🛡️ 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

1,186,285 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1470.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3030.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,7740.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system758,93564.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,7527.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-01 14:22).

📋 One autonomous system

758,935 domains
DomainNameservers and addresses
6seven.dkns1.dlx.dk 2a00:1b18:1337:1337::53 AS47527, 46.30.121.210 AS47527
ns2.dlx.dk 185.208.212.124 AS47527, 2a00:1b19:1337:1337::53 AS47527
6shop.dkns1.loopiagroup.com 2a10:bbc0::11 AS25234, 45.10.97.11 AS25234
ns2.loopiagroup.com 185.71.159.12 AS25234, 2a02:250:3::12 AS25234
6stjerner.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
6stjernet.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
6stjernetfacility.dkns1.dnsserver.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123
ns2.dnsserver.dk 2a02:2339:1:10f::123:123, 91.197.248.75
6tube.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
6tus.dkns1-01.azure-dns.com 13.107.236.1 AS8075, 2603:1061:0:700::1 AS8075
ns2-01.azure-dns.net 150.171.21.1 AS8075, 2620:1ec:8ec:700::1 AS8075
ns3-01.azure-dns.org 204.14.183.1 AS8075, 2a01:111:4000:700::1 AS8075
ns4-01.azure-dns.info 208.84.5.1 AS8075, 2620:1ec:bda:700::1 AS8075
6tv.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
6ugersjobrettetuddannelse.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
6ugerskurser.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
6ugerskurserforledige.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
6ugerskursus.dkns-1230.awsdns-25.org 205.251.196.206 AS16509, 2600:9000:5304:ce00::1 AS16509
ns-1632.awsdns-12.co.uk 205.251.198.96 AS16509, 2600:9000:5306:6000::1 AS16509
ns-164.awsdns-20.com 205.251.192.164 AS16509, 2600:9000:5300:a400::1 AS16509
ns-825.awsdns-39.net 205.251.195.57 AS16509, 2600:9000:5303:3900::1 AS16509
6ugerskursusforledige.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
6uv.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
6w.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
6x.dkelisa.ns.cloudflare.com 108.162.194.54 AS13335, 162.159.38.54 AS13335, 172.64.34.54 AS13335, 2606:4700:50::a29f:2636 AS13335, 2803:f800:50::6ca2:c236 AS13335, 2a06:98c1:50::ac40:2236 AS13335
olof.ns.cloudflare.com 108.162.195.51 AS13335, 162.159.44.51 AS13335, 172.64.35.51 AS13335, 2606:4700:58::a29f:2c33 AS13335, 2803:f800:50::6ca2:c333 AS13335, 2a06:98c1:50::ac40:2333 AS13335
6x6.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
6xjacobsen.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
6xo-ejendomme.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
6xoejendomme.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
6y.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
6z.dkbrett.ns.cloudflare.com 108.162.193.76 AS13335, 172.64.33.76 AS13335, 173.245.59.76 AS13335, 2606:4700:58::adf5:3b4c AS13335, 2803:f800:50::6ca2:c14c AS13335, 2a06:98c1:50::ac40:214c AS13335
hera.ns.cloudflare.com 108.162.192.162 AS13335, 172.64.32.162 AS13335, 173.245.58.162 AS13335, 2606:4700:50::adf5:3aa2 AS13335, 2803:f800:50::6ca2:c0a2 AS13335, 2a06:98c1:50::ac40:20a2 AS13335
7-10-12.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
7-9-13-21.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
7-9-13.dkns.move-on.dk 77.233.252.246 AS31027
ns2.move-on.dk 77.233.252.247 AS31027
7-cup.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
7-eleven-dktestenvironment.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
7-eleven-dktestmiljø.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
7-elevenase.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
7-elevent.dkns10.dnsadmin.dk 208.94.148.4 AS16552, 2600:1800:10::1 AS16552
ns11.dns-admin.dk 208.80.124.4 AS16552, 2600:1801:11::1 AS16552
ns12.dnsadmin.dk 208.80.126.4 AS16552, 2600:1802:12::1 AS16552
ns13.dns-admin.dk 208.80.125.4 AS16552, 2600:1801:13::1 AS16552
