🛡️ 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
webtema.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
webtemplate.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
webtemplet.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
webtender.dkns00.ns0.com 216.92.60.60 AS7859, 2607:f440::d85c:3c3c AS7859
ns533.pair.com 209.68.5.149 AS7859
webterapi.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
webterminal.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
webtest.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
webtest1.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
webtestbupl.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
webtesten.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
webtester.dkns.co3.dk 208.80.124.159 AS16552
ns.ikastnet.dk 208.80.126.159 AS16552
webtesting.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
webtextshop.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
webthings.dkjonah.ns.cloudflare.com 108.162.193.186 AS13335, 172.64.33.186 AS13335, 173.245.59.186 AS13335, 2606:4700:58::adf5:3bba AS13335, 2803:f800:50::6ca2:c1ba AS13335, 2a06:98c1:50::ac40:21ba AS13335
tia.ns.cloudflare.com 108.162.192.229 AS13335, 172.64.32.229 AS13335, 173.245.58.229 AS13335, 2606:4700:50::adf5:3ae5 AS13335, 2803:f800:50::6ca2:c0e5 AS13335, 2a06:98c1:50::ac40:20e5 AS13335
webtia.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
webtiatest.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
webtid.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
webtidclassic.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
webtify.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
webtilgaengelig.dkaspen.ns.cloudflare.com 108.162.194.109 AS13335, 162.159.38.109 AS13335, 172.64.34.109 AS13335, 2606:4700:50::a29f:266d AS13335, 2803:f800:50::6ca2:c26d AS13335, 2a06:98c1:50::ac40:226d AS13335
titan.ns.cloudflare.com 108.162.195.93 AS13335, 162.159.44.93 AS13335, 172.64.35.93 AS13335, 2606:4700:58::a29f:2c5d AS13335, 2803:f800:50::6ca2:c35d AS13335, 2a06:98c1:50::ac40:235d AS13335
webtilgaengelighed.dkdina.ns.cloudflare.com 108.162.192.107 AS13335, 172.64.32.107 AS13335, 173.245.58.107 AS13335, 2606:4700:50::adf5:3a6b AS13335, 2803:f800:50::6ca2:c06b AS13335, 2a06:98c1:50::ac40:206b AS13335
duke.ns.cloudflare.com 108.162.193.110 AS13335, 172.64.33.110 AS13335, 173.245.59.110 AS13335, 2606:4700:58::adf5:3b6e AS13335, 2803:f800:50::6ca2:c16e AS13335, 2a06:98c1:50::ac40:216e AS13335
webtilgeangelighed.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
webtilgængelig.dkaspen.ns.cloudflare.com 108.162.194.109 AS13335, 162.159.38.109 AS13335, 172.64.34.109 AS13335, 2606:4700:50::a29f:266d AS13335, 2803:f800:50::6ca2:c26d AS13335, 2a06:98c1:50::ac40:226d AS13335
titan.ns.cloudflare.com 108.162.195.93 AS13335, 162.159.44.93 AS13335, 172.64.35.93 AS13335, 2606:4700:58::a29f:2c5d AS13335, 2803:f800:50::6ca2:c35d AS13335, 2a06:98c1:50::ac40:235d AS13335
webtilgængelighed.dkdina.ns.cloudflare.com 108.162.192.107 AS13335, 172.64.32.107 AS13335, 173.245.58.107 AS13335, 2606:4700:50::adf5:3a6b AS13335, 2803:f800:50::6ca2:c06b AS13335, 2a06:98c1:50::ac40:206b AS13335
duke.ns.cloudflare.com 108.162.193.110 AS13335, 172.64.33.110 AS13335, 173.245.59.110 AS13335, 2606:4700:58::adf5:3b6e AS13335, 2803:f800:50::6ca2:c16e AS13335, 2a06:98c1:50::ac40:216e AS13335
webtilio.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
webtillid.dkns1.dns-parking.com 162.159.24.201 AS13335, 2400:cb00:2049:1::a29f:18c9 AS13335
ns2.dns-parking.com 162.159.25.42 AS13335, 2400:cb00:2049:1::a29f:192a AS13335
webtilmeldinger.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
webtilsyn.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
webtimiser-erhvervsklub.dkelsa.ns.cloudflare.com 108.162.192.111 AS13335, 172.64.32.111 AS13335, 173.245.58.111 AS13335, 2606:4700:50::adf5:3a6f AS13335, 2803:f800:50::6ca2:c06f AS13335, 2a06:98c1:50::ac40:206f AS13335
logan.ns.cloudflare.com 108.162.193.198 AS13335, 172.64.33.198 AS13335, 173.245.59.198 AS13335, 2606:4700:58::adf5:3bc6 AS13335, 2803:f800:50::6ca2:c1c6 AS13335, 2a06:98c1:50::ac40:21c6 AS13335
webtimized.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
webting.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
webtip.dkjoan.ns.cloudflare.com 108.162.192.173 AS13335, 172.64.32.173 AS13335, 173.245.58.173 AS13335, 2606:4700:50::adf5:3aad AS13335, 2803:f800:50::6ca2:c0ad AS13335, 2a06:98c1:50::ac40:20ad AS13335
lloyd.ns.cloudflare.com 108.162.193.197 AS13335, 172.64.33.197 AS13335, 173.245.59.197 AS13335, 2606:4700:58::adf5:3bc5 AS13335, 2803:f800:50::6ca2:c1c5 AS13335, 2a06:98c1:50::ac40:21c5 AS13335
webtjeneste.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
webto.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
webtoday.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
webtohosting.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
webtolk.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
webtomail.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
webtomatic.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
webtomove.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
webtonet.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
webtool-oeland.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
webtool-øland.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
webtools.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
webtoprint.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
webtothemax.dkns1.carlsonnet.eu 192.185.108.30 AS31898
ns2.carlsonnet.eu 192.185.108.31 AS31898
webtoweb.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
webtrack.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
webtrade.dktan-dns01.tang.ind.yacn.dk 193.88.11.6 AS3292
tan-dns02.tang.ind.yacn.dk 193.88.11.7 AS3292
webtrader.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
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