🛡️ 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

1,183,542 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 address1,3040.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6770.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system758,00864.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,4057.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-05 05:55).

📋 One autonomous system

758,008 domains
DomainNameservers and addresses
acier.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
acierstudio.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
acim.dkpns21.cloudns.net 185.136.96.96 AS203391, 2a06:fb00:1::1:96 AS203391
pns22.cloudns.net 185.136.97.96 AS203391, 2a06:fb00:1::2:96 AS203391
pns23.cloudns.net 185.136.98.96 AS203391, 2a06:fb00:1::3:96 AS203391
pns24.cloudns.net 185.136.99.96 AS203391, 2a06:fb00:1::4:96 AS203391
acinfinity.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
acinfo.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
acing.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
acinstal.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
acinstall.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
acinta.dkns1.wendt-net.dk 185.189.180.19 AS213023, 2a0b:f380:0:1:6::101 AS213023
ns2.wendt-net.dk 185.189.180.16 AS213023, 2a0b:f380:0:1:6::112 AS213023
ns3.wendt-net.dk 185.189.180.23 AS213023, 2a0b:f380:0:1:6::102 AS213023
acinvest.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
acit.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
acj-maskiner.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
acj-prodig.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
acj.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
ack.dkduke.ns.cloudflare.com 108.162.193.110 AS13335, 172.64.33.110 AS13335, 173.245.59.110 AS13335, 2606:4700:58::adf5:3b6e AS13335, 2803:f800:50::6ca2:c16e AS13335, 2a06:98c1:50::ac40:216e AS13335
kiki.ns.cloudflare.com 108.162.192.180 AS13335, 172.64.32.180 AS13335, 173.245.58.180 AS13335, 2606:4700:50::adf5:3ab4 AS13335, 2803:f800:50::6ca2:c0b4 AS13335, 2a06:98c1:50::ac40:20b4 AS13335
acker.dkns1.digitalocean.com 172.64.52.210 AS13335, 2606:4700:52::ac40:34d2 AS13335
ns2.digitalocean.com 172.64.53.21 AS13335, 2606:4700:5a::ac40:3515 AS13335
ns3.digitalocean.com 172.64.49.209 AS13335, 2606:4700:52::ac40:31d1 AS13335
ackermann.dkburt.ns.cloudflare.com 108.162.193.79 AS13335, 172.64.33.79 AS13335, 173.245.59.79 AS13335, 2606:4700:58::adf5:3b4f AS13335, 2803:f800:50::6ca2:c14f AS13335, 2a06:98c1:50::ac40:214f AS13335
tegan.ns.cloudflare.com 108.162.192.226 AS13335, 172.64.32.226 AS13335, 173.245.58.226 AS13335, 2606:4700:50::adf5:3ae2 AS13335, 2803:f800:50::6ca2:c0e2 AS13335, 2a06:98c1:50::ac40:20e2 AS13335
ackermannkommunikation.dkburt.ns.cloudflare.com 108.162.193.79 AS13335, 172.64.33.79 AS13335, 173.245.59.79 AS13335, 2606:4700:58::adf5:3b4f AS13335, 2803:f800:50::6ca2:c14f AS13335, 2a06:98c1:50::ac40:214f AS13335
tegan.ns.cloudflare.com 108.162.192.226 AS13335, 172.64.32.226 AS13335, 173.245.58.226 AS13335, 2606:4700:50::adf5:3ae2 AS13335, 2803:f800:50::6ca2:c0e2 AS13335, 2a06:98c1:50::ac40:20e2 AS13335
ackm.dkharley.ns.cloudflare.com 108.162.195.128 AS13335, 162.159.44.128 AS13335, 172.64.35.128 AS13335, 2606:4700:58::a29f:2c80 AS13335, 2803:f800:50::6ca2:c380 AS13335, 2a06:98c1:50::ac40:2380 AS13335
sloan.ns.cloudflare.com 108.162.194.52 AS13335, 162.159.38.52 AS13335, 172.64.34.52 AS13335, 2606:4700:50::a29f:2634 AS13335, 2803:f800:50::6ca2:c234 AS13335, 2a06:98c1:50::ac40:2234 AS13335
acknowledge.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
ackrowell.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
acks.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
ackt.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
ackthårprodukter.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
acktlikeyou.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
ackunstterapi.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
acl-haandlaesning.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
aclakering.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
aclass.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
aclasscms.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
aclassdvp.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
aclausen.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
aclbyg.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
acldesk.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
acleanspirit.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
acln.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
aclo.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
aclon.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
acloseshave.dkns1.123hotel.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.123hotel.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
acloudberrybog.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
acloudpartner.dkadrian.ns.cloudflare.com 108.162.192.57 AS13335, 172.64.32.57 AS13335, 173.245.58.57 AS13335, 2606:4700:50::adf5:3a39 AS13335, 2803:f800:50::6ca2:c039 AS13335, 2a06:98c1:50::ac40:2039 AS13335
bill.ns.cloudflare.com 108.162.193.74 AS13335, 172.64.33.74 AS13335, 173.245.59.74 AS13335, 2606:4700:58::adf5:3b4a AS13335, 2803:f800:50::6ca2:c14a AS13335, 2a06:98c1:50::ac40:214a AS13335
aclub.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
acm-consulting.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
acm-invest.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
acmab.dkns1.loopiagroup.com 2a10:bbc0::11 AS25234, 45.10.97.11 AS25234
ns2.loopiagroup.com 185.71.159.12 AS25234, 2a02:250:3::12 AS25234
acmail.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
acmaler.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
acmalerfirma.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
acmalerservice.dkns1.ravn-hjemmesider.dk 2a01:4f8:13b:3146::1 AS24940, 94.130.138.185 AS24940
ns2.ravn-hjemmesider.dk 2a01:4f8:c17:5f0a::2 AS24940, 88.99.15.5 AS24940
ns3.ravn-hjemmesider.dk 2a01:4f8:c17:6a6e::2 AS24940, 88.99.39.181 AS24940
acmarine.dkdara.ns.cloudflare.com 108.162.192.91 AS13335, 172.64.32.91 AS13335, 173.245.58.91 AS13335, 2606:4700:50::adf5:3a5b AS13335, 2803:f800:50::6ca2:c05b AS13335, 2a06:98c1:50::ac40:205b AS13335
kip.ns.cloudflare.com 108.162.193.128 AS13335, 172.64.33.128 AS13335, 173.245.59.128 AS13335, 2606:4700:58::adf5:3b80 AS13335, 2803:f800:50::6ca2:c180 AS13335, 2a06:98c1:50::ac40:2180 AS13335
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