🛡️ 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

1,183,325 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 address1,3110.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6890.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,85464.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,3487.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-04 05:03).

📋 One autonomous system

757,854 domains
DomainNameservers and addresses
williamdemantfoundation.dkns1-04.azure-dns.com 13.107.236.4 AS8075, 2603:1061:0:700::4 AS8075
ns2-04.azure-dns.net 150.171.21.4 AS8075, 2620:1ec:8ec:700::4 AS8075
ns3-04.azure-dns.org 204.14.183.4 AS8075, 2a01:111:4000:700::4 AS8075
ns4-04.azure-dns.info 208.84.5.4 AS8075, 2620:1ec:bda:700::4 AS8075
williamdemantholding.dkns1-04.azure-dns.com 13.107.236.4 AS8075, 2603:1061:0:700::4 AS8075
ns2-04.azure-dns.net 150.171.21.4 AS8075, 2620:1ec:8ec:700::4 AS8075
ns3-04.azure-dns.org 204.14.183.4 AS8075, 2a01:111:4000:700::4 AS8075
ns4-04.azure-dns.info 208.84.5.4 AS8075, 2620:1ec:bda:700::4 AS8075
williamdemantinvest.dkns1-04.azure-dns.com 13.107.236.4 AS8075, 2603:1061:0:700::4 AS8075
ns2-04.azure-dns.net 150.171.21.4 AS8075, 2620:1ec:8ec:700::4 AS8075
ns3-04.azure-dns.org 204.14.183.4 AS8075, 2a01:111:4000:700::4 AS8075
ns4-04.azure-dns.info 208.84.5.4 AS8075, 2620:1ec:bda:700::4 AS8075
williamharder.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
williamhillcasino.dkdns1.p08.nsone.net 198.51.44.8 AS62597, 2620:4d:4000:6259:7:8:0:1 AS62597
dns2.p08.nsone.net 198.51.45.8 AS62597, 2a00:edc0:6259:7:8::2 AS62597
dns3.p08.nsone.net 198.51.44.72 AS62597, 2620:4d:4000:6259:7:8:0:3 AS62597
dns4.p08.nsone.net 198.51.45.72 AS62597, 2a00:edc0:6259:7:8::4 AS62597
williamhillodds.dknelly.ns.cloudflare.com 108.162.192.209 AS13335, 172.64.32.209 AS13335, 173.245.58.209 AS13335, 2606:4700:50::adf5:3ad1 AS13335, 2803:f800:50::6ca2:c0d1 AS13335, 2a06:98c1:50::ac40:20d1 AS13335
sevki.ns.cloudflare.com 108.162.195.164 AS13335, 162.159.44.164 AS13335, 172.64.35.164 AS13335, 2606:4700:58::a29f:2ca4 AS13335, 2803:f800:50::6ca2:c3a4 AS13335, 2a06:98c1:50::ac40:23a4 AS13335
williamhillplc.dkdns1.idp365.net 162.159.27.131 AS13335, 2400:cb00:2049:1::a29f:1b83 AS13335
dns2.idp365.net 162.159.48.3 AS13335, 2400:cb00:2049:1::a29f:3003 AS13335
dns3.idp365.net 162.159.49.254 AS13335, 2400:cb00:2049:1::a29f:31fe AS13335
williamhillpoker.dkdns1.idp365.net 162.159.27.131 AS13335, 2400:cb00:2049:1::a29f:1b83 AS13335
dns2.idp365.net 162.159.48.3 AS13335, 2400:cb00:2049:1::a29f:3003 AS13335
dns3.idp365.net 162.159.49.254 AS13335, 2400:cb00:2049:1::a29f:31fe AS13335
williamhillspil.dkjoyce.ns.cloudflare.com 108.162.194.14 AS13335, 162.159.38.14 AS13335, 172.64.34.14 AS13335, 2606:4700:50::a29f:260e AS13335, 2803:f800:50::6ca2:c20e AS13335, 2a06:98c1:50::ac40:220e 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
williamhusum.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
williaminvest.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
williamjensen.dkdemi.ns.cloudflare.com 108.162.192.95 AS13335, 172.64.32.95 AS13335, 173.245.58.95 AS13335, 2606:4700:50::adf5:3a5f AS13335, 2803:f800:50::6ca2:c05f AS13335, 2a06:98c1:50::ac40:205f AS13335
otto.ns.cloudflare.com 108.162.195.135 AS13335, 162.159.44.135 AS13335, 172.64.35.135 AS13335, 2606:4700:58::a29f:2c87 AS13335, 2803:f800:50::6ca2:c387 AS13335, 2a06:98c1:50::ac40:2387 AS13335
williamlarsen.dkmajor.ns.cloudflare.com 108.162.193.241 AS13335, 172.64.33.241 AS13335, 173.245.59.241 AS13335, 2606:4700:58::adf5:3bf1 AS13335, 2803:f800:50::6ca2:c1f1 AS13335, 2a06:98c1:50::ac40:21f1 AS13335
maria.ns.cloudflare.com 108.162.192.192 AS13335, 172.64.32.192 AS13335, 173.245.58.192 AS13335, 2606:4700:50::adf5:3ac0 AS13335, 2803:f800:50::6ca2:c0c0 AS13335, 2a06:98c1:50::ac40:20c0 AS13335
williamlaursen.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
williamleonard.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
