🛡️ 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

1,186,235 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1510.01%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 IPv610,8040.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system756,41863.8%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,9667.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-09-30 13:10).

📋 One autonomous system

756,418 domains
DomainNameservers and addresses
2ndthought.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
2ndtonone.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
2ndtosun.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
2ndunit.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
2ndwind.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
2neb.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
2ned.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
2ni.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
2nielsen.dkaldo.ns.cloudflare.com 108.162.195.248 AS13335, 162.159.44.248 AS13335, 172.64.35.248 AS13335, 2606:4700:58::a29f:2cf8 AS13335, 2803:f800:50::6ca2:c3f8 AS13335, 2a06:98c1:50::ac40:23f8 AS13335
jen.ns.cloudflare.com 108.162.194.185 AS13335, 162.159.38.185 AS13335, 172.64.34.185 AS13335, 2606:4700:50::a29f:26b9 AS13335, 2803:f800:50::6ca2:c2b9 AS13335, 2a06:98c1:50::ac40:22b9 AS13335
2night.dksage.ns.cloudflare.com 108.162.195.236 AS13335, 162.159.44.236 AS13335, 172.64.35.236 AS13335, 2606:4700:58::a29f:2cec AS13335, 2803:f800:50::6ca2:c3ec AS13335, 2a06:98c1:50::ac40:23ec AS13335
veronica.ns.cloudflare.com 108.162.194.173 AS13335, 162.159.38.173 AS13335, 172.64.34.173 AS13335, 2606:4700:50::a29f:26ad AS13335, 2803:f800:50::6ca2:c2ad AS13335, 2a06:98c1:50::ac40:22ad AS13335
2nmaskinservice.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
2nmobilevideo.dkns-1093.awsdns-08.org 205.251.196.69 AS16509, 2600:9000:5304:4500::1 AS16509
ns-1874.awsdns-42.co.uk 205.251.199.82 AS16509, 2600:9000:5307:5200::1 AS16509
ns-303.awsdns-37.com 205.251.193.47 AS16509, 2600:9000:5301:2f00::1 AS16509
ns-523.awsdns-01.net 205.251.194.11 AS16509, 2600:9000:5302:b00::1 AS16509
2nny.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
2noerder.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
2note.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
2npharma.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
2nz.dkchin.ns.cloudflare.com 108.162.192.84 AS13335, 172.64.32.84 AS13335, 173.245.58.84 AS13335, 2606:4700:50::adf5:3a54 AS13335, 2803:f800:50::6ca2:c054 AS13335, 2a06:98c1:50::ac40:2054 AS13335
greg.ns.cloudflare.com 108.162.193.115 AS13335, 172.64.33.115 AS13335, 173.245.59.115 AS13335, 2606:4700:58::adf5:3b73 AS13335, 2803:f800:50::6ca2:c173 AS13335, 2a06:98c1:50::ac40:2173 AS13335
2nørder.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
2o.dkkate.ns.cloudflare.com 108.162.192.124 AS13335, 172.64.32.124 AS13335, 173.245.58.124 AS13335, 2606:4700:50::adf5:3a7c AS13335, 2803:f800:50::6ca2:c07c AS13335, 2a06:98c1:50::ac40:207c AS13335
terry.ns.cloudflare.com 108.162.193.237 AS13335, 172.64.33.237 AS13335, 173.245.59.237 AS13335, 2606:4700:58::adf5:3bed AS13335, 2803:f800:50::6ca2:c1ed AS13335, 2a06:98c1:50::ac40:21ed AS13335
2od.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
2oe.dkguy.ns.cloudflare.com 108.162.193.173 AS13335, 172.64.33.173 AS13335, 173.245.59.173 AS13335, 2606:4700:58::adf5:3bad AS13335, 2803:f800:50::6ca2:c1ad AS13335, 2a06:98c1:50::ac40:21ad AS13335
melina.ns.cloudflare.com 108.162.194.184 AS13335, 162.159.38.184 AS13335, 172.64.34.184 AS13335, 2606:4700:50::a29f:26b8 AS13335, 2803:f800:50::6ca2:c2b8 AS13335, 2a06:98c1:50::ac40:22b8 AS13335
2omhundetraening.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
2oolbox.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
2op.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
2optimize.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
2order.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
2ordr.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
2os.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
2ottesen.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
2p-klip.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
2p-produktion.dkns1.itwebhotel.dk 136.243.153.136 AS24940
ns2.itwebhotel.dk 136.243.153.176 AS24940
ns3.itwebhotel.dk 136.243.153.199 AS24940
2p0.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
2p2.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
2pac.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
2partner.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
2peter.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
2pfashion.dkkimora.ns.cloudflare.com 108.162.194.243 AS13335, 162.159.38.243 AS13335, 172.64.34.243 AS13335, 2606:4700:50::a29f:26f3 AS13335, 2803:f800:50::6ca2:c2f3 AS13335, 2a06:98c1:50::ac40:22f3 AS13335
memphis.ns.cloudflare.com 108.162.195.189 AS13335, 162.159.44.189 AS13335, 172.64.35.189 AS13335, 2606:4700:58::a29f:2cbd AS13335, 2803:f800:50::6ca2:c3bd AS13335, 2a06:98c1:50::ac40:23bd AS13335
2ph.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
2phase.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
2pklip.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
2plan.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
2planhuset.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
2playerstudio.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
2plus-revision.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
2plus1.dkkipp.ns.cloudflare.com 108.162.195.240 AS13335, 162.159.44.240 AS13335, 172.64.35.240 AS13335, 2606:4700:58::a29f:2cf0 AS13335, 2803:f800:50::6ca2:c3f0 AS13335, 2a06:98c1:50::ac40:23f0 AS13335
ulla.ns.cloudflare.com 108.162.192.233 AS13335, 172.64.32.233 AS13335, 173.245.58.233 AS13335, 2606:4700:50::adf5:3ae9 AS13335, 2803:f800:50::6ca2:c0e9 AS13335, 2a06:98c1:50::ac40:20e9 AS13335
2plus2er4.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
2plus2regnskab.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
2plus5.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
2plusto.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
2pos.dkdee.ns.cloudflare.com 108.162.192.93 AS13335, 172.64.32.93 AS13335, 173.245.58.93 AS13335, 2606:4700:50::adf5:3a5d AS13335, 2803:f800:50::6ca2:c05d AS13335, 2a06:98c1:50::ac40:205d AS13335
hugh.ns.cloudflare.com 108.162.193.117 AS13335, 172.64.33.117 AS13335, 173.245.59.117 AS13335, 2606:4700:58::adf5:3b75 AS13335, 2803:f800:50::6ca2:c175 AS13335, 2a06:98c1:50::ac40:2175 AS13335
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