🛡️ 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
advera.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
adverco.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
adverfy.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
adverise.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
adverr.dkaugustus.ns.cloudflare.com 108.162.195.2 AS13335, 162.159.44.2 AS13335, 172.64.35.2 AS13335, 2606:4700:58::a29f:2c02 AS13335, 2803:f800:50::6ca2:c302 AS13335, 2a06:98c1:50::ac40:2302 AS13335
evangeline.ns.cloudflare.com 108.162.194.6 AS13335, 162.159.38.6 AS13335, 172.64.34.6 AS13335, 2606:4700:50::a29f:2606 AS13335, 2803:f800:50::6ca2:c206 AS13335, 2a06:98c1:50::ac40:2206 AS13335
adversus-internal.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
adversus-server.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
adversus.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
advert.dkstan.ns.cloudflare.com 108.162.193.235 AS13335, 172.64.33.235 AS13335, 173.245.59.235 AS13335, 2606:4700:58::adf5:3beb AS13335, 2803:f800:50::6ca2:c1eb AS13335, 2a06:98c1:50::ac40:21eb AS13335
ullis.ns.cloudflare.com 108.162.194.127 AS13335, 162.159.38.127 AS13335, 172.64.34.127 AS13335, 2606:4700:50::a29f:267f AS13335, 2803:f800:50::6ca2:c27f AS13335, 2a06:98c1:50::ac40:227f AS13335
advertheis.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
adverti.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
advertic.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
advertiger.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
advertime.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
advertise.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
advertiseme.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
advertisers.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
advertising.dkns1.parkingcrew.net 13.248.158.159 AS16509
ns2.parkingcrew.net 76.223.21.9 AS16509
advertisinggifts.dkauth200.ns.uu.net 195.129.12.82 AS702, 2001:600:1c0:e000::35:2 AS702
auth210.ns.uu.net 195.129.12.74 AS702, 2001:600:1c0:e001::35:2 AS702
advertize.dketta.ns.cloudflare.com 108.162.192.156 AS13335, 172.64.32.156 AS13335, 173.245.58.156 AS13335, 2606:4700:50::adf5:3a9c AS13335, 2803:f800:50::6ca2:c09c AS13335, 2a06:98c1:50::ac40:209c AS13335
watson.ns.cloudflare.com 108.162.195.23 AS13335, 162.159.44.23 AS13335, 172.64.35.23 AS13335, 2606:4700:58::a29f:2c17 AS13335, 2803:f800:50::6ca2:c317 AS13335, 2a06:98c1:50::ac40:2317 AS13335
advertorials.dkns1.parkingcrew.net 13.248.158.159 AS16509
ns2.parkingcrew.net 76.223.21.9 AS16509
adverts.dkstan.ns.cloudflare.com 108.162.193.235 AS13335, 172.64.33.235 AS13335, 173.245.59.235 AS13335, 2606:4700:58::adf5:3beb AS13335, 2803:f800:50::6ca2:c1eb AS13335, 2a06:98c1:50::ac40:21eb AS13335
ullis.ns.cloudflare.com 108.162.194.127 AS13335, 162.159.38.127 AS13335, 172.64.34.127 AS13335, 2606:4700:50::a29f:267f AS13335, 2803:f800:50::6ca2:c27f AS13335, 2a06:98c1:50::ac40:227f AS13335
adveva.dkns1.brandshelter.com 193.227.117.9 AS1921, 2a04:2b00:14cc::9 AS1921
ns2.brandshelter.de 194.50.187.11 AS1921, 2a04:2b00:14dd::11 AS1921
ns3.brandshelter.info 194.0.182.12 AS1921, 2a04:2b00:14ee::12 AS1921
ns4.brandshelter.net 193.227.117.10 AS1921, 2a04:2b00:14cc::10 AS1921
ns5.brandshelter.us 194.50.187.14 AS1921, 2a04:2b00:14dd::14 AS1921
advexo.dkchelsea.ns.cloudflare.com 108.162.194.177 AS13335, 162.159.38.177 AS13335, 172.64.34.177 AS13335, 2606:4700:50::a29f:26b1 AS13335, 2803:f800:50::6ca2:c2b1 AS13335, 2a06:98c1:50::ac40:22b1 AS13335
sonny.ns.cloudflare.com 108.162.195.66 AS13335, 162.159.44.66 AS13335, 172.64.35.66 AS13335, 2606:4700:58::a29f:2c42 AS13335, 2803:f800:50::6ca2:c342 AS13335, 2a06:98c1:50::ac40:2342 AS13335
advfalkronne.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
advfinance.dkns.datacenter.no 185.7.60.115 AS39783
ns2.datacenter.no 91.192.220.132 AS39783
advfrb.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
advfønix.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
advhannibal.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
advic.dkns1.telecomx.dk 62.192.160.190 AS205984
ns2.telecomx.dk 62.192.160.191 AS205984
advica.dkns1.siteground.net 75.2.77.104 AS16509
ns2.siteground.net 99.83.229.113 AS16509
advice-it.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
advice-plus.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
advice.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
advice360.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
adviceas.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
adviceasdev.dkcoraline.ns.cloudflare.com 108.162.194.88 AS13335, 162.159.38.88 AS13335, 172.64.34.88 AS13335, 2606:4700:50::a29f:2658 AS13335, 2803:f800:50::6ca2:c258 AS13335, 2a06:98c1:50::ac40:2258 AS13335
huxley.ns.cloudflare.com 108.162.195.188 AS13335, 162.159.44.188 AS13335, 172.64.35.188 AS13335, 2606:4700:58::a29f:2cbc AS13335, 2803:f800:50::6ca2:c3bc AS13335, 2a06:98c1:50::ac40:23bc AS13335
advicebolig.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
advicebridges.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
advicecapital.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
advicedbyb.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
advicedigital.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
advicehero.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
adviceit.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
advicelaw.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
advicemarketing.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
advicenet.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
advicepensionogforsikring.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
advicepeople.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
advicepf.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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