🛡️ 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

1,183,339 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1460.01%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 IPv610,6840.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,75064.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,1697.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-06 00:32).

📋 One autonomous system

757,750 domains
DomainNameservers and addresses
agurat.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
agurka.dkns.datacenter.no 185.7.60.115 AS39783
ns2.datacenter.no 91.192.220.132 AS39783
agurkeplanter.dknoel.ns.cloudflare.com 108.162.193.216 AS13335, 172.64.33.216 AS13335, 173.245.59.216 AS13335, 2606:4700:58::adf5:3bd8 AS13335, 2803:f800:50::6ca2:c1d8 AS13335, 2a06:98c1:50::ac40:21d8 AS13335
ulla.ns.cloudflare.com 108.162.192.233 AS13335, 172.64.32.233 AS13335, 173.245.58.233 AS13335, 2606:4700:50::adf5:3ae9 AS13335, 2803:f800:50::6ca2:c0e9 AS13335, 2a06:98c1:50::ac40:20e9 AS13335
agurketid.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
agurketider.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
aguro.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
agus.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
agusta.dknoel.ns.cloudflare.com 108.162.193.216 AS13335, 172.64.33.216 AS13335, 173.245.59.216 AS13335, 2606:4700:58::adf5:3bd8 AS13335, 2803:f800:50::6ca2:c1d8 AS13335, 2a06:98c1:50::ac40:21d8 AS13335
ulla.ns.cloudflare.com 108.162.192.233 AS13335, 172.64.32.233 AS13335, 173.245.58.233 AS13335, 2606:4700:50::adf5:3ae9 AS13335, 2803:f800:50::6ca2:c0e9 AS13335, 2a06:98c1:50::ac40:20e9 AS13335
agustson.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
agustsson.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
agv-scandinavia.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
agv10.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
agvarmeteknik.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
agvscandinavia.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
agvvsteknik.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
agwa.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
agweb.dkgiancarlo.ns.cloudflare.com 108.162.195.5 AS13335, 162.159.44.5 AS13335, 172.64.35.5 AS13335, 2606:4700:58::a29f:2c05 AS13335, 2803:f800:50::6ca2:c305 AS13335, 2a06:98c1:50::ac40:2305 AS13335
lila.ns.cloudflare.com 108.162.192.186 AS13335, 172.64.32.186 AS13335, 173.245.58.186 AS13335, 2606:4700:50::adf5:3aba AS13335, 2803:f800:50::6ca2:c0ba AS13335, 2a06:98c1:50::ac40:20ba AS13335
agx-byg.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
agx-lab.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
agx-nordic.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
agx-shop.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
agxtend.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
agy.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
dan.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
ah-a.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
ah-arbejdsmiljo.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
ah-auto.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
ah-design.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
ah-digital.dkns1.creoble.dk 35.197.225.59 AS396982
ns2.creoble.dk 146.148.28.88 AS396982
ns3.creoble.dk 35.198.79.191 AS396982
ns4.creoble.dk 104.196.137.209 AS396982
ah-dk.dkns1.ecidns.net 162.159.2.142 AS13335, 2400:cb00:2049:1::a29f:28e AS13335
ns2.ecidns.net 162.159.3.110 AS13335, 2400:cb00:2049:1::a29f:36e AS13335
ns3.ecidns.net 162.159.4.47 AS13335, 2400:cb00:2049:1::a29f:42f AS13335
