50::6ca2:c18c AS13335, 2a06:98c1:50::ac40:218c AS13335
4050.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
40500100.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
40508022.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
4050skibby.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
40540301.dkcarlos.ns.cloudflare.com 108.162.195.112 AS13335, 162.159.44.112 AS13335, 172.64.35.112 AS13335, 2606:4700:58::a29f:2c70 AS13335, 2803:f800:50::6ca2:c370 AS13335, 2a06:98c1:50::ac40:2370 AS13335
marlowe.ns.cloudflare.com 108.162.194.212 AS13335, 162.159.38.212 AS13335, 172.64.34.212 AS13335, 2606:4700:50::a29f:26d4 AS13335, 2803:f800:50::6ca2:c2d4 AS13335, 2a06:98c1:50::ac40:22d4 AS13335
40541333.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
4056.dkada.ns.cloudflare.com 108.162.192.54 AS13335, 172.64.32.54 AS13335, 173.245.58.54 AS13335, 2606:4700:50::adf5:3a36 AS13335, 2803:f800:50::6ca2:c036 AS13335, 2a06:98c1:50::ac40:2036 AS13335
leonidas.ns.cloudflare.com 108.162.195.101 AS13335, 162.159.44.101 AS13335, 172.64.35.101 AS13335, 2606:4700:58::a29f:2c65 AS13335, 2803:f800:50::6ca2:c365 AS13335, 2a06:98c1:50::ac40:2365 AS13335
40568283.dkada.ns.cloudflare.com 108.162.192.54 AS13335, 172.64.32.54 AS13335, 173.245.58.54 AS13335, 2606:4700:50::adf5:3a36 AS13335, 2803:f800:50::6ca2:c036 AS13335, 2a06:98c1:50::ac40:2036 AS13335
leonidas.ns.cloudflare.com 108.162.195.101 AS13335, 162.159.44.101 AS13335, 172.64.35.101 AS13335, 2606:4700:58::a29f:2c65 AS13335, 2803:f800:50::6ca2:c365 AS13335, 2a06:98c1:50::ac40:2365 AS13335
4060.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
40615557.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
4070.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
40737373.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
40754938.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
40763030.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
40776000.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
40780417.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
40784750.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
40795369.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
40808080.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
40842008.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
40881616.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
40888881.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
4096.dkhugh.ns.cloudflare.com 108.162.193.117 AS13335, 172.64.33.117 AS13335, 173.245.59.117 AS13335, 2606:4700:58::adf5:3b75 AS13335, 2803:f800:50::6ca2:c175 AS13335, 2a06:98c1:50::ac40:2175 AS13335
lara.ns.cloudflare.com 108.162.192.128 AS13335, 172.64.32.128 AS13335, 173.245.58.128 AS13335, 2606:4700:50::adf5:3a80 AS13335, 2803:f800:50::6ca2:c080 AS13335, 2a06:98c1:50::ac40:2080 AS13335
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