🛡️ 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

1,183,657 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 address1,3070.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6840.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system758,17064.1%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,3597.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-04 17:29).

📋 One autonomous system

758,170 domains
DomainNameservers and addresses
westendahl.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
westendgolden.dkns7.bricksite.net 35.246.226.10 AS396982
ns8.bricksite.net 35.242.190.82 AS396982
westendgruppen.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
westenholtz.dkhugh.ns.cloudflare.com 108.162.193.117 AS13335, 172.64.33.117 AS13335, 173.245.59.117 AS13335, 2606:4700:58::adf5:3b75 AS13335, 2803:f800:50::6ca2:c175 AS13335, 2a06:98c1:50::ac40:2175 AS13335
meera.ns.cloudflare.com 108.162.192.195 AS13335, 172.64.32.195 AS13335, 173.245.58.195 AS13335, 2606:4700:50::adf5:3ac3 AS13335, 2803:f800:50::6ca2:c0c3 AS13335, 2a06:98c1:50::ac40:20c3 AS13335
westenholz.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
wester-outdoor.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
westerberg.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
westerbjerg.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
westerboestudio.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
westerboetrailerservice.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
westerbro-linedance.dkfay.ns.cloudflare.com 108.162.192.115 AS13335, 172.64.32.115 AS13335, 173.245.58.115 AS13335, 2606:4700:50::adf5:3a73 AS13335, 2803:f800:50::6ca2:c073 AS13335, 2a06:98c1:50::ac40:2073 AS13335
todd.ns.cloudflare.com 108.162.193.146 AS13335, 172.64.33.146 AS13335, 173.245.59.146 AS13335, 2606:4700:58::adf5:3b92 AS13335, 2803:f800:50::6ca2:c192 AS13335, 2a06:98c1:50::ac40:2192 AS13335
westerbrolinedance.dkgina.ns.cloudflare.com 108.162.192.117 AS13335, 172.64.32.117 AS13335, 173.245.58.117 AS13335, 2606:4700:50::adf5:3a75 AS13335, 2803:f800:50::6ca2:c075 AS13335, 2a06:98c1:50::ac40:2075 AS13335
mark.ns.cloudflare.com 108.162.193.130 AS13335, 172.64.33.130 AS13335, 173.245.59.130 AS13335, 2606:4700:58::adf5:3b82 AS13335, 2803:f800:50::6ca2:c182 AS13335, 2a06:98c1:50::ac40:2182 AS13335
westerby.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
westerbyejendomme.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
westercoaching.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
westerdahl-net.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
westergaard-blomster.dkns1.dlx.dk 2a00:1b18:1337:1337::53 AS47527, 46.30.121.210 AS47527
ns2.dlx.dk 185.208.212.124 AS47527, 2a00:1b19:1337:1337::53 AS47527
westergaard-el.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
westergaard-gardiner.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
westergaard.dkluke.ns.cloudflare.com 108.162.193.200 AS13335, 172.64.33.200 AS13335, 173.245.59.200 AS13335, 2606:4700:58::adf5:3bc8 AS13335, 2803:f800:50::6ca2:c1c8 AS13335, 2a06:98c1:50::ac40:21c8 AS13335
paityn.ns.cloudflare.com 108.162.194.18 AS13335, 162.159.38.18 AS13335, 172.64.34.18 AS13335, 2606:4700:50::a29f:2612 AS13335, 2803:f800:50::6ca2:c212 AS13335, 2a06:98c1:50::ac40:2212 AS13335
westergaardbolig.dkhal.ns.cloudflare.com 108.162.193.174 AS13335, 172.64.33.174 AS13335, 173.245.59.174 AS13335, 2606:4700:58::adf5:3bae AS13335, 2803:f800:50::6ca2:c1ae AS13335, 2a06:98c1:50::ac40:21ae AS13335
pat.ns.cloudflare.com 108.162.192.139 AS13335, 172.64.32.139 AS13335, 173.245.58.139 AS13335, 2606:4700:50::adf5:3a8b AS13335, 2803:f800:50::6ca2:c08b AS13335, 2a06:98c1:50::ac40:208b AS13335
westergaardejendomsservice.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
westergaardjakobsen.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
westergaardkikkenborg.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
westergaardpsykiatri.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
westergaards-service.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
westergaards.dkns1.bytebob.com 79.170.40.2 AS20738
ns2.bytebob.com 79.170.43.3 AS20738
westergaardshotel.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
westergaardsmultirens.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
westergaardsolutions.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
westergaardtech.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
westergreen.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
westergren.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
westerguardian.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
westergård-blomster.dkns1.dlx.dk 2a00:1b18:1337:1337::53 AS47527, 46.30.121.210 AS47527
ns2.dlx.dk 185.208.212.124 AS47527, 2a00:1b19:1337:1337::53 AS47527
westergård.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
westerhausen.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
westerhavshytten.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
westerhaw.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
westerhoff.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
westerholm.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
westerholt.dkkatja.ns.cloudflare.com 108.162.194.53 AS13335, 162.159.38.53 AS13335, 172.64.34.53 AS13335, 2606:4700:50::a29f:2635 AS13335, 2803:f800:50::6ca2:c235 AS13335, 2a06:98c1:50::ac40:2235 AS13335
odin.ns.cloudflare.com 108.162.195.208 AS13335, 162.159.44.208 AS13335, 172.64.35.208 AS13335, 2606:4700:58::a29f:2cd0 AS13335, 2803:f800:50::6ca2:c3d0 AS13335, 2a06:98c1:50::ac40:23d0 AS13335
westerhus.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
westerkam.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
westerkopi.dkns-1311.awsdns-35.org 205.251.197.31 AS16509, 2600:9000:5305:1f00::1 AS16509
ns-153.awsdns-19.com 205.251.192.153 AS16509, 2600:9000:5300:9900::1 AS16509
ns-1700.awsdns-20.co.uk 205.251.198.164 AS16509, 2600:9000:5306:a400::1 AS16509
ns-823.awsdns-38.net 205.251.195.55 AS16509, 2600:9000:5303:3700::1 AS16509
westerland.dkchin.ns.cloudflare.com 108.162.192.84 AS13335, 172.64.32.84 AS13335, 173.245.58.84 AS13335, 2606:4700:50::adf5:3a54 AS13335, 2803:f800:50::6ca2:c054 AS13335, 2a06:98c1:50::ac40:2054 AS13335
jobs.ns.cloudflare.com 108.162.193.183 AS13335, 172.64.33.183 AS13335, 173.245.59.183 AS13335, 2606:4700:58::adf5:3bb7 AS13335, 2803:f800:50::6ca2:c1b7 AS13335, 2a06:98c1:50::ac40:21b7 AS13335
westerlin.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
westerlund.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
westermann-danmark.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
westermann.dkcarrera.ns.cloudflare.com 108.162.194.231 AS13335, 162.159.38.231 AS13335, 172.64.34.231 AS13335, 2606:4700:50::a29f:26e7 AS13335, 2803:f800:50::6ca2:c2e7 AS13335, 2a06:98c1:50::ac40:22e7 AS13335
jihoon.ns.cloudflare.com 108.162.195.233 AS13335, 162.159.44.233 AS13335, 172.64.35.233 AS13335, 2606:4700:58::a29f:2ce9 AS13335, 2803:f800:50::6ca2:c3e9 AS13335, 2a06:98c1:50::ac40:23e9 AS13335
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