🛡️ 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

1,186,223 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1500.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3100.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,8040.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,13763.8%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,9357.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-09-30 19:36).

📋 One autonomous system

757,137 domains
DomainNameservers and addresses
3650.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
3654u.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
365academy.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
365addin.dkns1.bdm.microsoftonline.com 13.107.236.208 AS8075, 2603:1061:0:700::d0 AS8075
ns2.bdm.microsoftonline.com 150.171.21.208 AS8075, 2620:1ec:8ec:700::d0 AS8075
ns3.bdm.microsoftonline.com 204.14.183.208 AS8075, 2a01:111:4000:700::d0 AS8075
ns4.bdm.microsoftonline.com 208.84.5.208 AS8075, 2620:1ec:bda:700::d0 AS8075
365advisor.dkns1.advizor.net 208.94.148.4 AS16552, 2600:1800:10::1 AS16552
ns2.advizor.net 208.80.124.4 AS16552, 2600:1801:11::1 AS16552
ns3.advizor.net 208.80.126.4 AS16552, 2600:1802:12::1 AS16552
365ansvar.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
365architects.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
365arkitekterne.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
365auto.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
365backup.dkns1-04.azure-dns.com 13.107.236.4 AS8075, 2603:1061:0:700::4 AS8075
ns2-04.azure-dns.net 150.171.21.4 AS8075, 2620:1ec:8ec:700::4 AS8075
ns3-04.azure-dns.org 204.14.183.4 AS8075, 2a01:111:4000:700::4 AS8075
ns4-04.azure-dns.info 208.84.5.4 AS8075, 2620:1ec:bda:700::4 AS8075
365baseline.dkeverton.ns.cloudflare.com 108.162.195.201 AS13335, 162.159.44.201 AS13335, 172.64.35.201 AS13335, 2606:4700:58::a29f:2cc9 AS13335, 2803:f800:50::6ca2:c3c9 AS13335, 2a06:98c1:50::ac40:23c9 AS13335
ophelia.ns.cloudflare.com 108.162.194.248 AS13335, 162.159.38.248 AS13335, 172.64.34.248 AS13335, 2606:4700:50::a29f:26f8 AS13335, 2803:f800:50::6ca2:c2f8 AS13335, 2a06:98c1:50::ac40:22f8 AS13335
365basyd.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
365beskyttelse.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
365blog.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
365bolig.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
365box.dkporter.ns.cloudflare.com 108.162.195.243 AS13335, 162.159.44.243 AS13335, 172.64.35.243 AS13335, 2606:4700:58::a29f:2cf3 AS13335, 2803:f800:50::6ca2:c3f3 AS13335, 2a06:98c1:50::ac40:23f3 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
365businesscentral.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
365c.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
365campus.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
365connect.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
365consult.dkalice.ns.cloudflare.com 108.162.192.60 AS13335, 172.64.32.60 AS13335, 173.245.58.60 AS13335, 2606:4700:50::adf5:3a3c AS13335, 2803:f800:50::6ca2:c03c AS13335, 2a06:98c1:50::ac40:203c AS13335
rayden.ns.cloudflare.com 108.162.195.163 AS13335, 162.159.44.163 AS13335, 172.64.35.163 AS13335, 2606:4700:58::a29f:2ca3 AS13335, 2803:f800:50::6ca2:c3a3 AS13335, 2a06:98c1:50::ac40:23a3 AS13335
365consulting.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
365dage.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
365dagemedblomster.dkalgin.ns.cloudflare.com 108.162.193.61 AS13335, 172.64.33.61 AS13335, 173.245.59.61 AS13335, 2606:4700:58::adf5:3b3d AS13335, 2803:f800:50::6ca2:c13d AS13335, 2a06:98c1:50::ac40:213d AS13335
cortney.ns.cloudflare.com 108.162.192.87 AS13335, 172.64.32.87 AS13335, 173.245.58.87 AS13335, 2606:4700:50::adf5:3a57 AS13335, 2803:f800:50::6ca2:c057 AS13335, 2a06:98c1:50::ac40:2057 AS13335
365daysofdesign.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
365defender.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
365design.dkbetty.ns.cloudflare.com 108.162.192.75 AS13335, 172.64.32.75 AS13335, 173.245.58.75 AS13335, 2606:4700:50::adf5:3a4b AS13335, 2803:f800:50::6ca2:c04b AS13335, 2a06:98c1:50::ac40:204b AS13335
noel.ns.cloudflare.com 108.162.193.216 AS13335, 172.64.33.216 AS13335, 173.245.59.216 AS13335, 2606:4700:58::adf5:3bd8 AS13335, 2803:f800:50::6ca2:c1d8 AS13335, 2a06:98c1:50::ac40:21d8 AS13335
365direkte.dkns1.brandshelter.com 193.227.117.9 AS1921
ns2.brandshelter.de 194.50.187.11 AS1921
ns3.brandshelter.info 194.0.182.12 AS1921, 2a04:2b00:14ee::12 AS1921
ns4.brandshelter.net 193.227.117.10 AS1921, 2a04:2b00:14cc::10 AS1921
ns5.brandshelter.us 194.50.187.14 AS1921, 2a04:2b00:14dd::14 AS1921
365discount.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
365dynamics.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
365eggrindsted.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
365entreprise.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
365fodbold.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
365games.dkfish.ns.cloudflare.com 108.162.194.252 AS13335, 162.159.38.252 AS13335, 172.64.34.252 AS13335, 2606:4700:50::a29f:26fc AS13335, 2803:f800:50::6ca2:c2fc AS13335, 2a06:98c1:50::ac40:22fc AS13335
pranab.ns.cloudflare.com 108.162.195.199 AS13335, 162.159.44.199 AS13335, 172.64.35.199 AS13335, 2606:4700:58::a29f:2cc7 AS13335, 2803:f800:50::6ca2:c3c7 AS13335, 2a06:98c1:50::ac40:23c7 AS13335
365graphic.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
365graphics.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
365hey.dkali.ns.cloudflare.com 108.162.192.59 AS13335, 172.64.32.59 AS13335, 173.245.58.59 AS13335, 2606:4700:50::adf5:3a3b AS13335, 2803:f800:50::6ca2:c03b AS13335, 2a06:98c1:50::ac40:203b AS13335
terin.ns.cloudflare.com 108.162.193.236 AS13335, 172.64.33.236 AS13335, 173.245.59.236 AS13335, 2606:4700:58::adf5:3bec AS13335, 2803:f800:50::6ca2:c1ec AS13335, 2a06:98c1:50::ac40:21ec AS13335
365hhfvuc.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
365huset.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
365konsulenter.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
365køreskole.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
365logistik.dkns1.ecdn.dk 88.198.108.151 AS24940
ns2.ecdn.dk 138.201.245.113 AS24940
365ma.dkns1.siteground.net 75.2.77.104 AS16509
ns2.siteground.net 99.83.229.113 AS16509
365maaltider.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
365mail.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
365media.dkns1.digitalocean.com 172.64.52.210 AS13335, 2606:4700:52::ac40:34d2 AS13335
ns2.digitalocean.com 172.64.53.21 AS13335, 2606:4700:5a::ac40:3515 AS13335
ns3.digitalocean.com 172.64.49.209 AS13335, 2606:4700:52::ac40:31d1 AS13335
365nem.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
365ngage.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
365ninja.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
365now.dkns1.blueit.dk 185.195.172.82 AS42686
ns2.blueit.dk 185.195.172.83 AS42686
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