🛡️ 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

1,185,762 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1480.01%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 IPv610,8150.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system754,61263.6%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver86,0127.3%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-09-30 00:23).

📋 One autonomous system

754,612 domains
DomainNameservers and addresses
1848fond.dkns1.provi.dk 88.99.120.238 AS24940
ns2.provi.dk 94.130.170.39 AS24940
185.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
1855.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
18558213125.dkns1.mono.net 185.58.212.1 AS201595
ns2.mono.net 185.130.160.1 AS201595
ns3.mono.net 185.130.160.2 AS201595
1855cru.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
1856.dkns1.egdatainform.dk 185.154.242.113 AS48854
ns2.egdatainform.dk 185.154.242.112 AS48854
1857.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
1858.dkbella.ns.cloudflare.com 108.162.192.74 AS13335, 172.64.32.74 AS13335, 173.245.58.74 AS13335, 2606:4700:50::adf5:3a4a AS13335, 2803:f800:50::6ca2:c04a AS13335, 2a06:98c1:50::ac40:204a AS13335
mark.ns.cloudflare.com 108.162.193.130 AS13335, 172.64.33.130 AS13335, 173.245.59.130 AS13335, 2606:4700:58::adf5:3b82 AS13335, 2803:f800:50::6ca2:c182 AS13335, 2a06:98c1:50::ac40:2182 AS13335
186.dkheather.ns.cloudflare.com 108.162.192.161 AS13335, 172.64.32.161 AS13335, 173.245.58.161 AS13335, 2606:4700:50::adf5:3aa1 AS13335, 2803:f800:50::6ca2:c0a1 AS13335, 2a06:98c1:50::ac40:20a1 AS13335
vick.ns.cloudflare.com 108.162.193.244 AS13335, 172.64.33.244 AS13335, 173.245.59.244 AS13335, 2606:4700:58::adf5:3bf4 AS13335, 2803:f800:50::6ca2:c1f4 AS13335, 2a06:98c1:50::ac40:21f4 AS13335
1864.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
1864dage.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
1864live.dkns1.wordpress.com 198.181.116.9 AS2635, 2a04:fa87:ffff::c6b5:7409 AS2635
ns2.wordpress.com 198.181.117.9 AS2635, 2a04:fa87:ffff::c6b5:7509 AS2635
ns3.wordpress.com 192.0.74.9 AS2635, 2620:115:c00f::c000:4a09 AS2635
1866.dkns.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
1867.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
1872stormflod.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
187927.dkclark.ns.cloudflare.com 108.162.193.87 AS13335, 172.64.33.87 AS13335, 173.245.59.87 AS13335, 2606:4700:58::adf5:3b57 AS13335, 2803:f800:50::6ca2:c157 AS13335, 2a06:98c1:50::ac40:2157 AS13335
sandra.ns.cloudflare.com 108.162.194.34 AS13335, 162.159.38.34 AS13335, 172.64.34.34 AS13335, 2606:4700:50::a29f:2622 AS13335, 2803:f800:50::6ca2:c222 AS13335, 2a06:98c1:50::ac40:2222 AS13335
1881.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
1883.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
1885.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
1887consulting.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
1888.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
1889.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
188bet.dkns1.instradns.com 75.2.6.34 AS16509
ns2.instradns.com 75.2.85.37 AS16509
188sport.dkns1.instradns.com 75.2.6.34 AS16509
ns2.instradns.com 75.2.85.37 AS16509
ns3.instradns.com 99.83.188.20 AS16509
189.dkns1.obox.dk 195.189.130.1 AS62121
ns2.obox.dk 195.189.131.1 AS62121
1893hh.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
1894.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
1895.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
1899.dkns.powerserver2.net 184.154.193.210 AS32475
ns2.powerserver2.net 184.154.193.212 AS32475
18aars.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
18alkohol.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
18ars.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
18b.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
18hx.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
18juni.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
18maj.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
18maj2024.dkkia.ns.cloudflare.com 108.162.192.179 AS13335, 172.64.32.179 AS13335, 173.245.58.179 AS13335, 2606:4700:50::adf5:3ab3 AS13335, 2803:f800:50::6ca2:c0b3 AS13335, 2a06:98c1:50::ac40:20b3 AS13335
terin.ns.cloudflare.com 108.162.193.236 AS13335, 172.64.33.236 AS13335, 173.245.59.236 AS13335, 2606:4700:58::adf5:3bec AS13335, 2803:f800:50::6ca2:c1ec AS13335, 2a06:98c1:50::ac40:21ec AS13335
18nov.dkns2.wixdns.net 216.239.36.100 AS15169
ns3.wixdns.net 216.239.38.100 AS15169
18november.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
18tat.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
18tee.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
18års.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
19-71.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
19-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
19.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
190.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
1900al.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
1900am.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
1900gymnastik.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
1900mtb.dkganz.ns.cloudflare.com 108.162.195.40 AS13335, 162.159.44.40 AS13335, 172.64.35.40 AS13335, 2606:4700:58::a29f:2c28 AS13335, 2803:f800:50::6ca2:c328 AS13335, 2a06:98c1:50::ac40:2328 AS13335
melany.ns.cloudflare.com 108.162.194.138 AS13335, 162.159.38.138 AS13335, 172.64.34.138 AS13335, 2606:4700:50::a29f:268a AS13335, 2803:f800:50::6ca2:c28a AS13335, 2a06:98c1:50::ac40:228a AS13335
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