🛡️ 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
ah-motorcykler.dkns-1443.awsdns-52.org 205.251.197.163 AS16509, 2600:9000:5305:a300::1 AS16509
ns-1633.awsdns-12.co.uk 205.251.198.97 AS16509, 2600:9000:5306:6100::1 AS16509
ns-274.awsdns-34.com 205.251.193.18 AS16509, 2600:9000:5301:1200::1 AS16509
ns-979.awsdns-58.net 205.251.195.211 AS16509, 2600:9000:5303:d300::1 AS16509
ah-motorsport.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
ah-murer.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
ah-racing.dkns-1393.awsdns-46.org 205.251.197.113 AS16509, 2600:9000:5305:7100::1 AS16509
ns-1623.awsdns-10.co.uk 205.251.198.87 AS16509, 2600:9000:5306:5700::1 AS16509
ns-215.awsdns-26.com 205.251.192.215 AS16509, 2600:9000:5300:d700::1 AS16509
ns-570.awsdns-07.net 205.251.194.58 AS16509, 2600:9000:5302:3a00::1 AS16509
ah-racingogmc.dkns-1201.awsdns-22.org 205.251.196.177 AS16509, 2600:9000:5304:b100::1 AS16509
ns-2040.awsdns-63.co.uk 205.251.199.248 AS16509, 2600:9000:5307:f800::1 AS16509
ns-33.awsdns-04.com 205.251.192.33 AS16509, 2600:9000:5300:2100::1 AS16509
ns-851.awsdns-42.net 205.251.195.83 AS16509, 2600:9000:5303:5300::1 AS16509
ah-reptiles.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
ah-resources.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
ah-smedemontage.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
ah-smykker.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
ah-soendergaarden.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
ah-thaimassage.dkcosmos.dns-parking.com 172.64.53.200 AS13335, 2606:4700:5a::ac40:35c8 AS13335
nova.dns-parking.com 172.64.52.46 AS13335, 2606:4700:52::ac40:342e AS13335
ah-tomrer.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
ah-transport-service.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
ah-transport.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
ah-tuning.dkannalise.ns.cloudflare.com 108.162.194.234 AS13335, 162.159.38.234 AS13335, 172.64.34.234 AS13335, 2606:4700:50::a29f:26ea AS13335, 2803:f800:50::6ca2:c2ea AS13335, 2a06:98c1:50::ac40:22ea AS13335
mcgrory.ns.cloudflare.com 108.162.195.170 AS13335, 162.159.44.170 AS13335, 172.64.35.170 AS13335, 2606:4700:58::a29f:2caa AS13335, 2803:f800:50::6ca2:c3aa AS13335, 2a06:98c1:50::ac40:23aa AS13335
ah-vib.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
ah1.dkdesi.ns.cloudflare.com 108.162.192.96 AS13335, 172.64.32.96 AS13335, 173.245.58.96 AS13335, 2606:4700:50::adf5:3a60 AS13335, 2803:f800:50::6ca2:c060 AS13335, 2a06:98c1:50::ac40:2060 AS13335
tim.ns.cloudflare.com 108.162.193.145 AS13335, 172.64.33.145 AS13335, 173.245.59.145 AS13335, 2606:4700:58::adf5:3b91 AS13335, 2803:f800:50::6ca2:c191 AS13335, 2a06:98c1:50::ac40:2191 AS13335
ah2.dkbob.ns.cloudflare.com 108.162.193.104 AS13335, 172.64.33.104 AS13335, 173.245.59.104 AS13335, 2606:4700:58::adf5:3b68 AS13335, 2803:f800:50::6ca2:c168 AS13335, 2a06:98c1:50::ac40:2168 AS13335
mary.ns.cloudflare.com 108.162.192.134 AS13335, 172.64.32.134 AS13335, 173.245.58.134 AS13335, 2606:4700:50::adf5:3a86 AS13335, 2803:f800:50::6ca2:c086 AS13335, 2a06:98c1:50::ac40:2086 AS13335
ah2012.dkns6.sitnet.dk 107.162.234.197 AS55002, 2604:e180:1071::3:1 AS55002
ns7.sitnet.dk 107.162.176.221 AS55002, 2604:e180:1071::ffff:6ba2:b0dd AS55002
ah23.dkns1-08.azure-dns.com 13.107.236.8 AS8075, 2603:1061:0:700::8 AS8075
ns2-08.azure-dns.net 150.171.21.8 AS8075, 2620:1ec:8ec:700::8 AS8075
ns3-08.azure-dns.org 204.14.183.8 AS8075, 2a01:111:4000:700::8 AS8075
ns4-08.azure-dns.info 208.84.5.8 AS8075, 2620:1ec:bda:700::8 AS8075
ah3000.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
ah84.dkandy.ns.cloudflare.com 108.162.193.101 AS13335, 172.64.33.101 AS13335, 173.245.59.101 AS13335, 2606:4700:58::adf5:3b65 AS13335, 2803:f800:50::6ca2:c165 AS13335, 2a06:98c1:50::ac40:2165 AS13335
lady.ns.cloudflare.com 108.162.192.127 AS13335, 172.64.32.127 AS13335, 173.245.58.127 AS13335, 2606:4700:50::adf5:3a7f AS13335, 2803:f800:50::6ca2:c07f AS13335, 2a06:98c1:50::ac40:207f AS13335
