🛡️ 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

1,185,859 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1470.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3060.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,7960.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system758,38264.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,8087.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-01 08:10).

📋 One autonomous system

758,382 domains
DomainNameservers and addresses
wøldiche.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
wølf.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
wølundogwraae.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
wørd.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
wørdle.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
wørdsmatter.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
wüko.dkns2.xc-ns.de 193.227.117.225 AS1921, 2a04:2b00:14cc::225 AS1921
ns5.xc-ns.de 194.50.187.225 AS1921, 2a04:2b00:14dd::225 AS1921
würtz.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
wüstenberg.dkns1.messagingengine.com 162.159.24.178 AS13335
ns2.messagingengine.com 162.159.25.191 AS13335
x-332.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
x-35worlds2011.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
devin.ns.cloudflare.com 108.162.195.49 AS13335, 162.159.44.49 AS13335, 172.64.35.49 AS13335, 2606:4700:58::a29f:2c31 AS13335, 2803:f800:50::6ca2:c331 AS13335, 2a06:98c1:50::ac40:2331 AS13335
x-account.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
x-akt.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
x-allergi.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
x-aut.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
x-automation.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
x-bess.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
x-boks.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
x-booster.dkdns101.ovh.net 2001:41d0:d00:fb00::2 AS16276, 5.196.38.125 AS16276
ns101.ovh.net 2001:41d0:b00:f500::2 AS16276, 5.135.53.37 AS16276
x-boxlive.dkdee.ns.cloudflare.com 108.162.192.93 AS13335, 172.64.32.93 AS13335, 173.245.58.93 AS13335, 2606:4700:50::adf5:3a5d AS13335, 2803:f800:50::6ca2:c05d AS13335, 2a06:98c1:50::ac40:205d AS13335
marty.ns.cloudflare.com 108.162.193.204 AS13335, 172.64.33.204 AS13335, 173.245.59.204 AS13335, 2606:4700:58::adf5:3bcc AS13335, 2803:f800:50::6ca2:c1cc AS13335, 2a06:98c1:50::ac40:21cc AS13335
x-c.dkphil.ns.cloudflare.com 108.162.193.137 AS13335, 172.64.33.137 AS13335, 173.245.59.137 AS13335, 2606:4700:58::adf5:3b89 AS13335, 2803:f800:50::6ca2:c189 AS13335, 2a06:98c1:50::ac40:2189 AS13335
zoe.ns.cloudflare.com 108.162.192.149 AS13335, 172.64.32.149 AS13335, 173.245.58.149 AS13335, 2606:4700:50::adf5:3a95 AS13335, 2803:f800:50::6ca2:c095 AS13335, 2a06:98c1:50::ac40:2095 AS13335
x-cars.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
x-cave.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
x-cdc.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
x-change.dkjason.ns.cloudflare.com 108.162.193.179 AS13335, 172.64.33.179 AS13335, 173.245.59.179 AS13335, 2606:4700:58::adf5:3bb3 AS13335, 2803:f800:50::6ca2:c1b3 AS13335, 2a06:98c1:50::ac40:21b3 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
x-changing.dkns1.netnames.net 156.154.130.100 AS12008, 2610:a1:1022::100 AS12008
ns2.netnames.net 156.154.131.100 AS12008, 2610:a1:1023::100 AS12008
x-cite.dkandy.ns.cloudflare.com 108.162.193.101 AS13335, 172.64.33.101 AS13335, 173.245.59.101 AS13335, 2606:4700:58::adf5:3b65 AS13335, 2803:f800:50::6ca2:c165 AS13335, 2a06:98c1:50::ac40:2165 AS13335
brianna.ns.cloudflare.com 108.162.192.245 AS13335, 172.64.32.245 AS13335, 173.245.58.245 AS13335, 2606:4700:50::adf5:3af5 AS13335, 2803:f800:50::6ca2:c0f5 AS13335, 2a06:98c1:50::ac40:20f5 AS13335
x-cma.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
x-company.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
x-connect.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
x-core.dkns1.dns-parking.com 162.159.24.201 AS13335, 2400:cb00:2049:1::a29f:18c9 AS13335
ns2.dns-parking.com 162.159.25.42 AS13335, 2400:cb00:2049:1::a29f:192a AS13335
x-dream.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
x-drone.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
x-dust.dkns1.gnrx.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.gnrx.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
x-dustshop.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
x-e.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
x-eltavler.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
x-factor.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
x-feltet.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
x-files.dknorm.ns.cloudflare.com 108.162.193.134 AS13335, 172.64.33.134 AS13335, 173.245.59.134 AS13335, 2606:4700:58::adf5:3b86 AS13335, 2803:f800:50::6ca2:c186 AS13335, 2a06:98c1:50::ac40:2186 AS13335
rose.ns.cloudflare.com 108.162.192.141 AS13335, 172.64.32.141 AS13335, 173.245.58.141 AS13335, 2606:4700:50::adf5:3a8d AS13335, 2803:f800:50::6ca2:c08d AS13335, 2a06:98c1:50::ac40:208d AS13335
x-fitfightcancer.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
x-fodbold.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
x-formation.dkns-1297.awsdns-34.org 205.251.197.17 AS16509, 2600:9000:5305:1100::1 AS16509
ns-1805.awsdns-33.co.uk 205.251.199.13 AS16509, 2600:9000:5307:d00::1 AS16509
ns-214.awsdns-26.com 205.251.192.214 AS16509, 2600:9000:5300:d600::1 AS16509
ns-879.awsdns-45.net 205.251.195.111 AS16509, 2600:9000:5303:6f00::1 AS16509
x-frisor-aarhus.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78
ns2.simply.com 185.25.141.15, 2a02:2339:4006:101::4562:4562
ns3.simply.com 91.197.248.79
x-games.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
x-gym.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
x-hair.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
x-hale.dkns1.eurodns.com 199.167.66.107 AS23393, 2610:1c8:b002::107 AS23393
ns2.eurodns.com 104.37.178.107 AS23393, 2610:1c8:b001::107 AS23393
ns3.eurodns.com 199.167.66.108 AS23393, 2610:1c8:b002::108 AS23393
ns4.eurodns.com 104.37.178.108 AS23393, 2610:1c8:b001::108 AS23393
x-host.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
x-house.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
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