🛡️ 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

1,186,235 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1510.01%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 IPv610,8040.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system756,41863.8%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,9667.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-09-30 13:10).

📋 One autonomous system

756,418 domains
DomainNameservers and addresses
2xmadmor.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
2xn.dkdns109.ovh.net 2001:41d0:d01:300::2 AS16276, 5.196.41.217 AS16276
ns109.ovh.net 2001:41d0:b00:fd00::2 AS16276, 5.135.67.9 AS16276
2xnielsen.dkmns01.domaincontrol.com 2603:5:2143::1f AS44273, 97.74.100.31 AS44273
mns02.domaincontrol.com 173.201.68.31 AS44273, 2603:5:2243::1f AS44273
2xr.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
2xrent.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
2xs-content.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
2xt.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
2xu.dkns-1307.awsdns-35.org 205.251.197.27 AS16509, 2600:9000:5305:1b00::1 AS16509
ns-1997.awsdns-57.co.uk 205.251.199.205 AS16509, 2600:9000:5307:cd00::1 AS16509
ns-427.awsdns-53.com 205.251.193.171 AS16509, 2600:9000:5301:ab00::1 AS16509
ns-816.awsdns-38.net 205.251.195.48 AS16509, 2600:9000:5303:3000::1 AS16509
2xv.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
2xwagner.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
2xy.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
2årigstudentereksamen.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
2årigstudentereksamenherning.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
2ø.dkguy.ns.cloudflare.com 108.162.193.173 AS13335, 172.64.33.173 AS13335, 173.245.59.173 AS13335, 2606:4700:58::adf5:3bad AS13335, 2803:f800:50::6ca2:c1ad AS13335, 2a06:98c1:50::ac40:21ad AS13335
melina.ns.cloudflare.com 108.162.194.184 AS13335, 162.159.38.184 AS13335, 172.64.34.184 AS13335, 2606:4700:50::a29f:26b8 AS13335, 2803:f800:50::6ca2:c2b8 AS13335, 2a06:98c1:50::ac40:22b8 AS13335
2øl.dkns1.web24tech.com 85.215.129.49 AS8560
ns2.web24tech.com 85.215.133.5 AS8560
3-0.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
3-1.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
3-16.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
3-2-1-byg.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
3-2-1.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
3-2-1byg.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
3-4-seng.dkcamilo.ns.cloudflare.com 108.162.195.118 AS13335, 162.159.44.118 AS13335, 172.64.35.118 AS13335, 2606:4700:58::a29f:2c76 AS13335, 2803:f800:50::6ca2:c376 AS13335, 2a06:98c1:50::ac40:2376 AS13335
ziggy.ns.cloudflare.com 108.162.194.237 AS13335, 162.159.38.237 AS13335, 172.64.34.237 AS13335, 2606:4700:50::a29f:26ed AS13335, 2803:f800:50::6ca2:c2ed AS13335, 2a06:98c1:50::ac40:22ed AS13335
3-a.dkns1.azehosting.net 2a01:4f8:13b:3146::1 AS24940, 94.130.138.185 AS24940
ns2.azehosting.net 2a01:4f8:c17:5f0a::2 AS24940, 88.99.15.5 AS24940
ns3.azehosting.net 2a01:4f8:c17:6a6e::2 AS24940, 88.99.39.181 AS24940
3-b.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
3-bilpriser.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
3-biltilbud.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
3-bjorne.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
3-bjørne.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