aha-design.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
aha-mentor.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
aha-rådgivning.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
aha-tech.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
aha-technologies.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
aha.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
ahac.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
ahaco.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
ahacreations.dkns1-36.azure-dns.com 150.171.10.36 AS8075, 2603:1061:0:10::24 AS8075
ns2-36.azure-dns.net 150.171.16.36 AS8075, 2620:1ec:8ec:10::24 AS8075
ns3-36.azure-dns.org 13.107.222.36 AS8075, 2a01:111:4000:10::24 AS8075
ns4-36.azure-dns.info 13.107.206.36 AS8075, 2620:1ec:bda:10::24 AS8075
ahaditerapi.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
ns3.azehosting.net 2a01:4f8:c17:6a6e::2 AS24940, 88.99.39.181 AS24940
ahadriaz.dkmarek.ns.cloudflare.com 108.162.193.202 AS13335, 172.64.33.202 AS13335, 173.245.59.202 AS13335, 2606:4700:58::adf5:3bca AS13335, 2803:f800:50::6ca2:c1ca AS13335, 2a06:98c1:50::ac40:21ca AS13335
nicole.ns.cloudflare.com 108.162.192.211 AS13335, 172.64.32.211 AS13335, 173.245.58.211 AS13335, 2606:4700:50::adf5:3ad3 AS13335, 2803:f800:50::6ca2:c0d3 AS13335, 2a06:98c1:50::ac40:20d3 AS13335
ahah.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
ahaircare.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
ahait.dknf1.nordfast.com 2a06:fb00:2::1:93 AS203391, 45.83.248.93 AS203391
nf2.nordfast.com 2a06:fb00:2::2:93 AS203391, 45.83.249.93 AS203391
nf3.nordfast.com 2a06:fb00:2::3:93 AS203391, 45.83.250.93 AS203391
nf4.nordfast.com 2a06:fb00:2::4:93 AS203391, 45.83.251.93 AS203391
pns73.cloudns.net 2a06:fb00:2::3:12 AS203391, 45.83.250.12 AS203391
pns74.cloudns.uk 2a06:fb00:2::4:12 AS203391, 45.83.251.12 AS203391
ahalgerens.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
ahali.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
ahalivestage.dkns1-33.azure-dns.com 150.171.10.33 AS8075, 2603:1061:0:10::21 AS8075
ns2-33.azure-dns.net 150.171.16.33 AS8075, 2620:1ec:8ec:10::21 AS8075
ns3-33.azure-dns.org 13.107.222.33 AS8075, 2a01:111:4000:10::21 AS8075
ns4-33.azure-dns.info 13.107.206.33 AS8075, 2620:1ec:bda:10::21 AS8075
ahandel.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
ahandyhand.dkasa.ns.cloudflare.com 108.162.192.246 AS13335, 172.64.32.246 AS13335, 173.245.58.246 AS13335, 2606:4700:50::adf5:3af6 AS13335, 2803:f800:50::6ca2:c0f6 AS13335, 2a06:98c1:50::ac40:20f6 AS13335
toby.ns.cloudflare.com 108.162.193.239 AS13335, 172.64.33.239 AS13335, 173.245.59.239 AS13335, 2606:4700:58::adf5:3bef AS13335, 2803:f800:50::6ca2:c1ef AS13335, 2a06:98c1:50::ac40:21ef AS13335
ahanger.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
ahani.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
ahansen.dkns1.webaway.dk 77.247.70.130 AS31590
ns2.webaway.dk 77.247.70.131 AS31590
ahaph-byg.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
aharsmann.dkns7.bricksite.net 35.246.226.10 AS396982
ns8.bricksite.net 35.242.190.82 AS396982
ahas.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
ahaservice.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
ahasverussen.dkalec.ns.cloudflare.com 108.162.193.59 AS13335, 172.64.33.59 AS13335, 173.245.59.59 AS13335, 2606:4700:58::adf5:3b3b AS13335, 2803:f800:50::6ca2:c13b AS13335, 2a06:98c1:50::ac40:213b AS13335
heidi.ns.cloudflare.com 108.162.194.236 AS13335, 162.159.38.236 AS13335, 172.64.34.236 AS13335, 2606:4700:50::a29f:26ec AS13335, 2803:f800:50::6ca2:c2ec AS13335, 2a06:98c1:50::ac40:22ec AS13335
ahauntinginvenice.dkns112.twdcns.co.uk 205.251.199.56 AS16509, 2600:9000:5307:3800::1 AS16509
ns112.twdcns.com 205.251.192.163 AS16509, 2600:9000:5300:a300::1 AS16509
ns112.twdcns.net 205.251.194.147 AS16509, 2600:9000:5302:9300::1 AS16509
ns112.twdcns.org 205.251.196.47 AS16509, 2600:9000:5304:2f00::1 AS16509
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