🛡️ 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

1,185,715 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1490.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3130.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,8080.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system755,25063.7%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,9817.3%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-09-30 06:38).

📋 One autonomous system

755,250 domains
DomainNameservers and addresses
2001.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
2002.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
2004.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
2006.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
2006design.dkhuxley.ns.cloudflare.com 108.162.195.188 AS13335, 162.159.44.188 AS13335, 172.64.35.188 AS13335, 2606:4700:58::a29f:2cbc AS13335, 2803:f800:50::6ca2:c3bc AS13335, 2a06:98c1:50::ac40:23bc AS13335
romina.ns.cloudflare.com 108.162.194.159 AS13335, 162.159.38.159 AS13335, 172.64.34.159 AS13335, 2606:4700:50::a29f:269f AS13335, 2803:f800:50::6ca2:c29f AS13335, 2a06:98c1:50::ac40:229f AS13335
2006km.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
2009.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
200for200.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
200iq.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
200kr.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
201.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
2010.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
20104510.dkgwen.ns.cloudflare.com 108.162.192.160 AS13335, 172.64.32.160 AS13335, 173.245.58.160 AS13335, 2606:4700:50::adf5:3aa0 AS13335, 2803:f800:50::6ca2:c0a0 AS13335, 2a06:98c1:50::ac40:20a0 AS13335
jacob.ns.cloudflare.com 108.162.195.162 AS13335, 162.159.44.162 AS13335, 172.64.35.162 AS13335, 2606:4700:58::a29f:2ca2 AS13335, 2803:f800:50::6ca2:c3a2 AS13335, 2a06:98c1:50::ac40:23a2 AS13335
2011.dkrobin.ns.cloudflare.com 108.162.192.218 AS13335, 172.64.32.218 AS13335, 173.245.58.218 AS13335, 2606:4700:50::adf5:3ada AS13335, 2803:f800:50::6ca2:c0da AS13335, 2a06:98c1:50::ac40:20da AS13335
sri.ns.cloudflare.com 108.162.193.234 AS13335, 172.64.33.234 AS13335, 173.245.59.234 AS13335, 2606:4700:58::adf5:3bea AS13335, 2803:f800:50::6ca2:c1ea AS13335, 2a06:98c1:50::ac40:21ea AS13335
20111001.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
20111610.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
20113208.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
2011melges24europeans.dkbeau.ns.cloudflare.com 108.162.193.73 AS13335, 172.64.33.73 AS13335, 173.245.59.73 AS13335, 2606:4700:58::adf5:3b49 AS13335, 2803:f800:50::6ca2:c149 AS13335, 2a06:98c1:50::ac40:2149 AS13335
clara.ns.cloudflare.com 108.162.194.219 AS13335, 162.159.38.219 AS13335, 172.64.34.219 AS13335, 2606:4700:50::a29f:26db AS13335, 2803:f800:50::6ca2:c2db AS13335, 2a06:98c1:50::ac40:22db AS13335
2014.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
2017aarhusianere.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
2017iranders.dkparkdns1.ilkari.tech 147.28.17.14 AS205436
parkdns2.ilkari.tech 147.28.17.20 AS205436
2018.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
2019.dkeloise.ns.cloudflare.com 108.162.194.208 AS13335, 162.159.38.208 AS13335, 172.64.34.208 AS13335, 2606:4700:50::a29f:26d0 AS13335, 2803:f800:50::6ca2:c2d0 AS13335, 2a06:98c1:50::ac40:22d0 AS13335
lewis.ns.cloudflare.com 108.162.195.159 AS13335, 162.159.44.159 AS13335, 172.64.35.159 AS13335, 2606:4700:58::a29f:2c9f AS13335, 2803:f800:50::6ca2:c39f AS13335, 2a06:98c1:50::ac40:239f AS13335
2020.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
20202070.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
20202216.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
20202422.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
20203005.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
20205255.dkfrida.ns.cloudflare.com 108.162.194.137 AS13335, 162.159.38.137 AS13335, 172.64.34.137 AS13335, 2606:4700:50::a29f:2689 AS13335, 2803:f800:50::6ca2:c289 AS13335, 2a06:98c1:50::ac40:2289 AS13335
leo.ns.cloudflare.com 108.162.195.241 AS13335, 162.159.44.241 AS13335, 172.64.35.241 AS13335, 2606:4700:58::a29f:2cf1 AS13335, 2803:f800:50::6ca2:c3f1 AS13335, 2a06:98c1:50::ac40:23f1 AS13335
2020automation.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
2020visions.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
20224010.dkns6151.hostgator.com 50.87.144.95 AS31898
ns6152.hostgator.com 192.232.218.100 AS31898
20230008.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
20241130.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
20241515.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
2024estate.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
2024yr4.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
20251212.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
2025denmark.dkns6.sitnet.dk 107.162.234.197 AS55002, 2604:e180:1071::3:1 AS55002
ns7.sitnet.dk 107.162.176.221 AS55002, 2604:e180:1071::ffff:6ba2:b0dd AS55002
2025eu.dkns6.sitnet.dk 107.162.234.197 AS55002, 2604:e180:1071::3:1 AS55002
ns7.sitnet.dk 107.162.176.221 AS55002, 2604:e180:1071::ffff:6ba2:b0dd AS55002
2025transport.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
2030limitless.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
2030skoler.dklochlan.ns.cloudflare.com 108.162.195.234 AS13335, 162.159.44.234 AS13335, 172.64.35.234 AS13335, 2606:4700:58::a29f:2cea AS13335, 2803:f800:50::6ca2:c3ea AS13335, 2a06:98c1:50::ac40:23ea AS13335
macy.ns.cloudflare.com 108.162.194.78 AS13335, 162.159.38.78 AS13335, 172.64.34.78 AS13335, 2606:4700:50::a29f:264e AS13335, 2803:f800:50::6ca2:c24e AS13335, 2a06:98c1:50::ac40:224e AS13335
2030skov.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
2030skove.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
2031.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
20320883.dkns1.bdm.microsoftonline.com 13.107.236.208 AS8075, 2603:1061:0:700::d0 AS8075
ns2.bdm.microsoftonline.com 150.171.21.208 AS8075, 2620:1ec:8ec:700::d0 AS8075
ns3.bdm.microsoftonline.com 204.14.183.208 AS8075, 2a01:111:4000:700::d0 AS8075
ns4.bdm.microsoftonline.com 208.84.5.208 AS8075, 2620:1ec:bda:700::d0 AS8075
20329077.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
2033.dkisaac.ns.cloudflare.com 108.162.193.177 AS13335, 172.64.33.177 AS13335, 173.245.59.177 AS13335, 2606:4700:58::adf5:3bb1 AS13335, 2803:f800:50::6ca2:c1b1 AS13335, 2a06:98c1:50::ac40:21b1 AS13335
june.ns.cloudflare.com 108.162.192.176 AS13335, 172.64.32.176 AS13335, 173.245.58.176 AS13335, 2606:4700:50::adf5:3ab0 AS13335, 2803:f800:50::6ca2:c0b0 AS13335, 2a06:98c1:50::ac40:20b0 AS13335
20346494.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
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