🛡️ 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
4220.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
4230.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
4230montage.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
42314032.dklloyd.ns.cloudflare.com 108.162.193.197 AS13335, 172.64.33.197 AS13335, 173.245.59.197 AS13335, 2606:4700:58::adf5:3bc5 AS13335, 2803:f800:50::6ca2:c1c5 AS13335, 2a06:98c1:50::ac40:21c5 AS13335
nola.ns.cloudflare.com 108.162.192.212 AS13335, 172.64.32.212 AS13335, 173.245.58.212 AS13335, 2606:4700:50::adf5:3ad4 AS13335, 2803:f800:50::6ca2:c0d4 AS13335, 2a06:98c1:50::ac40:20d4 AS13335
42363947.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
42403838.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
42412429.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
4245.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
42461111.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
42490474.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
42611068.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
42686.dkns1.blueit.dk 185.195.172.82 AS42686
ns2.blueit.dk 185.195.172.83 AS42686
4270.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
4270hong.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
428.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
4295.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
42advisory.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
42aei.dkmerlin.ns.cloudflare.com 108.162.193.205 AS13335, 172.64.33.205 AS13335, 173.245.59.205 AS13335, 2606:4700:58::adf5:3bcd AS13335, 2803:f800:50::6ca2:c1cd AS13335, 2a06:98c1:50::ac40:21cd AS13335
surina.ns.cloudflare.com 108.162.194.19 AS13335, 162.159.38.19 AS13335, 172.64.34.19 AS13335, 2606:4700:50::a29f:2613 AS13335, 2803:f800:50::6ca2:c213 AS13335, 2a06:98c1:50::ac40:2213 AS13335
42appen.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
42blue.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
42cdn.dkns0094.secondary.cloudflare.com 162.159.32.95 AS13335, 2606:4700:51::a29f:205f AS13335
ns0218.secondary.cloudflare.com 162.159.33.93 AS13335, 2606:4700:59::a29f:215d AS13335
42cg.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
42cows.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
42dk.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
42e.dkblue.foundationdns.com 108.162.198.1 AS13335, 162.159.60.1 AS13335, 172.64.40.1 AS13335, 2606:4700:57::6ca2:c601 AS13335, 2803:f800:52::a29f:3c01 AS13335, 2a06:98c1:56::ac40:2801 AS13335
blue.foundationdns.net 108.162.198.31 AS13335, 162.159.60.31 AS13335, 172.64.40.31 AS13335, 2606:4700:57::6ca2:c61f AS13335, 2803:f800:52::a29f:3c1f AS13335, 2a06:98c1:56::ac40:281f AS13335
blue.foundationdns.org 108.162.198.61 AS13335, 162.159.60.61 AS13335, 172.64.40.61 AS13335, 2606:4700:57::6ca2:c63d AS13335, 2803:f800:52::a29f:3c3d AS13335, 2a06:98c1:56::ac40:283d AS13335
42energy.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
42faq.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
42fish.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
42fisk.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
42floors.dkns-1085.awsdns-07.org 205.251.196.61 AS16509, 2600:9000:5304:3d00::1 AS16509
ns-1731.awsdns-24.co.uk 205.251.198.195 AS16509, 2600:9000:5306:c300::1 AS16509
ns-480.awsdns-60.com 205.251.193.224 AS16509, 2600:9000:5301:e000::1 AS16509