ns14.dnsadmin.dk 208.80.127.4 AS16552, 2600:1802:14::1 AS16552
ns15.dns-admin.dk 208.94.149.4 AS16552, 2600:1800:15::1 AS16552
7-kabale-gratis.dkharlan.ns.cloudflare.com 108.162.195.250 AS13335, 162.159.44.250 AS13335, 172.64.35.250 AS13335, 2606:4700:58::a29f:2cfa AS13335, 2803:f800:50::6ca2:c3fa AS13335, 2a06:98c1:50::ac40:23fa AS13335
tori.ns.cloudflare.com 108.162.192.231 AS13335, 172.64.32.231 AS13335, 173.245.58.231 AS13335, 2606:4700:50::adf5:3ae7 AS13335, 2803:f800:50::6ca2:c0e7 AS13335, 2a06:98c1:50::ac40:20e7 AS13335
7-kabale.dkbeth.ns.cloudflare.com 108.162.192.103 AS13335, 172.64.32.103 AS13335, 173.245.58.103 AS13335, 2606:4700:50::adf5:3a67 AS13335, 2803:f800:50::6ca2:c067 AS13335, 2a06:98c1:50::ac40:2067 AS13335
jim.ns.cloudflare.com 108.162.193.125 AS13335, 172.64.33.125 AS13335, 173.245.59.125 AS13335, 2606:4700:58::adf5:3b7d AS13335, 2803:f800:50::6ca2:c17d AS13335, 2a06:98c1:50::ac40:217d AS13335
7-kabalen.dkbeth.ns.cloudflare.com 108.162.192.103 AS13335, 172.64.32.103 AS13335, 173.245.58.103 AS13335, 2606:4700:50::adf5:3a67 AS13335, 2803:f800:50::6ca2:c067 AS13335, 2a06:98c1:50::ac40:2067 AS13335
jim.ns.cloudflare.com 108.162.193.125 AS13335, 172.64.33.125 AS13335, 173.245.59.125 AS13335, 2606:4700:58::adf5:3b7d AS13335, 2803:f800:50::6ca2:c17d AS13335, 2a06:98c1:50::ac40:217d AS13335
7-kabaler.dkbeth.ns.cloudflare.com 108.162.192.103 AS13335, 172.64.32.103 AS13335, 173.245.58.103 AS13335, 2606:4700:50::adf5:3a67 AS13335, 2803:f800:50::6ca2:c067 AS13335, 2a06:98c1:50::ac40:2067 AS13335
jim.ns.cloudflare.com 108.162.193.125 AS13335, 172.64.33.125 AS13335, 173.245.59.125 AS13335, 2606:4700:58::adf5:3b7d AS13335, 2803:f800:50::6ca2:c17d AS13335, 2a06:98c1:50::ac40:217d AS13335
7-kanten.dkcurns01.dnsadmin.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
curns02.dnsadmin.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
7-melons.dkaspen.ns.cloudflare.com 108.162.194.109 AS13335, 162.159.38.109 AS13335, 172.64.34.109 AS13335, 2606:4700:50::a29f:266d AS13335, 2803:f800:50::6ca2:c26d AS13335, 2a06:98c1:50::ac40:226d AS13335
major.ns.cloudflare.com 108.162.193.241 AS13335, 172.64.33.241 AS13335, 173.245.59.241 AS13335, 2606:4700:58::adf5:3bf1 AS13335, 2803:f800:50::6ca2:c1f1 AS13335, 2a06:98c1:50::ac40:21f1 AS13335
7-nutrition.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
7-rocks.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
7-steel.dkns1.websupport.cz 2a10:bbc0::11 AS25234, 45.10.97.11 AS25234
ns2.websupport.cz 185.71.159.12 AS25234, 2a02:250:3::12 AS25234
ns3.websupport.eu 2a10:bbc0::13 AS25234, 45.10.97.13 AS25234
7-steelnordic.dkns1.websupport.cz 2a10:bbc0::11 AS25234, 45.10.97.11 AS25234
ns2.websupport.cz 185.71.159.12 AS25234, 2a02:250:3::12 AS25234
ns3.websupport.eu 2a10:bbc0::13 AS25234, 45.10.97.13 AS25234
7-steelservice.dkdns01.beebyte.se 185.133.204.45 AS12552, 2a01:a560::4 AS12552
dns02.beebyte.se 185.133.204.66 AS12552, 2a01:a560:0:1::8 AS12552
7-summits.dkhenrik.ns.cloudflare.com 108.162.195.105 AS13335, 162.159.44.105 AS13335, 172.64.35.105 AS13335, 2606:4700:58::a29f:2c69 AS13335, 2803:f800:50::6ca2:c369 AS13335, 2a06:98c1:50::ac40:2369 AS13335
leah.ns.cloudflare.com 108.162.192.129 AS13335, 172.64.32.129 AS13335, 173.245.58.129 AS13335, 2606:4700:50::adf5:3a81 AS13335, 2803:f800:50::6ca2:c081 AS13335, 2a06:98c1:50::ac40:2081 AS13335
70-nummer.dkns1.siteground.net 75.2.77.104 AS16509
ns2.siteground.net 99.83.229.113 AS16509
70-numre.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
70.dkns1.dreamhost.com 162.159.26.14 AS13335
ns2.dreamhost.com 162.159.26.81 AS13335
ns3.dreamhost.com 162.159.27.84 AS13335
700.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
7000-fredericia.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
7000.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
7000fredericia.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
700c.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
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