🛡️ 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
wittrup-marin.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
wittrup-motel.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
wittrup-seafood.dkkonnor.ns.cloudflare.com 108.162.195.106 AS13335, 162.159.44.106 AS13335, 172.64.35.106 AS13335, 2606:4700:58::a29f:2c6a AS13335, 2803:f800:50::6ca2:c36a AS13335, 2a06:98c1:50::ac40:236a AS13335
mary.ns.cloudflare.com 108.162.192.134 AS13335, 172.64.32.134 AS13335, 173.245.58.134 AS13335, 2606:4700:50::adf5:3a86 AS13335, 2803:f800:50::6ca2:c086 AS13335, 2a06:98c1:50::ac40:2086 AS13335
wittrup-willumsen.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
wittrupfoto.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
wittruphestefys.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
wittrupmail.dkns1.wwi.dk 208.94.148.4 AS16552, 2600:1800:10::1 AS16552
ns2.wwi.dk 208.80.124.4 AS16552, 2600:1801:11::1 AS16552
ns3.wwi.as 208.80.126.4 AS16552, 2600:1802:12::1 AS16552
ns4.wwi.eu 208.80.125.4 AS16552, 2600:1801:13::1 AS16552
wittrupmotel.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
wittrupregnskab.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
wittruprokkedal.dkned.ns.cloudflare.com 108.162.193.210 AS13335, 172.64.33.210 AS13335, 173.245.59.210 AS13335, 2606:4700:58::adf5:3bd2 AS13335, 2803:f800:50::6ca2:c1d2 AS13335, 2a06:98c1:50::ac40:21d2 AS13335
tegan.ns.cloudflare.com 108.162.192.226 AS13335, 172.64.32.226 AS13335, 173.245.58.226 AS13335, 2606:4700:50::adf5:3ae2 AS13335, 2803:f800:50::6ca2:c0e2 AS13335, 2a06:98c1:50::ac40:20e2 AS13335
wittrupsgarage.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
wittrupshus.dkalan.ns.cloudflare.com 108.162.193.57 AS13335, 172.64.33.57 AS13335, 173.245.59.57 AS13335, 2606:4700:58::adf5:3b39 AS13335, 2803:f800:50::6ca2:c139 AS13335, 2a06:98c1:50::ac40:2139 AS13335
naya.ns.cloudflare.com 108.162.194.242 AS13335, 162.159.38.242 AS13335, 172.64.34.242 AS13335, 2606:4700:50::a29f:26f2 AS13335, 2803:f800:50::6ca2:c2f2 AS13335, 2a06:98c1:50::ac40:22f2 AS13335
witts.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
wittservice.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
wittshop.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
wittsport.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
wittstudio.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
witttandlægeklinik.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
wittur.dkns1-09.azure-dns.com 13.107.236.9 AS8075, 2603:1061:0:700::9 AS8075
ns2-09.azure-dns.net 150.171.21.9 AS8075, 2620:1ec:8ec:700::9 AS8075
ns3-09.azure-dns.org 204.14.183.9 AS8075, 2a01:111:4000:700::9 AS8075
ns4-09.azure-dns.info 208.84.5.9 AS8075, 2620:1ec:bda:700::9 AS8075
wittus-data.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
wittvvs.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
wittware.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
wittyknit.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
witus.dkns1.wordpress.com 198.181.116.9 AS2635, 2a04:fa87:ffff::c6b5:7409 AS2635
ns2.wordpress.com 198.181.117.9 AS2635, 2a04:fa87:ffff::c6b5:7509 AS2635
ns3.wordpress.com 192.0.74.9 AS2635, 2620:115:c00f::c000:4a09 AS2635
witx.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
witya.dkelmo.ns.cloudflare.com 108.162.193.163 AS13335, 172.64.33.163 AS13335, 173.245.59.163 AS13335, 2606:4700:58::adf5:3ba3 AS13335, 2803:f800:50::6ca2:c1a3 AS13335, 2a06:98c1:50::ac40:21a3 AS13335
kim.ns.cloudflare.com 108.162.192.126 AS13335, 172.64.32.126 AS13335, 173.245.58.126 AS13335, 2606:4700:50::adf5:3a7e AS13335, 2803:f800:50::6ca2:c07e AS13335, 2a06:98c1:50::ac40:207e AS13335
witzansky.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
witzel.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
witzelhobby.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
witzelhorsecare.dkanuj.ns.cloudflare.com 108.162.193.65 AS13335, 172.64.33.65 AS13335, 173.245.59.65 AS13335, 2606:4700:58::adf5:3b41 AS13335, 2803:f800:50::6ca2:c141 AS13335, 2a06:98c1:50::ac40:2141 AS13335
yolanda.ns.cloudflare.com 108.162.192.241 AS13335, 172.64.32.241 AS13335, 173.245.58.241 AS13335, 2606:4700:50::adf5:3af1 AS13335, 2803:f800:50::6ca2:c0f1 AS13335, 2a06:98c1:50::ac40:20f1 AS13335
witzell.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
witzelvikar.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
witzend.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
witzner.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
wiuf.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
wiuff-hansen.dkcasey.ns.cloudflare.com 108.162.195.158 AS13335, 162.159.44.158 AS13335, 172.64.35.158 AS13335, 2606:4700:58::a29f:2c9e AS13335, 2803:f800:50::6ca2:c39e AS13335, 2a06:98c1:50::ac40:239e AS13335
kami.ns.cloudflare.com 108.162.192.177 AS13335, 172.64.32.177 AS13335, 173.245.58.177 AS13335, 2606:4700:50::adf5:3ab1 AS13335, 2803:f800:50::6ca2:c0b1 AS13335, 2a06:98c1:50::ac40:20b1 AS13335
wiuff.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
wiuffbageri.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
wiuffmail.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
stan.ns.cloudflare.com 108.162.193.235 AS13335, 172.64.33.235 AS13335, 173.245.59.235 AS13335, 2606:4700:58::adf5:3beb AS13335, 2803:f800:50::6ca2:c1eb AS13335, 2a06:98c1:50::ac40:21eb AS13335
wiuffmoller.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
wiuffs.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
wium-leverpostej.dkns1.curanet.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123
ns2.curanet.dk 2a02:2339:1:10f::123:123, 91.197.248.75
wiumleverpostej.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
wiumolesen.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
wiumoptik.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
wiums.dkns1.gnrx.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.gnrx.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
wivaejd.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
wivel-snejbjerg.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
wiver.dkns1.openprovider.nl 162.159.26.10 AS13335, 2400:cb00:2049:1::a29f:1a0a AS13335
ns2.openprovider.be 162.159.27.96 AS13335, 2400:cb00:2049:1::a29f:1b60 AS13335
ns3.openprovider.eu 162.159.48.89 AS13335, 2400:cb00:2049:1::a29f:3059 AS13335
wivian.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
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