🛡️ 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
zebra-kortprinter.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
zebra-pro.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
zebra.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
zebraanimation.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
zebracard.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
zebraconsulting.dkns-cloud-a1.googledomains.com 2001:4860:4802:32::6a AS15169, 216.239.32.106 AS15169
ns-cloud-a2.googledomains.com 2001:4860:4802:34::6a AS15169, 216.239.34.106 AS15169
ns-cloud-a3.googledomains.com 2001:4860:4802:36::6a AS15169, 216.239.36.106 AS15169
ns-cloud-a4.googledomains.com 2001:4860:4802:38::6a AS15169, 216.239.38.106 AS15169
zebradrab.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
zebraejendomsservice.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
zebraen.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
zebraetiketter.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
zebrafilm.dkns1.curanet.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123
ns2.curanet.dk 2a02:2339:1:10f::123:123, 91.197.248.75
zebrafolier.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
zebragruppen.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
zebrahest.dkmartin.ns.cloudflare.com 108.162.195.87 AS13335, 162.159.44.87 AS13335, 172.64.35.87 AS13335, 2606:4700:58::a29f:2c57 AS13335, 2803:f800:50::6ca2:c357 AS13335, 2a06:98c1:50::ac40:2357 AS13335
miki.ns.cloudflare.com 108.162.192.202 AS13335, 172.64.32.202 AS13335, 173.245.58.202 AS13335, 2606:4700:50::adf5:3aca AS13335, 2803:f800:50::6ca2:c0ca AS13335, 2a06:98c1:50::ac40:20ca AS13335
zebrahouse-aarhus.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
zebrahouseaarhus.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
zebrakill.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
zebraklubben.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
zebrakonsulenterne.dkns2.wixdns.net 216.239.36.100 AS15169
ns3.wixdns.net 216.239.38.100 AS15169
zebrakortprinter.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
zebraplus.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
zebraprint.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
zebrarengøring.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
zebrarevision.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
zebraskind.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
zebrasoft.dkjeff.ns.cloudflare.com 108.162.193.124 AS13335, 172.64.33.124 AS13335, 173.245.59.124 AS13335, 2606:4700:58::adf5:3b7c AS13335, 2803:f800:50::6ca2:c17c AS13335, 2a06:98c1:50::ac40:217c AS13335
pat.ns.cloudflare.com 108.162.192.139 AS13335, 172.64.32.139 AS13335, 173.245.58.139 AS13335, 2606:4700:50::adf5:3a8b AS13335, 2803:f800:50::6ca2:c08b AS13335, 2a06:98c1:50::ac40:208b AS13335
zebrass.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
zebrastudio.dkns1.zebrastudio.eu 77.235.46.47 AS60781
ns2.zebrastudio.eu 77.235.46.47 AS60781
zebravo.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
zebrawins.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
zebrazipship.dkns10.digicertdns.com 208.94.148.159 AS16552, 2600:1800::1:1f AS16552
ns11.digicertdns.com 208.80.124.159 AS16552, 2600:1801:1::1:1f AS16552
ns12.digicertdns.com 208.80.126.159 AS16552, 2600:1802:2::1:1f AS16552
ns13.digicertdns.net 208.80.125.159 AS16552, 2600:1801:3::1:1f AS16552
ns14.digicertdns.net 208.80.127.159 AS16552, 2600:1802:4::1:1f AS16552
ns15.digicertdns.net 208.94.149.159 AS16552, 2600:1800:8::1:1f AS16552
zebus.dkmary.ns.cloudflare.com 108.162.192.134 AS13335, 172.64.32.134 AS13335, 173.245.58.134 AS13335, 2606:4700:50::adf5:3a86 AS13335, 2803:f800:50::6ca2:c086 AS13335, 2a06:98c1:50::ac40:2086 AS13335
oswald.ns.cloudflare.com 108.162.193.218 AS13335, 172.64.33.218 AS13335, 173.245.59.218 AS13335, 2606:4700:58::adf5:3bda AS13335, 2803:f800:50::6ca2:c1da AS13335, 2a06:98c1:50::ac40:21da AS13335
zecevic.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
zechel.dkns5.kasserver.com 85.13.128.3 AS34788
ns6.kasserver.com 85.13.159.101 AS34788
zectomed.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
zed.dkns1.dlx.dk 2a00:1b18:1337:1337::53 AS47527, 46.30.121.210 AS47527
ns2.dlx.dk 185.208.212.124 AS47527, 2a00:1b19:1337:1337::53 AS47527
zederkof.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
tia.ns.cloudflare.com 108.162.192.229 AS13335, 172.64.32.229 AS13335, 173.245.58.229 AS13335, 2606:4700:50::adf5:3ae5 AS13335, 2803:f800:50::6ca2:c0e5 AS13335, 2a06:98c1:50::ac40:20e5 AS13335
zederkofserver.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
tia.ns.cloudflare.com 108.162.192.229 AS13335, 172.64.32.229 AS13335, 173.245.58.229 AS13335, 2606:4700:50::adf5:3ae5 AS13335, 2803:f800:50::6ca2:c0e5 AS13335, 2a06:98c1:50::ac40:20e5 AS13335
zederkofvin.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
zederkop.dkcurns01.dnsadmin.dk 185.25.141.12 AS48854, 2a02:2339:4006:108::123 AS48854
curns02.dnsadmin.dk 2a02:2339:1:10f::123:123 AS48854, 91.197.248.75 AS48854
zedke.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
hunts.ns.cloudflare.com 108.162.195.46 AS13335, 162.159.44.46 AS13335, 172.64.35.46 AS13335, 2606:4700:58::a29f:2c2e AS13335, 2803:f800:50::6ca2:c32e AS13335, 2a06:98c1:50::ac40:232e AS13335
zedmarketing.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
zedusco.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
zeeagency.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
zeebergconsult.dkns10.wixdns.net 216.239.36.100 AS15169
ns11.wixdns.net 216.239.38.100 AS15169
zeebet.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
zeed.dkart.ns.cloudflare.com 108.162.193.102 AS13335, 172.64.33.102 AS13335, 173.245.59.102 AS13335, 2606:4700:58::adf5:3b66 AS13335, 2803:f800:50::6ca2:c166 AS13335, 2a06:98c1:50::ac40:2166 AS13335
irma.ns.cloudflare.com 108.162.192.166 AS13335, 172.64.32.166 AS13335, 173.245.58.166 AS13335, 2606:4700:50::adf5:3aa6 AS13335, 2803:f800:50::6ca2:c0a6 AS13335, 2a06:98c1:50::ac40:20a6 AS13335
zeejuu.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
zeeker-mail.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
zeekoo.dkjade.ns.cloudflare.com 108.162.192.167 AS13335, 172.64.32.167 AS13335, 173.245.58.167 AS13335, 2606:4700:50::adf5:3aa7 AS13335, 2803:f800:50::6ca2:c0a7 AS13335, 2a06:98c1:50::ac40:20a7 AS13335
sean.ns.cloudflare.com 108.162.193.231 AS13335, 172.64.33.231 AS13335, 173.245.59.231 AS13335, 2606:4700:58::adf5:3be7 AS13335, 2803:f800:50::6ca2:c1e7 AS13335, 2a06:98c1:50::ac40:21e7 AS13335
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