🛡️ 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

1,182,584 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 address1,3040.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6830.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system757,07664.0%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,2097.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-03 04:10).

📋 One autonomous system

757,076 domains
DomainNameservers and addresses
wudwud.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
wuelverskov.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
wuergler.dkns0.incrediblebits.net 159.69.71.125 AS24940, 2a01:4f8:231:1657::2 AS24940
ns1.incrediblebits.net 2a01:4f8:10b:860::2 AS24940, 88.99.250.148 AS24940
ns2.incrediblebits.net 159.69.136.113 AS24940, 2a01:4f8:231:1cd8::2 AS24940
ns3.incrediblebits.net 2a01:4f8:222:2484::2 AS24940, 88.198.23.111 AS24940
wuerth-elektronik.dkns2.xc-ns.de 193.227.117.225 AS1921, 2a04:2b00:14cc::225 AS1921
ns5.xc-ns.de 194.50.187.225 AS1921, 2a04:2b00:14dd::225 AS1921
wuerth-industry.dkns2.xc-ns.de 193.227.117.225 AS1921, 2a04:2b00:14cc::225 AS1921
ns5.xc-ns.de 194.50.187.225 AS1921, 2a04:2b00:14dd::225 AS1921
wuerth-leasing.dkns2.xc-ns.de 193.227.117.225 AS1921, 2a04:2b00:14cc::225 AS1921
ns5.xc-ns.de 194.50.187.225 AS1921, 2a04:2b00:14dd::225 AS1921
wuerth-truck-lease.dkns2.xc-ns.de 193.227.117.225 AS1921, 2a04:2b00:14cc::225 AS1921
ns5.xc-ns.de 194.50.187.225 AS1921, 2a04:2b00:14dd::225 AS1921
wuerthelektronik.dkns2.xc-ns.de 193.227.117.225 AS1921, 2a04:2b00:14cc::225 AS1921
ns5.xc-ns.de 194.50.187.225 AS1921, 2a04:2b00:14dd::225 AS1921
wuerthindustri.dkns2.xc-ns.de 193.227.117.225 AS1921, 2a04:2b00:14cc::225 AS1921
ns5.xc-ns.de 194.50.187.225 AS1921, 2a04:2b00:14dd::225 AS1921
wuerthindustry.dkns2.xc-ns.de 193.227.117.225 AS1921, 2a04:2b00:14cc::225 AS1921
ns5.xc-ns.de 194.50.187.225 AS1921, 2a04:2b00:14dd::225 AS1921
wuerthtrucklease.dkns2.xc-ns.de 193.227.117.225 AS1921, 2a04:2b00:14cc::225 AS1921
ns5.xc-ns.de 194.50.187.225 AS1921, 2a04:2b00:14dd::225 AS1921
wuertz.dkns1.shellhost.dk 193.200.90.91 AS62121, 2001:67c:564::13 AS62121
ns2.shellhost.dk 193.200.91.90 AS62121, 2001:67c:564::12 AS62121
wuesthof.dkns1.domaindiscount24.net 193.227.117.34 AS1921, 2a04:2b00:14cc::34 AS1921
ns2.domaindiscount24.net 194.50.187.34 AS1921, 2a04:2b00:14dd::34 AS1921
ns3.domaindiscount24.net 194.0.182.34 AS1921, 2a04:2b00:14ee::34 AS1921
wuf-tastisk.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
wuf.dkada.ns.cloudflare.com 108.162.192.54 AS13335, 172.64.32.54 AS13335, 173.245.58.54 AS13335, 2606:4700:50::adf5:3a36 AS13335, 2803:f800:50::6ca2:c036 AS13335, 2a06:98c1:50::ac40:2036 AS13335
nico.ns.cloudflare.com 108.162.195.147 AS13335, 162.159.44.147 AS13335, 172.64.35.147 AS13335, 2606:4700:58::a29f:2c93 AS13335, 2803:f800:50::6ca2:c393 AS13335, 2a06:98c1:50::ac40:2393 AS13335
wuff.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
wuffe.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
wuffer-hospitalshund.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
wuffer-sygehushund.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
wuffer-terapihund.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
wuffer.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
wufferpåhospitalet.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
wuffie.dkdns1.p01.nsone.net 198.51.44.1 AS62597, 2620:4d:4000:6259:7:1:0:1 AS62597
