🛡️ 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

1,184,859 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 address1,2990.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,7490.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system758,13564.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,5897.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-01 20:42).

📋 One autonomous system

758,135 domains
DomainNameservers and addresses
wow365.dkdns1.safenames.com 162.159.48.132 AS13335, 2400:cb00:2049:1::a29f:3084 AS13335
dns2.safenames.net 162.159.49.170 AS13335, 2400:cb00:2049:1::a29f:31aa AS13335
dns3.safenames.org 172.64.48.23 AS13335, 2400:cb00:2049:1::ac40:3017 AS13335
wow4ever.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
wowair.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
cecelia.ns.cloudflare.com 108.162.194.135 AS13335, 162.159.38.135 AS13335, 172.64.34.135 AS13335, 2606:4700:50::a29f:2687 AS13335, 2803:f800:50::6ca2:c287 AS13335, 2a06:98c1:50::ac40:2287 AS13335
wowbaby.dkns.hostpoint.ch 217.26.51.254 AS29097, 2a00:d70:0:b::d AS29097
ns2.hostpoint.ch 217.26.53.254 AS29097, 2a00:d70:0:b::1d AS29097
ns3.hostpoint.ch 217.26.60.250 AS29097, 2a00:d70:0:b::b AS29097
wowbad.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
wowblomster.dkns1.nsec.dk 2a01:4f8:c0c:8726::1 AS24940, 94.130.173.147 AS24940
ns2.nsec.dk 159.69.124.71 AS24940, 2a01:4f8:c010:2c16::1 AS24940
wowbybikbok.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
wowchocolao.dkcosmos.dns-parking.com 172.64.53.200 AS13335, 2606:4700:5a::ac40:35c8 AS13335
nova.dns-parking.com 172.64.52.46 AS13335, 2606:4700:52::ac40:342e AS13335
wowcph.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
wowdeal.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
wowdeals.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
wowe.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
wowenergy.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
wowereit.dkhadlee.ns.cloudflare.com 108.162.194.67 AS13335, 162.159.38.67 AS13335, 172.64.34.67 AS13335, 2606:4700:50::a29f:2643 AS13335, 2803:f800:50::6ca2:c243 AS13335, 2a06:98c1:50::ac40:2243 AS13335
igor.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
wowernhr.dkdns10.telia.com 2001:2040:c001:301::4 AS3301, 81.228.9.98 AS3301
dns11.se.telia.net 2001:2040:c001:304::4 AS3301, 81.228.9.131 AS3301
dns12.se.telia.net 2001:2040:c001:401::5 AS3301, 81.228.10.69 AS3301
dns9.telia.com 2001:2040:c001:104::5 AS3301, 81.228.11.184 AS3301
wowforever.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
wowfrisoer.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
wowi.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
wowinnovation.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
wowkids.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
wowkidz.dkcloe.ns.cloudflare.com 108.162.192.86 AS13335, 172.64.32.86 AS13335, 173.245.58.86 AS13335, 2606:4700:50::adf5:3a56 AS13335, 2803:f800:50::6ca2:c056 AS13335, 2a06:98c1:50::ac40:2056 AS13335
terin.ns.cloudflare.com 108.162.193.236 AS13335, 172.64.33.236 AS13335, 173.245.59.236 AS13335, 2606:4700:58::adf5:3bec AS13335, 2803:f800:50::6ca2:c1ec AS13335, 2a06:98c1:50::ac40:21ec AS13335
wowkitchen.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
wowlab.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
wowmail.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
wowme.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
wowmedia.dkgigi.ns.cloudflare.com 108.162.194.12 AS13335, 162.159.38.12 AS13335, 172.64.34.12 AS13335, 2606:4700:50::a29f:260c AS13335, 2803:f800:50::6ca2:c20c AS13335, 2a06:98c1:50::ac40:220c AS13335
