🛡️ 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

1,183,573 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1450.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3060.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6800.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,94464.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,2767.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-05 18:29).

📋 One autonomous system

757,944 domains
DomainNameservers and addresses
web-udvikleren.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
web-udvikling.dkdiva.ns.cloudflare.com 108.162.192.97 AS13335, 172.64.32.97 AS13335, 173.245.58.97 AS13335, 2606:4700:50::adf5:3a61 AS13335, 2803:f800:50::6ca2:c061 AS13335, 2a06:98c1:50::ac40:2061 AS13335
donald.ns.cloudflare.com 108.162.193.158 AS13335, 172.64.33.158 AS13335, 173.245.59.158 AS13335, 2606:4700:58::adf5:3b9e AS13335, 2803:f800:50::6ca2:c19e AS13335, 2a06:98c1:50::ac40:219e AS13335
web-unlimited.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
web-vind.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
web-vision.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
web-visitkort.dkprimary.infoserv.dk 139.162.157.8 AS63949, 2a01:7e01::f03c:91ff:fe59:943d AS63949
secondary.infoserv.dk 139.162.227.162 AS63949, 2a01:7e00::f03c:92ff:fe07:7dc2 AS63949
web-væksteren.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
web-world.dkns1.euroteam.com 178.79.171.168 AS63949
ns2.euroteam.com 178.79.141.229 AS63949
web-x.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
web001.dkns1.247-365.dk 78.157.102.120 AS39642
ns2.247-365.dk 78.157.102.120 AS39642
ns3.247-365.dk 89.184.137.24 AS39642
ns4.247-365.dk 89.184.137.24 AS39642
web002.dkns1.247-365.dk 78.157.102.120 AS39642
ns2.247-365.dk 78.157.102.120 AS39642
ns3.247-365.dk 89.184.137.24 AS39642
ns4.247-365.dk 89.184.137.24 AS39642
web003.dkns1.247-365.dk 78.157.102.120 AS39642
ns2.247-365.dk 78.157.102.120 AS39642
ns3.247-365.dk 89.184.137.24 AS39642
ns4.247-365.dk 89.184.137.24 AS39642
web004.dkns1.247-365.dk 78.157.102.120 AS39642
ns2.247-365.dk 78.157.102.120 AS39642
ns3.247-365.dk 89.184.137.24 AS39642
ns4.247-365.dk 89.184.137.24 AS39642
web005.dkns1.247-365.dk 78.157.102.120 AS39642
ns2.247-365.dk 78.157.102.120 AS39642
ns3.247-365.dk 89.184.137.24 AS39642
ns4.247-365.dk 89.184.137.24 AS39642
web006.dkns1.247-365.dk 78.157.102.120 AS39642
ns2.247-365.dk 78.157.102.120 AS39642
ns3.247-365.dk 89.184.137.24 AS39642
ns4.247-365.dk 89.184.137.24 AS39642
web10.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
web12.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
web123.dkns1-05.azure-dns.com 13.107.236.5 AS8075, 2603:1061:0:700::5 AS8075
ns2-05.azure-dns.net 150.171.21.5 AS8075, 2620:1ec:8ec:700::5 AS8075
ns3-05.azure-dns.org 204.14.183.5 AS8075, 2a01:111:4000:700::5 AS8075
ns4-05.azure-dns.info 208.84.5.5 AS8075, 2620:1ec:bda:700::5 AS8075
web24-7.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
web247.dkcheryl.ns.cloudflare.com 108.162.192.83 AS13335, 172.64.32.83 AS13335, 173.245.58.83 AS13335, 2606:4700:50::adf5:3a53 AS13335, 2803:f800:50::6ca2:c053 AS13335, 2a06:98c1:50::ac40:2053 AS13335
valentin.ns.cloudflare.com 108.162.195.206 AS13335, 162.159.44.206 AS13335, 172.64.35.206 AS13335, 2606:4700:58::a29f:2cce AS13335, 2803:f800:50::6ca2:c3ce AS13335, 2a06:98c1:50::ac40:23ce AS13335
web24x7.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
web2and4all.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
web2day.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
web2inprint.dkns.andersenit.dk 185.200.74.101 AS198614
