🛡️ 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

1,186,235 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1510.01%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 IPv610,8040.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system756,41863.8%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,9667.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-09-30 13:10).

📋 One autonomous system

756,418 domains
DomainNameservers and addresses
zaoando.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
zaolando.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
zap-dee-thai-take-away.dkns1.shellhost.dk 193.200.90.91 AS62121, 2001:67c:564::13 AS62121
ns2.shellhost.dk 193.200.91.90 AS62121, 2001:67c:564::12 AS62121
zap-it.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
zap.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
zapando.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
zaparay.dkns1.eurodns.com 199.167.66.107 AS23393, 2610:1c8:b002::107 AS23393
ns2.eurodns.com 104.37.178.107 AS23393, 2610:1c8:b001::107 AS23393
ns3.eurodns.com 199.167.66.108 AS23393, 2610:1c8:b002::108 AS23393
ns4.eurodns.com 104.37.178.108 AS23393, 2610:1c8:b001::108 AS23393
zapaya.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
zapbil.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
zapbilleasing.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
zapconcept.dkns1.wannafind.dk 185.25.141.6 AS48854, 2a02:2339:4006:103:1c:3f6d:daba:dee AS48854
ns2.wannafind.dk 2a02:2339:1:104::daba:daa AS48854, 91.197.248.69 AS48854
zapfprofi.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
zaphir.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
zaphirno1.dkns1.aveo.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.aveo.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
zapiyo.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
zapleasing.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
zapliq.dkns1.eurodns.com 199.167.66.107 AS23393, 2610:1c8:b002::107 AS23393
ns2.eurodns.com 104.37.178.107 AS23393, 2610:1c8:b001::107 AS23393
ns3.eurodns.com 199.167.66.108 AS23393, 2610:1c8:b002::108 AS23393
ns4.eurodns.com 104.37.178.108 AS23393, 2610:1c8:b001::108 AS23393
zaplo.dkns-1176.awsdns-19.org 205.251.196.152 AS16509, 2600:9000:5304:9800::1 AS16509
ns-1539.awsdns-00.co.uk 205.251.198.3 AS16509, 2600:9000:5306:300::1 AS16509
ns-821.awsdns-38.net 205.251.195.53 AS16509, 2600:9000:5303:3500::1 AS16509
ns-97.awsdns-12.com 205.251.192.97 AS16509, 2600:9000:5300:6100::1 AS16509
zapmail.dkrommy.ns.cloudflare.com 108.162.195.20 AS13335, 162.159.44.20 AS13335, 172.64.35.20 AS13335, 2606:4700:58::a29f:2c14 AS13335, 2803:f800:50::6ca2:c314 AS13335, 2a06:98c1:50::ac40:2314 AS13335
sreeni.ns.cloudflare.com 108.162.194.178 AS13335, 162.159.38.178 AS13335, 172.64.34.178 AS13335, 2606:4700:50::a29f:26b2 AS13335, 2803:f800:50::6ca2:c2b2 AS13335, 2a06:98c1:50::ac40:22b2 AS13335
zapnet.dkrommy.ns.cloudflare.com 108.162.195.20 AS13335, 162.159.44.20 AS13335, 172.64.35.20 AS13335, 2606:4700:58::a29f:2c14 AS13335, 2803:f800:50::6ca2:c314 AS13335, 2a06:98c1:50::ac40:2314 AS13335
sreeni.ns.cloudflare.com 108.162.194.178 AS13335, 162.159.38.178 AS13335, 172.64.34.178 AS13335, 2606:4700:50::a29f:26b2 AS13335, 2803:f800:50::6ca2:c2b2 AS13335, 2a06:98c1:50::ac40:22b2 AS13335
zapolskistrygerne.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
zapoteca.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
zapp-energy.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
zapp.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
zappcloud.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
zappdivers.dkdamon.ns.cloudflare.com 108.162.193.96 AS13335, 172.64.33.96 AS13335, 173.245.59.96 AS13335, 2606:4700:58::adf5:3b60 AS13335, 2803:f800:50::6ca2:c160 AS13335, 2a06:98c1:50::ac40:2160 AS13335
