🛡️ 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

1,182,584 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 address1,3040.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6830.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,07664.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,2097.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-03 04:10).

📋 One autonomous system

757,076 domains
DomainNameservers and addresses
90909090.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
90920090.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
90920101.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
90920202.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
909mail.dkedns161.ultradns.biz 204.74.67.161 AS12008, 2610:a1:1015::2a1 AS12008
edns161.ultradns.com 2001:502:f3ff::2a1 AS12008, 204.74.66.161 AS12008
edns161.ultradns.net 204.74.110.161 AS12008, 2610:a1:1014::2a1 AS12008
edns161.ultradns.org 2001:502:4612::2a1 AS12008, 204.74.111.161 AS12008
90aarsfoedselsdag.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
90er-tøj.dkandronicus.ns.cloudflare.com 108.162.195.113 AS13335, 162.159.44.113 AS13335, 172.64.35.113 AS13335, 2606:4700:58::a29f:2c71 AS13335, 2803:f800:50::6ca2:c371 AS13335, 2a06:98c1:50::ac40:2371 AS13335
maleah.ns.cloudflare.com 108.162.194.118 AS13335, 162.159.38.118 AS13335, 172.64.34.118 AS13335, 2606:4700:50::a29f:2676 AS13335, 2803:f800:50::6ca2:c276 AS13335, 2a06:98c1:50::ac40:2276 AS13335
90erbiler.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
90erdiskoteket.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
90erdj.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
90ermusik.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
90erne.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
90erparty.dkns1.nordicnumber.com 91.198.138.46 AS51167
ns2.nordicnumber.com 91.198.138.47 AS51167
ns3.nordicnumber.com 213.136.93.70 AS51167
90min.dkcloe.ns.cloudflare.com 108.162.192.86 AS13335, 172.64.32.86 AS13335, 173.245.58.86 AS13335, 2606:4700:50::adf5:3a56 AS13335, 2803:f800:50::6ca2:c056 AS13335, 2a06:98c1:50::ac40:2056 AS13335
yisroel.ns.cloudflare.com 108.162.195.185 AS13335, 162.159.44.185 AS13335, 172.64.35.185 AS13335, 2606:4700:58::a29f:2cb9 AS13335, 2803:f800:50::6ca2:c3b9 AS13335, 2a06:98c1:50::ac40:23b9 AS13335
90minutter.dkcloe.ns.cloudflare.com 108.162.192.86 AS13335, 172.64.32.86 AS13335, 173.245.58.86 AS13335, 2606:4700:50::adf5:3a56 AS13335, 2803:f800:50::6ca2:c056 AS13335, 2a06:98c1:50::ac40:2056 AS13335
yisroel.ns.cloudflare.com 108.162.195.185 AS13335, 162.159.44.185 AS13335, 172.64.35.185 AS13335, 2606:4700:58::a29f:2cb9 AS13335, 2803:f800:50::6ca2:c3b9 AS13335, 2a06:98c1:50::ac40:23b9 AS13335
90p.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
90plus.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
90skids.dkns.hostpoint.ch 217.26.51.254 AS29097, 2a00:d70:0:b::d AS29097
ns2.hostpoint.ch 217.26.53.254 AS29097, 2a00:d70:0:b::1d AS29097
ns3.hostpoint.ch 217.26.60.250 AS29097, 2a00:d70:0:b::b AS29097
90årsfødselsdag.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
910.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
911as.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
911avisen.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
911casino.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
911sc.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
911teknik.dkns1-03.azure-dns.com 13.107.236.3 AS8075, 2603:1061:0:700::3 AS8075
ns2-03.azure-dns.net 150.171.21.3 AS8075, 2620:1ec:8ec:700::3 AS8075
ns3-03.azure-dns.org 204.14.183.3 AS8075, 2a01:111:4000:700::3 AS8075
ns4-03.azure-dns.info 208.84.5.3 AS8075, 2620:1ec:bda:700::3 AS8075
915.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
919.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
91929394.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
91x.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
9200.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
