🛡️ 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

1,183,573 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1450.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3060.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6800.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,94464.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,2767.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-05 18:29).

📋 One autonomous system

757,944 domains
DomainNameservers and addresses
admobility.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
admore.dkrocco.ns.cloudflare.com 108.162.195.121 AS13335, 162.159.44.121 AS13335, 172.64.35.121 AS13335, 2606:4700:58::a29f:2c79 AS13335, 2803:f800:50::6ca2:c379 AS13335, 2a06:98c1:50::ac40:2379 AS13335
uma.ns.cloudflare.com 108.162.192.146 AS13335, 172.64.32.146 AS13335, 173.245.58.146 AS13335, 2606:4700:50::adf5:3a92 AS13335, 2803:f800:50::6ca2:c092 AS13335, 2a06:98c1:50::ac40:2092 AS13335
adms.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
admservice.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
admship.dkns1.msvit.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.msvit.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
admsys.dkns01.stil.dk 195.231.240.53 AS3240, 2a10:cf80:1000:0:195:231:240:53 AS3240
ns02.stil.dk 195.231.128.53 AS3240, 2a10:cf80:2000:0:195:231:128:53 AS3240
ns03.stil.dk 195.231.236.53 AS3240, 2a10:cf80:1000:0:195:231:236:53 AS3240
ns04.stil.dk 195.231.129.53 AS3240, 2a10:cf80:2000:0:195:231:129:53 AS3240
admtech.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
admtek.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
admundo.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
dayana.ns.cloudflare.com 108.162.194.103 AS13335, 162.159.38.103 AS13335, 172.64.34.103 AS13335, 2606:4700:50::a29f:2667 AS13335, 2803:f800:50::6ca2:c267 AS13335, 2a06:98c1:50::ac40:2267 AS13335
adna.dkdane.ns.cloudflare.com 108.162.193.97 AS13335, 172.64.33.97 AS13335, 173.245.59.97 AS13335, 2606:4700:58::adf5:3b61 AS13335, 2803:f800:50::6ca2:c161 AS13335, 2a06:98c1:50::ac40:2161 AS13335
nora.ns.cloudflare.com 108.162.192.213 AS13335, 172.64.32.213 AS13335, 173.245.58.213 AS13335, 2606:4700:50::adf5:3ad5 AS13335, 2803:f800:50::6ca2:c0d5 AS13335, 2a06:98c1:50::ac40:20d5 AS13335
adnami.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
adnanaladhami.dkns8.wixdns.net 216.239.32.101 AS15169
ns9.wixdns.net 216.239.34.101 AS15169
adnandupont.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
adnation.dkns4.wixdns.net 216.239.36.101 AS15169
ns5.wixdns.net 216.239.38.101 AS15169
adnbyg.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
adnetics.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
adnic.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
adnik.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
adnoa.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
adnoccph.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
adnordic.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
adnordics.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
adnotam.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
adnovation.dkdorthy.ns.cloudflare.com 108.162.192.249 AS13335, 172.64.32.249 AS13335, 173.245.58.249 AS13335, 2606:4700:50::adf5:3af9 AS13335, 2803:f800:50::6ca2:c0f9 AS13335, 2a06:98c1:50::ac40:20f9 AS13335
kyree.ns.cloudflare.com 108.162.195.207 AS13335, 162.159.44.207 AS13335, 172.64.35.207 AS13335, 2606:4700:58::a29f:2ccf AS13335, 2803:f800:50::6ca2:c3cf AS13335, 2a06:98c1:50::ac40:23cf AS13335
adnskespil.dkns1-38.azure-dns.com 150.171.10.38 AS8075, 2603:1061:0:10::26 AS8075
ns2-38.azure-dns.net 150.171.16.38 AS8075, 2620:1ec:8ec:10::26 AS8075
ns3-38.azure-dns.org 13.107.222.38 AS8075, 2a01:111:4000:10::26 AS8075
