🛡️ 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

1,183,327 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1530.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3090.11%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 system757,76764.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,3247.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-03 16:39).

📋 One autonomous system

757,767 domains
DomainNameservers and addresses
aalborg-autohjælp.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
aalborg-autoophug.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
aalborg-bb.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
aalborg-beachvolley.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
aalborg-begravelsesforretning.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
aalborg-bilpleje.dkalexia.ns.cloudflare.com 108.162.194.175 AS13335, 162.159.38.175 AS13335, 172.64.34.175 AS13335, 2606:4700:50::a29f:26af AS13335, 2803:f800:50::6ca2:c2af AS13335, 2a06:98c1:50::ac40:22af AS13335
trevor.ns.cloudflare.com 108.162.195.154 AS13335, 162.159.44.154 AS13335, 172.64.35.154 AS13335, 2606:4700:58::a29f:2c9a AS13335, 2803:f800:50::6ca2:c39a AS13335, 2a06:98c1:50::ac40:239a AS13335
aalborg-bilsyn.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
aalborg-blomster.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
aalborg-blomsterbutik.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
aalborg-blomsterhandler.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
aalborg-boligadministration.dkns1.123hotel.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.123hotel.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
aalborg-botox.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
aalborg-buket.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
aalborg-cement.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
aalborg-citycup.dkns1-cloud.triple-it.nl 192.174.68.126 AS1921, 2001:67c:1bc::126 AS1921
ns2-cloud.triple-it.nl 176.97.158.126 AS1921, 2001:67c:10b8::126 AS1921
aalborg-curling.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
aalborg-data.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
aalborg-depotrum.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
aalborg-diamant.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
aalborg-divers.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
aalborg-dronefoto.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
aalborg-elektriker.dkbowen.ns.cloudflare.com 108.162.195.83 AS13335, 162.159.44.83 AS13335, 172.64.35.83 AS13335, 2606:4700:58::a29f:2c53 AS13335, 2803:f800:50::6ca2:c353 AS13335, 2a06:98c1:50::ac40:2353 AS13335
magnolia.ns.cloudflare.com 108.162.194.214 AS13335, 162.159.38.214 AS13335, 172.64.34.214 AS13335, 2606:4700:50::a29f:26d6 AS13335, 2803:f800:50::6ca2:c2d6 AS13335, 2a06:98c1:50::ac40:22d6 AS13335
aalborg-elektro.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
aalborg-elservice.dkbarbara.ns.cloudflare.com 108.162.192.248 AS13335, 172.64.32.248 AS13335, 173.245.58.248 AS13335, 2606:4700:50::adf5:3af8 AS13335, 2803:f800:50::6ca2:c0f8 AS13335, 2a06:98c1:50::ac40:20f8 AS13335
justin.ns.cloudflare.com 108.162.193.187 AS13335, 172.64.33.187 AS13335, 173.245.59.187 AS13335, 2606:4700:58::adf5:3bbb AS13335, 2803:f800:50::6ca2:c1bb AS13335, 2a06:98c1:50::ac40:21bb AS13335
aalborg-engineering.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
aalborg-ergonomi.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
aalborg-erhvervscenter.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
aalborg-forsyning.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
aalborg-friskole.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
aalborg-furnished-apartments.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
