🛡️ 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
22-bet.dkpns51.cloudns.net 185.136.96.192 AS203391, 2a06:fb00:1::1:192 AS203391
pns52.cloudns.net 185.136.97.192 AS203391, 2a06:fb00:1::2:192 AS203391
pns53.cloudns.net 185.136.98.192 AS203391, 2a06:fb00:1::3:192 AS203391
pns54.cloudns.net 185.136.99.192 AS203391, 2a06:fb00:1::4:192 AS203391
22.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
220.dkauthns1.cabocomm.dk 195.41.32.9 AS3292
authns2.cabocomm.dk 193.200.44.9 AS3292
2200.dkns1.nordicway.dk 2a01:4f8:1c1a:a1e7::1 AS24940, 91.98.140.195 AS24940
ns2.nordicway.dk 2a01:4f8:c012:4db6::1 AS24940, 49.13.80.249 AS24940
ns3.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
2200kbhn.dkmatt.ns.cloudflare.com 108.162.193.131 AS13335, 172.64.33.131 AS13335, 173.245.59.131 AS13335, 2606:4700:58::adf5:3b83 AS13335, 2803:f800:50::6ca2:c183 AS13335, 2a06:98c1:50::ac40:2183 AS13335
zara.ns.cloudflare.com 108.162.192.148 AS13335, 172.64.32.148 AS13335, 173.245.58.148 AS13335, 2606:4700:50::adf5:3a94 AS13335, 2803:f800:50::6ca2:c094 AS13335, 2a06:98c1:50::ac40:2094 AS13335
2200rask.dkeve.ns.cloudflare.com 108.162.194.204 AS13335, 162.159.38.204 AS13335, 172.64.34.204 AS13335, 2606:4700:50::a29f:26cc AS13335, 2803:f800:50::6ca2:c2cc AS13335, 2a06:98c1:50::ac40:22cc AS13335
keenan.ns.cloudflare.com 108.162.195.11 AS13335, 162.159.44.11 AS13335, 172.64.35.11 AS13335, 2606:4700:58::a29f:2c0b AS13335, 2803:f800:50::6ca2:c30b AS13335, 2a06:98c1:50::ac40:230b AS13335
2200x.dkbethany.ns.cloudflare.com 108.162.194.31 AS13335, 162.159.38.31 AS13335, 172.64.34.31 AS13335, 2606:4700:50::a29f:261f AS13335, 2803:f800:50::6ca2:c21f AS13335, 2a06:98c1:50::ac40:221f AS13335
carter.ns.cloudflare.com 108.162.193.80 AS13335, 172.64.33.80 AS13335, 173.245.59.80 AS13335, 2606:4700:58::adf5:3b50 AS13335, 2803:f800:50::6ca2:c150 AS13335, 2a06:98c1:50::ac40:2150 AS13335
220205.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
2206.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
220718.dkns1.nordicway.dk 2a01:4f8:1c1a:a1e7::1 AS24940, 91.98.140.195 AS24940
ns2.nordicway.dk 2a01:4f8:c012:4db6::1 AS24940, 49.13.80.249 AS24940
ns3.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
220volt.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
2210.dkheather.ns.cloudflare.com 108.162.192.161 AS13335, 172.64.32.161 AS13335, 173.245.58.161 AS13335, 2606:4700:50::adf5:3aa1 AS13335, 2803:f800:50::6ca2:c0a1 AS13335, 2a06:98c1:50::ac40:20a1 AS13335
lou.ns.cloudflare.com 108.162.193.199 AS13335, 172.64.33.199 AS13335, 173.245.59.199 AS13335, 2606:4700:58::adf5:3bc7 AS13335, 2803:f800:50::6ca2:c1c7 AS13335, 2a06:98c1:50::ac40:21c7 AS13335
22100200.dkns1.dnsserver.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.dnsserver.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
22117076.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
22141415.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
2218.dkkelly.ns.cloudflare.com 108.162.194.91 AS13335, 162.159.38.91 AS13335, 172.64.34.91 AS13335, 2606:4700:50::a29f:265b AS13335, 2803:f800:50::6ca2:c25b AS13335, 2a06:98c1:50::ac40:225b AS13335
merlin.ns.cloudflare.com 108.162.193.205 AS13335, 172.64.33.205 AS13335, 173.245.59.205 AS13335, 2606:4700:58::adf5:3bcd AS13335, 2803:f800:50::6ca2:c1cd AS13335, 2a06:98c1:50::ac40:21cd AS13335
222.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
22211100toemrer.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
22211100tømrer.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
22216660.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
2222.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
22222222.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
22223333.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
22224444.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
22228000.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
22228070.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
2223.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
22230050.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
22230055.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
22232526.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
22247824.dkns1.messagingengine.com 162.159.24.178 AS13335
ns2.messagingengine.com 162.159.25.191 AS13335
22250316.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
22283010.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
22283020.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
222cycles.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
22300300.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
2233.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
22333263.dkcesar.ns.cloudflare.com 108.162.195.119 AS13335, 162.159.44.119 AS13335, 172.64.35.119 AS13335, 2606:4700:58::a29f:2c77 AS13335, 2803:f800:50::6ca2:c377 AS13335, 2a06:98c1:50::ac40:2377 AS13335
sneh.ns.cloudflare.com 108.162.194.162 AS13335, 162.159.38.162 AS13335, 172.64.34.162 AS13335, 2606:4700:50::a29f:26a2 AS13335, 2803:f800:50::6ca2:c2a2 AS13335, 2a06:98c1:50::ac40:22a2 AS13335
22359460.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
22370123.dkns1.c-system.dk 49.12.60.90 AS24940
ns2.c-system.dk 49.12.60.94 AS24940
ns3.c-system.dk 37.27.223.112 AS24940
22372417.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
224.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
2244.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
22442216.dkauth31.ns.sonnit.dk 185.136.96.66 AS203391, 2a06:fb00:1::1:66 AS203391
auth32.ns.sonnit.dk 185.136.97.66 AS203391, 2a06:fb00:1::2:66 AS203391
auth33.ns.sonnit.dk 185.136.98.66 AS203391, 2a06:fb00:1::3:66 AS203391
auth34.ns.sonnit.dk 185.136.99.66 AS203391, 2a06:fb00:1::4:66 AS203391
22473277.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
22513087.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
22521100.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
22523001.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
22523002.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
22555444.dkalfred.ns.cloudflare.com 108.162.195.131 AS13335, 162.159.44.131 AS13335, 172.64.35.131 AS13335, 2606:4700:58::a29f:2c83 AS13335, 2803:f800:50::6ca2:c383 AS13335, 2a06:98c1:50::ac40:2383 AS13335
gail.ns.cloudflare.com 108.162.192.116 AS13335, 172.64.32.116 AS13335, 173.245.58.116 AS13335, 2606:4700:50::adf5:3a74 AS13335, 2803:f800:50::6ca2:c074 AS13335, 2a06:98c1:50::ac40:2074 AS13335
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