🛡️ 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 IPv4 /24 and no IPv6

10,804 domains
DomainNameservers and addresses
ravmuseum.dkns1.jetcom.dk 193.242.107.7 AS31027
ns2.jetcom.dk 193.242.107.8 AS31027
ravnholmskole.dkns1.rudersdal.dk 185.85.44.55 AS200538
ns2.rudersdal.dk 185.85.44.57 AS200538
ns3.rudersdal.dk 185.85.44.72 AS200538
ravnholmskolen.dkns1.rudersdal.dk 185.85.44.55 AS200538
ns2.rudersdal.dk 185.85.44.57 AS200538
ns3.rudersdal.dk 185.85.44.72 AS200538
rcparken.dkns3.webhot.dk 178.72.21.249 AS3342
ns4.webhot.dk 178.72.21.250 AS3342
rdataprotection.dkauth01.t26.dk 77.221.251.240 AS42876
auth02.t26.dk 77.221.251.241 AS42876
rdbogen.dkns1.ordbogen.com 91.240.88.19 AS198901
ns2.ordbogen.com 91.240.88.20 AS198901
rddaginst.dkns1.rudersdal.dk 185.85.44.55 AS200538
ns2.rudersdal.dk 185.85.44.57 AS200538
ns3.rudersdal.dk 185.85.44.72 AS200538
rdshosting.dkns01.athena-hosting.dk 217.30.38.181 AS47292
ns02.athena-hosting.dk 217.30.38.27 AS47292
ns03.athena-hosting.dk 217.30.38.30 AS47292
rdskoler.dkns1.rudersdal.dk 185.85.44.55 AS200538
ns2.rudersdal.dk 185.85.44.57 AS200538
ns3.rudersdal.dk 185.85.44.72 AS200538
realdealshop.dkns1.esis.dk 185.19.134.2 AS199374
ns2.esis.dk 185.19.134.3 AS199374
realestatematching24.dkns20912485153.a2dns.com 209.124.85.153 AS55293
ns20912485154.a2dns.com 209.124.85.154 AS55293
realisaprint.dkparking1.ovh.net 54.37.126.92 AS16276
parking2.ovh.net 54.37.126.93 AS16276
realskolevej2b.dkgate.profdoc.dk 80.62.243.243 AS3292
ns.profdoc.dk 80.62.243.242 AS3292
realtimemanufacturingservices.dkparking1.ovh.net 54.37.126.92 AS16276
parking2.ovh.net 54.37.126.93 AS16276
rebaekpizza.dkns1.eatonline.dk 77.235.50.60 AS60781
ns2.eatonline.dk 77.235.50.60 AS60781
rebeldot.dkns1.digitalit.ro 194.140.245.34 AS41151
ns2.digitalit.ro 194.140.245.66 AS41151
reboarddanmark.dkns1.voks.dk 185.69.240.154 AS34740
ns2.voks.dk 185.69.240.154 AS34740
reboarddenmark.dkns1.voks.dk 185.69.240.154 AS34740
ns2.voks.dk 185.69.240.154 AS34740
recept.dkns3.webhot.dk 178.72.21.249 AS3342
ns4.webhot.dk 178.72.21.250 AS3342
receptionsordbog.dkns1.ordbogen.com 91.240.88.19 AS198901
ns2.ordbogen.com 91.240.88.20 AS198901
receptionsstander.dkns1.dnsatconviator.com 185.106.119.62 AS201926
ns2.dnsatconviator.com 185.106.119.63 AS201926
ns3.dnsatconviator.com 185.106.119.64 AS201926
recke-el.dkns1.inihost.dk 87.48.171.11 AS3292
ns2.inihost.dk 87.48.171.13 AS3292
recognus.dks38.medialaget.net 2.59.211.18 AS208001
s45.medialaget.net 2.59.211.19 AS208001
recycon.dkns1.server-185-73-8-101.da.direct 185.73.8.101 AS52148
ns2.server-185-73-8-101.da.direct 185.73.8.101 AS52148
reda.dkns3.webhot.dk 178.72.21.249 AS3342
ns4.webhot.dk 178.72.21.250 AS3342
redchallenge.dkns1.basejump.dk 93.167.198.71 AS3292
ns2.basejump.dk 93.167.198.75 AS3292
reddeco.dkparking1.ovh.net 54.37.126.92 AS16276
parking2.ovh.net 54.37.126.93 AS16276
redhavnen.dkns1.webhotel.net 217.30.38.181 AS47292
ns2.webhotel.net 217.30.38.27 AS47292
rediger.dkns1.kortermann-hosting.dk 94.231.105.180 AS48854
ns2.kortermann-hosting.dk 94.231.105.146 AS48854
redintogreen.dkd.ns1.pl 77.65.215.253 AS210379
d.ns2.pl 77.65.215.254 AS210379
reduce.dkns1.onwelcom.dk 185.51.79.241 AS205984
ns2.onwelcom.dk 185.51.79.251 AS205984
redur.dkns1.redur.dk 46.17.94.187 AS15510
ns2.redur.dk 46.17.94.187 AS15510
reeves.dkns1.webaway.dk 77.247.70.130 AS31590
ns2.webaway.dk 77.247.70.131 AS31590
refo.dkns1.telecomx.dk 62.192.160.190 AS205984
ns2.telecomx.dk 62.192.160.191 AS205984
reformkommission.dkns2.sitnet.dk 188.64.157.26 AS58282
ns3.sitnet.dk 188.64.157.27 AS58282
reformr.dkns1.telecomx.dk 62.192.160.190 AS205984
ns2.telecomx.dk 62.192.160.191 AS205984
refsingholding.dkns1.telecomx.dk 62.192.160.190 AS205984
ns2.telecomx.dk 62.192.160.191 AS205984
refsnaes.dkns1.regsj.dk 91.198.168.21 AS43806
ns2.regsj.dk 91.198.168.22 AS43806
reg-sj.dkns1.regsj.dk 91.198.168.21 AS43806
ns2.regsj.dk 91.198.168.22 AS43806
regantis.dkns1.regantis.ro 80.96.35.231 AS50939
ns2.regantis.ro 80.96.35.232 AS50939
ns3.regantis.ro 80.96.35.231 AS50939
ns4.regantis.ro 80.96.35.232 AS50939
reghol.dkns.vest.net 185.221.30.10 AS31027
ns2.vest.net 185.221.30.11 AS31027
region-sjaelland.dkns1.regsj.dk 91.198.168.21 AS43806
ns2.regsj.dk 91.198.168.22 AS43806
regionerneshus.dkns.cohaesio.net 217.30.38.181 AS47292
ns2.cohaesio.net 217.30.38.27 AS47292
regionoest.dkns1.regsj.dk 91.198.168.21 AS43806
ns2.regsj.dk 91.198.168.22 AS43806
regionoestdanmark.dkns1.regsj.dk 91.198.168.21 AS43806
ns2.regsj.dk 91.198.168.22 AS43806
regionost.dkns1.regsj.dk 91.198.168.21 AS43806
ns2.regsj.dk 91.198.168.22 AS43806
regionostdanmark.dkns1.regsj.dk 91.198.168.21 AS43806
ns2.regsj.dk 91.198.168.22 AS43806
regionsj.dkns1.regsj.dk 91.198.168.21 AS43806
ns2.regsj.dk 91.198.168.22 AS43806
regionsjaelland-bloddonor.dkns1.regsj.dk 91.198.168.21 AS43806
ns2.regsj.dk 91.198.168.22 AS43806
regionsjaelland.dkns1.regsj.dk 91.198.168.21 AS43806
ns2.regsj.dk 91.198.168.22 AS43806
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