🛡️ 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
wittcare.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
ashton.ns.cloudflare.com 108.162.195.173 AS13335, 162.159.44.173 AS13335, 172.64.35.173 AS13335, 2606:4700:58::a29f:2cad AS13335, 2803:f800:50::6ca2:c3ad AS13335, 2a06:98c1:50::ac40:23ad AS13335
wittcarepro.dkanna.ns.cloudflare.com 108.162.192.102 AS13335, 172.64.32.102 AS13335, 173.245.58.102 AS13335, 2606:4700:50::adf5:3a66 AS13335, 2803:f800:50::6ca2:c066 AS13335, 2a06:98c1:50::ac40:2066 AS13335
jobs.ns.cloudflare.com 108.162.193.183 AS13335, 172.64.33.183 AS13335, 173.245.59.183 AS13335, 2606:4700:58::adf5:3bb7 AS13335, 2803:f800:50::6ca2:c1b7 AS13335, 2a06:98c1:50::ac40:21b7 AS13335
wittchen.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
wittclinic.dkanna.ns.cloudflare.com 108.162.192.102 AS13335, 172.64.32.102 AS13335, 173.245.58.102 AS13335, 2606:4700:50::adf5:3a66 AS13335, 2803:f800:50::6ca2:c066 AS13335, 2a06:98c1:50::ac40:2066 AS13335
jobs.ns.cloudflare.com 108.162.193.183 AS13335, 172.64.33.183 AS13335, 173.245.59.183 AS13335, 2606:4700:58::adf5:3bb7 AS13335, 2803:f800:50::6ca2:c1b7 AS13335, 2a06:98c1:50::ac40:21b7 AS13335
wittcofisk.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
wittcofiskogskaldyr.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
wittcosmetic.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
ashton.ns.cloudflare.com 108.162.195.173 AS13335, 162.159.44.173 AS13335, 172.64.35.173 AS13335, 2606:4700:58::a29f:2cad AS13335, 2803:f800:50::6ca2:c3ad AS13335, 2a06:98c1:50::ac40:23ad AS13335
wittcosmetics.dkanna.ns.cloudflare.com 108.162.192.102 AS13335, 172.64.32.102 AS13335, 173.245.58.102 AS13335, 2606:4700:50::adf5:3a66 AS13335, 2803:f800:50::6ca2:c066 AS13335, 2a06:98c1:50::ac40:2066 AS13335
jobs.ns.cloudflare.com 108.162.193.183 AS13335, 172.64.33.183 AS13335, 173.245.59.183 AS13335, 2606:4700:58::adf5:3bb7 AS13335, 2803:f800:50::6ca2:c1b7 AS13335, 2a06:98c1:50::ac40:21b7 AS13335
wittdesign.dkanna.ns.cloudflare.com 108.162.192.102 AS13335, 172.64.32.102 AS13335, 173.245.58.102 AS13335, 2606:4700:50::adf5:3a66 AS13335, 2803:f800:50::6ca2:c066 AS13335, 2a06:98c1:50::ac40:2066 AS13335
jobs.ns.cloudflare.com 108.162.193.183 AS13335, 172.64.33.183 AS13335, 173.245.59.183 AS13335, 2606:4700:58::adf5:3bb7 AS13335, 2803:f800:50::6ca2:c1b7 AS13335, 2a06:98c1:50::ac40:21b7 AS13335
witte-petersen.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
witte.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
witted.dkns-191-c.gandi.net 217.70.187.192 AS209453, 2604:3400:aaac::c0 AS209453
ns-209-a.gandi.net 173.246.100.210 AS209453, 2001:4b98:aaaa::d2 AS209453
ns-214-b.gandi.net 2001:4b98:aaab::d7 AS209453, 213.167.230.215 AS209453
wittekind.dkns.wannafind.dk 185.25.141.6 AS48854, 2a02:2339:4006:103:1c:3f6d:daba:dee AS48854
ns2.wannafind.dk 2a02:2339:1:104::daba:daa AS48854, 91.197.248.69 AS48854
witten.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
wittenberg.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
wittenborg-paulsen.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
wittenborn.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
wittenkamp.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
wittenskoreskole.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
wittenskøreskole.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
wittenstein.dkfish.ns.cloudflare.com 108.162.194.252 AS13335, 162.159.38.252 AS13335, 172.64.34.252 AS13335, 2606:4700:50::a29f:26fc AS13335, 2803:f800:50::6ca2:c2fc AS13335, 2a06:98c1:50::ac40:22fc AS13335
toby.ns.cloudflare.com 108.162.193.239 AS13335, 172.64.33.239 AS13335, 173.245.59.239 AS13335, 2606:4700:58::adf5:3bef AS13335, 2803:f800:50::6ca2:c1ef AS13335, 2a06:98c1:50::ac40:21ef AS13335
witteterapi.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
witthaus.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
witthoeft.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
witthoefts.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
witthoff.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
witthoft.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
wittig.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
zoe.ns.cloudflare.com 108.162.192.149 AS13335, 172.64.32.149 AS13335, 173.245.58.149 AS13335, 2606:4700:50::adf5:3a95 AS13335, 2803:f800:50::6ca2:c095 AS13335, 2a06:98c1:50::ac40:2095 AS13335
witting-ejendomme.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
witting.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
wittingdal.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
wittingejendomme.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
wittingfahlberg.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
wittinghoff.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
wittinginvest.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
wittjensen.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
wittklinik.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
ashton.ns.cloudflare.com 108.162.195.173 AS13335, 162.159.44.173 AS13335, 172.64.35.173 AS13335, 2606:4700:58::a29f:2cad AS13335, 2803:f800:50::6ca2:c3ad AS13335, 2a06:98c1:50::ac40:23ad AS13335
wittmail.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
wittmann.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
wittmax.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
wittmycook.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
ashton.ns.cloudflare.com 108.162.195.173 AS13335, 162.159.44.173 AS13335, 172.64.35.173 AS13335, 2606:4700:58::a29f:2cad AS13335, 2803:f800:50::6ca2:c3ad AS13335, 2a06:98c1:50::ac40:23ad AS13335
wittogco.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
wittoglarsen.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
wittomkring.dkns1.mono.net 185.58.212.1 AS201595
ns2.mono.net 185.130.160.1 AS201595
ns3.mono.net 185.130.160.2 AS201595
ns4.mono.net 185.58.212.2 AS201595
wittorff.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
wittrock-andersen.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
wittrog.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
wittrup-business.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
wittrup-el.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
wittrup-fisk.dkns.wannafind.dk 185.25.141.6 AS48854, 2a02:2339:4006:103:1c:3f6d:daba:dee AS48854
ns2.wannafind.dk 2a02:2339:1:104::daba:daa AS48854, 91.197.248.69 AS48854
dhd.dk [/] search Domains, Hosts & DNS — .dk zone