🛡️ 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

1,183,339 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 address1,3090.11%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 system757,75064.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,1697.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-06 00:32).

📋 One autonomous system

757,750 domains
DomainNameservers and addresses
adux.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
adv-bale.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
adv-bohansen.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
adv-borupjensen.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
adv-dk.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
adv-ec.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
adv-eegholm.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
adv-egsgaard.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
adv-fiskebakken2.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
adv-frb.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
adv-frederiksberg.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
adv-hessellund.dkjen.ns.cloudflare.com 108.162.194.185 AS13335, 162.159.38.185 AS13335, 172.64.34.185 AS13335, 2606:4700:50::a29f:26b9 AS13335, 2803:f800:50::6ca2:c2b9 AS13335, 2a06:98c1:50::ac40:22b9 AS13335
tanner.ns.cloudflare.com 108.162.195.97 AS13335, 162.159.44.97 AS13335, 172.64.35.97 AS13335, 2606:4700:58::a29f:2c61 AS13335, 2803:f800:50::6ca2:c361 AS13335, 2a06:98c1:50::ac40:2361 AS13335
adv-holch.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
adv-holck.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
adv-holk.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
adv-johnsen.dkns1.absaconit.dk 185.136.96.99 AS203391, 2a06:fb00:1::1:99 AS203391
ns2.absaconit.dk 185.136.97.99 AS203391, 2a06:fb00:1::2:99 AS203391
ns3.absaconit.dk 185.136.98.99 AS203391, 2a06:fb00:1::3:99 AS203391
ns4.absaconit.dk 185.136.99.99 AS203391, 2a06:fb00:1::4:99 AS203391
adv-kiraiqbal.dkns1.meep-meep.dk 94.130.138.185 AS24940
ns2.meep-meep.dk 88.99.15.5 AS24940
adv-kursus.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
adv-larsen.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
adv-lodberg.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
adv-martinelli.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
adv-mlt.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
adv-niels-nissen.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
adv-nygaard.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
adv-nyhavn.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
adv-sekretaeren.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
adv-sekretæren.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
adv-skan.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
adv-stubman.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
adv-thomsen.dknoel.ns.cloudflare.com 108.162.193.216 AS13335, 172.64.33.216 AS13335, 173.245.59.216 AS13335, 2606:4700:58::adf5:3bd8 AS13335, 2803:f800:50::6ca2:c1d8 AS13335, 2a06:98c1:50::ac40:21d8 AS13335
tara.ns.cloudflare.com 108.162.192.225 AS13335, 172.64.32.225 AS13335, 173.245.58.225 AS13335, 2606:4700:50::adf5:3ae1 AS13335, 2803:f800:50::6ca2:c0e1 AS13335, 2a06:98c1:50::ac40:20e1 AS13335
adv-tommy-v.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
adv-wandrup.dkchris.ns.cloudflare.com 108.162.193.85 AS13335, 172.64.33.85 AS13335, 173.245.59.85 AS13335, 2606:4700:58::adf5:3b55 AS13335, 2803:f800:50::6ca2:c155 AS13335, 2a06:98c1:50::ac40:2155 AS13335
pam.ns.cloudflare.com 108.162.192.138 AS13335, 172.64.32.138 AS13335, 173.245.58.138 AS13335, 2606:4700:50::adf5:3a8a AS13335, 2803:f800:50::6ca2:c08a AS13335, 2a06:98c1:50::ac40:208a AS13335
adv-wittenborn.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
adv24b.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
advaerk.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
advaita-vedanta.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
advalo-studio.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
advance-affinity.dkdns1.nominalia.com 2a01:8100:2911::2:184:3 AS39729, 81.88.61.3 AS39729
dns2.nominalia.com 81.88.63.48 AS39729
advance-it.dkns1.hostgoed.net 194.145.209.211 AS200514
ns2.hostgoed.net 194.145.209.211 AS200514
advance-line.dkdexter.ns.cloudflare.com 108.162.195.190 AS13335, 162.159.44.190 AS13335, 172.64.35.190 AS13335, 2606:4700:58::a29f:2cbe AS13335, 2803:f800:50::6ca2:c3be AS13335, 2a06:98c1:50::ac40:23be AS13335
grannbo.ns.cloudflare.com 108.162.194.150 AS13335, 162.159.38.150 AS13335, 172.64.34.150 AS13335, 2606:4700:50::a29f:2696 AS13335, 2803:f800:50::6ca2:c296 AS13335, 2a06:98c1:50::ac40:2296 AS13335
advance.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
advanceaffinity.dkdns1.nominalia.com 2a01:8100:2911::2:184:3 AS39729, 81.88.61.3 AS39729
dns2.nominalia.com 81.88.63.48 AS39729
advanced-armour.dkns1.hforb.com 81.26.219.100 AS31673
ns2.hforb.com 81.26.208.160 AS31673
advancedaiautonomi.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
advancedairmobility.dkevelyn.ns.cloudflare.com 108.162.194.213 AS13335, 162.159.38.213 AS13335, 172.64.34.213 AS13335, 2606:4700:50::a29f:26d5 AS13335, 2803:f800:50::6ca2:c2d5 AS13335, 2a06:98c1:50::ac40:22d5 AS13335
yoxall.ns.cloudflare.com 108.162.195.47 AS13335, 162.159.44.47 AS13335, 172.64.35.47 AS13335, 2606:4700:58::a29f:2c2f AS13335, 2803:f800:50::6ca2:c32f AS13335, 2a06:98c1:50::ac40:232f AS13335
advancedbionics.dkns1-32.azure-dns.com 150.171.10.32 AS8075, 2603:1061:0:10::20 AS8075
ns2-32.azure-dns.net 150.171.16.32 AS8075, 2620:1ec:8ec:10::20 AS8075
ns3-32.azure-dns.org 13.107.222.32 AS8075, 2a01:111:4000:10::20 AS8075
ns4-32.azure-dns.info 13.107.206.32 AS8075, 2620:1ec:bda:10::20 AS8075
advancedbusinessdevelopment.dkdns1.cscdns.net 156.154.130.100 AS12008, 2610:a1:1022::100 AS12008
dns2.cscdns.net 156.154.131.100 AS12008, 2610:a1:1023::100 AS12008
advancedcarlogistics.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
advancedcooling.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
advanceddataanalysis.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
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