🛡️ 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

1,185,715 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 address1,3130.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,8080.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system755,25063.7%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,9817.3%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-09-30 06:38).

📋 One autonomous system

755,250 domains
DomainNameservers and addresses
zoneterapihorsens.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
zoneterapihoselena.dkns7.bricksite.net 35.246.226.10 AS396982
ns8.bricksite.net 35.242.190.82 AS396982
zoneterapihund.dkblakely.ns.cloudflare.com 108.162.194.96 AS13335, 162.159.38.96 AS13335, 172.64.34.96 AS13335, 2606:4700:50::a29f:2660 AS13335, 2803:f800:50::6ca2:c260 AS13335, 2a06:98c1:50::ac40:2260 AS13335
hank.ns.cloudflare.com 108.162.193.116 AS13335, 172.64.33.116 AS13335, 173.245.59.116 AS13335, 2606:4700:58::adf5:3b74 AS13335, 2803:f800:50::6ca2:c174 AS13335, 2a06:98c1:50::ac40:2174 AS13335
zoneterapikoldingsyd.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
zoneterapiogmassage.dkns7.bricksite.net 35.246.226.10 AS396982
ns8.bricksite.net 35.242.190.82 AS396982
zoneterapiogmassagevejle.dkns1.mono.net 185.58.212.1 AS201595
ns2.mono.net 185.130.160.1 AS201595
ns3.mono.net 185.130.160.2 AS201595
ns4.mono.net 185.58.212.2 AS201595
zoneterapiogvelvære.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
zoneterapiskolen.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
zoneterapisten.dkjocelyn.ns.cloudflare.com 108.162.192.174 AS13335, 172.64.32.174 AS13335, 173.245.58.174 AS13335, 2606:4700:50::adf5:3aae AS13335, 2803:f800:50::6ca2:c0ae AS13335, 2a06:98c1:50::ac40:20ae AS13335
vasilii.ns.cloudflare.com 108.162.195.26 AS13335, 162.159.44.26 AS13335, 172.64.35.26 AS13335, 2606:4700:58::a29f:2c1a AS13335, 2803:f800:50::6ca2:c31a AS13335, 2a06:98c1:50::ac40:231a AS13335
zoneterapisvalen.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
zoneterapisvendborg.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
zoneterapiuniverset.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
zoneterapivalby.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
zoneterapivedsusannerosser.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
zoneterapivedsussi.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
zonetobewell.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
zonetp.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
zonetryg.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
zonetryk.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
zonevej.dkns1.min-it.dk 128.140.54.100 AS24940
ns2.min-it.dk 128.140.52.143 AS24940
zonevi.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
zonex.dkdns1.ipmanagerinc.net 193.227.117.15 AS1921, 2a04:2b00:14cc::15 AS1921
dns2.ipmanagerinc.net 194.50.187.16 AS1921, 2a04:2b00:14dd::16 AS1921
dns3.ipmanagerinc.net 193.227.117.15 AS1921, 2a04:2b00:14cc::15 AS1921
zonexlnt.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
zonexrp.dkdana.ns.cloudflare.com 108.162.192.105 AS13335, 172.64.32.105 AS13335, 173.245.58.105 AS13335, 2606:4700:50::adf5:3a69 AS13335, 2803:f800:50::6ca2:c069 AS13335, 2a06:98c1:50::ac40:2069 AS13335
dion.ns.cloudflare.com 108.162.193.156 AS13335, 172.64.33.156 AS13335, 173.245.59.156 AS13335, 2606:4700:58::adf5:3b9c AS13335, 2803:f800:50::6ca2:c19c AS13335, 2a06:98c1:50::ac40:219c AS13335
zonez.dkjakub.ns.cloudflare.com 108.162.195.85 AS13335, 162.159.44.85 AS13335, 172.64.35.85 AS13335, 2606:4700:58::a29f:2c55 AS13335, 2803:f800:50::6ca2:c355 AS13335, 2a06:98c1:50::ac40:2355 AS13335
rosalyn.ns.cloudflare.com 108.162.194.59 AS13335, 162.159.38.59 AS13335, 172.64.34.59 AS13335, 2606:4700:50::a29f:263b AS13335, 2803:f800:50::6ca2:c23b AS13335, 2a06:98c1:50::ac40:223b AS13335