3-byg.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
3-byggetilbud.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
3-d-printer.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
3-dagsferie.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
3-design.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
3-division.dkwally.ns.cloudflare.com 108.162.192.239 AS13335, 172.64.32.239 AS13335, 173.245.58.239 AS13335, 2606:4700:50::adf5:3aef AS13335, 2803:f800:50::6ca2:c0ef AS13335, 2a06:98c1:50::ac40:20ef AS13335
zac.ns.cloudflare.com 108.162.195.178 AS13335, 162.159.44.178 AS13335, 172.64.35.178 AS13335, 2606:4700:58::a29f:2cb2 AS13335, 2803:f800:50::6ca2:c3b2 AS13335, 2a06:98c1:50::ac40:23b2 AS13335
3-f.dkjay.ns.cloudflare.com 108.162.193.123 AS13335, 172.64.33.123 AS13335, 173.245.59.123 AS13335, 2606:4700:58::adf5:3b7b AS13335, 2803:f800:50::6ca2:c17b AS13335, 2a06:98c1:50::ac40:217b AS13335
uma.ns.cloudflare.com 108.162.192.146 AS13335, 172.64.32.146 AS13335, 173.245.58.146 AS13335, 2606:4700:50::adf5:3a92 AS13335, 2803:f800:50::6ca2:c092 AS13335, 2a06:98c1:50::ac40:2092 AS13335
3-gratis.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
3-hjulet-elcykel.dkcamilo.ns.cloudflare.com 108.162.195.118 AS13335, 162.159.44.118 AS13335, 172.64.35.118 AS13335, 2606:4700:58::a29f:2c76 AS13335, 2803:f800:50::6ca2:c376 AS13335, 2a06:98c1:50::ac40:2376 AS13335
ziggy.ns.cloudflare.com 108.162.194.237 AS13335, 162.159.38.237 AS13335, 172.64.34.237 AS13335, 2606:4700:50::a29f:26ed AS13335, 2803:f800:50::6ca2:c2ed AS13335, 2a06:98c1:50::ac40:22ed AS13335
3-i-een.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
3-kanten.dkmartin.ns.cloudflare.com 108.162.195.87 AS13335, 162.159.44.87 AS13335, 172.64.35.87 AS13335, 2606:4700:58::a29f:2c57 AS13335, 2803:f800:50::6ca2:c357 AS13335, 2a06:98c1:50::ac40:2357 AS13335
poppy.ns.cloudflare.com 108.162.194.33 AS13335, 162.159.38.33 AS13335, 172.64.34.33 AS13335, 2606:4700:50::a29f:2621 AS13335, 2803:f800:50::6ca2:c221 AS13335, 2a06:98c1:50::ac40:2221 AS13335
3-kubik.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
3-leasingtilbud.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
3-leaves.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
3-limfjordsforbindelse.dkns1.softlayer.com 2607:f0d0:0:f:1::1 AS36351, 67.228.254.4 AS36351
ns2.softlayer.com 2607:f0d0:0:f:2::1 AS36351, 67.228.255.5 AS36351
3-m.dka.ns.3m.com 162.159.8.174 AS13335, 2400:cb00:2049:1::a29f:8ae AS13335
b.ns.3m.com 173.245.58.19 AS13335, 2400:cb00:2049:1::adf5:3a13 AS13335
3-murer-tilbud.dkcortney.ns.cloudflare.com 108.162.192.87 AS13335, 172.64.32.87 AS13335, 173.245.58.87 AS13335, 2606:4700:50::adf5:3a57 AS13335, 2803:f800:50::6ca2:c057 AS13335, 2a06:98c1:50::ac40:2057 AS13335
rocco.ns.cloudflare.com 108.162.195.121 AS13335, 162.159.44.121 AS13335, 172.64.35.121 AS13335, 2606:4700:58::a29f:2c79 AS13335, 2803:f800:50::6ca2:c379 AS13335, 2a06:98c1:50::ac40:2379 AS13335
3-nordic.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
3-pac.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
3-personers-sofa.dkalexis.ns.cloudflare.com 108.162.193.60 AS13335, 172.64.33.60 AS13335, 173.245.59.60 AS13335, 2606:4700:58::adf5:3b3c AS13335, 2803:f800:50::6ca2:c13c AS13335, 2a06:98c1:50::ac40:213c 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
3-robotics.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
3-s.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
dhd.dk [/] search Domains, Hosts & DNS — .dk zone