🛡️ 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

1,186,285 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1470.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3030.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,7740.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system758,93564.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,7527.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-01 14:22).

📋 One autonomous system

758,935 domains
DomainNameservers and addresses
700kr.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
700vejle.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
70100100.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
70100111.dkns1.dnsatconviator.com 185.106.119.62 AS201926
ns2.dnsatconviator.com 185.106.119.63 AS201926
ns3.dnsatconviator.com 185.106.119.64 AS201926
70102030.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
70106600.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
70107700.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
70112112.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
70112407.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
70120121.dkns10.dnsadmin.dk 208.94.148.4 AS16552, 2600:1800:10::1 AS16552
ns11.dns-admin.dk 208.80.124.4 AS16552, 2600:1801:11::1 AS16552
ns12.dnsadmin.dk 208.80.126.4 AS16552, 2600:1802:12::1 AS16552
ns13.dns-admin.dk 208.80.125.4 AS16552, 2600:1801:13::1 AS16552
ns14.dnsadmin.dk 208.80.127.4 AS16552, 2600:1802:14::1 AS16552
ns15.dns-admin.dk 208.94.149.4 AS16552, 2600:1800:15::1 AS16552
70121416.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
70131060.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
70131415.dkdns.dsb.dk 193.28.147.132 AS41746
ns.dsb.dk 193.28.147.131 AS41746
70133003.dkdana.ns.cloudflare.com 108.162.192.105 AS13335, 172.64.32.105 AS13335, 173.245.58.105 AS13335, 2606:4700:50::adf5:3a69 AS13335, 2803:f800:50::6ca2:c069 AS13335, 2a06:98c1:50::ac40:2069 AS13335
john.ns.cloudflare.com 108.162.193.185 AS13335, 172.64.33.185 AS13335, 173.245.59.185 AS13335, 2606:4700:58::adf5:3bb9 AS13335, 2803:f800:50::6ca2:c1b9 AS13335, 2a06:98c1:50::ac40:21b9 AS13335
70137138.dkdante.ns.cloudflare.com 108.162.195.10 AS13335, 162.159.44.10 AS13335, 172.64.35.10 AS13335, 2606:4700:58::a29f:2c0a AS13335, 2803:f800:50::6ca2:c30a AS13335, 2a06:98c1:50::ac40:230a AS13335
mira.ns.cloudflare.com 108.162.192.204 AS13335, 172.64.32.204 AS13335, 173.245.58.204 AS13335, 2606:4700:50::adf5:3acc AS13335, 2803:f800:50::6ca2:c0cc AS13335, 2a06:98c1:50::ac40:20cc AS13335
70138080.dkns1-06.azure-dns.com 13.107.236.6 AS8075, 2603:1061:0:700::6 AS8075
ns2-06.azure-dns.net 150.171.21.6 AS8075, 2620:1ec:8ec:700::6 AS8075
ns3-06.azure-dns.org 204.14.183.6 AS8075, 2a01:111:4000:700::6 AS8075
ns4-06.azure-dns.info 208.84.5.6 AS8075, 2620:1ec:bda:700::6 AS8075
70138138.dkns1.wwi.dk 208.94.148.4 AS16552, 2600:1800:10::1 AS16552
ns2.wwi.dk 208.80.124.4 AS16552, 2600:1801:11::1 AS16552
ns3.wwi.as 208.80.126.4 AS16552, 2600:1802:12::1 AS16552
ns4.wwi.eu 208.80.125.4 AS16552, 2600:1801:13::1 AS16552
70151000.dkns10.dnsadmin.dk 208.94.148.4 AS16552, 2600:1800:10::1 AS16552
ns11.dns-admin.dk 208.80.124.4 AS16552, 2600:1801:11::1 AS16552
ns12.dnsadmin.dk 208.80.126.4 AS16552, 2600:1802:12::1 AS16552
ns13.dns-admin.dk 208.80.125.4 AS16552, 2600:1801:13::1 AS16552
ns14.dnsadmin.dk 208.80.127.4 AS16552, 2600:1802:14::1 AS16552
ns15.dns-admin.dk 208.94.149.4 AS16552, 2600:1800:15::1 AS16552
701510000.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
70151880.dkdns1.netdesign.dk 91.199.190.51 AS3292
dns2.netdesign.dk 91.199.190.52 AS3292
70155015.dkpns41.cloudns.net 185.136.96.79 AS203391, 2a06:fb00:1::1:79 AS203391
