🛡️ 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

1,185,715 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1490.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3130.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,8080.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system755,25063.7%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,9817.3%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-09-30 06:38).

📋 One autonomous system

755,250 domains
DomainNameservers and addresses
zoeb.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
zoedesign.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
zoef.dkns1.leaseweb.nl 23.19.196.53 AS28753, 2607:f5b5::53 AS28753
ns4.leaseweb.net 23.19.196.53 AS28753, 2607:f5b5::53 AS28753
ns5.leaseweb.nl 23.19.197.53 AS28753, 2607:f5b5:1::53 AS28753
zoegas.dkamsdns1.nestle.com 2001:502:f3ff::29a AS12008, 204.74.66.154 AS12008
aoadns1.nestle.com 204.74.67.154 AS12008, 2610:a1:1015::29a AS12008
ctrdns1.nestle.com 204.74.110.154 AS12008, 2610:a1:1014::29a AS12008
eurdns1.nestle.com 2001:502:4612::29a AS12008, 204.74.111.154 AS12008
zoekofod.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
zoeme.dkgeorgia.ns.cloudflare.com 108.162.194.48 AS13335, 162.159.38.48 AS13335, 172.64.34.48 AS13335, 2606:4700:50::a29f:2630 AS13335, 2803:f800:50::6ca2:c230 AS13335, 2a06:98c1:50::ac40:2230 AS13335
nolan.ns.cloudflare.com 108.162.195.56 AS13335, 162.159.44.56 AS13335, 172.64.35.56 AS13335, 2606:4700:58::a29f:2c38 AS13335, 2803:f800:50::6ca2:c338 AS13335, 2a06:98c1:50::ac40:2338 AS13335
zoern.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
zoes.dkns1.dreamhost.com 162.159.26.14 AS13335
ns2.dreamhost.com 162.159.26.81 AS13335
ns3.dreamhost.com 162.159.27.84 AS13335
zoetis.dkedns4.ultradns.biz 204.74.67.4 AS12008, 2610:a1:1015::204 AS12008
edns4.ultradns.com 2001:502:f3ff::204 AS12008, 204.74.66.4 AS12008
edns4.ultradns.net 204.74.110.4 AS12008, 2610:a1:1014::204 AS12008
edns4.ultradns.org 2001:502:4612::204 AS12008, 204.74.111.4 AS12008
zoetrope.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
zoeukhona.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
zoevn.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
zoewyke.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
zoey-denmark.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
zoey.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
zoeyadrianna.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
zoeyelinor.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
zoffmann-optik.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
zoffmannholm.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
zoffmannregnskab.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
zofiaenevoldsen.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
zofiia.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
zoftcorp.dkaarav.ns.cloudflare.com 108.162.195.60 AS13335, 162.159.44.60 AS13335, 172.64.35.60 AS13335, 2606:4700:58::a29f:2c3c AS13335, 2803:f800:50::6ca2:c33c AS13335, 2a06:98c1:50::ac40:233c AS13335
kim.ns.cloudflare.com 108.162.192.126 AS13335, 172.64.32.126 AS13335, 173.245.58.126 AS13335, 2606:4700:50::adf5:3a7e AS13335, 2803:f800:50::6ca2:c07e AS13335, 2a06:98c1:50::ac40:207e AS13335
zoftee.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
zoftlyx.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78
ns2.simply.com 185.25.141.15, 2a02:2339:4006:101::4562:4562
ns3.simply.com 91.197.248.79
zogajfitness.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
zoggy.dkcortney.ns.cloudflare.com 108.162.192.87 AS13335, 172.64.32.87 AS13335, 173.245.58.87 AS13335, 2606:4700:50::adf5:3a57 AS13335, 2803:f800:50::6ca2:c057 AS13335, 2a06:98c1:50::ac40:2057 AS13335
