🛡️ 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
willemoes-rejser.dkns.domainteam.dk 87.238.248.151 AS198614
ns2.domainteam.dk 185.200.74.103 AS198614
willemoes.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
willemoesbryghus.dkabby.ns.cloudflare.com 108.162.192.100 AS13335, 172.64.32.100 AS13335, 173.245.58.100 AS13335, 2606:4700:50::adf5:3a64 AS13335, 2803:f800:50::6ca2:c064 AS13335, 2a06:98c1:50::ac40:2064 AS13335
darl.ns.cloudflare.com 108.162.193.98 AS13335, 172.64.33.98 AS13335, 173.245.59.98 AS13335, 2606:4700:58::adf5:3b62 AS13335, 2803:f800:50::6ca2:c162 AS13335, 2a06:98c1:50::ac40:2162 AS13335
willemoesholding.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
willemoeskarreen.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
willemoesvej.dkmaya.ns.cloudflare.com 108.162.192.194 AS13335, 172.64.32.194 AS13335, 173.245.58.194 AS13335, 2606:4700:50::adf5:3ac2 AS13335, 2803:f800:50::6ca2:c0c2 AS13335, 2a06:98c1:50::ac40:20c2 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
willems-fotografi.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
willems-kristiansen.dkabby.ns.cloudflare.com 108.162.192.100 AS13335, 172.64.32.100 AS13335, 173.245.58.100 AS13335, 2606:4700:50::adf5:3a64 AS13335, 2803:f800:50::6ca2:c064 AS13335, 2a06:98c1:50::ac40:2064 AS13335
hank.ns.cloudflare.com 108.162.193.116 AS13335, 172.64.33.116 AS13335, 173.245.59.116 AS13335, 2606:4700:58::adf5:3b74 AS13335, 2803:f800:50::6ca2:c174 AS13335, 2a06:98c1:50::ac40:2174 AS13335
willems.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
willemund.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
willendrup.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
willenlund.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
willer-erhvervspsykologi.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
willer-hansen.dkns1.siteground.net 75.2.77.104 AS16509
ns2.siteground.net 99.83.229.113 AS16509
willer.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
willerhuset.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
willert.dkjade.ns.cloudflare.com 108.162.192.167 AS13335, 172.64.32.167 AS13335, 173.245.58.167 AS13335, 2606:4700:50::adf5:3aa7 AS13335, 2803:f800:50::6ca2:c0a7 AS13335, 2a06:98c1:50::ac40:20a7 AS13335
simon.ns.cloudflare.com 108.162.193.232 AS13335, 172.64.33.232 AS13335, 173.245.59.232 AS13335, 2606:4700:58::adf5:3be8 AS13335, 2803:f800:50::6ca2:c1e8 AS13335, 2a06:98c1:50::ac40:21e8 AS13335
willertrafik.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
willerup.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
willes.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
willesen.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
willeshave.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
willey.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
willflo.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
willfreeman.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
william-co.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
william-demant.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
william-hill.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
william-jensen.dkns1.inihost.dk 87.48.171.11 AS3292
ns2.inihost.dk 87.48.171.13 AS3292
william-overgaard.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
william-p.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
william-skilte.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
william1372.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
williamalberg.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
williamalken.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
williamatak.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
ethan.ns.cloudflare.com 108.162.195.232 AS13335, 162.159.44.232 AS13335, 172.64.35.232 AS13335, 2606:4700:58::a29f:2ce8 AS13335, 2803:f800:50::6ca2:c3e8 AS13335, 2a06:98c1:50::ac40:23e8 AS13335
williambach.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
williambachgislinge.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
williambaird.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
williambaxter.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
williambeck.dkns4.wixdns.net 216.239.36.101 AS15169
ns5.wixdns.net 216.239.38.101 AS15169
williambeier.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
williambenzin.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
williambjensen.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
williambo.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
williamboutrup.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
williamd.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
williamdam.dkanton.ns.cloudflare.com 108.162.195.175 AS13335, 162.159.44.175 AS13335, 172.64.35.175 AS13335, 2606:4700:58::a29f:2caf AS13335, 2803:f800:50::6ca2:c3af AS13335, 2a06:98c1:50::ac40:23af AS13335
chin.ns.cloudflare.com 108.162.192.84 AS13335, 172.64.32.84 AS13335, 173.245.58.84 AS13335, 2606:4700:50::adf5:3a54 AS13335, 2803:f800:50::6ca2:c054 AS13335, 2a06:98c1:50::ac40:2054 AS13335
williamdemant.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
williamdemantfonden.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
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