🛡️ 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

1,183,657 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1490.01%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 IPv610,6840.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system758,17064.1%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,3597.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-04 17:29).

📋 One autonomous system

758,170 domains
DomainNameservers and addresses
abfhedeparken.dkcameron.ns.cloudflare.com 108.162.195.107 AS13335, 162.159.44.107 AS13335, 172.64.35.107 AS13335, 2606:4700:58::a29f:2c6b AS13335, 2803:f800:50::6ca2:c36b AS13335, 2a06:98c1:50::ac40:236b AS13335
serena.ns.cloudflare.com 108.162.192.220 AS13335, 172.64.32.220 AS13335, 173.245.58.220 AS13335, 2606:4700:50::adf5:3adc AS13335, 2803:f800:50::6ca2:c0dc AS13335, 2a06:98c1:50::ac40:20dc AS13335
abfherholtsvej.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
abfhåndbogen.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
abfiber.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
abfinance.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
abfinans.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
abfinfo.dkns-1463.awsdns-54.org 205.251.197.183 AS16509, 2600:9000:5305:b700::1 AS16509
ns-1597.awsdns-07.co.uk 205.251.198.61 AS16509, 2600:9000:5306:3d00::1 AS16509
ns-344.awsdns-43.com 205.251.193.88 AS16509, 2600:9000:5301:5800::1 AS16509
ns-853.awsdns-42.net 205.251.195.85 AS16509, 2600:9000:5303:5500::1 AS16509
abfjordgaarden.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
abfkh.dkns7.bricksite.net 35.246.226.10 AS396982
ns8.bricksite.net 35.242.190.82 AS396982
abflex.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
abflinne.dkns3.webhot.dk 178.72.21.249 AS3342
ns4.webhot.dk 178.72.21.250 AS3342
abflinnesgade.dkns13.manufrog.com 46.246.119.115 AS42708
ns14.manufrog.com 46.246.119.116 AS42708
ns23.manufrog.com 46.246.119.115 AS42708
ns24.manufrog.com 46.246.119.116 AS42708
abflo.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
abflow.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
abflunden.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
abfmail.dkmaxim.ns.cloudflare.com 108.162.195.198 AS13335, 162.159.44.198 AS13335, 172.64.35.198 AS13335, 2606:4700:58::a29f:2cc6 AS13335, 2803:f800:50::6ca2:c3c6 AS13335, 2a06:98c1:50::ac40:23c6 AS13335
ollie.ns.cloudflare.com 108.162.194.71 AS13335, 162.159.38.71 AS13335, 172.64.34.71 AS13335, 2606:4700:50::a29f:2647 AS13335, 2803:f800:50::6ca2:c247 AS13335, 2a06:98c1:50::ac40:2247 AS13335
abfn63.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
abfnyt.dkmaxim.ns.cloudflare.com 108.162.195.198 AS13335, 162.159.44.198 AS13335, 172.64.35.198 AS13335, 2606:4700:58::a29f:2cc6 AS13335, 2803:f800:50::6ca2:c3c6 AS13335, 2a06:98c1:50::ac40:23c6 AS13335
ollie.ns.cloudflare.com 108.162.194.71 AS13335, 162.159.38.71 AS13335, 172.64.34.71 AS13335, 2606:4700:50::a29f:2647 AS13335, 2803:f800:50::6ca2:c247 AS13335, 2a06:98c1:50::ac40:2247 AS13335
abfo.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
abfodbold.dkgabe.ns.cloudflare.com 108.162.193.114 AS13335, 172.64.33.114 AS13335, 173.245.59.114 AS13335, 2606:4700:58::adf5:3b72 AS13335, 2803:f800:50::6ca2:c172 AS13335, 2a06:98c1:50::ac40:2172 AS13335
sue.ns.cloudflare.com 108.162.192.145 AS13335, 172.64.32.145 AS13335, 173.245.58.145 AS13335, 2606:4700:50::adf5:3a91 AS13335, 2803:f800:50::6ca2:c091 AS13335, 2a06:98c1:50::ac40:2091 AS13335
abfoerstehjaelp.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
abfoodservice.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
abforbruger.dkns6.sitnet.dk 107.162.234.197 AS55002, 2604:e180:1071::3:1 AS55002
ns7.sitnet.dk 107.162.176.221 AS55002, 2604:e180:1071::ffff:6ba2:b0dd AS55002
abfoto2019.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
abfpersonale.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
abfraadgivning.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
abfremad.dkns1.arrownet.dk 62.61.130.2 AS15516
ns2.arrownet.dk 62.61.131.2 AS15516
abfskibet.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
abfsmedegaarden.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
abfsmedegården.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
abfsoendermarken.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
abfsolvejen.dkns7.bricksite.net 35.246.226.10 AS396982
ns8.bricksite.net 35.242.190.82 AS396982
abfsorringhus.dkns7.bricksite.net 35.246.226.10 AS396982
ns8.bricksite.net 35.242.190.82 AS396982
abfstiftelse.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
abfudsigten.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
abfvalgte.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
abfweb.dkmaxim.ns.cloudflare.com 108.162.195.198 AS13335, 162.159.44.198 AS13335, 172.64.35.198 AS13335, 2606:4700:58::a29f:2cc6 AS13335, 2803:f800:50::6ca2:c3c6 AS13335, 2a06:98c1:50::ac40:23c6 AS13335
ollie.ns.cloudflare.com 108.162.194.71 AS13335, 162.159.38.71 AS13335, 172.64.34.71 AS13335, 2606:4700:50::a29f:2647 AS13335, 2803:f800:50::6ca2:c247 AS13335, 2a06:98c1:50::ac40:2247 AS13335
abfys.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
abfysio.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
abførstehjælp.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
abg.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
abg27.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
abg32.dkns1.flexonet.dk 185.9.7.223 AS61397
ns2.flexonet.dk 185.9.7.224 AS61397
abgaerdet-1747.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
abgai.dkns1.misspark.com 162.159.24.173 AS13335, 2400:cb00:2049:1::a29f:18ad AS13335
ns2.misspark.com 162.159.25.99 AS13335, 2400:cb00:2049:1::a29f:1963 AS13335
ns3.misspark.com 162.159.25.16 AS13335, 2400:cb00:2049:1::a29f:1910 AS13335
ns4.misspark.com 162.159.24.87 AS13335, 2400:cb00:2049:1::a29f:1857 AS13335
abgalleri.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
abgaming.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
abgg.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
abgladbo.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
abgladsaxe.dkns1.mcb.dk 178.23.177.69 AS47527, 2a00:1cf0:0:9::69 AS47527
ns2.mcb.dk 195.182.36.51 AS47527, 2a00:1cf0:0:5::3 AS47527
ns3.mcb.dk 185.208.212.121 AS47527, 2a00:1b19:2:1::121 AS47527
dhd.dk [/] search Domains, Hosts & DNS — .dk zone