🛡️ 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

1,185,715 working delegations with resolvable nameservers (lame excluded)
Every nameserver is on…DomainsShareWhy it matters
A single nameserver host1490.01%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 IPv610,8080.91%All nameservers share one network: a routing problem there takes them all down.
One autonomous system755,25063.7%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,9817.3%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-09-30 06:38).

📋 One autonomous system

755,250 domains
DomainNameservers and addresses
zoo-tv.dkns1.wordpress.com 198.181.116.9 AS2635, 2a04:fa87:ffff::c6b5:7409 AS2635
ns2.wordpress.com 198.181.117.9 AS2635, 2a04:fa87:ffff::c6b5:7509 AS2635
ns3.wordpress.com 192.0.74.9 AS2635, 2620:115:c00f::c000:4a09 AS2635
zoo.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
zoo365.dkelle.ns.cloudflare.com 108.162.192.110 AS13335, 172.64.32.110 AS13335, 173.245.58.110 AS13335, 2606:4700:50::adf5:3a6e AS13335, 2803:f800:50::6ca2:c06e AS13335, 2a06:98c1:50::ac40:206e AS13335
eric.ns.cloudflare.com 108.162.193.112 AS13335, 172.64.33.112 AS13335, 173.245.59.112 AS13335, 2606:4700:58::adf5:3b70 AS13335, 2803:f800:50::6ca2:c170 AS13335, 2a06:98c1:50::ac40:2170 AS13335
zooaalborg.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
zooapp.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
zooart.dkdns103.ovh.net 2001:41d0:d00:fd00::2 AS16276, 5.196.39.89 AS16276
ns103.ovh.net 2001:41d0:b00:f700::2 AS16276, 5.135.54.65 AS16276
zoobiopartner.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
zoobusiness.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
zoobutikken.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
zoocast.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
zoocenter.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
zoocentercph.dkmustafa.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
raphaela.ns.cloudflare.com 108.162.194.192 AS13335, 162.159.38.192 AS13335, 172.64.34.192 AS13335, 2606:4700:50::a29f:26c0 AS13335, 2803:f800:50::6ca2:c2c0 AS13335, 2a06:98c1:50::ac40:22c0 AS13335
zoocup.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
zoocurity.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
zoodesign.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
zoodex.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
zoofari.dkns.do-ex.com 193.227.117.225 AS1921, 2a04:2b00:14cc::225 AS1921
ns.do-ex.net 194.50.187.225 AS1921, 2a04:2b00:14dd::225 AS1921
ns.do-ex.org 194.0.182.225 AS1921, 2a04:2b00:14ee::225 AS1921
zooflow.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
zoohegn.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
zooingvar.dkns1.namesystem.se 195.238.76.18 AS42708, 2a02:750:aaaa::1 AS42708
ns2.namesystem.se 195.238.77.18 AS42708, 2a02:750:aaaa::2 AS42708
ns3.namesystem.se 195.20.206.18 AS42708, 2a02:750:aaaa::3 AS42708
zooit.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
zoojagt.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
zooka.dkjerry.ns.cloudflare.com 108.162.193.182 AS13335, 172.64.33.182 AS13335, 173.245.59.182 AS13335, 2606:4700:58::adf5:3bb6 AS13335, 2803:f800:50::6ca2:c1b6 AS13335, 2a06:98c1:50::ac40:21b6 AS13335
nicole.ns.cloudflare.com 108.162.192.211 AS13335, 172.64.32.211 AS13335, 173.245.58.211 AS13335, 2606:4700:50::adf5:3ad3 AS13335, 2803:f800:50::6ca2:c0d3 AS13335, 2a06:98c1:50::ac40:20d3 AS13335
zookelsti.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
zookonservator.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
zoolab.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
zoolando.dkns01.brandshelter.com 193.227.117.15 AS1921, 2a04:2b00:14cc::15 AS1921
ns02.brandshelter.net 194.50.187.16 AS1921, 2a04:2b00:14dd::16 AS1921
zoolini.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
zoologi.dkns3.webhot.dk 178.72.21.249 AS3342
ns4.webhot.dk 178.72.21.250 AS3342
zoologicalmuseum.dkns1.ku.dk 192.38.110.174 AS1835, 2001:878:1070:10::174 AS1835
ns2.ku.dk 192.38.110.190 AS1835, 2001:878:1070:11::190 AS1835
zoologiskhave.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
zoologiskmuseum.dkns1.ku.dk 192.38.110.174 AS1835, 2001:878:1070:10::174 AS1835
ns2.ku.dk 192.38.110.190 AS1835, 2001:878:1070:11::190 AS1835
zoologiskselskab.dkns1.greengeeks.net 75.2.69.7 AS16509
ns2.greengeeks.net 99.83.188.187 AS16509
zooloo.dkns1-07.azure-dns.com 13.107.236.7 AS8075, 2603:1061:0:700::7 AS8075
ns2-07.azure-dns.net 150.171.21.7 AS8075, 2620:1ec:8ec:700::7 AS8075
ns3-07.azure-dns.org 204.14.183.7 AS8075, 2a01:111:4000:700::7 AS8075
ns4-07.azure-dns.info 208.84.5.7 AS8075, 2620:1ec:bda:700::7 AS8075
zoom-film.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
zoom-in.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
zoom-odense.dkns.andersenit.dk 185.200.74.101 AS198614
ns1.andersenit.dk 87.238.248.10 AS198614
zoom.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
zoom1.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
zoomafocus.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
zoomaframe.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
zoomail.dksage.ns.cloudflare.com 108.162.195.236 AS13335, 162.159.44.236 AS13335, 172.64.35.236 AS13335, 2606:4700:58::a29f:2cec AS13335, 2803:f800:50::6ca2:c3ec AS13335, 2a06:98c1:50::ac40:23ec AS13335
veronica.ns.cloudflare.com 108.162.194.173 AS13335, 162.159.38.173 AS13335, 172.64.34.173 AS13335, 2606:4700:50::a29f:26ad AS13335, 2803:f800:50::6ca2:c2ad AS13335, 2a06:98c1:50::ac40:22ad AS13335
zoomalia.dkcory.ns.cloudflare.com 108.162.193.93 AS13335, 172.64.33.93 AS13335, 173.245.59.93 AS13335, 2606:4700:58::adf5:3b5d AS13335, 2803:f800:50::6ca2:c15d AS13335, 2a06:98c1:50::ac40:215d AS13335
crystal.ns.cloudflare.com 108.162.194.202 AS13335, 162.159.38.202 AS13335, 172.64.34.202 AS13335, 2606:4700:50::a29f:26ca AS13335, 2803:f800:50::6ca2:c2ca AS13335, 2a06:98c1:50::ac40:22ca AS13335
zoomarkitekter.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
zoomate.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
zoomax.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
zoomboom.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
zoombyzoom.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
zoomcar.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
zoomecasino.dkdorthy.ns.cloudflare.com 108.162.192.249 AS13335, 172.64.32.249 AS13335, 173.245.58.249 AS13335, 2606:4700:50::adf5:3af9 AS13335, 2803:f800:50::6ca2:c0f9 AS13335, 2a06:98c1:50::ac40:20f9 AS13335
leland.ns.cloudflare.com 108.162.195.8 AS13335, 162.159.44.8 AS13335, 172.64.35.8 AS13335, 2606:4700:58::a29f:2c08 AS13335, 2803:f800:50::6ca2:c308 AS13335, 2a06:98c1:50::ac40:2308 AS13335
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