🛡️ 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

1,184,859 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 address1,2990.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,7490.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system758,13564.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,5897.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-01 20:42).

📋 One autonomous system

758,135 domains
DomainNameservers and addresses
75820361.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
75820455.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
75821158.dkgate.profdoc.dk 80.62.243.243 AS3292
ns.profdoc.dk 80.62.243.242 AS3292
75821900.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
75823700.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
75840123.dkns-1.dcmediahosting.com 91.99.51.123 AS24940
ns-2.dcmediahosting.com 78.46.248.73 AS24940
ns-3.dcmediahosting.com 78.46.248.73 AS24940
ns-4.dcmediahosting.com 91.99.51.123 AS24940
ns-5.dcmediahosting.com 78.46.248.73 AS24940
75862988.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
75866700.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
75871033.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
75881888.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
75911800.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
75926066.dkgate.profdoc.dk 80.62.243.243 AS3292
ns.profdoc.dk 80.62.243.242 AS3292
75930460.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
75935220.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
75943900.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
76.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
7620rom.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
76240056.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
762mm.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
7660net.dkns1.dlx.dk 2a00:1b18:1337:1337::53 AS47527, 46.30.121.210 AS47527
ns2.dlx.dk 185.208.212.124 AS47527, 2a00:1b19:1337:1337::53 AS47527
7660vand.dkcarter.ns.cloudflare.com 108.162.193.80 AS13335, 172.64.33.80 AS13335, 173.245.59.80 AS13335, 2606:4700:58::adf5:3b50 AS13335, 2803:f800:50::6ca2:c150 AS13335, 2a06:98c1:50::ac40:2150 AS13335
kristin.ns.cloudflare.com 108.162.192.181 AS13335, 172.64.32.181 AS13335, 173.245.58.181 AS13335, 2606:4700:50::adf5:3ab5 AS13335, 2803:f800:50::6ca2:c0b5 AS13335, 2a06:98c1:50::ac40:20b5 AS13335
767.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
76700600.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
770.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
7700.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
77101010.dkcourtney.ns.cloudflare.com 108.162.194.130 AS13335, 162.159.38.130 AS13335, 172.64.34.130 AS13335, 2606:4700:50::a29f:2682 AS13335, 2803:f800:50::6ca2:c282 AS13335, 2a06:98c1:50::ac40:2282 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
7730.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
7742.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
777.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
7770thy.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
7777.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
777bet.dknovalee.ns.cloudflare.com 108.162.194.182 AS13335, 162.159.38.182 AS13335, 172.64.34.182 AS13335, 2606:4700:50::a29f:26b6 AS13335, 2803:f800:50::6ca2:c2b6 AS13335, 2a06:98c1:50::ac40:22b6 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
777casino.dknovalee.ns.cloudflare.com 108.162.194.182 AS13335, 162.159.38.182 AS13335, 172.64.34.182 AS13335, 2606:4700:50::a29f:26b6 AS13335, 2803:f800:50::6ca2:c2b6 AS13335, 2a06:98c1:50::ac40:22b6 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
777games.dkdns1.idp365.net 162.159.27.131 AS13335, 2400:cb00:2049:1::a29f:1b83 AS13335
dns2.idp365.net 162.159.48.3 AS13335, 2400:cb00:2049:1::a29f:3003 AS13335
dns3.idp365.net 162.159.49.254 AS13335, 2400:cb00:2049:1::a29f:31fe AS13335
777play.dkdns1.idp365.net 162.159.27.131 AS13335, 2400:cb00:2049:1::a29f:1b83 AS13335
dns2.idp365.net 162.159.48.3 AS13335, 2400:cb00:2049:1::a29f:3003 AS13335
dns3.idp365.net 162.159.49.254 AS13335, 2400:cb00:2049:1::a29f:31fe AS13335
778.dkns1.dyna-ns.net 162.159.26.92 AS13335, 162.159.27.158 AS13335, 2400:cb00:2049:1::a29f:1a5c AS13335, 2400:cb00:2049:1::a29f:1b9e AS13335
ns2.dyna-ns.net 162.159.24.5 AS13335, 162.159.25.5 AS13335, 2400:cb00:2049:1::a29f:1805 AS13335, 2400:cb00:2049:1::a29f:1905 AS13335
7790.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
77diamonds.dkkyree.ns.cloudflare.com 108.162.195.207 AS13335, 162.159.44.207 AS13335, 172.64.35.207 AS13335, 2606:4700:58::a29f:2ccf AS13335, 2803:f800:50::6ca2:c3cf AS13335, 2a06:98c1:50::ac40:23cf AS13335
violet.ns.cloudflare.com 108.162.192.237 AS13335, 172.64.32.237 AS13335, 173.245.58.237 AS13335, 2606:4700:50::adf5:3aed AS13335, 2803:f800:50::6ca2:c0ed AS13335, 2a06:98c1:50::ac40:20ed AS13335
77wima.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
78.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
7800.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
7800skive.dkjustin.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
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
7840.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
7840højslev.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
786.dkmelinda.ns.cloudflare.com 108.162.192.198 AS13335, 172.64.32.198 AS13335, 173.245.58.198 AS13335, 2606:4700:50::adf5:3ac6 AS13335, 2803:f800:50::6ca2:c0c6 AS13335, 2a06:98c1:50::ac40:20c6 AS13335
tom.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
786marketing.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
7879.dkns1.nordicway.dk 2a01:4f8:1c1a:a1e7::1 AS24940, 91.98.140.195 AS24940
ns2.nordicway.dk 2a01:4f8:c012:4db6::1 AS24940, 49.13.80.249 AS24940
ns3.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
788.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
789.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
79.dkns1.dreamhost.com 162.159.26.14 AS13335
ns2.dreamhost.com 162.159.26.81 AS13335
ns3.dreamhost.com 162.159.27.84 AS13335
dhd.dk [/] search Domains, Hosts & DNS — .dk zone