🛡️ 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

1,185,859 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 address1,3060.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,7960.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system758,38264.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,8087.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-01 08:10).

📋 One autonomous system

758,382 domains
DomainNameservers and addresses
3wk.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
3wm.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
3words.dkemma.ns.cloudflare.com 108.162.192.112 AS13335, 172.64.32.112 AS13335, 173.245.58.112 AS13335, 2606:4700:50::adf5:3a70 AS13335, 2803:f800:50::6ca2:c070 AS13335, 2a06:98c1:50::ac40:2070 AS13335
gordon.ns.cloudflare.com 108.162.193.170 AS13335, 172.64.33.170 AS13335, 173.245.59.170 AS13335, 2606:4700:58::adf5:3baa AS13335, 2803:f800:50::6ca2:c1aa AS13335, 2a06:98c1:50::ac40:21aa AS13335
3x.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
3x1986.dkmatt.ns.cloudflare.com 108.162.193.131 AS13335, 172.64.33.131 AS13335, 173.245.59.131 AS13335, 2606:4700:58::adf5:3b83 AS13335, 2803:f800:50::6ca2:c183 AS13335, 2a06:98c1:50::ac40:2183 AS13335
roxy.ns.cloudflare.com 108.162.192.142 AS13335, 172.64.32.142 AS13335, 173.245.58.142 AS13335, 2606:4700:50::adf5:3a8e AS13335, 2803:f800:50::6ca2:c08e AS13335, 2a06:98c1:50::ac40:208e AS13335
3x3.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
3x34-fyn.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
3x34-odense.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
3x34.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
3x34logistik.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
3x44.dkns1.nli.dk 91.198.138.48 AS51167
ns2.nli.dk 91.198.138.254 AS51167
ns3.nli.dk 79.143.177.196 AS51167
3x4x.dkns1.safebrands.fr 193.227.117.17 AS1921, 2a04:2b00:14cc::17 AS1921
ns2.safebrands.eu 194.50.187.18 AS1921, 2a04:2b00:14dd::18 AS1921
ns3.safebrands.com 194.0.182.19 AS1921, 2a04:2b00:14ee::19 AS1921
ns4.safebrands.org 193.227.117.20 AS1921, 2a04:2b00:14cc::20 AS1921
ns5.safebrands.tech 194.50.187.21 AS1921, 2a04:2b00:14dd::21 AS1921
3x4xoney.dkns1.safebrands.fr 193.227.117.17 AS1921, 2a04:2b00:14cc::17 AS1921
ns2.safebrands.eu 194.50.187.18 AS1921, 2a04:2b00:14dd::18 AS1921
ns3.safebrands.com 194.0.182.19 AS1921, 2a04:2b00:14ee::19 AS1921
ns4.safebrands.org 193.227.117.20 AS1921, 2a04:2b00:14cc::20 AS1921
ns5.safebrands.tech 194.50.187.21 AS1921, 2a04:2b00:14dd::21 AS1921
3x5.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
3x50.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
3x53.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
3x65.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
3x7.dkmarlowe.ns.cloudflare.com 108.162.194.212 AS13335, 162.159.38.212 AS13335, 172.64.34.212 AS13335, 2606:4700:50::a29f:26d4 AS13335, 2803:f800:50::6ca2:c2d4 AS13335, 2a06:98c1:50::ac40:22d4 AS13335
tom.ns.cloudflare.com 108.162.193.147 AS13335, 172.64.33.147 AS13335, 173.245.59.147 AS13335, 2606:4700:58::adf5:3b93 AS13335, 2803:f800:50::6ca2:c193 AS13335, 2a06:98c1:50::ac40:2193 AS13335
3xa.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
3xandersen.dkmilan.ns.cloudflare.com 108.162.195.21 AS13335, 162.159.44.21 AS13335, 172.64.35.21 AS13335, 2606:4700:58::a29f:2c15 AS13335, 2803:f800:50::6ca2:c315 AS13335, 2a06:98c1:50::ac40:2315 AS13335
robin.ns.cloudflare.com 108.162.192.218 AS13335, 172.64.32.218 AS13335, 173.245.58.218 AS13335, 2606:4700:50::adf5:3ada AS13335, 2803:f800:50::6ca2:c0da AS13335, 2a06:98c1:50::ac40:20da AS13335
3xatk.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
3xbyg.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
3xc.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
3xchristensen.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78
ns2.simply.com 185.25.141.15, 2a02:2339:4006:101::4562:4562
ns3.simply.com 91.197.248.79
ns4.simply.com 91.197.248.80
3xchub.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
3xd.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
3xdev.dkdan.ns.cloudflare.com 108.162.193.108 AS13335, 172.64.33.108 AS13335, 173.245.59.108 AS13335, 2606:4700:58::adf5:3b6c AS13335, 2803:f800:50::6ca2:c16c AS13335, 2a06:98c1:50::ac40:216c AS13335
kayleigh.ns.cloudflare.com 108.162.194.92 AS13335, 162.159.38.92 AS13335, 172.64.34.92 AS13335, 2606:4700:50::a29f:265c AS13335, 2803:f800:50::6ca2:c25c AS13335, 2a06:98c1:50::ac40:225c AS13335
3xdoc.dkdan.ns.cloudflare.com 108.162.193.108 AS13335, 172.64.33.108 AS13335, 173.245.59.108 AS13335, 2606:4700:58::adf5:3b6c AS13335, 2803:f800:50::6ca2:c16c AS13335, 2a06:98c1:50::ac40:216c AS13335
kayleigh.ns.cloudflare.com 108.162.194.92 AS13335, 162.159.38.92 AS13335, 172.64.34.92 AS13335, 2606:4700:50::a29f:265c AS13335, 2803:f800:50::6ca2:c25c AS13335, 2a06:98c1:50::ac40:225c AS13335
3xe.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
3xfoto.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
3xfriis.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
3xh.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
3xhansen.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
3xhjul.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
3xj.dkns1.apollodns.dk 193.32.65.45 AS3292
ns2.apollodns.dk 193.32.65.46 AS3292
3xjadm.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
3xl.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
3xm.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
3xo.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
3xp.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
3xr.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
3xsorensen.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
3xu.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
3xv.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
3xw.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
3xwilhelmsen.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
3yhta.dkns1.nhl-data.dk 185.136.96.11 AS203391, 2a06:fb00:1::1:11 AS203391
ns2.nhl-data.dk 185.136.97.11 AS203391, 2a06:fb00:1::2:11 AS203391
ns3.nhl-data.dk 185.136.98.11 AS203391, 2a06:fb00:1::3:11 AS203391
ns4.nhl-data.dk 185.136.99.11 AS203391, 2a06:fb00:1::4:11 AS203391
3ykg1973.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
3z65.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
3z81.dkamit.ns.cloudflare.com 108.162.193.63 AS13335, 172.64.33.63 AS13335, 173.245.59.63 AS13335, 2606:4700:58::adf5:3b3f AS13335, 2803:f800:50::6ca2:c13f AS13335, 2a06:98c1:50::ac40:213f AS13335
naya.ns.cloudflare.com 108.162.194.242 AS13335, 162.159.38.242 AS13335, 172.64.34.242 AS13335, 2606:4700:50::a29f:26f2 AS13335, 2803:f800:50::6ca2:c2f2 AS13335, 2a06:98c1:50::ac40:22f2 AS13335
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