🛡️ 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
4bc.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
4bcapital.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
4bconsult.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
4be.dkns-1475.awsdns-56.org 205.251.197.195 AS16509, 2600:9000:5305:c300::1 AS16509
ns-1552.awsdns-02.co.uk 205.251.198.16 AS16509, 2600:9000:5306:1000::1 AS16509
ns-249.awsdns-31.com 205.251.192.249 AS16509, 2600:9000:5300:f900::1 AS16509
ns-891.awsdns-47.net 205.251.195.123 AS16509, 2600:9000:5303:7b00::1 AS16509
4ben.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
4book.dkns5.kasserver.com 85.13.128.3 AS34788
ns6.kasserver.com 85.13.159.101 AS34788
4bowl.dkns5.kasserver.com 85.13.128.3 AS34788
ns6.kasserver.com 85.13.159.101 AS34788
4box.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
4bt.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
4btest.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
4builders.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
4casa.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
4cast.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
4cc.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
4cconsulting.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
4chan.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
4co.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
4cool.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
4curiosity.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
4curves.dkns1.designrus.dk 176.9.4.22 AS24940, 2a01:4f8:141:3416::2 AS24940
ns2.designrus.dk 2a01:4f8:242:5649::2 AS24940, 49.12.124.182 AS24940
4d-raw.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
4dagesarbejdsuge.dklily.ns.cloudflare.com 108.162.192.130 AS13335, 172.64.32.130 AS13335, 173.245.58.130 AS13335, 2606:4700:50::adf5:3a82 AS13335, 2803:f800:50::6ca2:c082 AS13335, 2a06:98c1:50::ac40:2082 AS13335
sonny.ns.cloudflare.com 108.162.195.66 AS13335, 162.159.44.66 AS13335, 172.64.35.66 AS13335, 2606:4700:58::a29f:2c42 AS13335, 2803:f800:50::6ca2:c342 AS13335, 2a06:98c1:50::ac40:2342 AS13335
4dagsarbejdsuge.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
4danesbrewery.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
4days-favrskov.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
4dd0.dkchad.ns.cloudflare.com 108.162.193.82 AS13335, 172.64.33.82 AS13335, 173.245.59.82 AS13335, 2606:4700:58::adf5:3b52 AS13335, 2803:f800:50::6ca2:c152 AS13335, 2a06:98c1:50::ac40:2152 AS13335
kate.ns.cloudflare.com 108.162.192.124 AS13335, 172.64.32.124 AS13335, 173.245.58.124 AS13335, 2606:4700:50::adf5:3a7c AS13335, 2803:f800:50::6ca2:c07c AS13335, 2a06:98c1:50::ac40:207c AS13335
4dele.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
4delphi.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
4dev.dkdane.ns.cloudflare.com 108.162.193.97 AS13335, 172.64.33.97 AS13335, 173.245.59.97 AS13335, 2606:4700:58::adf5:3b61 AS13335, 2803:f800:50::6ca2:c161 AS13335, 2a06:98c1:50::ac40:2161 AS13335
marjory.ns.cloudflare.com 108.162.192.193 AS13335, 172.64.32.193 AS13335, 173.245.58.193 AS13335, 2606:4700:50::adf5:3ac1 AS13335, 2803:f800:50::6ca2:c0c1 AS13335, 2a06:98c1:50::ac40:20c1 AS13335
4devs.dkdane.ns.cloudflare.com 108.162.193.97 AS13335, 172.64.33.97 AS13335, 173.245.59.97 AS13335, 2606:4700:58::adf5:3b61 AS13335, 2803:f800:50::6ca2:c161 AS13335, 2a06:98c1:50::ac40:2161 AS13335
marjory.ns.cloudflare.com 108.162.192.193 AS13335, 172.64.32.193 AS13335, 173.245.58.193 AS13335, 2606:4700:50::adf5:3ac1 AS13335, 2803:f800:50::6ca2:c0c1 AS13335, 2a06:98c1:50::ac40:20c1 AS13335
4dh.dkns1.aau.dk 130.225.52.5 AS1835, 2001:878:300:1::5 AS1835
ns2.aau.dk 130.225.54.5 AS1835, 2001:878:300:100::5 AS1835
4dimension.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
4dimensions.dkns10.dnsadmin.dk 208.94.148.4 AS16552, 2600:1800:10::1 AS16552
ns11.dns-admin.dk 208.80.124.4 AS16552, 2600:1801:11::1 AS16552
ns12.dnsadmin.dk 208.80.126.4 AS16552, 2600:1802:12::1 AS16552
ns13.dns-admin.dk 208.80.125.4 AS16552, 2600:1801:13::1 AS16552
ns14.dnsadmin.dk 208.80.127.4 AS16552, 2600:1802:14::1 AS16552
ns15.dns-admin.dk 208.94.149.4 AS16552, 2600:1800:15::1 AS16552
4dk.dkns.domainteam.dk 87.238.248.151 AS198614
ns2.domainteam.dk 185.200.74.103 AS198614
4dmobility.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
4docs.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
4dogjoy.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
4dprint.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
4draw.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
4dreklamer.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
4ds.dkjon.quicns.cloud 64.66.240.1 AS398367
kevin.quicns.com 64.66.241.1 AS398367
4dscan-api.dkdesiree.ns.cloudflare.com 108.162.194.13 AS13335, 162.159.38.13 AS13335, 172.64.34.13 AS13335, 2606:4700:50::a29f:260d AS13335, 2803:f800:50::6ca2:c20d AS13335, 2a06:98c1:50::ac40:220d AS13335
vern.ns.cloudflare.com 108.162.193.243 AS13335, 172.64.33.243 AS13335, 173.245.59.243 AS13335, 2606:4700:58::adf5:3bf3 AS13335, 2803:f800:50::6ca2:c1f3 AS13335, 2a06:98c1:50::ac40:21f3 AS13335
4dtoyshop.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
4dynamics.dkns1.4dynamics.dk 91.233.142.240 AS31027
ns2.4dynamics.dk 91.233.142.241 AS31027
4elements.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
4elementsnaturalpower.dkns1.dns-parking.com 162.159.24.201 AS13335, 2400:cb00:2049:1::a29f:18c9 AS13335
ns2.dns-parking.com 162.159.25.42 AS13335, 2400:cb00:2049:1::a29f:192a AS13335
4elementsnaturepower.dkns1.dns-parking.com 162.159.24.201 AS13335, 2400:cb00:2049:1::a29f:18c9 AS13335
ns2.dns-parking.com 162.159.25.42 AS13335, 2400:cb00:2049:1::a29f:192a AS13335
4elementspower.dkns1.dns-parking.com 162.159.24.201 AS13335, 2400:cb00:2049:1::a29f:18c9 AS13335
ns2.dns-parking.com 162.159.25.42 AS13335, 2400:cb00:2049:1::a29f:192a AS13335
4emma.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
4energy.dkeva.ns.cloudflare.com 108.162.192.114 AS13335, 172.64.32.114 AS13335, 173.245.58.114 AS13335, 2606:4700:50::adf5:3a72 AS13335, 2803:f800:50::6ca2:c072 AS13335, 2a06:98c1:50::ac40:2072 AS13335
rajeev.ns.cloudflare.com 108.162.193.224 AS13335, 172.64.33.224 AS13335, 173.245.59.224 AS13335, 2606:4700:58::adf5:3be0 AS13335, 2803:f800:50::6ca2:c1e0 AS13335, 2a06:98c1:50::ac40:21e0 AS13335
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