🛡️ 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

1,186,156 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 address1,3070.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,8010.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,81663.9%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,8847.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-01 01:58).

📋 One autonomous system

757,816 domains
DomainNameservers and addresses
3servicetilbud.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
3sfinans.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
3shape-dental.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
ns5.netnames.net 156.154.130.100 AS12008, 2610:a1:1022::100 AS12008
ns6.netnames.net 156.154.131.100 AS12008, 2610:a1:1023::100 AS12008
3shape.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
ns5.netnames.net 156.154.130.100 AS12008, 2610:a1:1022::100 AS12008
ns6.netnames.net 156.154.131.100 AS12008, 2610:a1:1023::100 AS12008
3shippingtilbud.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
3shop.dkdns1.cscdns.net 156.154.130.100 AS12008, 2610:a1:1022::100 AS12008
dns2.cscdns.net 156.154.131.100 AS12008, 2610:a1:1023::100 AS12008
3si.dkns1.aveo.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.aveo.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
3sider.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
3skiferietilbud.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
3skills.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
3skoennedage.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
3skrotbud.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
3skrotpriser.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
3skrottilbud.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
3skruerog1bolt.dkns1.dlx.dk 2a00:1b18:1337:1337::53 AS47527, 46.30.121.210 AS47527
ns2.dlx.dk 185.208.212.124 AS47527, 2a00:1b19:1337:1337::53 AS47527
3skypephone.dkns1-07.azure-dns.com 13.107.236.7 AS8075, 2603:1061:0:700::7 AS8075
ns2-07.azure-dns.net 150.171.21.7 AS8075, 2620:1ec:8ec:700::7 AS8075
ns3-07.azure-dns.org 204.14.183.7 AS8075, 2a01:111:4000:700::7 AS8075
ns4-07.azure-dns.info 208.84.5.7 AS8075, 2620:1ec:bda:700::7 AS8075
3smoney.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
3smågrise.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
3soekonomi.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
3speditionstilbud.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
3sst.dkara.ns.cloudflare.com 108.162.192.67 AS13335, 172.64.32.67 AS13335, 173.245.58.67 AS13335, 2606:4700:50::adf5:3a43 AS13335, 2803:f800:50::6ca2:c043 AS13335, 2a06:98c1:50::ac40:2043 AS13335
joel.ns.cloudflare.com 108.162.193.184 AS13335, 172.64.33.184 AS13335, 173.245.59.184 AS13335, 2606:4700:58::adf5:3bb8 AS13335, 2803:f800:50::6ca2:c1b8 AS13335, 2a06:98c1:50::ac40:21b8 AS13335
3star.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
3stepit-debitor.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
3stepit-kreditor.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
3stepit.dkns-fi.elisa.net 193.229.0.49 AS719, 2001:671:1::20 AS719
ns-se.elisa.net 2001:671:1::40 AS719, 62.248.254.2 AS719
3stepproduction.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
3stjernet.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
3striber.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
3svet.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
3søkonomi.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
3t-textil.dkelsa.ns.cloudflare.com 108.162.192.111 AS13335, 172.64.32.111 AS13335, 173.245.58.111 AS13335, 2606:4700:50::adf5:3a6f AS13335, 2803:f800:50::6ca2:c06f AS13335, 2a06:98c1:50::ac40:206f AS13335
rajeev.ns.cloudflare.com 108.162.193.224 AS13335, 172.64.33.224 AS13335, 173.245.59.224 AS13335, 2606:4700:58::adf5:3be0 AS13335, 2803:f800:50::6ca2:c1e0 AS13335, 2a06:98c1:50::ac40:21e0 AS13335
3t-tryk.dkelsa.ns.cloudflare.com 108.162.192.111 AS13335, 172.64.32.111 AS13335, 173.245.58.111 AS13335, 2606:4700:50::adf5:3a6f AS13335, 2803:f800:50::6ca2:c06f AS13335, 2a06:98c1:50::ac40:206f AS13335
rajeev.ns.cloudflare.com 108.162.193.224 AS13335, 172.64.33.224 AS13335, 173.245.59.224 AS13335, 2606:4700:58::adf5:3be0 AS13335, 2803:f800:50::6ca2:c1e0 AS13335, 2a06:98c1:50::ac40:21e0 AS13335
3t.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
3ta.dkkurt.ns.cloudflare.com 108.162.193.193 AS13335, 172.64.33.193 AS13335, 173.245.59.193 AS13335, 2606:4700:58::adf5:3bc1 AS13335, 2803:f800:50::6ca2:c1c1 AS13335, 2a06:98c1:50::ac40:21c1 AS13335
nadia.ns.cloudflare.com 108.162.192.207 AS13335, 172.64.32.207 AS13335, 173.245.58.207 AS13335, 2606:4700:50::adf5:3acf AS13335, 2803:f800:50::6ca2:c0cf AS13335, 2a06:98c1:50::ac40:20cf AS13335
3takterne.dkaustin.ns.cloudflare.com 108.162.193.70 AS13335, 172.64.33.70 AS13335, 173.245.59.70 AS13335, 2606:4700:58::adf5:3b46 AS13335, 2803:f800:50::6ca2:c146 AS13335, 2a06:98c1:50::ac40:2146 AS13335
hera.ns.cloudflare.com 108.162.192.162 AS13335, 172.64.32.162 AS13335, 173.245.58.162 AS13335, 2606:4700:50::adf5:3aa2 AS13335, 2803:f800:50::6ca2:c0a2 AS13335, 2a06:98c1:50::ac40:20a2 AS13335
3tal.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
3tandlaege.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
3tandlæge.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
3te.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
3teambuildingbud.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
3teambuildingtilbud.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
3tech-automation.dkkurt.ns.cloudflare.com 108.162.193.193 AS13335, 172.64.33.193 AS13335, 173.245.59.193 AS13335, 2606:4700:58::adf5:3bc1 AS13335, 2803:f800:50::6ca2:c1c1 AS13335, 2a06:98c1:50::ac40:21c1 AS13335
nadia.ns.cloudflare.com 108.162.192.207 AS13335, 172.64.32.207 AS13335, 173.245.58.207 AS13335, 2606:4700:50::adf5:3acf AS13335, 2803:f800:50::6ca2:c0cf AS13335, 2a06:98c1:50::ac40:20cf AS13335
3tech-group.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
3tech.dkkurt.ns.cloudflare.com 108.162.193.193 AS13335, 172.64.33.193 AS13335, 173.245.59.193 AS13335, 2606:4700:58::adf5:3bc1 AS13335, 2803:f800:50::6ca2:c1c1 AS13335, 2a06:98c1:50::ac40:21c1 AS13335
nadia.ns.cloudflare.com 108.162.192.207 AS13335, 172.64.32.207 AS13335, 173.245.58.207 AS13335, 2606:4700:50::adf5:3acf AS13335, 2803:f800:50::6ca2:c0cf AS13335, 2a06:98c1:50::ac40:20cf AS13335
3techgroup.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
3techrepair.dkdaisy.ns.cloudflare.com 108.162.192.90 AS13335, 172.64.32.90 AS13335, 173.245.58.90 AS13335, 2606:4700:50::adf5:3a5a AS13335, 2803:f800:50::6ca2:c05a AS13335, 2a06:98c1:50::ac40:205a 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
3teknik.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
3tf.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
3tg.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
3tgr.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
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