🛡️ 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

1,182,465 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 address1,3030.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6790.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system756,94864.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,1837.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-02 21:58).

📋 One autonomous system

756,948 domains
DomainNameservers and addresses
wwle.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
wwm.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
wwmadsen.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
wwoof.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
wws.dkns1.linode.com 2600:14c0:6::2 AS21342, 92.123.94.2 AS21342
ns2.linode.com 2600:14c0:6::3 AS21342, 92.123.94.3 AS21342
ns3.linode.com 2600:14c0:7::3 AS21342, 92.123.95.3 AS21342
ns4.linode.com 2600:14c0:7::4 AS21342, 92.123.95.4 AS21342
ns5.linode.com 2600:14c0:7::2 AS21342, 92.123.95.2 AS21342
wwsd.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
wwsires.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
wwsj.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
wwsolutions.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
wwt.dkhaley.ns.cloudflare.com 108.162.194.15 AS13335, 162.159.38.15 AS13335, 172.64.34.15 AS13335, 2606:4700:50::a29f:260f AS13335, 2803:f800:50::6ca2:c20f AS13335, 2a06:98c1:50::ac40:220f AS13335
merlin.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
wwte.dkpdns1.ultradns.net 2001:502:f3ff::1 AS12008, 204.74.108.1 AS12008
pdns2.ultradns.net 204.74.109.1 AS12008, 2610:a1:1014::1 AS12008
pdns3.ultradns.org 199.7.68.1 AS12008, 2610:a1:1015::1 AS12008
pdns4.ultradns.org 199.7.69.1 AS12008, 2001:502:4612::1 AS12008
pdns5.ultradns.info 204.74.114.1 AS12008, 2610:a1:1016::1 AS12008
pdns6.ultradns.co.uk 204.74.115.1 AS12008, 2610:a1:1017::1 AS12008
wwv.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
wwvaldemar.dkbrad.ns.cloudflare.com 108.162.193.105 AS13335, 172.64.33.105 AS13335, 173.245.59.105 AS13335, 2606:4700:58::adf5:3b69 AS13335, 2803:f800:50::6ca2:c169 AS13335, 2a06:98c1:50::ac40:2169 AS13335
kelly.ns.cloudflare.com 108.162.194.91 AS13335, 162.159.38.91 AS13335, 172.64.34.91 AS13335, 2606:4700:50::a29f:265b AS13335, 2803:f800:50::6ca2:c25b AS13335, 2a06:98c1:50::ac40:225b AS13335
wwviborg.dkns1.domain-box.dk 88.198.7.5 AS24940
ns2.domain-box.dk 178.63.46.111 AS24940
ns3.domain-box.dk 176.9.83.149 AS24940
www-40737373.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
www-bilka.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
www-boersen.dkns-cloud-a1.googledomains.com 2001:4860:4802:32::6a AS15169, 216.239.32.106 AS15169
ns-cloud-a2.googledomains.com 2001:4860:4802:34::6a AS15169, 216.239.34.106 AS15169
ns-cloud-a3.googledomains.com 2001:4860:4802:36::6a AS15169, 216.239.36.106 AS15169
ns-cloud-a4.googledomains.com 2001:4860:4802:38::6a AS15169, 216.239.38.106 AS15169
www-borsen.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
www-cybercity.dkns1.telenor.dk 2001:1580:0:1806::10 AS9158, 212.242.39.142 AS9158
ns2.telenor.dk 2001:1580:0:1206::10 AS9158, 212.242.39.166 AS9158
www-danskebank.dkns1.brandshelter.com 193.227.117.9 AS1921, 2a04:2b00:14cc::9 AS1921
ns2.brandshelter.de 194.50.187.11 AS1921, 2a04:2b00:14dd::11 AS1921
ns3.brandshelter.info 194.0.182.12 AS1921, 2a04:2b00:14ee::12 AS1921
ns4.brandshelter.net 193.227.117.10 AS1921, 2a04:2b00:14cc::10 AS1921
ns5.brandshelter.us 194.50.187.14 AS1921, 2a04:2b00:14dd::14 AS1921
www-danskekredit.dkns1.brandshelter.com 193.227.117.9 AS1921
ns2.brandshelter.de 194.50.187.11 AS1921
ns3.brandshelter.info 194.0.182.12 AS1921, 2a04:2b00:14ee::12 AS1921
ns4.brandshelter.net 193.227.117.10 AS1921, 2a04:2b00:14cc::10 AS1921
ns5.brandshelter.us 194.50.187.14 AS1921, 2a04:2b00:14dd::14 AS1921
