🛡️ 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

1,183,542 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 address1,3040.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6770.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system758,00864.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,4057.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-05 05:55).

📋 One autonomous system

758,008 domains
DomainNameservers and addresses
acceptcard.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
acceptcardjul.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
accepted.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
accepten.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
accepterditliv.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
acceptful.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
acceptio.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
acceptit.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
acceptlaan.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
acceptleasing.dkblair.ns.cloudflare.com 108.162.194.121 AS13335, 162.159.38.121 AS13335, 172.64.34.121 AS13335, 2606:4700:50::a29f:2679 AS13335, 2803:f800:50::6ca2:c279 AS13335, 2a06:98c1:50::ac40:2279 AS13335
frank.ns.cloudflare.com 108.162.193.166 AS13335, 172.64.33.166 AS13335, 173.245.59.166 AS13335, 2606:4700:58::adf5:3ba6 AS13335, 2803:f800:50::6ca2:c1a6 AS13335, 2a06:98c1:50::ac40:21a6 AS13335
accepto.dknikon.ns.cloudflare.com 108.162.195.176 AS13335, 162.159.44.176 AS13335, 172.64.35.176 AS13335, 2606:4700:58::a29f:2cb0 AS13335, 2803:f800:50::6ca2:c3b0 AS13335, 2a06:98c1:50::ac40:23b0 AS13335
tiffany.ns.cloudflare.com 108.162.194.60 AS13335, 162.159.38.60 AS13335, 172.64.34.60 AS13335, 2606:4700:50::a29f:263c AS13335, 2803:f800:50::6ca2:c23c AS13335, 2a06:98c1:50::ac40:223c AS13335
acceptogretning.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
accesia.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
access-atv.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
access-control.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
access-it.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
access-pr.dkns.domainteam.dk 87.238.248.151 AS198614
ns2.domainteam.dk 185.200.74.103 AS198614
access-privateequity.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
access-professionals.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
access-solution.dkmina.ns.cloudflare.com 108.162.194.251 AS13335, 162.159.38.251 AS13335, 172.64.34.251 AS13335, 2606:4700:50::a29f:26fb AS13335, 2803:f800:50::6ca2:c2fb AS13335, 2a06:98c1:50::ac40:22fb 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
access-solutions.dkmina.ns.cloudflare.com 108.162.194.251 AS13335, 162.159.38.251 AS13335, 172.64.34.251 AS13335, 2606:4700:50::a29f:26fb AS13335, 2803:f800:50::6ca2:c2fb AS13335, 2a06:98c1:50::ac40:22fb 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
access.dkns245.superhosting.bg 185.45.66.39 AS201200
ns246.superhosting.bg 185.45.67.39 AS201200
access2water.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
access4all.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
access4attics.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
accessafrica.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
accessaircharter.dkns.datacenter.no 185.7.60.115 AS39783
ns2.datacenter.no 91.192.220.132 AS39783
accessatv.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
accessbars.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
accessclient.dkns-1020.awsdns-63.net 205.251.195.252 AS16509, 2600:9000:5303:fc00::1 AS16509
ns-1301.awsdns-34.org 205.251.197.21 AS16509, 2600:9000:5305:1500::1 AS16509
ns-1633.awsdns-12.co.uk 205.251.198.97 AS16509, 2600:9000:5306:6100::1 AS16509
ns-375.awsdns-46.com 205.251.193.119 AS16509, 2600:9000:5301:7700::1 AS16509
accessconsult.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
accesscontrol.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
accesscreed.dkdns100.ovh.net 2001:41d0:d00:fa00::2 AS16276, 5.135.250.177 AS16276
ns100.ovh.net 2001:41d0:b00:f400::2 AS16276, 5.135.44.185 AS16276
accessdata.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
accessdemo.dkpdns77.ultradns.biz 156.154.66.77 AS12008, 2610:a1:1015::71 AS12008
pdns77.ultradns.com 156.154.64.77 AS12008, 2001:502:f3ff::71 AS12008
pdns77.ultradns.net 156.154.65.77 AS12008, 2610:a1:1014::71 AS12008
pdns77.ultradns.org 156.154.67.77 AS12008, 2001:502:4612::71 AS12008
accessdenmark.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
accessforum.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
accessfoto.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
accesshero.dkcora.ns.cloudflare.com 108.162.194.195 AS13335, 162.159.38.195 AS13335, 172.64.34.195 AS13335, 2606:4700:50::a29f:26c3 AS13335, 2803:f800:50::6ca2:c2c3 AS13335, 2a06:98c1:50::ac40:22c3 AS13335
jaime.ns.cloudflare.com 108.162.195.102 AS13335, 162.159.44.102 AS13335, 172.64.35.102 AS13335, 2606:4700:58::a29f:2c66 AS13335, 2803:f800:50::6ca2:c366 AS13335, 2a06:98c1:50::ac40:2366 AS13335
accessibility.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
accessible.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
accessid.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
accessinvest.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
accessiway.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
accesskursus.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
accessmanager.dkns-1188.awsdns-20.org 205.251.196.164 AS16509, 2600:9000:5304:a400::1 AS16509
ns-1989.awsdns-56.co.uk 205.251.199.197 AS16509, 2600:9000:5307:c500::1 AS16509
ns-434.awsdns-54.com 205.251.193.178 AS16509, 2600:9000:5301:b200::1 AS16509
ns-920.awsdns-51.net 205.251.195.152 AS16509, 2600:9000:5303:9800::1 AS16509
accessmassage.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
accessoirecheveux.dkns-111-a.gandi.net 173.246.100.112 AS209453, 2001:4b98:aaaa::70 AS209453
ns-162-b.gandi.net 2001:4b98:aaab::a3 AS209453, 213.167.230.163 AS209453
ns-177-c.gandi.net 217.70.187.178 AS209453, 2604:3400:aaac::b2 AS209453
accessoires.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
accessone.dkgrannbo.ns.cloudflare.com 108.162.194.150 AS13335, 162.159.38.150 AS13335, 172.64.34.150 AS13335, 2606:4700:50::a29f:2696 AS13335, 2803:f800:50::6ca2:c296 AS13335, 2a06:98c1:50::ac40:2296 AS13335
sean.ns.cloudflare.com 108.162.193.231 AS13335, 172.64.33.231 AS13335, 173.245.59.231 AS13335, 2606:4700:58::adf5:3be7 AS13335, 2803:f800:50::6ca2:c1e7 AS13335, 2a06:98c1:50::ac40:21e7 AS13335
dhd.dk [/] search Domains, Hosts & DNS — .dk zone