🛡️ 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
advicepublishing.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
advicer.dkdeborah.ns.cloudflare.com 108.162.194.111 AS13335, 162.159.38.111 AS13335, 172.64.34.111 AS13335, 2606:4700:50::a29f:266f AS13335, 2803:f800:50::6ca2:c26f AS13335, 2a06:98c1:50::ac40:226f AS13335
sullivan.ns.cloudflare.com 108.162.195.161 AS13335, 162.159.44.161 AS13335, 172.64.35.161 AS13335, 2606:4700:58::a29f:2ca1 AS13335, 2803:f800:50::6ca2:c3a1 AS13335, 2a06:98c1:50::ac40:23a1 AS13335
advicera.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
advicerhub.dkdeborah.ns.cloudflare.com 108.162.194.111 AS13335, 162.159.38.111 AS13335, 172.64.34.111 AS13335, 2606:4700:50::a29f:266f AS13335, 2803:f800:50::6ca2:c26f AS13335, 2a06:98c1:50::ac40:226f AS13335
sullivan.ns.cloudflare.com 108.162.195.161 AS13335, 162.159.44.161 AS13335, 172.64.35.161 AS13335, 2606:4700:58::a29f:2ca1 AS13335, 2803:f800:50::6ca2:c3a1 AS13335, 2a06:98c1:50::ac40:23a1 AS13335
advida.dkbyron.ns.cloudflare.com 108.162.195.67 AS13335, 162.159.44.67 AS13335, 172.64.35.67 AS13335, 2606:4700:58::a29f:2c43 AS13335, 2803:f800:50::6ca2:c343 AS13335, 2a06:98c1:50::ac40:2343 AS13335
jamie.ns.cloudflare.com 108.162.192.168 AS13335, 172.64.32.168 AS13335, 173.245.58.168 AS13335, 2606:4700:50::adf5:3aa8 AS13335, 2803:f800:50::6ca2:c0a8 AS13335, 2a06:98c1:50::ac40:20a8 AS13335
advideora.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
adviise.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
advil.dkns-cloud-c1.googledomains.com 2001:4860:4802:32::6c AS15169, 216.239.32.108 AS15169
ns-cloud-c2.googledomains.com 2001:4860:4802:34::6c AS15169, 216.239.34.108 AS15169
ns-cloud-c3.googledomains.com 2001:4860:4802:36::6c AS15169, 216.239.36.108 AS15169
ns-cloud-c4.googledomains.com 2001:4860:4802:38::6c AS15169, 216.239.38.108 AS15169
advilcoldandsinus.dkns-cloud-c1.googledomains.com 2001:4860:4802:32::6c AS15169, 216.239.32.108 AS15169
ns-cloud-c2.googledomains.com 2001:4860:4802:34::6c AS15169, 216.239.34.108 AS15169
ns-cloud-c3.googledomains.com 2001:4860:4802:36::6c AS15169, 216.239.36.108 AS15169
ns-cloud-c4.googledomains.com 2001:4860:4802:38::6c AS15169, 216.239.38.108 AS15169
advini.dkdns106.ovh.net 2001:41d0:d01::2 AS16276, 5.196.41.1 AS16276
ns106.ovh.net 2001:41d0:b00:fa00::2 AS16276, 5.135.65.21 AS16276
advink.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
advinord.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
advio.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
advior.dkali.ns.cloudflare.com 108.162.192.59 AS13335, 172.64.32.59 AS13335, 173.245.58.59 AS13335, 2606:4700:50::adf5:3a3b AS13335, 2803:f800:50::6ca2:c03b AS13335, 2a06:98c1:50::ac40:203b AS13335
kareem.ns.cloudflare.com 108.162.195.22 AS13335, 162.159.44.22 AS13335, 172.64.35.22 AS13335, 2606:4700:58::a29f:2c16 AS13335, 2803:f800:50::6ca2:c316 AS13335, 2a06:98c1:50::ac40:2316 AS13335
advis.dkns1.edelkey.net 213.138.147.136 AS1342, 213.138.147.140 AS1342
ns2.edelkey.net 213.138.147.137 AS1342, 213.138.147.141 AS1342
advisa.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
advisedby.dkns1.aveo.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123
ns2.aveo.dk 2a02:2339:1:10f::123:123, 91.197.248.75
advisehero.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
advisement.dkeve.ns.cloudflare.com 108.162.194.204 AS13335, 162.159.38.204 AS13335, 172.64.34.204 AS13335, 2606:4700:50::a29f:26cc AS13335, 2803:f800:50::6ca2:c2cc AS13335, 2a06:98c1:50::ac40:22cc AS13335
