🛡️ 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
zyro.dkchad.ns.cloudflare.com 108.162.193.82 AS13335, 172.64.33.82 AS13335, 173.245.59.82 AS13335, 2606:4700:58::adf5:3b52 AS13335, 2803:f800:50::6ca2:c152 AS13335, 2a06:98c1:50::ac40:2152 AS13335
zainab.ns.cloudflare.com 108.162.194.149 AS13335, 162.159.38.149 AS13335, 172.64.34.149 AS13335, 2606:4700:50::a29f:2695 AS13335, 2803:f800:50::6ca2:c295 AS13335, 2a06:98c1:50::ac40:2295 AS13335
zyroa.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
zyron.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
zyrtify.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
zys.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
zystem.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
zystm.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
zystmlab.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
zystmmedia.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
zytet.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
zytex.dkns1.box.cache.dk 168.119.235.168 AS24940, 2a01:4f8:1c1e:6dba::1 AS24940
ns2.box.cache.dk 168.119.235.168 AS24940, 2a01:4f8:1c1e:6dba::1 AS24940
zytomics.dkns5.kasserver.com 85.13.128.3 AS34788
ns6.kasserver.com 85.13.159.101 AS34788
zyttrence.dknsgbr.comlaude.co.uk 198.51.44.11 AS62597, 2620:4d:4000:6259:7:11:0:1 AS62597
nssui.comlaude.ch 198.51.45.11 AS62597, 2a00:edc0:6259:7:11::2 AS62597
nsusa.comlaude.net 198.51.44.75 AS62597, 2620:4d:4000:6259:7:11:0:3 AS62597
zyvax.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
zyvenstudio.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
zyvera.dkbristol.ns.cloudflare.com 108.162.194.47 AS13335, 162.159.38.47 AS13335, 172.64.34.47 AS13335, 2606:4700:50::a29f:262f AS13335, 2803:f800:50::6ca2:c22f AS13335, 2a06:98c1:50::ac40:222f 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
zyx-tablet.dkns1.brandshelter.com 193.227.117.9 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
ns5.brandshelter.us 194.50.187.14 AS1921
zyxtablet.dkns-1022.awsdns-63.net 205.251.195.254 AS16509, 2600:9000:5303:fe00::1 AS16509
ns-1108.awsdns-10.org 205.251.196.84 AS16509, 2600:9000:5304:5400::1 AS16509
ns-2007.awsdns-58.co.uk 205.251.199.215 AS16509, 2600:9000:5307:d700::1 AS16509
ns-430.awsdns-53.com 205.251.193.174 AS16509, 2600:9000:5301:ae00::1 AS16509
zyz.dkns1.siteground.net 75.2.77.104 AS16509
ns2.siteground.net 99.83.229.113 AS16509
zyztech.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
zz9.dkns1.he.net 2001:470:100::2 AS6939, 216.218.130.2 AS6939
ns2.he.net 2001:470:200::2 AS6939, 216.218.131.2 AS6939
ns3.he.net 2001:470:300::2 AS6939, 216.218.132.2 AS6939
ns4.he.net 2001:470:400::2 AS6939, 216.66.1.2 AS6939
ns5.he.net 2001:470:500::2 AS6939, 216.66.80.18 AS6939
zz9pluralzalpha.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
zzbyg.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
zzegna.dkdns1.cscdns.net 156.154.130.100 AS12008, 2610:a1:1022::100 AS12008
dns2.cscdns.net 156.154.131.100 AS12008, 2610:a1:1023::100 AS12008
zzen.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
zzgames.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
zzhombres.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
zzhop.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
zzip.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
zzjam.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
zzleep.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
zzm.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
zzpit.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
zzup.dkannalise.ns.cloudflare.com 108.162.194.234 AS13335, 162.159.38.234 AS13335, 172.64.34.234 AS13335, 2606:4700:50::a29f:26ea AS13335, 2803:f800:50::6ca2:c2ea AS13335, 2a06:98c1:50::ac40:22ea AS13335
elliott.ns.cloudflare.com 108.162.195.228 AS13335, 162.159.44.228 AS13335, 172.64.35.228 AS13335, 2606:4700:58::a29f:2ce4 AS13335, 2803:f800:50::6ca2:c3e4 AS13335, 2a06:98c1:50::ac40:23e4 AS13335
zzx.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
zzyzx.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
zzzz.dkns1.dan.com 2603:5:2125::43 AS44273, 97.74.98.67 AS44273
ns2.dan.com 173.201.66.67 AS44273, 2603:5:2225::43 AS44273
zæ.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
zætlan.dklisa.ns.cloudflare.com 108.162.192.131 AS13335, 172.64.32.131 AS13335, 173.245.58.131 AS13335, 2606:4700:50::adf5:3a83 AS13335, 2803:f800:50::6ca2:c083 AS13335, 2a06:98c1:50::ac40:2083 AS13335
oswald.ns.cloudflare.com 108.162.193.218 AS13335, 172.64.33.218 AS13335, 173.245.59.218 AS13335, 2606:4700:58::adf5:3bda AS13335, 2803:f800:50::6ca2:c1da AS13335, 2a06:98c1:50::ac40:21da AS13335
zætland.dklisa.ns.cloudflare.com 108.162.192.131 AS13335, 172.64.32.131 AS13335, 173.245.58.131 AS13335, 2606:4700:50::adf5:3a83 AS13335, 2803:f800:50::6ca2:c083 AS13335, 2a06:98c1:50::ac40:2083 AS13335
oswald.ns.cloudflare.com 108.162.193.218 AS13335, 172.64.33.218 AS13335, 173.245.59.218 AS13335, 2606:4700:58::adf5:3bda AS13335, 2803:f800:50::6ca2:c1da AS13335, 2a06:98c1:50::ac40:21da AS13335
zén.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
zöllner.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
zøllner.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
zølwen.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
zørn.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
zøvn.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
zürich.dkdns1.cscdns.net 156.154.130.100 AS12008, 2610:a1:1022::100 AS12008
dns2.cscdns.net 156.154.131.100 AS12008, 2610:a1:1023::100 AS12008
ß.dkitzel.ns.cloudflare.com 108.162.194.42 AS13335, 162.159.38.42 AS13335, 172.64.34.42 AS13335, 2606:4700:50::a29f:262a AS13335, 2803:f800:50::6ca2:c22a AS13335, 2a06:98c1:50::ac40:222a AS13335
nico.ns.cloudflare.com 108.162.195.147 AS13335, 162.159.44.147 AS13335, 172.64.35.147 AS13335, 2606:4700:58::a29f:2c93 AS13335, 2803:f800:50::6ca2:c393 AS13335, 2a06:98c1:50::ac40:2393 AS13335
ä.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
äbc.dkns1.digitalocean.com 172.64.52.210 AS13335, 2606:4700:52::ac40:34d2 AS13335
ns2.digitalocean.com 172.64.53.21 AS13335, 2606:4700:5a::ac40:3515 AS13335
ns3.digitalocean.com 172.64.49.209 AS13335, 2606:4700:52::ac40:31d1 AS13335
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