meilani.ns.cloudflare.com 108.162.194.196 AS13335, 162.159.38.196 AS13335, 172.64.34.196 AS13335, 2606:4700:50::a29f:26c4 AS13335, 2803:f800:50::6ca2:c2c4 AS13335, 2a06:98c1:50::ac40:22c4 AS13335
zappe.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
zapped.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
zappel.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
zappenergy.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
zappesen.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
zappmobility.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
zappo.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
zappos.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
zappshelter.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
zappy.dkns1.hosting2you.org 37.61.233.194 AS41000
ns2.hosting2you.org 193.33.178.194 AS41000
zaprinta.dkns1.eurodns.com 199.167.66.107 AS23393, 2610:1c8:b002::107 AS23393
ns2.eurodns.com 104.37.178.107 AS23393, 2610:1c8:b001::107 AS23393
ns3.eurodns.com 199.167.66.108 AS23393, 2610:1c8:b002::108 AS23393
ns4.eurodns.com 104.37.178.108 AS23393, 2610:1c8:b001::108 AS23393
zaproo.dkns-1221.awsdns-24.org 205.251.196.197 AS16509, 2600:9000:5304:c500::1 AS16509
ns-1793.awsdns-32.co.uk 205.251.199.1 AS16509, 2600:9000:5307:100::1 AS16509
ns-552.awsdns-05.net 205.251.194.40 AS16509, 2600:9000:5302:2800::1 AS16509
ns-65.awsdns-08.com 205.251.192.65 AS16509, 2600:9000:5300:4100::1 AS16509
zapshowteater.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
zapstar.dkarely.ns.cloudflare.com 108.162.194.164 AS13335, 162.159.38.164 AS13335, 172.64.34.164 AS13335, 2606:4700:50::a29f:26a4 AS13335, 2803:f800:50::6ca2:c2a4 AS13335, 2a06:98c1:50::ac40:22a4 AS13335
arnold.ns.cloudflare.com 108.162.193.69 AS13335, 172.64.33.69 AS13335, 173.245.59.69 AS13335, 2606:4700:58::adf5:3b45 AS13335, 2803:f800:50::6ca2:c145 AS13335, 2a06:98c1:50::ac40:2145 AS13335
zapteam.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
zapto.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
zaptor.dkdom.ns.cloudflare.com 108.162.193.157 AS13335, 172.64.33.157 AS13335, 173.245.59.157 AS13335, 2606:4700:58::adf5:3b9d AS13335, 2803:f800:50::6ca2:c19d AS13335, 2a06:98c1:50::ac40:219d AS13335
isabel.ns.cloudflare.com 108.162.194.104 AS13335, 162.159.38.104 AS13335, 172.64.34.104 AS13335, 2606:4700:50::a29f:2668 AS13335, 2803:f800:50::6ca2:c268 AS13335, 2a06:98c1:50::ac40:2268 AS13335
zaq1.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
zaqq.dkdesi.ns.cloudflare.com 108.162.192.96 AS13335, 172.64.32.96 AS13335, 173.245.58.96 AS13335, 2606:4700:50::adf5:3a60 AS13335, 2803:f800:50::6ca2:c060 AS13335, 2a06:98c1:50::ac40:2060 AS13335
marty.ns.cloudflare.com 108.162.193.204 AS13335, 172.64.33.204 AS13335, 173.245.59.204 AS13335, 2606:4700:58::adf5:3bcc AS13335, 2803:f800:50::6ca2:c1cc AS13335, 2a06:98c1:50::ac40:21cc AS13335
zara.dkdns1.p03.nsone.net 198.51.44.3 AS62597, 2620:4d:4000:6259:7:3:0:1 AS62597
dns2.p03.nsone.net 198.51.45.3 AS62597, 2a00:edc0:6259:7:3::2 AS62597
dns3.p03.nsone.net 198.51.44.67 AS62597, 2620:4d:4000:6259:7:3:0:3 AS62597
dns4.p03.nsone.net 198.51.45.67 AS62597, 2a00:edc0:6259:7:3::4 AS62597
zarabiam.dkparking1.ovh.net 54.37.126.92 AS16276
parking2.ovh.net 54.37.126.93 AS16276
zaracph.dkns1-08.azure-dns.com 13.107.236.8 AS8075, 2603:1061:0:700::8 AS8075
ns2-08.azure-dns.net 150.171.21.8 AS8075, 2620:1ec:8ec:700::8 AS8075
ns3-08.azure-dns.org 204.14.183.8 AS8075, 2a01:111:4000:700::8 AS8075
ns4-08.azure-dns.info 208.84.5.8 AS8075, 2620:1ec:bda:700::8 AS8075
zarada.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
zarah.dkns.andersenit.dk 185.200.74.101 AS198614
ns1.andersenit.dk 87.238.248.10 AS198614
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