zonezono.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
zoni.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
zonic.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
zonicevent.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
zonicmusicgroup.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
zonicpro.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
zonicteater.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
zonik.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
zonika.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
zonith.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
zonix.dkricardo.ns.cloudflare.com 108.162.195.211 AS13335, 162.159.44.211 AS13335, 172.64.35.211 AS13335, 2606:4700:58::a29f:2cd3 AS13335, 2803:f800:50::6ca2:c3d3 AS13335, 2a06:98c1:50::ac40:23d3 AS13335
ruth.ns.cloudflare.com 108.162.192.143 AS13335, 172.64.32.143 AS13335, 173.245.58.143 AS13335, 2606:4700:50::adf5:3a8f AS13335, 2803:f800:50::6ca2:c08f AS13335, 2a06:98c1:50::ac40:208f AS13335
zonkerz.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
miki.ns.cloudflare.com 108.162.192.202 AS13335, 172.64.32.202 AS13335, 173.245.58.202 AS13335, 2606:4700:50::adf5:3aca AS13335, 2803:f800:50::6ca2:c0ca AS13335, 2a06:98c1:50::ac40:20ca AS13335
zonkey.dkns1.websupport.cz 2a10:bbc0::11 AS25234, 45.10.97.11 AS25234
ns2.websupport.cz 185.71.159.12 AS25234, 2a02:250:3::12 AS25234
ns3.websupport.eu 2a10:bbc0::13 AS25234, 45.10.97.13 AS25234
zonkjer.dkeva.ns.cloudflare.com 108.162.192.114 AS13335, 172.64.32.114 AS13335, 173.245.58.114 AS13335, 2606:4700:50::adf5:3a72 AS13335, 2803:f800:50::6ca2:c072 AS13335, 2a06:98c1:50::ac40:2072 AS13335
jeff.ns.cloudflare.com 108.162.193.124 AS13335, 172.64.33.124 AS13335, 173.245.59.124 AS13335, 2606:4700:58::adf5:3b7c AS13335, 2803:f800:50::6ca2:c17c AS13335, 2a06:98c1:50::ac40:217c AS13335
zonky.dkns1.websupport.cz 2a10:bbc0::11 AS25234, 45.10.97.11 AS25234
ns2.websupport.cz 185.71.159.12 AS25234, 2a02:250:3::12 AS25234
ns3.websupport.eu 2a10:bbc0::13 AS25234, 45.10.97.13 AS25234
zonnic.dknsgbr.comlaude.co.uk 198.51.44.11 AS62597, 2620:4d:4000:6259:7:11:0:1 AS62597
nssui.comlaude.ch 198.51.45.11 AS62597, 2a00:edc0:6259:7:11::2 AS62597
nsusa.comlaude.net 198.51.44.75 AS62597, 2620:4d:4000:6259:7:11:0:3 AS62597
zonqi.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
zonta.dkartemis.dns-parking.com 172.64.53.131 AS13335, 2606:4700:5a::ac40:3583 AS13335
hermes.dns-parking.com 172.64.52.144 AS13335, 2606:4700:52::ac40:3490 AS13335
zonuu.dkram.ns.cloudflare.com 108.162.193.225 AS13335, 172.64.33.225 AS13335, 173.245.59.225 AS13335, 2606:4700:58::adf5:3be1 AS13335, 2803:f800:50::6ca2:c1e1 AS13335, 2a06:98c1:50::ac40:21e1 AS13335
sandy.ns.cloudflare.com 108.162.192.219 AS13335, 172.64.32.219 AS13335, 173.245.58.219 AS13335, 2606:4700:50::adf5:3adb AS13335, 2803:f800:50::6ca2:c0db AS13335, 2a06:98c1:50::ac40:20db AS13335
zonz.dkns.andersenit.dk 185.200.74.101 AS198614
ns1.andersenit.dk 87.238.248.10 AS198614
zonzini.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
zoo-center.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
zoo-kbh.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
zoo-konservator.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
zoo-park.dklaila.ns.cloudflare.com 108.162.194.122 AS13335, 162.159.38.122 AS13335, 172.64.34.122 AS13335, 2606:4700:50::a29f:267a AS13335, 2803:f800:50::6ca2:c27a AS13335, 2a06:98c1:50::ac40:227a AS13335
margo.ns.cloudflare.com 108.162.195.144 AS13335, 162.159.44.144 AS13335, 172.64.35.144 AS13335, 2606:4700:58::a29f:2c90 AS13335, 2803:f800:50::6ca2:c390 AS13335, 2a06:98c1:50::ac40:2390 AS13335
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