williammagnus.dkaragorn.ns.cloudflare.com 108.162.193.67 AS13335, 172.64.33.67 AS13335, 173.245.59.67 AS13335, 2606:4700:58::adf5:3b43 AS13335, 2803:f800:50::6ca2:c143 AS13335, 2a06:98c1:50::ac40:2143 AS13335
bailey.ns.cloudflare.com 108.162.194.41 AS13335, 162.159.38.41 AS13335, 172.64.34.41 AS13335, 2606:4700:50::a29f:2629 AS13335, 2803:f800:50::6ca2:c229 AS13335, 2a06:98c1:50::ac40:2229 AS13335
williammcfeely.dkbrenna.ns.cloudflare.com 108.162.194.176 AS13335, 162.159.38.176 AS13335, 172.64.34.176 AS13335, 2606:4700:50::a29f:26b0 AS13335, 2803:f800:50::6ca2:c2b0 AS13335, 2a06:98c1:50::ac40:22b0 AS13335
garrett.ns.cloudflare.com 108.162.195.195 AS13335, 162.159.44.195 AS13335, 172.64.35.195 AS13335, 2606:4700:58::a29f:2cc3 AS13335, 2803:f800:50::6ca2:c3c3 AS13335, 2a06:98c1:50::ac40:23c3 AS13335
williamml.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
williammoller.dkns1.shellhost.dk 193.200.90.91 AS62121, 2001:67c:564::13 AS62121
ns2.shellhost.dk 193.200.91.90 AS62121, 2001:67c:564::12 AS62121
williammoore.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
williammortensen.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
williamn.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
williamnielsenogsøn.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
williamnoah.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
williamogathena.dkanna.ns.cloudflare.com 108.162.192.102 AS13335, 172.64.32.102 AS13335, 173.245.58.102 AS13335, 2606:4700:50::adf5:3a66 AS13335, 2803:f800:50::6ca2:c066 AS13335, 2a06:98c1:50::ac40:2066 AS13335
jeremy.ns.cloudflare.com 108.162.193.180 AS13335, 172.64.33.180 AS13335, 173.245.59.180 AS13335, 2606:4700:58::adf5:3bb4 AS13335, 2803:f800:50::6ca2:c1b4 AS13335, 2a06:98c1:50::ac40:21b4 AS13335
williamolesen.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
williampedersen.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
williamroest.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
williamroos.dkdaniella.ns.cloudflare.com 108.162.194.228 AS13335, 162.159.38.228 AS13335, 172.64.34.228 AS13335, 2606:4700:50::a29f:26e4 AS13335, 2803:f800:50::6ca2:c2e4 AS13335, 2a06:98c1:50::ac40:22e4 AS13335
rory.ns.cloudflare.com 108.162.195.166 AS13335, 162.159.44.166 AS13335, 172.64.35.166 AS13335, 2606:4700:58::a29f:2ca6 AS13335, 2803:f800:50::6ca2:c3a6 AS13335, 2a06:98c1:50::ac40:23a6 AS13335
williams-engineering.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
williams-sonoma.dkasgi101a004ib90.wsgc.com 45.45.130.100 AS17381
rkat1011910ib60.wsgc.com 45.45.129.100 AS17381
williams.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
williamsborg.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
williamsbutcherstable.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
williamschultz.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
williamsconsulting.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
williamsedb.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
ns3.azehosting.net 2a01:4f8:c17:6a6e::2 AS24940, 88.99.39.181 AS24940
williamsen.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
williamsf1.dkns1.netnames.net 156.154.130.100 AS12008, 2610:a1:1022::100 AS12008
ns2.netnames.net 156.154.131.100 AS12008, 2610:a1:1023::100 AS12008
williamshimmel.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
williamsillemann.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
williamskilte.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
williamskonfirmation.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
williamslego.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
ns3.azehosting.net 2a01:4f8:c17:6a6e::2 AS24940, 88.99.39.181 AS24940
williamsnmarketing.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
williamson.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
williamssyndrom.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
williamthogersen.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
williamtofthojwarrer.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
williamtolstrup.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
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