kaiser.ns.cloudflare.com 108.162.195.9 AS13335, 162.159.44.9 AS13335, 172.64.35.9 AS13335, 2606:4700:58::a29f:2c09 AS13335, 2803:f800:50::6ca2:c309 AS13335, 2a06:98c1:50::ac40:2309 AS13335
advisence.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
advisense.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
adviser.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
adviserly.dkns1.vercel-dns.com 198.51.44.13 AS62597, 2620:4d:4000:6259:7:13:0:1 AS62597
ns2.vercel-dns.com 198.51.45.13 AS62597, 2a00:edc0:6259:7:13::2 AS62597
advisers.dkns1.telenor.dk 2001:1580:0:1806::10 AS9158, 212.242.39.142 AS9158
ns2.telenor.dk 2001:1580:0:1206::10 AS9158, 212.242.39.166 AS9158
advisia.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
advisible.dkns-cloud-e1.googledomains.com 2001:4860:4802:32::6e AS15169, 216.239.32.110 AS15169
ns-cloud-e2.googledomains.com 2001:4860:4802:34::6e AS15169, 216.239.34.110 AS15169
ns-cloud-e3.googledomains.com 2001:4860:4802:36::6e AS15169, 216.239.36.110 AS15169
ns-cloud-e4.googledomains.com 2001:4860:4802:38::6e AS15169, 216.239.38.110 AS15169
advisio.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
advision.dkns4.dns-123.net 35.198.132.83 AS396982
ns5.dns-123.net 35.187.184.173 AS396982
ns6.dns-123.net 35.228.54.1 AS396982
advisionize.dkbeau.ns.cloudflare.com 108.162.193.73 AS13335, 172.64.33.73 AS13335, 173.245.59.73 AS13335, 2606:4700:58::adf5:3b49 AS13335, 2803:f800:50::6ca2:c149 AS13335, 2a06:98c1:50::ac40:2149 AS13335
diana.ns.cloudflare.com 108.162.194.23 AS13335, 162.159.38.23 AS13335, 172.64.34.23 AS13335, 2606:4700:50::a29f:2617 AS13335, 2803:f800:50::6ca2:c217 AS13335, 2a06:98c1:50::ac40:2217 AS13335
advisiosoftware.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
advisiowelding.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
adviso.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
advisor247.dkns.datacenter.no 185.7.60.115 AS39783
ns2.datacenter.no 91.192.220.132 AS39783
advisora.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
advisorbrief.dkns-1165.awsdns-17.org 205.251.196.141 AS16509, 2600:9000:5304:8d00::1 AS16509
ns-1715.awsdns-22.co.uk 205.251.198.179 AS16509, 2600:9000:5306:b300::1 AS16509
ns-414.awsdns-51.com 205.251.193.158 AS16509, 2600:9000:5301:9e00::1 AS16509
ns-691.awsdns-22.net 205.251.194.179 AS16509, 2600:9000:5302:b300::1 AS16509
advisorhr.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
advisorii.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
advisorma.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
advisors.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
advisorwebsites.dkpdns03.domaincontrol.com 2603:5:21f0::33 AS44273, 97.74.111.51 AS44273
pdns04.domaincontrol.com 173.201.79.51 AS44273, 2603:5:22f0::33 AS44273
advisory-team.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
advisory.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
advisoryboard.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
advisoryboardasaservice.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
advisoryboards.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
advisorynord.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
advisoryserver.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
advisoryteam.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
advisorz.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
advisr.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
dhd.dk [/] search Domains, Hosts & DNS — .dk zone