🛡️ 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

1,183,321 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1520.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3100.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6870.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,79364.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,3377.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-03 22:50).

📋 One autonomous system

757,793 domains
DomainNameservers and addresses
aapc.dkpeyton.ns.cloudflare.com 108.162.193.221 AS13335, 172.64.33.221 AS13335, 173.245.59.221 AS13335, 2606:4700:58::adf5:3bdd AS13335, 2803:f800:50::6ca2:c1dd AS13335, 2a06:98c1:50::ac40:21dd AS13335
samara.ns.cloudflare.com 108.162.194.160 AS13335, 162.159.38.160 AS13335, 172.64.34.160 AS13335, 2606:4700:50::a29f:26a0 AS13335, 2803:f800:50::6ca2:c2a0 AS13335, 2a06:98c1:50::ac40:22a0 AS13335
aapetersen.dkns1.dnsserver.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.dnsserver.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
aaphuset.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
aapi.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
aapkiawaz.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
aapkk.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
aaplus.dkns3.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
aaplusdata.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
aaplussolutions.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
aapo-app.dkns1.wannafind.dk 185.25.141.6 AS48854, 2a02:2339:4006:103:1c:3f6d:daba:dee AS48854
ns2.wannafind.dk 2a02:2339:1:104::daba:daa AS48854, 91.197.248.69 AS48854
aapo.dkaddilyn.ns.cloudflare.com 108.162.194.217 AS13335, 162.159.38.217 AS13335, 172.64.34.217 AS13335, 2606:4700:50::a29f:26d9 AS13335, 2803:f800:50::6ca2:c2d9 AS13335, 2a06:98c1:50::ac40:22d9 AS13335
doug.ns.cloudflare.com 108.162.193.159 AS13335, 172.64.33.159 AS13335, 173.245.59.159 AS13335, 2606:4700:58::adf5:3b9f AS13335, 2803:f800:50::6ca2:c19f AS13335, 2a06:98c1:50::ac40:219f AS13335
aapolering.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
aapost.dkns6.sitnet.dk 107.162.234.197 AS55002, 2604:e180:1071::3:1 AS55002
ns7.sitnet.dk 107.162.176.221 AS55002, 2604:e180:1071::ffff:6ba2:b0dd AS55002
aapoteket.dkns1.wannafind.dk 185.25.141.6 AS48854, 2a02:2339:4006:103:1c:3f6d:daba:dee AS48854
ns2.wannafind.dk 2a02:2339:1:104::daba:daa AS48854, 91.197.248.69 AS48854
aapromenaden.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
aapskole.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
aaqc.dkanirban.ns.cloudflare.com 108.162.193.64 AS13335, 172.64.33.64 AS13335, 173.245.59.64 AS13335, 2606:4700:58::adf5:3b40 AS13335, 2803:f800:50::6ca2:c140 AS13335, 2a06:98c1:50::ac40:2140 AS13335
sneh.ns.cloudflare.com 108.162.194.162 AS13335, 162.159.38.162 AS13335, 172.64.34.162 AS13335, 2606:4700:50::a29f:26a2 AS13335, 2803:f800:50::6ca2:c2a2 AS13335, 2a06:98c1:50::ac40:22a2 AS13335
aaquist-el.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
aaquist.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
aaquistaps.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
aar-facility.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
aar-lifte.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
aar-opbevaring.dkcurns01.dnsadmin.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
curns02.dnsadmin.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
aar-selfstorage.dkcurns01.dnsadmin.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
curns02.dnsadmin.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
aar.dklucy.ns.cloudflare.com 108.162.192.133 AS13335, 172.64.32.133 AS13335, 173.245.58.133 AS13335, 2606:4700:50::adf5:3a85 AS13335, 2803:f800:50::6ca2:c085 AS13335, 2a06:98c1:50::ac40:2085 AS13335
nikon.ns.cloudflare.com 108.162.195.176 AS13335, 162.159.44.176 AS13335, 172.64.35.176 AS13335, 2606:4700:58::a29f:2cb0 AS13335, 2803:f800:50::6ca2:c3b0 AS13335, 2a06:98c1:50::ac40:23b0 AS13335
aarbus.dkns10.dnsadmin.dk 208.94.148.4 AS16552, 2600:1800:10::1 AS16552
ns11.dns-admin.dk 208.80.124.4 AS16552, 2600:1801:11::1 AS16552
ns12.dnsadmin.dk 208.80.126.4 AS16552, 2600:1802:12::1 AS16552
ns13.dns-admin.dk 208.80.125.4 AS16552, 2600:1801:13::1 AS16552
ns14.dnsadmin.dk 208.80.127.4 AS16552, 2600:1802:14::1 AS16552
ns15.dns-admin.dk 208.94.149.4 AS16552, 2600:1800:15::1 AS16552
aarbyforsamlingshus.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
aarbyfritid.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
aarbykirke.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
aarcb.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
aarcfm.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
aardal.dkns1.bdm.microsoftonline.com 13.107.236.208 AS8075, 2603:1061:0:700::d0 AS8075
ns2.bdm.microsoftonline.com 150.171.21.208 AS8075, 2620:1ec:8ec:700::d0 AS8075
ns3.bdm.microsoftonline.com 204.14.183.208 AS8075, 2a01:111:4000:700::d0 AS8075
ns4.bdm.microsoftonline.com 208.84.5.208 AS8075, 2620:1ec:bda:700::d0 AS8075
aardassem.dklakas.ns.cloudflare.com 108.162.193.194 AS13335, 172.64.33.194 AS13335, 173.245.59.194 AS13335, 2606:4700:58::adf5:3bc2 AS13335, 2803:f800:50::6ca2:c1c2 AS13335, 2a06:98c1:50::ac40:21c2 AS13335
martha.ns.cloudflare.com 108.162.194.142 AS13335, 162.159.38.142 AS13335, 172.64.34.142 AS13335, 2606:4700:50::a29f:268e AS13335, 2803:f800:50::6ca2:c28e AS13335, 2a06:98c1:50::ac40:228e AS13335
aardestrup.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
aardevo.dkns-1348.awsdns-40.org 205.251.197.68 AS16509, 2600:9000:5305:4400::1 AS16509
ns-1838.awsdns-37.co.uk 205.251.199.46 AS16509, 2600:9000:5307:2e00::1 AS16509
ns-254.awsdns-31.com 205.251.192.254 AS16509, 2600:9000:5300:fe00::1 AS16509
ns-789.awsdns-34.net 205.251.195.21 AS16509, 2600:9000:5303:1500::1 AS16509
aardvark.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
aardwork.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
aareafkalkning.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
aareafkalkningslisten.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
aareahrenkiel.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
aaregionmidt.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
aaregionnordjylland.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
aaregnordsj.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
aarejser.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
aareknudecenter-kbh.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
aareknudecenterkbh.dkns4.wixdns.net 216.239.36.101 AS15169
ns5.wixdns.net 216.239.38.101 AS15169
aareknudeklinikken.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
aareknudeklinikkerne.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
aaren.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
aarenstrup.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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