ns4.ecidns.net 162.159.5.14 AS13335, 2400:cb00:2049:1::a29f:50e AS13335
ah-e.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
ah-ejendomsservice.dkgabriella.ns.cloudflare.com 108.162.194.134 AS13335, 162.159.38.134 AS13335, 172.64.34.134 AS13335, 2606:4700:50::a29f:2686 AS13335, 2803:f800:50::6ca2:c286 AS13335, 2a06:98c1:50::ac40:2286 AS13335
mitch.ns.cloudflare.com 108.162.193.208 AS13335, 172.64.33.208 AS13335, 173.245.59.208 AS13335, 2606:4700:58::adf5:3bd0 AS13335, 2803:f800:50::6ca2:c1d0 AS13335, 2a06:98c1:50::ac40:21d0 AS13335
ah-el.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
ah-energi.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
ah-engros.dkaisha.ns.cloudflare.com 108.162.194.186 AS13335, 162.159.38.186 AS13335, 172.64.34.186 AS13335, 2606:4700:50::a29f:26ba AS13335, 2803:f800:50::6ca2:c2ba AS13335, 2a06:98c1:50::ac40:22ba AS13335
albert.ns.cloudflare.com 108.162.193.58 AS13335, 172.64.33.58 AS13335, 173.245.59.58 AS13335, 2606:4700:58::adf5:3b3a AS13335, 2803:f800:50::6ca2:c13a AS13335, 2a06:98c1:50::ac40:213a AS13335
ah-es.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
ah-gardiner.dkns1.d-n-s.dk 185.215.92.135 AS209959
ns2.d-n-s.dk 185.215.92.136 AS209959
ns3.d-n-s.dk 185.215.92.137 AS209959
ns4.d-n-s.dk 185.215.92.138 AS209959
ns5.d-n-s.dk 185.215.92.139 AS209959
ah-globusbarer.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
ah-group.dkns01.dansknet.dk 85.233.224.58 AS35158
ns02.dansknet.dk 85.233.225.242 AS35158
ah-gruppen.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
ah-h.dkns1-08.azure-dns.com 13.107.236.8 AS8075, 2603:1061:0:700::8 AS8075
ns2-08.azure-dns.net 150.171.21.8 AS8075, 2620:1ec:8ec:700::8 AS8075
ns3-08.azure-dns.org 204.14.183.8 AS8075, 2a01:111:4000:700::8 AS8075
ns4-08.azure-dns.info 208.84.5.8 AS8075, 2620:1ec:bda:700::8 AS8075
ah-hjelm.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
ah-hundesalon.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
ah-industries.dkalla.ns.cloudflare.com 108.162.192.62 AS13335, 172.64.32.62 AS13335, 173.245.58.62 AS13335, 2606:4700:50::adf5:3a3e AS13335, 2803:f800:50::6ca2:c03e AS13335, 2a06:98c1:50::ac40:203e AS13335
sullivan.ns.cloudflare.com 108.162.195.161 AS13335, 162.159.44.161 AS13335, 172.64.35.161 AS13335, 2606:4700:58::a29f:2ca1 AS13335, 2803:f800:50::6ca2:c3a1 AS13335, 2a06:98c1:50::ac40:23a1 AS13335
ah-info.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
ah-l.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
ah-laase.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
wesley.ns.cloudflare.com 108.162.193.246 AS13335, 172.64.33.246 AS13335, 173.245.59.246 AS13335, 2606:4700:58::adf5:3bf6 AS13335, 2803:f800:50::6ca2:c1f6 AS13335, 2a06:98c1:50::ac40:21f6 AS13335
ah-laasemontage.dkns-102-b.gandi.net 2001:4b98:aaab::67 AS209453, 213.167.230.103 AS209453
ns-244-a.gandi.net 173.246.100.245 AS209453, 2001:4b98:aaaa::f5 AS209453
ns-64-c.gandi.net 217.70.187.65 AS209453, 2604:3400:aaac::41 AS209453
ah-marketing.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
ah-mc.dkns-1089.awsdns-08.org 205.251.196.65 AS16509, 2600:9000:5304:4100::1 AS16509
ns-2018.awsdns-60.co.uk 205.251.199.226 AS16509, 2600:9000:5307:e200::1 AS16509
ns-311.awsdns-38.com 205.251.193.55 AS16509, 2600:9000:5301:3700::1 AS16509
ns-663.awsdns-18.net 205.251.194.151 AS16509, 2600:9000:5302:9700::1 AS16509
ah-modegarn.dkns1.simpleagencygroup.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.simpleagencygroup.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
dhd.dk [/] search Domains, Hosts & DNS — .dk zone