🛡️ 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
365nyheder.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
365on.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
365online.dkjaziel.ns.cloudflare.com 108.162.195.55 AS13335, 162.159.44.55 AS13335, 172.64.35.55 AS13335, 2606:4700:58::a29f:2c37 AS13335, 2803:f800:50::6ca2:c337 AS13335, 2a06:98c1:50::ac40:2337 AS13335
peaches.ns.cloudflare.com 108.162.194.239 AS13335, 162.159.38.239 AS13335, 172.64.34.239 AS13335, 2606:4700:50::a29f:26ef AS13335, 2803:f800:50::6ca2:c2ef AS13335, 2a06:98c1:50::ac40:22ef AS13335
365pim.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
365portal.dkjihoon.ns.cloudflare.com 108.162.195.233 AS13335, 162.159.44.233 AS13335, 172.64.35.233 AS13335, 2606:4700:58::a29f:2ce9 AS13335, 2803:f800:50::6ca2:c3e9 AS13335, 2a06:98c1:50::ac40:23e9 AS13335
june.ns.cloudflare.com 108.162.192.176 AS13335, 172.64.32.176 AS13335, 173.245.58.176 AS13335, 2606:4700:50::adf5:3ab0 AS13335, 2803:f800:50::6ca2:c0b0 AS13335, 2a06:98c1:50::ac40:20b0 AS13335
365portalen.dkjihoon.ns.cloudflare.com 108.162.195.233 AS13335, 162.159.44.233 AS13335, 172.64.35.233 AS13335, 2606:4700:58::a29f:2ce9 AS13335, 2803:f800:50::6ca2:c3e9 AS13335, 2a06:98c1:50::ac40:23e9 AS13335
june.ns.cloudflare.com 108.162.192.176 AS13335, 172.64.32.176 AS13335, 173.245.58.176 AS13335, 2606:4700:50::adf5:3ab0 AS13335, 2803:f800:50::6ca2:c0b0 AS13335, 2a06:98c1:50::ac40:20b0 AS13335
365post.dkns1.msvit.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.msvit.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
365power.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
365privat.dkns1.brandshelter.com 193.227.117.9 AS1921, 2a04:2b00:14cc::9 AS1921
ns2.brandshelter.de 194.50.187.11 AS1921, 2a04:2b00:14dd::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
365real.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
365rengøring.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
365reservedele.dkns-1352.awsdns-41.org 205.251.197.72 AS16509, 2600:9000:5305:4800::1 AS16509
ns-1557.awsdns-02.co.uk 205.251.198.21 AS16509, 2600:9000:5306:1500::1 AS16509
ns-210.awsdns-26.com 205.251.192.210 AS16509, 2600:9000:5300:d200::1 AS16509
ns-582.awsdns-08.net 205.251.194.70 AS16509, 2600:9000:5302:4600::1 AS16509
365safe.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
365salg.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
365secure.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
365securescore.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
365security.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
365sikker.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
365sikkerhed.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
365sikkerhedsscore.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
365sikring.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
365silke.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
365solution.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
365solutions.dkns1-06.azure-dns.com 13.107.236.6 AS8075, 2603:1061:0:700::6 AS8075
ns2-06.azure-dns.net 150.171.21.6 AS8075, 2620:1ec:8ec:700::6 AS8075
ns3-06.azure-dns.org 204.14.183.6 AS8075, 2a01:111:4000:700::6 AS8075
ns4-06.azure-dns.info 208.84.5.6 AS8075, 2620:1ec:bda:700::6 AS8075
365specialist.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
365struergym.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
365supporten.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
365tech.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
365tipp.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
365tjek.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
365tryghed.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
365ucrs.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
365viborg.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
365web.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
365websites.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
365wzm.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
365x24.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
3660.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
366kbhv.dkpatryk.ns.cloudflare.com 108.162.195.122 AS13335, 162.159.44.122 AS13335, 172.64.35.122 AS13335, 2606:4700:58::a29f:2c7a AS13335, 2803:f800:50::6ca2:c37a AS13335, 2a06:98c1:50::ac40:237a AS13335
sarah.ns.cloudflare.com 108.162.194.218 AS13335, 162.159.38.218 AS13335, 172.64.34.218 AS13335, 2606:4700:50::a29f:26da AS13335, 2803:f800:50::6ca2:c2da AS13335, 2a06:98c1:50::ac40:22da AS13335
36704197.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
36705099.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
36750999.dkgate.profdoc.dk 80.62.243.243 AS3292
ns.profdoc.dk 80.62.243.242 AS3292
36786636.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
367ture.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
369.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
369casino.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
36alps.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
3700.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
370z.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
370zroadster.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
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