🛡️ 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

1,183,339 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1460.01%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 IPv610,6840.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,75064.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,1697.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-06 00:32).

📋 One autonomous system

757,750 domains
DomainNameservers and addresses
ahauto.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
ahautocenter.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
ahautoservice.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
ahava.dkcleo.ns.cloudflare.com 108.162.193.89 AS13335, 172.64.33.89 AS13335, 173.245.59.89 AS13335, 2606:4700:58::adf5:3b59 AS13335, 2803:f800:50::6ca2:c159 AS13335, 2a06:98c1:50::ac40:2159 AS13335
sandy.ns.cloudflare.com 108.162.192.219 AS13335, 172.64.32.219 AS13335, 173.245.58.219 AS13335, 2606:4700:50::adf5:3adb AS13335, 2803:f800:50::6ca2:c0db AS13335, 2a06:98c1:50::ac40:20db AS13335
ahb-oss.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
ahbang.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
ahbb.dkanita.ns.cloudflare.com 108.162.194.82 AS13335, 162.159.38.82 AS13335, 172.64.34.82 AS13335, 2606:4700:50::a29f:2652 AS13335, 2803:f800:50::6ca2:c252 AS13335, 2a06:98c1:50::ac40:2252 AS13335
casey.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
ahbdanmark.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
ahbeauty.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
ahbh.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
ahbil.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
ahbiler.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
ahbilvask.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
ahbodyzone.dkrory.ns.cloudflare.com 108.162.195.166 AS13335, 162.159.44.166 AS13335, 172.64.35.166 AS13335, 2606:4700:58::a29f:2ca6 AS13335, 2803:f800:50::6ca2:c3a6 AS13335, 2a06:98c1:50::ac40:23a6 AS13335
wren.ns.cloudflare.com 108.162.194.141 AS13335, 162.159.38.141 AS13335, 172.64.34.141 AS13335, 2606:4700:50::a29f:268d AS13335, 2803:f800:50::6ca2:c28d AS13335, 2a06:98c1:50::ac40:228d AS13335
ahbooking.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
ahbork.dklennon.ns.cloudflare.com 108.162.195.165 AS13335, 162.159.44.165 AS13335, 172.64.35.165 AS13335, 2606:4700:58::a29f:2ca5 AS13335, 2803:f800:50::6ca2:c3a5 AS13335, 2a06:98c1:50::ac40:23a5 AS13335
margaret.ns.cloudflare.com 108.162.194.107 AS13335, 162.159.38.107 AS13335, 172.64.34.107 AS13335, 2606:4700:50::a29f:266b AS13335, 2803:f800:50::6ca2:c26b AS13335, 2a06:98c1:50::ac40:226b AS13335
ahbyg-risskov.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
ahbyg.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
ahbyggeradgivning.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
ahc-agro.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
ahckids.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
ahcompany.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
ahconsult.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
ahconsulting.dkns1.novaram.net 84.246.245.111 AS34165
ns2.novaram.net 84.246.245.113 AS34165
ahcorp.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
ahcreative.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
ahctoemrer.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
ahd.dkns.phx2.nearlyfreespeech.net 208.94.116.33 AS40630, 2607:ff18:80:53::2 AS40630
ns.phx4.nearlyfreespeech.net 208.94.116.97 AS40630, 2607:ff18:80:53::4 AS40630
ahdanielsen.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
ahdc.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
ahdelta.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
ahdesign.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
ahdiag.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
ahdiagnostics.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
ahea.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
ahead-it.dkgina.ns.cloudflare.com 108.162.192.117 AS13335, 172.64.32.117 AS13335, 173.245.58.117 AS13335, 2606:4700:50::adf5:3a75 AS13335, 2803:f800:50::6ca2:c075 AS13335, 2a06:98c1:50::ac40:2075 AS13335
rob.ns.cloudflare.com 108.162.193.140 AS13335, 172.64.33.140 AS13335, 173.245.59.140 AS13335, 2606:4700:58::adf5:3b8c AS13335, 2803:f800:50::6ca2:c18c AS13335, 2a06:98c1:50::ac40:218c AS13335
aheadandamazing.dkns5.kasserver.com 85.13.128.3 AS34788
ns6.kasserver.com 85.13.159.101 AS34788
aheadcph.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
aheadit.dkgina.ns.cloudflare.com 108.162.192.117 AS13335, 172.64.32.117 AS13335, 173.245.58.117 AS13335, 2606:4700:50::adf5:3a75 AS13335, 2803:f800:50::6ca2:c075 AS13335, 2a06:98c1:50::ac40:2075 AS13335
rob.ns.cloudflare.com 108.162.193.140 AS13335, 172.64.33.140 AS13335, 173.245.59.140 AS13335, 2606:4700:58::adf5:3b8c AS13335, 2803:f800:50::6ca2:c18c AS13335, 2a06:98c1:50::ac40:218c AS13335
aheadmusic.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
aheadofnew.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
aheadofperformance.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
aheadofthegame.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
aheadprogramme.dkns1.bms.com 198.155.167.250 AS7246
ns2.bms.com 198.155.167.248 AS7246
ns3.bms.com 198.155.223.8 AS7246
ns4.bms.com 158.117.22.129 AS7246
aheadrecords.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
ahealingheart.dkns1.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
ahegaard.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
ahegao.dkns1.nordic.hosting 2a01:4f9:c010:6122::1 AS24940, 95.217.17.109 AS24940
ns2.nordic.hosting 159.69.107.119 AS24940, 2a01:4f8:c2c:dc72::1 AS24940
ahellum.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
ahelms.dkmicah.ns.cloudflare.com 108.162.193.206 AS13335, 172.64.33.206 AS13335, 173.245.59.206 AS13335, 2606:4700:58::adf5:3bce AS13335, 2803:f800:50::6ca2:c1ce AS13335, 2a06:98c1:50::ac40:21ce AS13335
venus.ns.cloudflare.com 108.162.192.235 AS13335, 172.64.32.235 AS13335, 173.245.58.235 AS13335, 2606:4700:50::adf5:3aeb AS13335, 2803:f800:50::6ca2:c0eb AS13335, 2a06:98c1:50::ac40:20eb AS13335
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