🛡️ 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
zolenergi.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
zoles.dkns-1454.awsdns-53.org 205.251.197.174 AS16509, 2600:9000:5305:ae00::1 AS16509
ns-2026.awsdns-61.co.uk 205.251.199.234 AS16509, 2600:9000:5307:ea00::1 AS16509
ns-476.awsdns-59.com 205.251.193.220 AS16509, 2600:9000:5301:dc00::1 AS16509
ns-649.awsdns-17.net 205.251.194.137 AS16509, 2600:9000:5302:8900::1 AS16509
zolex.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
zolgt.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
zolid.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
zolidtal.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
zolio.dkns1.siteground.net 75.2.77.104 AS16509
ns2.siteground.net 99.83.229.113 AS16509
zoll.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
zoll3.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
zollaed.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
zollaed3.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
zollaeds.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
zollantik.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
zollantiques.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
ns4.simply.com 91.197.248.80
zoller-byg.dkchris.ns.cloudflare.com 108.162.193.85 AS13335, 172.64.33.85 AS13335, 173.245.59.85 AS13335, 2606:4700:58::adf5:3b55 AS13335, 2803:f800:50::6ca2:c155 AS13335, 2a06:98c1:50::ac40:2155 AS13335
dell.ns.cloudflare.com 108.162.192.94 AS13335, 172.64.32.94 AS13335, 173.245.58.94 AS13335, 2606:4700:50::adf5:3a5e AS13335, 2803:f800:50::6ca2:c05e AS13335, 2a06:98c1:50::ac40:205e AS13335
zoller.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
zollgaard.dkclark.ns.cloudflare.com 108.162.193.87 AS13335, 172.64.33.87 AS13335, 173.245.59.87 AS13335, 2606:4700:58::adf5:3b57 AS13335, 2803:f800:50::6ca2:c157 AS13335, 2a06:98c1:50::ac40:2157 AS13335
magnolia.ns.cloudflare.com 108.162.194.214 AS13335, 162.159.38.214 AS13335, 172.64.34.214 AS13335, 2606:4700:50::a29f:26d6 AS13335, 2803:f800:50::6ca2:c2d6 AS13335, 2a06:98c1:50::ac40:22d6 AS13335
zollhjertestarter.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
zollmedical.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
zollner.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
zollwerk.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
zolo-ark.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
zoloft.dkns-1320.awsdns-37.org 205.251.197.40 AS16509, 2600:9000:5305:2800::1 AS16509
ns-1602.awsdns-08.co.uk 205.251.198.66 AS16509, 2600:9000:5306:4200::1 AS16509
ns-397.awsdns-49.com 205.251.193.141 AS16509, 2600:9000:5301:8d00::1 AS16509
ns-948.awsdns-54.net 205.251.195.180 AS16509, 2600:9000:5303:b400::1 AS16509
zologroup.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
zolomio.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
zolt.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
zolutionz.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
zolva.dklove.ns.cloudflare.com 108.162.194.119 AS13335, 162.159.38.119 AS13335, 172.64.34.119 AS13335, 2606:4700:50::a29f:2677 AS13335, 2803:f800:50::6ca2:c277 AS13335, 2a06:98c1:50::ac40:2277 AS13335
viddy.ns.cloudflare.com 108.162.195.99 AS13335, 162.159.44.99 AS13335, 172.64.35.99 AS13335, 2606:4700:58::a29f:2c63 AS13335, 2803:f800:50::6ca2:c363 AS13335, 2a06:98c1:50::ac40:2363 AS13335
zolwen.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
zom.dkcarol.ns.cloudflare.com 108.162.192.80 AS13335, 172.64.32.80 AS13335, 173.245.58.80 AS13335, 2606:4700:50::adf5:3a50 AS13335, 2803:f800:50::6ca2:c050 AS13335, 2a06:98c1:50::ac40:2050 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
zoma.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
zomacare.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
zomacton.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
zomas.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
zomaterapi.dkns8.wixdns.net 216.239.32.101 AS15169
ns9.wixdns.net 216.239.34.101 AS15169
zomato.dkns-1174.awsdns-18.org 205.251.196.150 AS16509, 2600:9000:5304:9600::1 AS16509
ns-1627.awsdns-11.co.uk 205.251.198.91 AS16509, 2600:9000:5306:5b00::1 AS16509
ns-466.awsdns-58.com 205.251.193.210 AS16509, 2600:9000:5301:d200::1 AS16509
ns-807.awsdns-36.net 205.251.195.39 AS16509, 2600:9000:5303:2700::1 AS16509
zomax.dkhugh.ns.cloudflare.com 108.162.193.117 AS13335, 172.64.33.117 AS13335, 173.245.59.117 AS13335, 2606:4700:58::adf5:3b75 AS13335, 2803:f800:50::6ca2:c175 AS13335, 2a06:98c1:50::ac40:2175 AS13335
zara.ns.cloudflare.com 108.162.192.148 AS13335, 172.64.32.148 AS13335, 173.245.58.148 AS13335, 2606:4700:50::adf5:3a94 AS13335, 2803:f800:50::6ca2:c094 AS13335, 2a06:98c1:50::ac40:2094 AS13335
zombi.dkns1.parkingcrew.net 13.248.158.159 AS16509
ns2.parkingcrew.net 76.223.21.9 AS16509
zombieescape.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
zombiegaming.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
zombieludo.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
zombien.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
zombierobotics.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
zombies.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
zombievaccine.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
zome.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
zomima.dkmitchell.ns.cloudflare.com 108.162.195.231 AS13335, 162.159.44.231 AS13335, 172.64.35.231 AS13335, 2606:4700:58::a29f:2ce7 AS13335, 2803:f800:50::6ca2:c3e7 AS13335, 2a06:98c1:50::ac40:23e7 AS13335
riya.ns.cloudflare.com 108.162.194.155 AS13335, 162.159.38.155 AS13335, 172.64.34.155 AS13335, 2606:4700:50::a29f:269b AS13335, 2803:f800:50::6ca2:c29b AS13335, 2a06:98c1:50::ac40:229b AS13335
zonagro.dkns2.wixdns.net 216.239.36.100 AS15169
ns3.wixdns.net 216.239.38.100 AS15169
zonal.dkjoan.ns.cloudflare.com 108.162.192.173 AS13335, 172.64.32.173 AS13335, 173.245.58.173 AS13335, 2606:4700:50::adf5:3aad AS13335, 2803:f800:50::6ca2:c0ad AS13335, 2a06:98c1:50::ac40:20ad AS13335
lloyd.ns.cloudflare.com 108.162.193.197 AS13335, 172.64.33.197 AS13335, 173.245.59.197 AS13335, 2606:4700:58::adf5:3bc5 AS13335, 2803:f800:50::6ca2:c1c5 AS13335, 2a06:98c1:50::ac40:21c5 AS13335
zonavita.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
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