www-danskespil.dkns1-35.azure-dns.com 150.171.10.35 AS8075, 2603:1061:0:10::23 AS8075
ns2-35.azure-dns.net 150.171.16.35 AS8075, 2620:1ec:8ec:10::23 AS8075
ns3-35.azure-dns.org 13.107.222.35 AS8075, 2a01:111:4000:10::23 AS8075
ns4-35.azure-dns.info 13.107.206.35 AS8075, 2620:1ec:bda:10::23 AS8075
www-ddb.dkns1.brandshelter.com 193.227.117.9 AS1921, 2a04:2b00:14cc::9 AS1921
ns2.brandshelter.de 194.50.187.11 AS1921, 2a04:2b00:14dd::11 AS1921
ns3.brandshelter.info 194.0.182.12 AS1921, 2a04:2b00:14ee::12 AS1921
ns4.brandshelter.net 193.227.117.10 AS1921, 2a04:2b00:14cc::10 AS1921
ns5.brandshelter.us 194.50.187.14 AS1921, 2a04:2b00:14dd::14 AS1921
www-digitalpost.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
www-ds.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
www-dsb.dkdns.dsb.dk 193.28.147.132 AS41746
ns.dsb.dk 193.28.147.131 AS41746
www-fdm.dkns1-09.azure-dns.com 13.107.236.9 AS8075, 2603:1061:0:700::9 AS8075
ns2-09.azure-dns.net 150.171.21.9 AS8075, 2620:1ec:8ec:700::9 AS8075
ns3-09.azure-dns.org 204.14.183.9 AS8075, 2a01:111:4000:700::9 AS8075
ns4-09.azure-dns.info 208.84.5.9 AS8075, 2620:1ec:bda:700::9 AS8075
www-firmaflytning.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
www-flytning.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
www-flyttefirma.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
www-jp.dkns-1349.awsdns-40.org 205.251.197.69 AS16509, 2600:9000:5305:4500::1 AS16509
ns-1841.awsdns-38.co.uk 205.251.199.49 AS16509, 2600:9000:5307:3100::1 AS16509
ns-338.awsdns-42.com 205.251.193.82 AS16509, 2600:9000:5301:5200::1 AS16509
ns-707.awsdns-24.net 205.251.194.195 AS16509, 2600:9000:5302:c300::1 AS16509
www-jyskebank.dkben.ns.cloudflare.com 108.162.193.103 AS13335, 172.64.33.103 AS13335, 173.245.59.103 AS13335, 2606:4700:58::adf5:3b67 AS13335, 2803:f800:50::6ca2:c167 AS13335, 2a06:98c1:50::ac40:2167 AS13335
deborah.ns.cloudflare.com 108.162.194.111 AS13335, 162.159.38.111 AS13335, 172.64.34.111 AS13335, 2606:4700:50::a29f:266f AS13335, 2803:f800:50::6ca2:c26f AS13335, 2a06:98c1:50::ac40:226f AS13335
www-lingeri.dkudns1.cscdns.net 2001:502:f3ff::201 AS12008, 204.74.66.1 AS12008
udns2.cscdns.uk 2001:502:4612::201 AS12008, 204.74.111.1 AS12008
www-markiser.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
www-nemsms.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
www-nykredit.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
www-putandtake.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
www-rejseplanen.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
www-sf.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
www-soehoejlandets-fiskepark.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
www-spabad.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
www-swimmingpool.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
www-tdc.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
www-tdconline.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
www-telenor.dkns-cloud-d1.googledomains.com 2001:4860:4802:32::6d AS15169, 216.239.32.109 AS15169
ns-cloud-d2.googledomains.com 2001:4860:4802:34::6d AS15169, 216.239.34.109 AS15169
ns-cloud-d3.googledomains.com 2001:4860:4802:36::6d AS15169, 216.239.36.109 AS15169
ns-cloud-d4.googledomains.com 2001:4860:4802:38::6d AS15169, 216.239.38.109 AS15169
www-telia.dkdns1.telia.com 2001:2040:c001:101::5 AS3301, 81.228.11.67 AS3301
dns2.telia.com 2001:2040:c001:401::6 AS3301, 81.228.10.67 AS3301
www-transport.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
www-triumph.dkudns1.cscdns.net 2001:502:f3ff::201 AS12008, 204.74.66.1 AS12008
udns2.cscdns.uk 2001:502:4612::201 AS12008, 204.74.111.1 AS12008
www-tryg.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
www-udespa.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
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