🛡️ 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

1,185,715 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 address1,3130.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,8080.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system755,25063.7%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,9817.3%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-09-30 06:38).

📋 One autonomous system

755,250 domains
DomainNameservers and addresses
zupreem.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
zuq.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
zura.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
zurbuchen.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
zure.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
zurf.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
zurface.dkns1.absaconit.dk 185.136.96.99 AS203391, 2a06:fb00:1::1:99 AS203391
ns2.absaconit.dk 185.136.97.99 AS203391, 2a06:fb00:1::2:99 AS203391
ns3.absaconit.dk 185.136.98.99 AS203391, 2a06:fb00:1::3:99 AS203391
ns4.absaconit.dk 185.136.99.99 AS203391, 2a06:fb00:1::4:99 AS203391
zurg.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
zurich.dkns1.a0.impervasecuredns.net 192.230.121.1 AS19551, 2a02:e980:4::1 AS19551
ns1.a1.impervasecuredns.net 192.230.122.1 AS19551, 2a02:e980:5::1 AS19551
ns1.a2.impervasecuredns.net 192.230.123.1 AS19551, 2a02:e980:6::1 AS19551
zurk.dkns4.dns-123.net 35.198.132.83 AS396982
ns5.dns-123.net 35.187.184.173 AS396982
ns6.dns-123.net 35.228.54.1 AS396982
zurl.dkdiana.ns.cloudflare.com 108.162.194.23 AS13335, 162.159.38.23 AS13335, 172.64.34.23 AS13335, 2606:4700:50::a29f:2617 AS13335, 2803:f800:50::6ca2:c217 AS13335, 2a06:98c1:50::ac40:2217 AS13335
mcgrory.ns.cloudflare.com 108.162.195.170 AS13335, 162.159.44.170 AS13335, 172.64.35.170 AS13335, 2606:4700:58::a29f:2caa AS13335, 2803:f800:50::6ca2:c3aa AS13335, 2a06:98c1:50::ac40:23aa AS13335
zusa.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
zusammen-rapstedt.dkns5.kasserver.com 85.13.128.3 AS34788
ns6.kasserver.com 85.13.159.101 AS34788
zusammen.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
zusammenlernen.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
zusastreet.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
zusje.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
zusse.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
zusslin.dkdns107.ovh.net 2001:41d0:d01:100::2 AS16276, 5.196.41.137 AS16276
ns107.ovh.net 2001:41d0:b00:fb00::2 AS16276, 5.135.65.209 AS16276
zustain.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
zustained.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
zut.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
zutkopf.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
zutsko.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
zuture.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
zuus.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
zuut.dkdns1.idp365.net 162.159.27.131 AS13335, 2400:cb00:2049:1::a29f:1b83 AS13335
dns2.idp365.net 162.159.48.3 AS13335, 2400:cb00:2049:1::a29f:3003 AS13335
dns3.idp365.net 162.159.49.254 AS13335, 2400:cb00:2049:1::a29f:31fe AS13335
zuwa.dkns7.bricksite.net 35.246.226.10 AS396982
ns8.bricksite.net 35.242.190.82 AS396982
zuzana.dkheidi.ns.cloudflare.com 108.162.194.236 AS13335, 162.159.38.236 AS13335, 172.64.34.236 AS13335, 2606:4700:50::a29f:26ec AS13335, 2803:f800:50::6ca2:c2ec AS13335, 2a06:98c1:50::ac40:22ec AS13335
stanley.ns.cloudflare.com 108.162.195.141 AS13335, 162.159.44.141 AS13335, 172.64.35.141 AS13335, 2606:4700:58::a29f:2c8d AS13335, 2803:f800:50::6ca2:c38d AS13335, 2a06:98c1:50::ac40:238d AS13335
zuzanna.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
zuzannaranuszkiewicz.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
zuzizrideterapi.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
zuznelumbo.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
zuztainia.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78
ns2.simply.com 185.25.141.15, 2a02:2339:4006:101::4562:4562
ns3.simply.com 91.197.248.79
ns4.simply.com 91.197.248.80
zuzu.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
zuzzi.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
zv-vest.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
olof.ns.cloudflare.com 108.162.195.51 AS13335, 162.159.44.51 AS13335, 172.64.35.51 AS13335, 2606:4700:58::a29f:2c33 AS13335, 2803:f800:50::6ca2:c333 AS13335, 2a06:98c1:50::ac40:2333 AS13335
zvara.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
zvare.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
zvarelo.dkns1.dyna-ns.net 162.159.26.92 AS13335, 162.159.27.158 AS13335, 2400:cb00:2049:1::a29f:1a5c AS13335, 2400:cb00:2049:1::a29f:1b9e AS13335
ns2.dyna-ns.net 162.159.24.5 AS13335, 162.159.25.5 AS13335, 2400:cb00:2049:1::a29f:1805 AS13335, 2400:cb00:2049:1::a29f:1905 AS13335
zve.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
zvf.dkleia.ns.cloudflare.com 108.162.192.184 AS13335, 172.64.32.184 AS13335, 173.245.58.184 AS13335, 2606:4700:50::adf5:3ab8 AS13335, 2803:f800:50::6ca2:c0b8 AS13335, 2a06:98c1:50::ac40:20b8 AS13335
rohin.ns.cloudflare.com 108.162.195.153 AS13335, 162.159.44.153 AS13335, 172.64.35.153 AS13335, 2606:4700:58::a29f:2c99 AS13335, 2803:f800:50::6ca2:c399 AS13335, 2a06:98c1:50::ac40:2399 AS13335
zvoove.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
zvq.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
zvz.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
zwanenburg.dkns1.123hotel.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.123hotel.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
zwap.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
zwapgrid.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
zwartbles.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
zwartblesgg.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
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