pns42.cloudns.net 185.136.97.79 AS203391, 2a06:fb00:1::2:79 AS203391
pns43.cloudns.net 185.136.98.79 AS203391, 2a06:fb00:1::3:79 AS203391
pns44.cloudns.net 185.136.99.79 AS203391, 2a06:fb00:1::4:79 AS203391
702.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
70200632.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
70201015.dkinet.dti.dk 87.54.37.66 AS3292
inet2.dti.dk 62.243.15.66 AS3292
70202022.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
70204960.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
70209944.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
70210026.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
70213214.dkns1.wwi.dk 208.94.148.4 AS16552, 2600:1800:10::1 AS16552
ns2.wwi.dk 208.80.124.4 AS16552, 2600:1801:11::1 AS16552
ns3.wwi.as 208.80.126.4 AS16552, 2600:1802:12::1 AS16552
ns4.wwi.eu 208.80.125.4 AS16552, 2600:1801:13::1 AS16552
70223545.dkns01.curadc.dk 185.158.206.52 AS212991
ns02.curadc.dk 185.158.206.53 AS212991
70225072.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
70232323.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
70233234.dkns1.dataspecialisten.dk 2a01:4f8:13b:3146::1 AS24940, 94.130.138.185 AS24940
ns2.dataspecialisten.dk 2a01:4f8:c17:5f0a::2 AS24940, 88.99.15.5 AS24940
70234512.dkabby.ns.cloudflare.com 108.162.192.100 AS13335, 172.64.32.100 AS13335, 173.245.58.100 AS13335, 2606:4700:50::adf5:3a64 AS13335, 2803:f800:50::6ca2:c064 AS13335, 2a06:98c1:50::ac40:2064 AS13335
olof.ns.cloudflare.com 108.162.195.51 AS13335, 162.159.44.51 AS13335, 172.64.35.51 AS13335, 2606:4700:58::a29f:2c33 AS13335, 2803:f800:50::6ca2:c333 AS13335, 2a06:98c1:50::ac40:2333 AS13335
70235700.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
70235770.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
70237732.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
70251517.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
70252518.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
70253515.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
70253630.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
70260000.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
70261272.dkns0.dnsmadeeasy.com 208.94.148.2 AS16552, 2600:1800::1 AS16552
ns1.dnsmadeeasy.com 208.80.124.2 AS16552, 2600:1801:1::1 AS16552
ns2.dnsmadeeasy.com 208.80.126.2 AS16552, 2600:1802:2::1 AS16552
ns3.dnsmadeeasy.com 208.80.125.2 AS16552, 2600:1801:3::1 AS16552
ns4.dnsmadeeasy.com 208.80.127.2 AS16552, 2600:1802:4::1 AS16552
70261880.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
70262444.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
70266000.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
70267730.dkns1.novaram.net 84.246.245.111 AS34165
ns2.novaram.net 84.246.245.113 AS34165
70279707.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
7030.dkbrad.ns.cloudflare.com 108.162.193.105 AS13335, 172.64.33.105 AS13335, 173.245.59.105 AS13335, 2606:4700:58::adf5:3b69 AS13335, 2803:f800:50::6ca2:c169 AS13335, 2a06:98c1:50::ac40:2169 AS13335
raquel.ns.cloudflare.com 108.162.194.210 AS13335, 162.159.38.210 AS13335, 172.64.34.210 AS13335, 2606:4700:50::a29f:26d2 AS13335, 2803:f800:50::6ca2:c2d2 AS13335, 2a06:98c1:50::ac40:22d2 AS13335
70300300.dkjay.ns.cloudflare.com 108.162.193.123 AS13335, 172.64.33.123 AS13335, 173.245.59.123 AS13335, 2606:4700:58::adf5:3b7b AS13335, 2803:f800:50::6ca2:c17b AS13335, 2a06:98c1:50::ac40:217b AS13335
uma.ns.cloudflare.com 108.162.192.146 AS13335, 172.64.32.146 AS13335, 173.245.58.146 AS13335, 2606:4700:50::adf5:3a92 AS13335, 2803:f800:50::6ca2:c092 AS13335, 2a06:98c1:50::ac40:2092 AS13335
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