🛡️ 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
ahklinik.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
ahkloak.dkbarbara.ns.cloudflare.com 108.162.192.248 AS13335, 172.64.32.248 AS13335, 173.245.58.248 AS13335, 2606:4700:50::adf5:3af8 AS13335, 2803:f800:50::6ca2:c0f8 AS13335, 2a06:98c1:50::ac40:20f8 AS13335
justin.ns.cloudflare.com 108.162.193.187 AS13335, 172.64.33.187 AS13335, 173.245.59.187 AS13335, 2606:4700:58::adf5:3bbb AS13335, 2803:f800:50::6ca2:c1bb AS13335, 2a06:98c1:50::ac40:21bb AS13335
ahkommunikation.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
ahkpro.dkleonard.ns.cloudflare.com 108.162.195.54 AS13335, 162.159.44.54 AS13335, 172.64.35.54 AS13335, 2606:4700:58::a29f:2c36 AS13335, 2803:f800:50::6ca2:c336 AS13335, 2a06:98c1:50::ac40:2336 AS13335
wally.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
ahkropogsind.dkdahlia.ns.cloudflare.com 108.162.192.89 AS13335, 172.64.32.89 AS13335, 173.245.58.89 AS13335, 2606:4700:50::adf5:3a59 AS13335, 2803:f800:50::6ca2:c059 AS13335, 2a06:98c1:50::ac40:2059 AS13335
dom.ns.cloudflare.com 108.162.193.157 AS13335, 172.64.33.157 AS13335, 173.245.59.157 AS13335, 2606:4700:58::adf5:3b9d AS13335, 2803:f800:50::6ca2:c19d AS13335, 2a06:98c1:50::ac40:219d AS13335
ahkurser.dkns1.mcb.dk 178.23.177.69 AS47527, 2a00:1cf0:0:9::69 AS47527
ns2.mcb.dk 195.182.36.51 AS47527, 2a00:1cf0:0:5::3 AS47527
ns3.mcb.dk 185.208.212.121 AS47527, 2a00:1b19:2:1::121 AS47527
ahl-draenlaug.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
ahl-in-one.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
ahl01.dkgordon.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
hera.ns.cloudflare.com 108.162.192.162 AS13335, 172.64.32.162 AS13335, 173.245.58.162 AS13335, 2606:4700:50::adf5:3aa2 AS13335, 2803:f800:50::6ca2:c0a2 AS13335, 2a06:98c1:50::ac40:20a2 AS13335
ahlarsen.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
ahlbeck.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
ahlberg.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
ahlblad.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
ahlborn.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
ahlburgsprog.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
ahlcon.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
ahlder.dkns1.misspark.com 162.159.24.173 AS13335, 2400:cb00:2049:1::a29f:18ad AS13335
ns2.misspark.com 162.159.25.99 AS13335, 2400:cb00:2049:1::a29f:1963 AS13335
ns3.misspark.com 162.159.25.16 AS13335, 2400:cb00:2049:1::a29f:1910 AS13335
ns4.misspark.com 162.159.24.87 AS13335, 2400:cb00:2049:1::a29f:1857 AS13335
ahle.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
ahleasing.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
ahlefeld.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
ahlefeldt-laurvig-lehn.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
ahlefeldt-laurvigen.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
ahlefeldtlaurviglehn.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
ahler.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
ahlerrumogdesign.dkgerald.ns.cloudflare.com 108.162.193.168 AS13335, 172.64.33.168 AS13335, 173.245.59.168 AS13335, 2606:4700:58::adf5:3ba8 AS13335, 2803:f800:50::6ca2:c1a8 AS13335, 2a06:98c1:50::ac40:21a8 AS13335
tina.ns.cloudflare.com 108.162.192.230 AS13335, 172.64.32.230 AS13335, 173.245.58.230 AS13335, 2606:4700:50::adf5:3ae6 AS13335, 2803:f800:50::6ca2:c0e6 AS13335, 2a06:98c1:50::ac40:20e6 AS13335
ahlers-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
ahlers-jensen.dkns.andersenit.dk 185.200.74.101 AS198614
ns1.andersenit.dk 87.238.248.10 AS198614
ahlersandersen.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
ahlersindustrimontage.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
ahlersmaskinservice.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
ahlersservice.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
ahlgade44.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
ahlgade47.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
ahlgreens.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
ahlgrenandersen.dkvera.ns.cloudflare.com 108.162.192.147 AS13335, 172.64.32.147 AS13335, 173.245.58.147 AS13335, 2606:4700:50::adf5:3a93 AS13335, 2803:f800:50::6ca2:c093 AS13335, 2a06:98c1:50::ac40:2093 AS13335
wilson.ns.cloudflare.com 108.162.195.110 AS13335, 162.159.44.110 AS13335, 172.64.35.110 AS13335, 2606:4700:58::a29f:2c6e AS13335, 2803:f800:50::6ca2:c36e AS13335, 2a06:98c1:50::ac40:236e AS13335
ahlgrenarmbaand.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
ahlhundesalon.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
ahlinone.dkgordon.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
hera.ns.cloudflare.com 108.162.192.162 AS13335, 172.64.32.162 AS13335, 173.245.58.162 AS13335, 2606:4700:50::adf5:3aa2 AS13335, 2803:f800:50::6ca2:c0a2 AS13335, 2a06:98c1:50::ac40:20a2 AS13335
ahlk.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
ahlmann-olesen.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
ahlmann-rasmussen.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
ahlmann.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
ahlmannaps.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
ahlmannco.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
ahlmanndaek.dkns1.designrus.dk 176.9.4.22 AS24940, 2a01:4f8:141:3416::2 AS24940
ns2.designrus.dk 2a01:4f8:242:5649::2 AS24940, 49.12.124.182 AS24940
ahlmannvigh.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
ahlmsmalerservice.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
ahlnor.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
ahlogson.dkalfred.ns.cloudflare.com 108.162.195.131 AS13335, 162.159.44.131 AS13335, 172.64.35.131 AS13335, 2606:4700:58::a29f:2c83 AS13335, 2803:f800:50::6ca2:c383 AS13335, 2a06:98c1:50::ac40:2383 AS13335
isla.ns.cloudflare.com 108.162.192.119 AS13335, 172.64.32.119 AS13335, 173.245.58.119 AS13335, 2606:4700:50::adf5:3a77 AS13335, 2803:f800:50::6ca2:c077 AS13335, 2a06:98c1:50::ac40:2077 AS13335
ahlorentzen.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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