🛡️ 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

1,183,325 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1520.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3110.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6890.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,85464.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,3487.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-04 05:03).

📋 One autonomous system

757,854 domains
DomainNameservers and addresses
aarhushistorier.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
aarhushjaelper.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
aarhushjerte.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
aarhushjerteklinik.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
aarhushockey.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
aarhushomes.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
aarhushostel.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
aarhushosteloghotel.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
aarhushotel.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
aarhushovedpineterapi.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
aarhushud.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
aarhushudcenter.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
aarhushudlægen.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
aarhushudplejeklinik.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
aarhushund.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
aarhushunde.dkns1.vercel-dns.com 198.51.44.13 AS62597, 2620:4d:4000:6259:7:13:0:1 AS62597
ns2.vercel-dns.com 198.51.45.13 AS62597, 2a00:edc0:6259:7:13::2 AS62597
aarhushundeshop.dknia.ns.cloudflare.com 108.162.192.210 AS13335, 172.64.32.210 AS13335, 173.245.58.210 AS13335, 2606:4700:50::adf5:3ad2 AS13335, 2803:f800:50::6ca2:c0d2 AS13335, 2a06:98c1:50::ac40:20d2 AS13335
tosana.ns.cloudflare.com 108.162.195.43 AS13335, 162.159.44.43 AS13335, 172.64.35.43 AS13335, 2606:4700:58::a29f:2c2b AS13335, 2803:f800:50::6ca2:c32b AS13335, 2a06:98c1:50::ac40:232b AS13335
aarhushvf.dkns1.onwelcom.dk 185.51.79.241 AS205984
ns2.onwelcom.dk 185.51.79.251 AS205984
aarhushvidevareservice.dkmeiling.ns.cloudflare.com 108.162.194.254 AS13335, 162.159.38.254 AS13335, 172.64.34.254 AS13335, 2606:4700:50::a29f:26fe AS13335, 2803:f800:50::6ca2:c2fe AS13335, 2a06:98c1:50::ac40:22fe AS13335
sullivan.ns.cloudflare.com 108.162.195.161 AS13335, 162.159.44.161 AS13335, 172.64.35.161 AS13335, 2606:4700:58::a29f:2ca1 AS13335, 2803:f800:50::6ca2:c3a1 AS13335, 2a06:98c1:50::ac40:23a1 AS13335
aarhushydraulik.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
aarhushylder.dkns-1388.awsdns-45.org 205.251.197.108 AS16509, 2600:9000:5305:6c00::1 AS16509
ns-1753.awsdns-27.co.uk 205.251.198.217 AS16509, 2600:9000:5306:d900::1 AS16509
ns-369.awsdns-46.com 205.251.193.113 AS16509, 2600:9000:5301:7100::1 AS16509
ns-551.awsdns-04.net 205.251.194.39 AS16509, 2600:9000:5302:2700::1 AS16509
aarhusiaarhus.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
aarhusianer.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
aarhusianere.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
aarhusianeren.dkbayan.ns.cloudflare.com 108.162.193.72 AS13335, 172.64.33.72 AS13335, 173.245.59.72 AS13335, 2606:4700:58::adf5:3b48 AS13335, 2803:f800:50::6ca2:c148 AS13335, 2a06:98c1:50::ac40:2148 AS13335
cora.ns.cloudflare.com 108.162.194.195 AS13335, 162.159.38.195 AS13335, 172.64.34.195 AS13335, 2606:4700:50::a29f:26c3 AS13335, 2803:f800:50::6ca2:c2c3 AS13335, 2a06:98c1:50::ac40:22c3 AS13335
aarhusiansk.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
aarhusibevaegelse.dkns1.eurodns.com 199.167.66.107 AS23393, 2610:1c8:b002::107 AS23393
ns2.eurodns.com 104.37.178.107 AS23393, 2610:1c8:b001::107 AS23393
ns3.eurodns.com 199.167.66.108 AS23393, 2610:1c8:b002::108 AS23393
ns4.eurodns.com 104.37.178.108 AS23393, 2610:1c8:b001::108 AS23393
aarhusidag.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
aarhusidrætsklinik.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
aarhusiforening.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
aarhusimages.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
aarhusimpact.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
aarhusimprov.dkns1.dns-parking.com 162.159.24.201 AS13335, 2400:cb00:2049:1::a29f:18c9 AS13335
ns2.dns-parking.com 162.159.25.42 AS13335, 2400:cb00:2049:1::a29f:192a AS13335
aarhusindependent.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
aarhusinfo.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
aarhusingeniørerne.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
aarhusinside.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
aarhusinternationalhouse.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
aarhusinternationalschool.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
aarhusinvestorsummit.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
aarhusisenkram.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
aarhusisolering.dkns1.telanco.dk 84.246.245.104 AS34165
ns2.telanco.dk 84.246.247.29 AS34165
aarhusit.dkns1.site4now.net 204.188.197.246 AS46844, 204.188.197.84 AS46844, 70.39.73.45 AS46844
ns2.site4now.net 208.98.36.41 AS46844, 45.58.159.232 AS46844, 45.58.159.233 AS46844
ns3.site4now.net 208.98.36.42 AS46844, 45.58.159.230 AS46844, 45.58.159.231 AS46844
aarhusithjaelp.dkbetty.ns.cloudflare.com 108.162.192.75 AS13335, 172.64.32.75 AS13335, 173.245.58.75 AS13335, 2606:4700:50::adf5:3a4b AS13335, 2803:f800:50::6ca2:c04b AS13335, 2a06:98c1:50::ac40:204b AS13335
guy.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
aarhusithjælp.dkbetty.ns.cloudflare.com 108.162.192.75 AS13335, 172.64.32.75 AS13335, 173.245.58.75 AS13335, 2606:4700:50::adf5:3a4b AS13335, 2803:f800:50::6ca2:c04b AS13335, 2a06:98c1:50::ac40:204b AS13335
guy.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
aarhusitservice.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
aarhusjazzquartet.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
aarhusjob.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
aarhusjournalen.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
aarhusjudoklub.dkkeyla.ns.cloudflare.com 108.162.194.170 AS13335, 162.159.38.170 AS13335, 172.64.34.170 AS13335, 2606:4700:50::a29f:26aa AS13335, 2803:f800:50::6ca2:c2aa AS13335, 2a06:98c1:50::ac40:22aa AS13335
porter.ns.cloudflare.com 108.162.195.243 AS13335, 162.159.44.243 AS13335, 172.64.35.243 AS13335, 2606:4700:58::a29f:2cf3 AS13335, 2803:f800:50::6ca2:c3f3 AS13335, 2a06:98c1:50::ac40:23f3 AS13335
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