ray.ns.cloudflare.com 108.162.193.138 AS13335, 172.64.33.138 AS13335, 173.245.59.138 AS13335, 2606:4700:58::adf5:3b8a AS13335, 2803:f800:50::6ca2:c18a AS13335, 2a06:98c1:50::ac40:218a AS13335
wowmodel.dkns1045.ui-dns.biz 185.132.33.45 AS15418, 2607:f1c0:fe:53:185:132:33:45 AS15418
ns1045.ui-dns.com 185.132.34.45 AS15418, 2607:f1c0:fe:53:185:132:34:45 AS15418
ns1045.ui-dns.de 185.132.32.45 AS15418, 2607:f1c0:fe:53:185:132:32:45 AS15418
ns1045.ui-dns.org 185.132.35.45 AS15418, 2607:f1c0:fe:53:185:132:35:45 AS15418
wowmom.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
wowmounts.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
wownordic.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
wowpadel.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
wowpark.dkadam.ns.cloudflare.com 108.162.193.54 AS13335, 172.64.33.54 AS13335, 173.245.59.54 AS13335, 2606:4700:58::adf5:3b36 AS13335, 2803:f800:50::6ca2:c136 AS13335, 2a06:98c1:50::ac40:2136 AS13335
nora.ns.cloudflare.com 108.162.192.213 AS13335, 172.64.32.213 AS13335, 173.245.58.213 AS13335, 2606:4700:50::adf5:3ad5 AS13335, 2803:f800:50::6ca2:c0d5 AS13335, 2a06:98c1:50::ac40:20d5 AS13335
wowpedia.dkart.ns.cloudflare.com 108.162.193.102 AS13335, 172.64.33.102 AS13335, 173.245.59.102 AS13335, 2606:4700:58::adf5:3b66 AS13335, 2803:f800:50::6ca2:c166 AS13335, 2a06:98c1:50::ac40:2166 AS13335
lara.ns.cloudflare.com 108.162.192.128 AS13335, 172.64.32.128 AS13335, 173.245.58.128 AS13335, 2606:4700:50::adf5:3a80 AS13335, 2803:f800:50::6ca2:c080 AS13335, 2a06:98c1:50::ac40:2080 AS13335
wowprint.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
wowpriser.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
wowproductions.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
wowrengoring.dkns1.siteground.net 75.2.77.104 AS16509
ns2.siteground.net 99.83.229.113 AS16509
wowsadler.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
wowsadlerdanmark.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
wowservice.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
wowstudio.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
wowtea.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
wowtranslation.dkjasper.ns.cloudflare.com 108.162.195.182 AS13335, 162.159.44.182 AS13335, 172.64.35.182 AS13335, 2606:4700:58::a29f:2cb6 AS13335, 2803:f800:50::6ca2:c3b6 AS13335, 2a06:98c1:50::ac40:23b6 AS13335
melissa.ns.cloudflare.com 108.162.192.199 AS13335, 172.64.32.199 AS13335, 173.245.58.199 AS13335, 2606:4700:50::adf5:3ac7 AS13335, 2803:f800:50::6ca2:c0c7 AS13335, 2a06:98c1:50::ac40:20c7 AS13335
woww.dkns.zone.eu 217.146.66.65 AS49604
ns2.zone.ee 2a02:29e9:30:53::a AS49604, 85.234.242.32 AS49604
ns3.zonedata.net 2a02:29e9:20:53::a AS49604, 85.234.247.50 AS49604
wowweb.dkchloe.ns.cloudflare.com 108.162.192.85 AS13335, 172.64.32.85 AS13335, 173.245.58.85 AS13335, 2606:4700:50::adf5:3a55 AS13335, 2803:f800:50::6ca2:c055 AS13335, 2a06:98c1:50::ac40:2055 AS13335
gordon.ns.cloudflare.com 108.162.193.170 AS13335, 172.64.33.170 AS13335, 173.245.59.170 AS13335, 2606:4700:58::adf5:3baa AS13335, 2803:f800:50::6ca2:c1aa AS13335, 2a06:98c1:50::ac40:21aa AS13335
wowwow.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
woxholt.dkns1.dnsserver.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.dnsserver.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
woxholtauktioner.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
woxob.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
woythal.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
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