🛡️ 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

1,183,573 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1450.01%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 IPv610,6800.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,94464.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,2767.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-05 18:29).

📋 One autonomous system

757,944 domains
DomainNameservers and addresses
adteknik.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
adtension.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
adtentionmedia.dkns61.domaincontrol.com 2603:5:2153::20 AS44273, 97.74.101.32 AS44273
ns62.domaincontrol.com 173.201.69.32 AS44273, 2603:5:2253::20 AS44273
adth.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
adtiering.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
adtify.dkjack.ns.cloudflare.com 108.162.193.121 AS13335, 172.64.33.121 AS13335, 173.245.59.121 AS13335, 2606:4700:58::adf5:3b79 AS13335, 2803:f800:50::6ca2:c179 AS13335, 2a06:98c1:50::ac40:2179 AS13335
mallory.ns.cloudflare.com 108.162.194.83 AS13335, 162.159.38.83 AS13335, 172.64.34.83 AS13335, 2606:4700:50::a29f:2653 AS13335, 2803:f800:50::6ca2:c253 AS13335, 2a06:98c1:50::ac40:2253 AS13335
adtime.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
adtimera.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
adtimize-server.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
adtimize-showcase.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
adtimize.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
adtivity.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
adtocart.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
adtomic.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
adtomicwix.dkns14.wixdns.net 216.239.32.100 AS15169
ns15.wixdns.net 216.239.34.100 AS15169
adtool.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
adtracker.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
adtraction.dkns-1199.awsdns-21.org 205.251.196.175 AS16509, 2600:9000:5304:af00::1 AS16509
ns-1731.awsdns-24.co.uk 205.251.198.195 AS16509, 2600:9000:5306:c300::1 AS16509
ns-18.awsdns-02.com 205.251.192.18 AS16509, 2600:9000:5300:1200::1 AS16509
ns-561.awsdns-06.net 205.251.194.49 AS16509, 2600:9000:5302:3100::1 AS16509
adtrader.dkns61.domaincontrol.com 2603:5:2153::20 AS44273, 97.74.101.32 AS44273
ns62.domaincontrol.com 173.201.69.32 AS44273, 2603:5:2253::20 AS44273
adtran.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
adtv.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
adu.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
adua.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
aducanumab.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
aduhelm.dkns-1194.awsdns-21.org 205.251.196.170 AS16509, 2600:9000:5304:aa00::1 AS16509
ns-1756.awsdns-27.co.uk 205.251.198.220 AS16509, 2600:9000:5306:dc00::1 AS16509
ns-527.awsdns-01.net 205.251.194.15 AS16509, 2600:9000:5302:f00::1 AS16509
ns-82.awsdns-10.com 205.251.192.82 AS16509, 2600:9000:5300:5200::1 AS16509
aduin.dkns61.domaincontrol.com 2603:5:2153::20 AS44273, 97.74.101.32 AS44273
ns62.domaincontrol.com 173.201.69.32 AS44273, 2603:5:2253::20 AS44273
adult.dkns1.dan.com 2603:5:2125::43 AS44273, 97.74.98.67 AS44273
ns2.dan.com 173.201.66.67 AS44273, 2603:5:2225::43 AS44273
adultboutique.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
adultcasting.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
adultfun.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
adultlivestreaming.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
adultresilience.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
adultswim.dkns-1270.awsdns-30.org 205.251.196.246 AS16509, 2600:9000:5304:f600::1 AS16509
ns-129.awsdns-16.com 205.251.192.129 AS16509, 2600:9000:5300:8100::1 AS16509
ns-1824.awsdns-36.co.uk 205.251.199.32 AS16509, 2600:9000:5307:2000::1 AS16509
ns-978.awsdns-58.net 205.251.195.210 AS16509, 2600:9000:5303:d200::1 AS16509
adultworld.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
adumed.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
adumi.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
aduncanpt.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
aduncker.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
adur.dkns.andersenit.dk 185.200.74.101 AS198614
ns1.andersenit.dk 87.238.248.10 AS198614
aduro-skorsten.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
aduro.dkcamilo.ns.cloudflare.com 108.162.195.118 AS13335, 162.159.44.118 AS13335, 172.64.35.118 AS13335, 2606:4700:58::a29f:2c76 AS13335, 2803:f800:50::6ca2:c376 AS13335, 2a06:98c1:50::ac40:2376 AS13335
delilah.ns.cloudflare.com 108.162.194.99 AS13335, 162.159.38.99 AS13335, 172.64.34.99 AS13335, 2606:4700:50::a29f:2663 AS13335, 2803:f800:50::6ca2:c263 AS13335, 2a06:98c1:50::ac40:2263 AS13335
adurocloud.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
adurofire.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
adurogo.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
adurolight.dkns01.is.nl 213.75.63.33 AS1136, 2a02:a47f:ac:1::1153 AS1136
ns02.is.nl 213.75.63.68 AS1136, 2a02:a47f:ac:1::1253 AS1136
ns03.is.nl 213.75.63.34 AS1136, 2a02:a47f:ac:1::1353 AS1136
ns13.kpn.net 213.75.63.34 AS1136, 2a02:a47f:ac:1::1353 AS1136
ns3.kpn.net 194.151.228.42 AS1136, 2a02:a47f:ac:1::353 AS1136
aduroservice.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
aduroshop.dkcamilo.ns.cloudflare.com 108.162.195.118 AS13335, 162.159.44.118 AS13335, 172.64.35.118 AS13335, 2606:4700:58::a29f:2c76 AS13335, 2803:f800:50::6ca2:c376 AS13335, 2a06:98c1:50::ac40:2376 AS13335
delilah.ns.cloudflare.com 108.162.194.99 AS13335, 162.159.38.99 AS13335, 172.64.34.99 AS13335, 2606:4700:50::a29f:2663 AS13335, 2803:f800:50::6ca2:c263 AS13335, 2a06:98c1:50::ac40:2263 AS13335
adurosmart.dkns1.argewebhosting.eu 2a05:1500:702:0:1c00:eff:fe00:ce AS48635, 31.25.98.210 AS48635
ns2.argewebhosting.com 2a05:1500:702:0:1c00:13ff:fe00:a5 AS48635, 31.25.98.169 AS48635
ns3.argewebhosting.nl 92.63.168.137 AS48635
adus.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
adusum.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
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