🛡️ 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

1,183,657 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 address1,3070.11%Several NS names, but they all resolve to one IP, so they are really one server.
One IPv4 /24 and no IPv610,6840.90%All nameservers share one network: a routing problem there takes them all down.
One autonomous system758,17064.1%Common and usually fine with a large provider, but one network outage still takes all nameservers down.
No IPv6 nameserver85,3597.2%IPv6-only resolvers cannot reach the zone.

Click a row to list its domains (computed 2026-10-04 17:29).

📋 One autonomous system

758,170 domains
DomainNameservers and addresses
whalewatch.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
whalewatching.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
whalewatchingtours.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
whaleworld.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
whalgreen.dkgrace.ns.cloudflare.com 108.162.192.159 AS13335, 172.64.32.159 AS13335, 173.245.58.159 AS13335, 2606:4700:50::adf5:3a9f AS13335, 2803:f800:50::6ca2:c09f AS13335, 2a06:98c1:50::ac40:209f AS13335
grant.ns.cloudflare.com 108.162.195.130 AS13335, 162.159.44.130 AS13335, 172.64.35.130 AS13335, 2606:4700:58::a29f:2c82 AS13335, 2803:f800:50::6ca2:c382 AS13335, 2a06:98c1:50::ac40:2382 AS13335
whallberg.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
ullis.ns.cloudflare.com 108.162.194.127 AS13335, 162.159.38.127 AS13335, 172.64.34.127 AS13335, 2606:4700:50::a29f:267f AS13335, 2803:f800:50::6ca2:c27f AS13335, 2a06:98c1:50::ac40:227f AS13335
whammer.dklloyd.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
tess.ns.cloudflare.com 108.162.192.227 AS13335, 172.64.32.227 AS13335, 173.245.58.227 AS13335, 2606:4700:50::adf5:3ae3 AS13335, 2803:f800:50::6ca2:c0e3 AS13335, 2a06:98c1:50::ac40:20e3 AS13335
whamwam.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
whanau.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
whanudu.dkalice.ns.cloudflare.com 108.162.192.60 AS13335, 172.64.32.60 AS13335, 173.245.58.60 AS13335, 2606:4700:50::adf5:3a3c AS13335, 2803:f800:50::6ca2:c03c AS13335, 2a06:98c1:50::ac40:203c AS13335
gannon.ns.cloudflare.com 108.162.195.59 AS13335, 162.159.44.59 AS13335, 172.64.35.59 AS13335, 2606:4700:58::a29f:2c3b AS13335, 2803:f800:50::6ca2:c33b AS13335, 2a06:98c1:50::ac40:233b AS13335
wharf.dkjosh.ns.cloudflare.com 108.162.193.126 AS13335, 172.64.33.126 AS13335, 173.245.59.126 AS13335, 2606:4700:58::adf5:3b7e AS13335, 2803:f800:50::6ca2:c17e AS13335, 2a06:98c1:50::ac40:217e AS13335
ursula.ns.cloudflare.com 108.162.194.191 AS13335, 162.159.38.191 AS13335, 172.64.34.191 AS13335, 2606:4700:50::a29f:26bf AS13335, 2803:f800:50::6ca2:c2bf AS13335, 2a06:98c1:50::ac40:22bf AS13335
whart.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
what-e.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
what-on.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
what-to-do.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
what2do.dkns1.dreamhost.com 162.159.26.14 AS13335
ns2.dreamhost.com 162.159.26.81 AS13335
ns3.dreamhost.com 162.159.27.84 AS13335
what2watch.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
what3words.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
whatabeautifulwasteoftime.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
whatabird.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
whatabout.dkns1.supercp.com 13.248.158.180 AS16509
ns2.supercp.com 75.2.118.134 AS16509
ns3.supercp.com 76.223.26.245 AS16509
ns4.supercp.com 99.83.147.209 AS16509
whataboutyou.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
whatacircus.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
whataday.dkfred.ns.cloudflare.com 108.162.193.113 AS13335, 172.64.33.113 AS13335, 173.245.59.113 AS13335, 2606:4700:58::adf5:3b71 AS13335, 2803:f800:50::6ca2:c171 AS13335, 2a06:98c1:50::ac40:2171 AS13335
maria.ns.cloudflare.com 108.162.192.192 AS13335, 172.64.32.192 AS13335, 173.245.58.192 AS13335, 2606:4700:50::adf5:3ac0 AS13335, 2803:f800:50::6ca2:c0c0 AS13335, 2a06:98c1:50::ac40:20c0 AS13335
whataparty.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
whatawonderfulweld.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
whatbox.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
whatbunkers.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
whatcar.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
whatdrivesyou.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
whatelsewear.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
whateveryouwant.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
whati.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
whatido.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
whatif.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
whatisdigitalcopy.dkns1-b2.warnerbros.com 205.251.198.161 AS16509
ns2-b2.warnerbros.com 205.251.196.102 AS16509
ns3-b2.warnerbros.com 205.251.194.221 AS16509
ns4-b2.warnerbros.com 205.251.193.169 AS16509
whatisee.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
whatisgoingon.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
whatislife.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
ns3.azehosting.net 2a01:4f8:c17:6a6e::2 AS24940, 88.99.39.181 AS24940
whatismyip.dkns1.dreamhost.com 162.159.26.14 AS13335
ns2.dreamhost.com 162.159.26.81 AS13335
ns3.dreamhost.com 162.159.27.84 AS13335
whatismyipaddress.dkns1.bb-online.net 185.206.123.1 AS212217
ns2.bb-online.org 81.30.104.2 AS212217
ns3.bb-online.uk 46.253.129.1 AS212217
ns4.bb-online.biz 46.253.129.4 AS212217
whatisyourwhy.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
whatknows.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
whatmail.dkns1.wpdns.host 173.199.96.96 AS20473, 2001:19f0:ccd::1 AS20473
ns2.wpdns.host 173.199.96.97 AS20473, 2001:19f0:ccd::2 AS20473
ns3.wpdns.host 173.199.96.96 AS20473, 2001:19f0:ccd::1 AS20473
whatmenwant.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
whatnot.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
whatnow.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
whats-happening.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
whats-on.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
whatsaalborg.dknoel.ns.cloudflare.com 108.162.193.216 AS13335, 172.64.33.216 AS13335, 173.245.59.216 AS13335, 2606:4700:58::adf5:3bd8 AS13335, 2803:f800:50::6ca2:c1d8 AS13335, 2a06:98c1:50::ac40:21d8 AS13335
ulla.ns.cloudflare.com 108.162.192.233 AS13335, 172.64.32.233 AS13335, 173.245.58.233 AS13335, 2606:4700:50::adf5:3ae9 AS13335, 2803:f800:50::6ca2:c0e9 AS13335, 2a06:98c1:50::ac40:20e9 AS13335
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