🛡️ 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
aho.dkbeth.ns.cloudflare.com 108.162.192.103 AS13335, 172.64.32.103 AS13335, 173.245.58.103 AS13335, 2606:4700:50::adf5:3a67 AS13335, 2803:f800:50::6ca2:c067 AS13335, 2a06:98c1:50::ac40:2067 AS13335
jim.ns.cloudflare.com 108.162.193.125 AS13335, 172.64.33.125 AS13335, 173.245.59.125 AS13335, 2606:4700:58::adf5:3b7d AS13335, 2803:f800:50::6ca2:c17d AS13335, 2a06:98c1:50::ac40:217d AS13335
ahoarkitekter.dkns1.wordpress.com 198.181.116.9 AS2635, 2a04:fa87:ffff::c6b5:7409 AS2635
ns2.wordpress.com 198.181.117.9 AS2635, 2a04:fa87:ffff::c6b5:7509 AS2635
ns3.wordpress.com 192.0.74.9 AS2635, 2620:115:c00f::c000:4a09 AS2635
ahoc.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
ahodense.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
ahoejfeldt.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
ahoejgaard.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
ahoejslev.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
ahoi.dkns5.kasserver.com 85.13.128.3 AS34788
ns6.kasserver.com 85.13.159.101 AS34788
ahokeramik.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
ahol.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
aholatransport.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
ahold.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
aholiday.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
aholm.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
aholst-tomrer.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
aholst.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
ahonnens.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
ahop.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
ahorizon.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
ahorn-camp.dkns5.kasserver.com 85.13.128.3 AS34788
ns6.kasserver.com 85.13.159.101 AS34788
ahorn.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
ahornantik.dkns7.bricksite.net 35.246.226.10 AS396982
ns8.bricksite.net 35.242.190.82 AS396982
ahorncamp.dkns5.kasserver.com 85.13.128.3 AS34788
ns6.kasserver.com 85.13.159.101 AS34788
ahornkronen.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
ahornlunden.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
ahornraekkerne-soekvarteret.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
ahornsgade8ac.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
ahorntræ.dknoel.ns.cloudflare.com 108.162.193.216 AS13335, 172.64.33.216 AS13335, 173.245.59.216 AS13335, 2606:4700:58::adf5:3bd8 AS13335, 2803:f800:50::6ca2:c1d8 AS13335, 2a06:98c1:50::ac40:21d8 AS13335
ulla.ns.cloudflare.com 108.162.192.233 AS13335, 172.64.32.233 AS13335, 173.245.58.233 AS13335, 2606:4700:50::adf5:3ae9 AS13335, 2803:f800:50::6ca2:c0e9 AS13335, 2a06:98c1:50::ac40:20e9 AS13335
ahornvej5.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
ahos.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
ahosmind.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
ahost.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
ahot.dkdanica.ns.cloudflare.com 108.162.194.187 AS13335, 162.159.38.187 AS13335, 172.64.34.187 AS13335, 2606:4700:50::a29f:26bb AS13335, 2803:f800:50::6ca2:c2bb AS13335, 2a06:98c1:50::ac40:22bb AS13335
zeus.ns.cloudflare.com 108.162.193.249 AS13335, 172.64.33.249 AS13335, 173.245.59.249 AS13335, 2606:4700:58::adf5:3bf9 AS13335, 2803:f800:50::6ca2:c1f9 AS13335, 2a06:98c1:50::ac40:21f9 AS13335
ahouseofhair-varde.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
ahovgaard.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
ahoy.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
ahp-vin.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
ahpaintingaps.dkns1.mysecurecloudhost.com 13.248.158.180 AS16509
ns2.mysecurecloudhost.com 75.2.118.134 AS16509
ns3.mysecurecloudhost.com 76.223.26.245 AS16509
ns4.mysecurecloudhost.com 99.83.147.209 AS16509
ahpfly.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
ahphotography.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
ahpro.dkns14.wixdns.net 216.239.32.100 AS15169
ns15.wixdns.net 216.239.34.100 AS15169
ahpvvs.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
ahracing.dkns-1139.awsdns-14.org 205.251.196.115 AS16509, 2600:9000:5304:7300::1 AS16509
ns-1594.awsdns-07.co.uk 205.251.198.58 AS16509, 2600:9000:5306:3a00::1 AS16509
ns-369.awsdns-46.com 205.251.193.113 AS16509, 2600:9000:5301:7100::1 AS16509
ns-641.awsdns-16.net 205.251.194.129 AS16509, 2600:9000:5302:8100::1 AS16509
ahracingogmc.dkns-1394.awsdns-46.org 205.251.197.114 AS16509, 2600:9000:5305:7200::1 AS16509
ns-1855.awsdns-39.co.uk 205.251.199.63 AS16509, 2600:9000:5307:3f00::1 AS16509
ns-236.awsdns-29.com 205.251.192.236 AS16509, 2600:9000:5300:ec00::1 AS16509
ns-778.awsdns-33.net 205.251.195.10 AS16509, 2600:9000:5303:a00::1 AS16509
ahrasmussen.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
ahrefs.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
ahregnskabsassistance.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
ahrendt-jensen-el-entreprise.dkns1.gnrx.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
ns2.gnrx.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
ahrendtsen.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
ahrendtspsp.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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