aalborg-fys.dkrafe.ns.cloudflare.com 108.162.192.216 AS13335, 172.64.32.216 AS13335, 173.245.58.216 AS13335, 2606:4700:50::adf5:3ad8 AS13335, 2803:f800:50::6ca2:c0d8 AS13335, 2a06:98c1:50::ac40:20d8 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
aalborg-fysio.dkanderson.ns.cloudflare.com 108.162.195.177 AS13335, 162.159.44.177 AS13335, 172.64.35.177 AS13335, 2606:4700:58::a29f:2cb1 AS13335, 2803:f800:50::6ca2:c3b1 AS13335, 2a06:98c1:50::ac40:23b1 AS13335
stephane.ns.cloudflare.com 108.162.194.112 AS13335, 162.159.38.112 AS13335, 172.64.34.112 AS13335, 2606:4700:50::a29f:2670 AS13335, 2803:f800:50::6ca2:c270 AS13335, 2a06:98c1:50::ac40:2270 AS13335
aalborg-fysioterapeut.dkanderson.ns.cloudflare.com 108.162.195.177 AS13335, 162.159.44.177 AS13335, 172.64.35.177 AS13335, 2606:4700:58::a29f:2cb1 AS13335, 2803:f800:50::6ca2:c3b1 AS13335, 2a06:98c1:50::ac40:23b1 AS13335
stephane.ns.cloudflare.com 108.162.194.112 AS13335, 162.159.38.112 AS13335, 172.64.34.112 AS13335, 2606:4700:50::a29f:2670 AS13335, 2803:f800:50::6ca2:c270 AS13335, 2a06:98c1:50::ac40:2270 AS13335
aalborg-fysioterapeuten.dkanderson.ns.cloudflare.com 108.162.195.177 AS13335, 162.159.44.177 AS13335, 172.64.35.177 AS13335, 2606:4700:58::a29f:2cb1 AS13335, 2803:f800:50::6ca2:c3b1 AS13335, 2a06:98c1:50::ac40:23b1 AS13335
stephane.ns.cloudflare.com 108.162.194.112 AS13335, 162.159.38.112 AS13335, 172.64.34.112 AS13335, 2606:4700:50::a29f:2670 AS13335, 2803:f800:50::6ca2:c270 AS13335, 2a06:98c1:50::ac40:2270 AS13335
aalborg-fysioterapeuter.dkanderson.ns.cloudflare.com 108.162.195.177 AS13335, 162.159.44.177 AS13335, 172.64.35.177 AS13335, 2606:4700:58::a29f:2cb1 AS13335, 2803:f800:50::6ca2:c3b1 AS13335, 2a06:98c1:50::ac40:23b1 AS13335
stephane.ns.cloudflare.com 108.162.194.112 AS13335, 162.159.38.112 AS13335, 172.64.34.112 AS13335, 2606:4700:50::a29f:2670 AS13335, 2803:f800:50::6ca2:c270 AS13335, 2a06:98c1:50::ac40:2270 AS13335
aalborg-fysioterapeuterne.dkanderson.ns.cloudflare.com 108.162.195.177 AS13335, 162.159.44.177 AS13335, 172.64.35.177 AS13335, 2606:4700:58::a29f:2cb1 AS13335, 2803:f800:50::6ca2:c3b1 AS13335, 2a06:98c1:50::ac40:23b1 AS13335
stephane.ns.cloudflare.com 108.162.194.112 AS13335, 162.159.38.112 AS13335, 172.64.34.112 AS13335, 2606:4700:50::a29f:2670 AS13335, 2803:f800:50::6ca2:c270 AS13335, 2a06:98c1:50::ac40:2270 AS13335
aalborg-fysioterapi.dkanderson.ns.cloudflare.com 108.162.195.177 AS13335, 162.159.44.177 AS13335, 172.64.35.177 AS13335, 2606:4700:58::a29f:2cb1 AS13335, 2803:f800:50::6ca2:c3b1 AS13335, 2a06:98c1:50::ac40:23b1 AS13335
stephane.ns.cloudflare.com 108.162.194.112 AS13335, 162.159.38.112 AS13335, 172.64.34.112 AS13335, 2606:4700:50::a29f:2670 AS13335, 2803:f800:50::6ca2:c270 AS13335, 2a06:98c1:50::ac40:2270 AS13335
aalborg-gardiner-markiser.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
aalborg-gardiner.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
aalborg-glarmester.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
aalborg-gravidscanning.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
aalborg-grunde.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
aalborg-guiden.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
aalborg-gulvservice.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
aalborg-handyman.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
aalborg-hestepraksis.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
aalborg-hk.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
aalborg-hotel-apartments.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
aalborg-hotel.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
aalborg-hovedpineklinik.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
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