dns2.p01.nsone.net 198.51.45.1 AS62597, 2a00:edc0:6259:7:1::2 AS62597
dns3.p01.nsone.net 198.51.44.65 AS62597, 2620:4d:4000:6259:7:1:0:3 AS62597
dns4.p01.nsone.net 198.51.45.65 AS62597, 2a00:edc0:6259:7:1::4 AS62597
wuffitup.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
wuffmart.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
wuffr.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
wuffsnacks.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
wuffy.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
wufio.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
wufoo.dkns-1241.awsdns-27.org 205.251.196.217 AS16509, 2600:9000:5304:d900::1 AS16509
ns-1901.awsdns-45.co.uk 205.251.199.109 AS16509, 2600:9000:5307:6d00::1 AS16509
ns-250.awsdns-31.com 205.251.192.250 AS16509, 2600:9000:5300:fa00::1 AS16509
ns-963.awsdns-56.net 205.251.195.195 AS16509, 2600:9000:5303:c300::1 AS16509
wugtlarsen.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
wuhuu-boxers.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
wuhuw.dkjoan.ns.cloudflare.com 108.162.192.173 AS13335, 172.64.32.173 AS13335, 173.245.58.173 AS13335, 2606:4700:50::adf5:3aad AS13335, 2803:f800:50::6ca2:c0ad AS13335, 2a06:98c1:50::ac40:20ad AS13335
lloyd.ns.cloudflare.com 108.162.193.197 AS13335, 172.64.33.197 AS13335, 173.245.59.197 AS13335, 2606:4700:58::adf5:3bc5 AS13335, 2803:f800:50::6ca2:c1c5 AS13335, 2a06:98c1:50::ac40:21c5 AS13335
wuhuxi.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
wui.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
wuja.dkns10.wixdns.net 216.239.36.100 AS15169
ns11.wixdns.net 216.239.38.100 AS15169
wuji.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
wujigong.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
wuka.dkns01.trademarkarea.com 162.159.26.201 AS13335, 2400:cb00:2049:1::a29f:1ac9 AS13335
ns02.trademarkarea.com 162.159.27.43 AS13335, 2400:cb00:2049:1::a29f:1b2b AS13335
ns03.trademarkarea.com 162.159.26.221 AS13335, 2400:cb00:2049:1::a29f:1add AS13335
wukato.dkns2.xc-ns.de 193.227.117.225 AS1921, 2a04:2b00:14cc::225 AS1921
ns5.xc-ns.de 194.50.187.225 AS1921, 2a04:2b00:14dd::225 AS1921
wuki.dkarnold.ns.cloudflare.com 108.162.193.69 AS13335, 172.64.33.69 AS13335, 173.245.59.69 AS13335, 2606:4700:58::adf5:3b45 AS13335, 2803:f800:50::6ca2:c145 AS13335, 2a06:98c1:50::ac40:2145 AS13335
deb.ns.cloudflare.com 108.162.192.92 AS13335, 172.64.32.92 AS13335, 173.245.58.92 AS13335, 2606:4700:50::adf5:3a5c AS13335, 2803:f800:50::6ca2:c05c AS13335, 2a06:98c1:50::ac40:205c AS13335
wukruse.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
wuldnarp.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
wulf-vissing.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
wulf.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
wulff-biler.dkns1.nhl-data.dk 185.136.96.11 AS203391, 2a06:fb00:1::1:11 AS203391
ns2.nhl-data.dk 185.136.97.11 AS203391, 2a06:fb00:1::2:11 AS203391
ns3.nhl-data.dk 185.136.98.11 AS203391, 2a06:fb00:1::3:11 AS203391
ns4.nhl-data.dk 2a06:fb00:1::4:11 AS203391
wulff-boats.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
wulff-clausen.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
wulff-ea.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
wulff-levin.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
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