921.dkns1.linode.com 2600:14c0:6::2 AS21342, 92.123.94.2 AS21342
ns2.linode.com 2600:14c0:6::3 AS21342, 92.123.94.3 AS21342
ns3.linode.com 2600:14c0:7::3 AS21342, 92.123.95.3 AS21342
ns4.linode.com 2600:14c0:7::4 AS21342, 92.123.95.4 AS21342
ns5.linode.com 2600:14c0:7::2 AS21342, 92.123.95.2 AS21342
9210.dkcleo.ns.cloudflare.com 108.162.193.89 AS13335, 172.64.33.89 AS13335, 173.245.59.89 AS13335, 2606:4700:58::adf5:3b59 AS13335, 2803:f800:50::6ca2:c159 AS13335, 2a06:98c1:50::ac40:2159 AS13335
ursula.ns.cloudflare.com 108.162.194.191 AS13335, 162.159.38.191 AS13335, 172.64.34.191 AS13335, 2606:4700:50::a29f:26bf AS13335, 2803:f800:50::6ca2:c2bf AS13335, 2a06:98c1:50::ac40:22bf AS13335
922.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
9220-aalborg-koreskole.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
9220-aalborg-køreskole.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
9220.dkjerry.ns.cloudflare.com 108.162.193.182 AS13335, 172.64.33.182 AS13335, 173.245.59.182 AS13335, 2606:4700:58::adf5:3bb6 AS13335, 2803:f800:50::6ca2:c1b6 AS13335, 2a06:98c1:50::ac40:21b6 AS13335
nicole.ns.cloudflare.com 108.162.192.211 AS13335, 172.64.32.211 AS13335, 173.245.58.211 AS13335, 2606:4700:50::adf5:3ad3 AS13335, 2803:f800:50::6ca2:c0d3 AS13335, 2a06:98c1:50::ac40:20d3 AS13335
923.dkns-1458.awsdns-54.org 205.251.197.178 AS16509, 2600:9000:5305:b200::1 AS16509
ns-1758.awsdns-27.co.uk 205.251.198.222 AS16509, 2600:9000:5306:de00::1 AS16509
ns-439.awsdns-54.com 205.251.193.183 AS16509, 2600:9000:5301:b700::1 AS16509
ns-924.awsdns-51.net 205.251.195.156 AS16509, 2600:9000:5303:9c00::1 AS16509
9230.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
924.dkns-1061.awsdns-04.org 205.251.196.37 AS16509, 2600:9000:5304:2500::1 AS16509
ns-1609.awsdns-09.co.uk 205.251.198.73 AS16509, 2600:9000:5306:4900::1 AS16509
ns-383.awsdns-47.com 205.251.193.127 AS16509, 2600:9000:5301:7f00::1 AS16509
ns-720.awsdns-26.net 205.251.194.208 AS16509, 2600:9000:5302:d000::1 AS16509
9240.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
925.dkns-1182.awsdns-19.org 205.251.196.158 AS16509, 2600:9000:5304:9e00::1 AS16509
ns-2003.awsdns-58.co.uk 205.251.199.211 AS16509, 2600:9000:5307:d300::1 AS16509
ns-29.awsdns-03.com 205.251.192.29 AS16509, 2600:9000:5300:1d00::1 AS16509
ns-789.awsdns-34.net 205.251.195.21 AS16509, 2600:9000:5303:1500::1 AS16509
925craft.dkjosh.ns.cloudflare.com 108.162.193.126 AS13335, 172.64.33.126 AS13335, 173.245.59.126 AS13335, 2606:4700:58::adf5:3b7e AS13335, 2803:f800:50::6ca2:c17e AS13335, 2a06:98c1:50::ac40:217e AS13335
melissa.ns.cloudflare.com 108.162.192.199 AS13335, 172.64.32.199 AS13335, 173.245.58.199 AS13335, 2606:4700:50::adf5:3ac7 AS13335, 2803:f800:50::6ca2:c0c7 AS13335, 2a06:98c1:50::ac40:20c7 AS13335
926.dkns-1305.awsdns-35.org 205.251.197.25 AS16509, 2600:9000:5305:1900::1 AS16509
ns-158.awsdns-19.com 205.251.192.158 AS16509, 2600:9000:5300:9e00::1 AS16509
ns-1938.awsdns-50.co.uk 205.251.199.146 AS16509, 2600:9000:5307:9200::1 AS16509
ns-617.awsdns-13.net 205.251.194.105 AS16509, 2600:9000:5302:6900::1 AS16509
9260.dkns-1060.awsdns-04.org 205.251.196.36 AS16509, 2600:9000:5304:2400::1 AS16509
ns-1931.awsdns-49.co.uk 205.251.199.139 AS16509, 2600:9000:5307:8b00::1 AS16509
ns-374.awsdns-46.com 205.251.193.118 AS16509, 2600:9000:5301:7600::1 AS16509
ns-574.awsdns-07.net 205.251.194.62 AS16509, 2600:9000:5302:3e00::1 AS16509
9260gistrup.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
927.dkns-1048.awsdns-03.org 205.251.196.24 AS16509, 2600:9000:5304:1800::1 AS16509
ns-1878.awsdns-42.co.uk 205.251.199.86 AS16509, 2600:9000:5307:5600::1 AS16509
ns-220.awsdns-27.com 205.251.192.220 AS16509, 2600:9000:5300:dc00::1 AS16509
ns-943.awsdns-53.net 205.251.195.175 AS16509, 2600:9000:5303:af00::1 AS16509
9270.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
9280.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
9293.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
92c.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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