ns-721.awsdns-26.net 205.251.194.209 AS16509, 2600:9000:5302:d100::1 AS16509
42i.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
42invest.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
42labs.dkjerry.ns.cloudflare.com 108.162.193.182 AS13335, 172.64.33.182 AS13335, 173.245.59.182 AS13335, 2606:4700:58::adf5:3bb6 AS13335, 2803:f800:50::6ca2:c1b6 AS13335, 2a06:98c1:50::ac40:21b6 AS13335
wanda.ns.cloudflare.com 108.162.192.240 AS13335, 172.64.32.240 AS13335, 173.245.58.240 AS13335, 2606:4700:50::adf5:3af0 AS13335, 2803:f800:50::6ca2:c0f0 AS13335, 2a06:98c1:50::ac40:20f0 AS13335
42m.dkns0002.secondary.cloudflare.com 162.159.32.3 AS13335, 2606:4700:51::a29f:2003 AS13335
ns0211.secondary.cloudflare.com 162.159.33.86 AS13335, 2606:4700:59::a29f:2156 AS13335
42n.dkns0118.secondary.cloudflare.com 162.159.32.119 AS13335, 2606:4700:51::a29f:2077 AS13335
ns0240.secondary.cloudflare.com 162.159.33.115 AS13335, 2606:4700:59::a29f:2173 AS13335
42q.dkns0002.secondary.cloudflare.com 162.159.32.3 AS13335, 2606:4700:51::a29f:2003 AS13335
ns0211.secondary.cloudflare.com 162.159.33.86 AS13335, 2606:4700:59::a29f:2156 AS13335
42raw.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
42renewables.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
42service.dkns4.wixdns.net 216.239.36.101 AS15169
ns5.wixdns.net 216.239.38.101 AS15169
42skat.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
42tax.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
42th.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
42things.dkns-cloud-e1.googledomains.com 2001:4860:4802:32::6e AS15169, 216.239.32.110 AS15169
ns-cloud-e2.googledomains.com 2001:4860:4802:34::6e AS15169, 216.239.34.110 AS15169
ns-cloud-e3.googledomains.com 2001:4860:4802:36::6e AS15169, 216.239.36.110 AS15169
ns-cloud-e4.googledomains.com 2001:4860:4802:38::6e AS15169, 216.239.38.110 AS15169
42tv.dkns0094.secondary.cloudflare.com 162.159.32.95 AS13335, 2606:4700:51::a29f:205f AS13335
ns0218.secondary.cloudflare.com 162.159.33.93 AS13335, 2606:4700:59::a29f:215d AS13335
42æi.dkmerlin.ns.cloudflare.com 108.162.193.205 AS13335, 172.64.33.205 AS13335, 173.245.59.205 AS13335, 2606:4700:58::adf5:3bcd AS13335, 2803:f800:50::6ca2:c1cd AS13335, 2a06:98c1:50::ac40:21cd AS13335
surina.ns.cloudflare.com 108.162.194.19 AS13335, 162.159.38.19 AS13335, 172.64.34.19 AS13335, 2606:4700:50::a29f:2613 AS13335, 2803:f800:50::6ca2:c213 AS13335, 2a06:98c1:50::ac40:2213 AS13335
4300hulbaek.dkleah.ns.cloudflare.com 108.162.192.129 AS13335, 172.64.32.129 AS13335, 173.245.58.129 AS13335, 2606:4700:50::adf5:3a81 AS13335, 2803:f800:50::6ca2:c081 AS13335, 2a06:98c1:50::ac40:2081 AS13335
tim.ns.cloudflare.com 108.162.193.145 AS13335, 172.64.33.145 AS13335, 173.245.59.145 AS13335, 2606:4700:58::adf5:3b91 AS13335, 2803:f800:50::6ca2:c191 AS13335, 2a06:98c1:50::ac40:2191 AS13335
4305.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
4320.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
4321.dkigor.ns.cloudflare.com 108.162.193.119 AS13335, 172.64.33.119 AS13335, 173.245.59.119 AS13335, 2606:4700:58::adf5:3b77 AS13335, 2803:f800:50::6ca2:c177 AS13335, 2a06:98c1:50::ac40:2177 AS13335
jessica.ns.cloudflare.com 108.162.192.171 AS13335, 172.64.32.171 AS13335, 173.245.58.171 AS13335, 2606:4700:50::adf5:3aab AS13335, 2803:f800:50::6ca2:c0ab AS13335, 2a06:98c1:50::ac40:20ab AS13335
43270000.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
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