🛡️ 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

1,185,762 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1480.01%Any outage or mistake on that host takes the domain offline; RFC 1034 asks for at least two.
A single nameserver address1,3100.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,8150.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system754,61263.6%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver86,0127.3%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-09-30 00:23).

📋 One autonomous system

754,612 domains
DomainNameservers and addresses
131.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
1310.dkns.wannafind.dk 185.25.141.6 AS48854, 2a02:2339:4006:103:1c:3f6d:daba:dee AS48854
ns2.wannafind.dk 2a02:2339:1:104::daba:daa AS48854, 91.197.248.69 AS48854
1311.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
131262.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
1313starwars.dkdns1.cscdns.net 156.154.130.100 AS12008, 2610:a1:1022::100 AS12008
dns2.cscdns.net 156.154.131.100 AS12008, 2610:a1:1023::100 AS12008
1313sw.dkdns1.cscdns.net 156.154.130.100 AS12008, 2610:a1:1022::100 AS12008
dns2.cscdns.net 156.154.131.100 AS12008, 2610:a1:1023::100 AS12008
1314.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
1315.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
132.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
1325.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
1326.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
1328.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
133.dkns1.awork.dk 185.136.96.79 AS203391
ns2.awork.dk 185.136.97.79 AS203391
ns3.awork.dk 185.136.98.79 AS203391
ns4.awork.dk 185.136.99.79 AS203391
1331.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
1337-consulting.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
1337-face.dkbailey.ns.cloudflare.com 108.162.194.41 AS13335, 162.159.38.41 AS13335, 172.64.34.41 AS13335, 2606:4700:50::a29f:2629 AS13335, 2803:f800:50::6ca2:c229 AS13335, 2a06:98c1:50::ac40:2229 AS13335
mustafa.ns.cloudflare.com 108.162.195.27 AS13335, 162.159.44.27 AS13335, 172.64.35.27 AS13335, 2606:4700:58::a29f:2c1b AS13335, 2803:f800:50::6ca2:c31b AS13335, 2a06:98c1:50::ac40:231b AS13335
1337.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
1342.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
1374.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
137c.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
13829.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
13a.dkns.andersenit.dk 185.200.74.101 AS198614
ns1.andersenit.dk 87.238.248.10 AS198614
13dageskuren.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
13fishing.dkdns1.cscdns.net 156.154.130.100 AS12008, 2610:a1:1022::100 AS12008
dns2.cscdns.net 156.154.131.100 AS12008, 2610:a1:1023::100 AS12008
13g.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
13grader.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
13k.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
13prise.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
13th.dkdavina.ns.cloudflare.com 108.162.194.40 AS13335, 162.159.38.40 AS13335, 172.64.34.40 AS13335, 2606:4700:50::a29f:2628 AS13335, 2803:f800:50::6ca2:c228 AS13335, 2a06:98c1:50::ac40:2228 AS13335
langston.ns.cloudflare.com 108.162.195.252 AS13335, 162.159.44.252 AS13335, 172.64.35.252 AS13335, 2606:4700:58::a29f:2cfc AS13335, 2803:f800:50::6ca2:c3fc AS13335, 2a06:98c1:50::ac40:23fc AS13335
13thstreet.dkpdns1.ultradns.net 2001:502:f3ff::1 AS12008, 204.74.108.1 AS12008
pdns2.ultradns.net 204.74.109.1 AS12008, 2610:a1:1014::1 AS12008
pdns3.ultradns.org 199.7.68.1 AS12008, 2610:a1:1015::1 AS12008
pdns4.ultradns.org 199.7.69.1 AS12008, 2001:502:4612::1 AS12008
pdns5.ultradns.info 204.74.114.1 AS12008, 2610:a1:1016::1 AS12008
pdns6.ultradns.co.uk 204.74.115.1 AS12008, 2610:a1:1017::1 AS12008
13thstreetuniversal.dkpdns1.ultradns.net 2001:502:f3ff::1 AS12008, 204.74.108.1 AS12008
pdns2.ultradns.net 204.74.109.1 AS12008, 2610:a1:1014::1 AS12008
pdns3.ultradns.org 199.7.68.1 AS12008, 2610:a1:1015::1 AS12008
pdns4.ultradns.org 199.7.69.1 AS12008, 2001:502:4612::1 AS12008
pdns5.ultradns.info 204.74.114.1 AS12008, 2610:a1:1016::1 AS12008
pdns6.ultradns.co.uk 204.74.115.1 AS12008, 2610:a1:1017::1 AS12008
13z.dkkallie.ns.cloudflare.com 108.162.194.85 AS13335, 162.159.38.85 AS13335, 172.64.34.85 AS13335, 2606:4700:50::a29f:2655 AS13335, 2803:f800:50::6ca2:c255 AS13335, 2a06:98c1:50::ac40:2255 AS13335
keenan.ns.cloudflare.com 108.162.195.11 AS13335, 162.159.44.11 AS13335, 172.64.35.11 AS13335, 2606:4700:58::a29f:2c0b AS13335, 2803:f800:50::6ca2:c30b AS13335, 2a06:98c1:50::ac40:230b AS13335
14-14.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
14-3.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
14.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
1406.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
1409.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
141.dkns-1.dcmediahosting.com 91.99.51.123 AS24940
ns-2.dcmediahosting.com 78.46.248.73 AS24940
ns-3.dcmediahosting.com 78.46.248.73 AS24940
ns-4.dcmediahosting.com 91.99.51.123 AS24940
ns-5.dcmediahosting.com 78.46.248.73 AS24940
1412.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
1413.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
1415.dkdns.dsb.dk 193.28.147.132 AS41746
ns.dsb.dk 193.28.147.131 AS41746
14159265358979323846264338327950288419716939937510582097494.dkdarwin.ns.cloudflare.com 108.162.193.151 AS13335, 172.64.33.151 AS13335, 173.245.59.151 AS13335, 2606:4700:58::adf5:3b97 AS13335, 2803:f800:50::6ca2:c197 AS13335, 2a06:98c1:50::ac40:2197 AS13335
hera.ns.cloudflare.com 108.162.192.162 AS13335, 172.64.32.162 AS13335, 173.245.58.162 AS13335, 2606:4700:50::adf5:3aa2 AS13335, 2803:f800:50::6ca2:c0a2 AS13335, 2a06:98c1:50::ac40:20a2 AS13335
141592653589793238462643383279502884197169399375105820974944592.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
1416.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
142.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
1420.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
142857.dkns3.webhot.dk 178.72.21.249 AS3342
ns4.webhot.dk 178.72.21.250 AS3342
1431.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
1435.dkns11.infomaniak.ch 2001:1600:0:aaaa::7 AS29222, 93.88.255.151 AS29222
ns12.infomaniak.ch 2001:1600:0:aaaa::8 AS29222, 93.88.255.152 AS29222
144.dkns1.linuxhus.dk 37.128.222.18 AS39642
ns2.linuxhus.dk 37.128.222.19 AS39642
ns3.linuxhus.dk 37.128.222.20 AS39642
dhd.dk [/] search Domains, Hosts & DNS — .dk zone