ns4-38.azure-dns.info 13.107.206.38 AS8075, 2620:1ec:bda:10::26 AS8075
adnudger.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
adnudging.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
ado16.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
adobe-direct.dkns201.adobe.net 2001:502:f3ff::e AS12008, 204.74.108.252 AS12008
ns202.adobe.net 204.74.109.252 AS12008, 2610:a1:1014::e AS12008
ns203.adobe.net 199.7.68.252 AS12008, 2610:a1:1015::e AS12008
ns204.adobe.net 199.7.69.252 AS12008, 2001:502:4612::e AS12008
ns205.adobe.net 204.74.114.252 AS12008, 2610:a1:1016::e AS12008
ns206.adobe.net 204.74.115.252 AS12008, 2610:a1:1017::e AS12008
adock.dkns1.instradns.com 75.2.6.34 AS16509
ns2.instradns.com 75.2.85.37 AS16509
ns3.instradns.com 99.83.188.20 AS16509
adocon.dkns1.bdm.microsoftonline.com 13.107.236.208 AS8075, 2603:1061:0:700::d0 AS8075
ns2.bdm.microsoftonline.com 150.171.21.208 AS8075, 2620:1ec:8ec:700::d0 AS8075
ns3.bdm.microsoftonline.com 204.14.183.208 AS8075, 2a01:111:4000:700::d0 AS8075
ns4.bdm.microsoftonline.com 208.84.5.208 AS8075, 2620:1ec:bda:700::d0 AS8075
adoflhitler.dkelsa.ns.cloudflare.com 108.162.192.111 AS13335, 172.64.32.111 AS13335, 173.245.58.111 AS13335, 2606:4700:50::adf5:3a6f AS13335, 2803:f800:50::6ca2:c06f AS13335, 2a06:98c1:50::ac40:206f AS13335
robert.ns.cloudflare.com 108.162.195.140 AS13335, 162.159.44.140 AS13335, 172.64.35.140 AS13335, 2606:4700:58::a29f:2c8c AS13335, 2803:f800:50::6ca2:c38c AS13335, 2a06:98c1:50::ac40:238c AS13335
adoleo.dkns1.ispapi.net 194.50.187.134 AS1921, 2a04:2b00:14cc::4 AS1921
ns2.ispapi.net 194.0.182.1 AS1921, 2a04:2b00:14dd::4 AS1921
ns3.ispapi.net 193.227.117.124 AS1921, 2a04:2b00:14ee::4 AS1921
adolfhitler.dkaaden.ns.cloudflare.com 108.162.195.92 AS13335, 162.159.44.92 AS13335, 172.64.35.92 AS13335, 2606:4700:58::a29f:2c5c AS13335, 2803:f800:50::6ca2:c35c AS13335, 2a06:98c1:50::ac40:235c AS13335
selah.ns.cloudflare.com 108.162.194.21 AS13335, 162.159.38.21 AS13335, 172.64.34.21 AS13335, 2606:4700:50::a29f:2615 AS13335, 2803:f800:50::6ca2:c215 AS13335, 2a06:98c1:50::ac40:2215 AS13335
adolfmeister.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
adolph.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
adomas.dkbyte.dns-parking.com 172.64.53.67 AS13335, 2606:4700:5a::ac40:3543 AS13335
pixel.dns-parking.com 172.64.52.230 AS13335, 2606:4700:52::ac40:34e6 AS13335
adomeitogco.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
adomsten.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
adon.dkbarbara.ns.cloudflare.com 108.162.192.248 AS13335, 172.64.32.248 AS13335, 173.245.58.248 AS13335, 2606:4700:50::adf5:3af8 AS13335, 2803:f800:50::6ca2:c0f8 AS13335, 2a06:98c1:50::ac40:20f8 AS13335
dan.ns.cloudflare.com 108.162.193.108 AS13335, 172.64.33.108 AS13335, 173.245.59.108 AS13335, 2606:4700:58::adf5:3b6c AS13335, 2803:f800:50::6ca2:c16c AS13335, 2a06:98c1:50::ac40:216c AS13335
adonai.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
adonaj.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
adonis-klinik.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
adonis.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
adonisbeauty.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
adonisblomster.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
adonisvej36.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
adonline.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
adonyssklinik.dkns1.openprovider.nl 162.159.26.10 AS13335, 2400:cb00:2049:1::a29f:1a0a AS13335
ns2.openprovider.be 162.159.27.96 AS13335, 2400:cb00:2049:1::a29f:1b60 AS13335
ns3.openprovider.eu 162.159.48.89 AS13335, 2400:cb00:2049:1::a29f:3059 AS13335
adoodleaday.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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