ns1.andersenit.dk 87.238.248.10 AS198614
web2log.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
web2market.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
web2media.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
web2move.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
web2people.dkpam.ns.cloudflare.com 108.162.192.138 AS13335, 172.64.32.138 AS13335, 173.245.58.138 AS13335, 2606:4700:50::adf5:3a8a AS13335, 2803:f800:50::6ca2:c08a AS13335, 2a06:98c1:50::ac40:208a AS13335
tim.ns.cloudflare.com 108.162.193.145 AS13335, 172.64.33.145 AS13335, 173.245.59.145 AS13335, 2606:4700:58::adf5:3b91 AS13335, 2803:f800:50::6ca2:c191 AS13335, 2a06:98c1:50::ac40:2191 AS13335
web2print.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
web2sale.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
web2tryk.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
web2you.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
web3-raadgivning.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
web3.dked.ns.cloudflare.com 108.162.193.111 AS13335, 172.64.33.111 AS13335, 173.245.59.111 AS13335, 2606:4700:58::adf5:3b6f AS13335, 2803:f800:50::6ca2:c16f AS13335, 2a06:98c1:50::ac40:216f AS13335
jillian.ns.cloudflare.com 108.162.194.44 AS13335, 162.159.38.44 AS13335, 172.64.34.44 AS13335, 2606:4700:50::a29f:262c AS13335, 2803:f800:50::6ca2:c22c AS13335, 2a06:98c1:50::ac40:222c AS13335
web365.dkns1.bdm.microsoftonline.com 13.107.236.208 AS8075, 2603:1061:0:700::d0 AS8075
ns2.bdm.microsoftonline.com 150.171.21.208 AS8075, 2620:1ec:8ec:700::d0 AS8075
ns3.bdm.microsoftonline.com 204.14.183.208 AS8075, 2a01:111:4000:700::d0 AS8075
ns4.bdm.microsoftonline.com 208.84.5.208 AS8075, 2620:1ec:bda:700::d0 AS8075
web3d.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
web3zero.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
web4-raadgivning.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
web4.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
web42.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
web48.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
web4bizz.dkarushi.ns.cloudflare.com 108.162.194.61 AS13335, 162.159.38.61 AS13335, 172.64.34.61 AS13335, 2606:4700:50::a29f:263d AS13335, 2803:f800:50::6ca2:c23d AS13335, 2a06:98c1:50::ac40:223d AS13335
steven.ns.cloudflare.com 108.162.195.17 AS13335, 162.159.44.17 AS13335, 172.64.35.17 AS13335, 2606:4700:58::a29f:2c11 AS13335, 2803:f800:50::6ca2:c311 AS13335, 2a06:98c1:50::ac40:2311 AS13335
web4fun.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
web4it.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
web4marketing.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
web4me.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
web4media.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
web4one.dkbuck.ns.cloudflare.com 108.162.193.78 AS13335, 172.64.33.78 AS13335, 173.245.59.78 AS13335, 2606:4700:58::adf5:3b4e AS13335, 2803:f800:50::6ca2:c14e AS13335, 2a06:98c1:50::ac40:214e AS13335
ivy.ns.cloudflare.com 108.162.192.120 AS13335, 172.64.32.120 AS13335, 173.245.58.120 AS13335, 2606:4700:50::adf5:3a78 AS13335, 2803:f800:50::6ca2:c078 AS13335, 2a06:98c1:50::ac40:2078 AS13335
web4print.dkhattie.ns.cloudflare.com 108.162.194.172 AS13335, 162.159.38.172 AS13335, 172.64.34.172 AS13335, 2606:4700:50::a29f:26ac AS13335, 2803:f800:50::6ca2:c2ac AS13335, 2a06:98c1:50::ac40:22ac AS13335
henrik.ns.cloudflare.com 108.162.195.105 AS13335, 162.159.44.105 AS13335, 172.64.35.105 AS13335, 2606:4700:58::a29f:2c69 AS13335, 2803:f800:50::6ca2:c369 AS13335, 2a06:98c1:50::ac40:2369 AS13335
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