🛡️ 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

1,186,285 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 address1,3030.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,7740.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system758,93564.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,7527.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-01 14:22).

📋 One autonomous system

758,935 domains
DomainNameservers and addresses
59480480.dkns.vest.net 185.221.30.10 AS31027
ns2.vest.net 185.221.30.11 AS31027
59511500.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
59513132.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
59550055.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
59595992.dkgate.profdoc.dk 80.62.243.243 AS3292
ns.profdoc.dk 80.62.243.242 AS3292
59650013.dkgate.profdoc.dk 80.62.243.243 AS3292
ns.profdoc.dk 80.62.243.242 AS3292
59654500.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
599.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
59910257.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
59961026.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
59cadillac.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
59eldo.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
59eldorado.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
5ab.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
5aktproduktion.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
5alive.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
5am.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
5asa.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
5b.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
5bedste.dkdawn.ns.cloudflare.com 108.162.192.106 AS13335, 172.64.32.106 AS13335, 173.245.58.106 AS13335, 2606:4700:50::adf5:3a6a AS13335, 2803:f800:50::6ca2:c06a AS13335, 2a06:98c1:50::ac40:206a AS13335
will.ns.cloudflare.com 108.162.193.149 AS13335, 172.64.33.149 AS13335, 173.245.59.149 AS13335, 2606:4700:58::adf5:3b95 AS13335, 2803:f800:50::6ca2:c195 AS13335, 2a06:98c1:50::ac40:2195 AS13335
5bnb.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
5bogstaver.dkalbert.ns.cloudflare.com 108.162.193.58 AS13335, 172.64.33.58 AS13335, 173.245.59.58 AS13335, 2606:4700:58::adf5:3b3a AS13335, 2803:f800:50::6ca2:c13a AS13335, 2a06:98c1:50::ac40:213a AS13335
sarah.ns.cloudflare.com 108.162.194.218 AS13335, 162.159.38.218 AS13335, 172.64.34.218 AS13335, 2606:4700:50::a29f:26da AS13335, 2803:f800:50::6ca2:c2da AS13335, 2a06:98c1:50::ac40:22da AS13335
5brandt.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
5c-cns.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
5caroe.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
5cats.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
5chmidt.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
5coin.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
5consulting.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
5creative.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
5d.dkbeth.ns.cloudflare.com 108.162.192.103 AS13335, 172.64.32.103 AS13335, 173.245.58.103 AS13335, 2606:4700:50::adf5:3a67 AS13335, 2803:f800:50::6ca2:c067 AS13335, 2a06:98c1:50::ac40:2067 AS13335
jim.ns.cloudflare.com 108.162.193.125 AS13335, 172.64.33.125 AS13335, 173.245.59.125 AS13335, 2606:4700:58::adf5:3b7d AS13335, 2803:f800:50::6ca2:c17d AS13335, 2a06:98c1:50::ac40:217d AS13335
5daysdeo.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
5ddiamondpaint.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
henry.ns.cloudflare.com 108.162.193.176 AS13335, 172.64.33.176 AS13335, 173.245.59.176 AS13335, 2606:4700:58::adf5:3bb0 AS13335, 2803:f800:50::6ca2:c1b0 AS13335, 2a06:98c1:50::ac40:21b0 AS13335
5ddiamondpainting.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
5dperler.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
5e-byg.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
5ebyg.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
5emner.dkcortney.ns.cloudflare.com 108.162.192.87 AS13335, 172.64.32.87 AS13335, 173.245.58.87 AS13335, 2606:4700:50::adf5:3a57 AS13335, 2803:f800:50::6ca2:c057 AS13335, 2a06:98c1:50::ac40:2057 AS13335
eric.ns.cloudflare.com 108.162.193.112 AS13335, 172.64.33.112 AS13335, 173.245.59.112 AS13335, 2606:4700:58::adf5:3b70 AS13335, 2803:f800:50::6ca2:c170 AS13335, 2a06:98c1:50::ac40:2170 AS13335
5eren.dkeva.ns.cloudflare.com 108.162.192.114 AS13335, 172.64.32.114 AS13335, 173.245.58.114 AS13335, 2606:4700:50::adf5:3a72 AS13335, 2803:f800:50::6ca2:c072 AS13335, 2a06:98c1:50::ac40:2072 AS13335
jeff.ns.cloudflare.com 108.162.193.124 AS13335, 172.64.33.124 AS13335, 173.245.59.124 AS13335, 2606:4700:58::adf5:3b7c AS13335, 2803:f800:50::6ca2:c17c AS13335, 2a06:98c1:50::ac40:217c AS13335
5fag.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
5finger.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
5flyttetilbud.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
5fventilation.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
5g-internet.dkcoby.ns.cloudflare.com 108.162.193.92 AS13335, 172.64.33.92 AS13335, 173.245.59.92 AS13335, 2606:4700:58::adf5:3b5c AS13335, 2803:f800:50::6ca2:c15c AS13335, 2a06:98c1:50::ac40:215c AS13335
tia.ns.cloudflare.com 108.162.192.229 AS13335, 172.64.32.229 AS13335, 173.245.58.229 AS13335, 2606:4700:50::adf5:3ae5 AS13335, 2803:f800:50::6ca2:c0e5 AS13335, 2a06:98c1:50::ac40:20e5 AS13335
5g-nej-tak.dksneh.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
thomas.ns.cloudflare.com 108.162.193.238 AS13335, 172.64.33.238 AS13335, 173.245.59.238 AS13335, 2606:4700:58::adf5:3bee AS13335, 2803:f800:50::6ca2:c1ee AS13335, 2a06:98c1:50::ac40:21ee AS13335
5g-netvaerk.dkns-1432.awsdns-51.org 205.251.197.152 AS16509, 2600:9000:5305:9800::1 AS16509
ns-1832.awsdns-37.co.uk 205.251.199.40 AS16509, 2600:9000:5307:2800::1 AS16509
ns-423.awsdns-52.com 205.251.193.167 AS16509, 2600:9000:5301:a700::1 AS16509
ns-530.awsdns-02.net 205.251.194.18 AS16509, 2600:9000:5302:1200::1 AS16509
5g-netværk.dkns-1516.awsdns-61.org 205.251.197.236 AS16509, 2600:9000:5305:ec00::1 AS16509
ns-1891.awsdns-44.co.uk 205.251.199.99 AS16509, 2600:9000:5307:6300::1 AS16509
ns-281.awsdns-35.com 205.251.193.25 AS16509, 2600:9000:5301:1900::1 AS16509
ns-647.awsdns-16.net 205.251.194.135 AS16509, 2600:9000:5302:8700::1 AS16509
5g-router.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
5g-speed.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
5g.dkbayan.ns.cloudflare.com 108.162.193.72 AS13335, 172.64.33.72 AS13335, 173.245.59.72 AS13335, 2606:4700:58::adf5:3b48 AS13335, 2803:f800:50::6ca2:c148 AS13335, 2a06:98c1:50::ac40:2148 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
dhd.dk [/] search Domains, Hosts & DNS — .dk zone