dean.ns.cloudflare.com 108.162.193.153 AS13335, 172.64.33.153 AS13335, 173.245.59.153 AS13335, 2606:4700:58::adf5:3b99 AS13335, 2803:f800:50::6ca2:c199 AS13335, 2a06:98c1:50::ac40:2199 AS13335
zogoza.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
zohair.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
zohdy.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
zohnesen.dkjarred.ns.cloudflare.com 108.162.195.126 AS13335, 162.159.44.126 AS13335, 172.64.35.126 AS13335, 2606:4700:58::a29f:2c7e AS13335, 2803:f800:50::6ca2:c37e AS13335, 2a06:98c1:50::ac40:237e AS13335
peaches.ns.cloudflare.com 108.162.194.239 AS13335, 162.159.38.239 AS13335, 172.64.34.239 AS13335, 2606:4700:50::a29f:26ef AS13335, 2803:f800:50::6ca2:c2ef AS13335, 2a06:98c1:50::ac40:22ef AS13335
zoho.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
zoid.dkcosmin.ns.cloudflare.com 108.162.195.45 AS13335, 162.159.44.45 AS13335, 172.64.35.45 AS13335, 2606:4700:58::a29f:2c2d AS13335, 2803:f800:50::6ca2:c32d AS13335, 2a06:98c1:50::ac40:232d 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
zoidberg.dkns1.dnsplatform.dk 94.130.53.176 AS24940
ns2.dnsplatform.dk 159.69.139.109 AS24940
zoj.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
zojirushi.dkrns1.rightsdns.com 172.64.52.112 AS13335, 172.64.53.26 AS13335
rns2.rightsdns.com 172.64.52.56 AS13335, 172.64.53.102 AS13335
zok.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
zokazoki.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
zokei.dkns1.instradns.com 75.2.6.34 AS16509
ns2.instradns.com 75.2.85.37 AS16509
zoko.dkstephane.ns.cloudflare.com 108.162.194.112 AS13335, 162.159.38.112 AS13335, 172.64.34.112 AS13335, 2606:4700:50::a29f:2670 AS13335, 2803:f800:50::6ca2:c270 AS13335, 2a06:98c1:50::ac40:2270 AS13335
todd.ns.cloudflare.com 108.162.193.146 AS13335, 172.64.33.146 AS13335, 173.245.59.146 AS13335, 2606:4700:58::adf5:3b92 AS13335, 2803:f800:50::6ca2:c192 AS13335, 2a06:98c1:50::ac40:2192 AS13335
zol.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
zola.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
zoladex.dkdns1.comlaude-dns.com 198.51.44.11 AS62597, 2620:4d:4000:6259:7:11:0:1 AS62597
dns2.comlaude-dns.net 198.51.45.11 AS62597, 2a00:edc0:6259:7:11::2 AS62597
dns3.comlaude-dns.co.uk 198.51.44.75 AS62597, 2620:4d:4000:6259:7:11:0:3 AS62597
dns4.comlaude-dns.eu 198.51.45.75 AS62597, 2a00:edc0:6259:7:11::4 AS62597
zolafashion.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
zolando.dkns01.brandshelter.com 193.227.117.15 AS1921, 2a04:2b00:14cc::15 AS1921
ns02.brandshelter.net 194.50.187.16 AS1921, 2a04:2b00:14dd::16 AS1921
zolaro.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
zolas.dkarcher.ns.cloudflare.com 108.162.195.136 AS13335, 162.159.44.136 AS13335, 172.64.35.136 AS13335, 2606:4700:58::a29f:2c88 AS13335, 2803:f800:50::6ca2:c388 AS13335, 2a06:98c1:50::ac40:2388 AS13335
tina.ns.cloudflare.com 108.162.192.230 AS13335, 172.64.32.230 AS13335, 173.245.58.230 AS13335, 2606:4700:50::adf5:3ae6 AS13335, 2803:f800:50::6ca2:c0e6 AS13335, 2a06:98c1:50::ac40:20e6 AS13335
zolecph.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
zolefashion.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
zolemba.dkns-1300.awsdns-34.org 205.251.197.20 AS16509, 2600:9000:5305:1400::1 AS16509
ns-1595.awsdns-07.co.uk 205.251.198.59 AS16509, 2600:9000:5306:3b00::1 AS16509
ns-41.awsdns-05.com 205.251.192.41 AS16509, 2600:9000:5300:2900::1 AS16509
ns-809.awsdns-37.net 205.251.195.41 AS16509, 2600:9000:5303:2900::1 AS16509
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