🛡️ 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 autonomous system

756,418 domains
DomainNameservers and addresses
zacher.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
zacheradvokater.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
zacherinvest.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
zacheryjorgensen.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
zachhau.dkbarbara.ns.cloudflare.com 108.162.192.248 AS13335, 172.64.32.248 AS13335, 173.245.58.248 AS13335, 2606:4700:50::adf5:3af8 AS13335, 2803:f800:50::6ca2:c0f8 AS13335, 2a06:98c1:50::ac40:20f8 AS13335
isaac.ns.cloudflare.com 108.162.193.177 AS13335, 172.64.33.177 AS13335, 173.245.59.177 AS13335, 2606:4700:58::adf5:3bb1 AS13335, 2803:f800:50::6ca2:c1b1 AS13335, 2a06:98c1:50::ac40:21b1 AS13335
zachi.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
zachmagnusson.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
zacho-boye.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
zacho-lind.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
zacho-web.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
zacho.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
zachocoaching.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78
ns2.simply.com 185.25.141.15, 2a02:2339:4006:101::4562:4562
ns3.simply.com 91.197.248.79
ns4.simply.com 91.197.248.80
zachodesign.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
zachofys.dkns1.ravn-hjemmesider.dk 2a01:4f8:13b:3146::1 AS24940, 94.130.138.185 AS24940
ns2.ravn-hjemmesider.dk 2a01:4f8:c17:5f0a::2 AS24940, 88.99.15.5 AS24940
ns3.ravn-hjemmesider.dk 2a01:4f8:c17:6a6e::2 AS24940, 88.99.39.181 AS24940
zacholind.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78
ns2.simply.com 185.25.141.15, 2a02:2339:4006:101::4562:4562
ns3.simply.com 91.197.248.79
ns4.simply.com 91.197.248.80
zachoo.dkns1.messagingengine.com 162.159.24.178 AS13335
ns2.messagingengine.com 162.159.25.191 AS13335
zachoogco.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
zachopsykoterapi.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
zachostormbyg.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
zachotechnic.dkns1.dnshotel.dk 2a01:4f8:1c17:4999::2 AS24940, 88.99.120.238 AS24940
ns2.dnshotel.dk 2a01:4f8:c0c:4051::2 AS24940, 94.130.170.39 AS24940
zachotex.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
zachs.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
zachsnedkeri.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
zack.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
zackhealth.dkmerlin.ns.cloudflare.com 108.162.193.205 AS13335, 172.64.33.205 AS13335, 173.245.59.205 AS13335, 2606:4700:58::adf5:3bcd AS13335, 2803:f800:50::6ca2:c1cd AS13335, 2a06:98c1:50::ac40:21cd AS13335
mia.ns.cloudflare.com 108.162.192.200 AS13335, 172.64.32.200 AS13335, 173.245.58.200 AS13335, 2606:4700:50::adf5:3ac8 AS13335, 2803:f800:50::6ca2:c0c8 AS13335, 2a06:98c1:50::ac40:20c8 AS13335
zacmatrix.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
zacrid.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
zacunost.dkns-1041.awsdns-02.org 205.251.196.17 AS16509, 2600:9000:5304:1100::1 AS16509
ns-1583.awsdns-05.co.uk 205.251.198.47 AS16509, 2600:9000:5306:2f00::1 AS16509
ns-396.awsdns-49.com 205.251.193.140 AS16509, 2600:9000:5301:8c00::1 AS16509
ns-701.awsdns-23.net 205.251.194.189 AS16509, 2600:9000:5302:bd00::1 AS16509
zada.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
zadaa.dkbrenda.ns.cloudflare.com 108.162.192.77 AS13335, 172.64.32.77 AS13335, 173.245.58.77 AS13335, 2606:4700:50::adf5:3a4d AS13335, 2803:f800:50::6ca2:c04d AS13335, 2a06:98c1:50::ac40:204d AS13335
buck.ns.cloudflare.com 108.162.193.78 AS13335, 172.64.33.78 AS13335, 173.245.59.78 AS13335, 2606:4700:58::adf5:3b4e AS13335, 2803:f800:50::6ca2:c14e AS13335, 2a06:98c1:50::ac40:214e AS13335
zadelman.dkmelissa.ns.cloudflare.com 108.162.192.199 AS13335, 172.64.32.199 AS13335, 173.245.58.199 AS13335, 2606:4700:50::adf5:3ac7 AS13335, 2803:f800:50::6ca2:c0c7 AS13335, 2a06:98c1:50::ac40:20c7 AS13335
sri.ns.cloudflare.com 108.162.193.234 AS13335, 172.64.33.234 AS13335, 173.245.59.234 AS13335, 2606:4700:58::adf5:3bea AS13335, 2803:f800:50::6ca2:c1ea AS13335, 2a06:98c1:50::ac40:21ea AS13335
zadig.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
zadkiel.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
zadrobyg.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
zae.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
zaedow.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
zaela.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
zaemont.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
zaetteberg.dkns2.wixdns.net 216.239.36.100 AS15169
ns3.wixdns.net 216.239.38.100 AS15169
zafariqbal.dkbrian.ns.cloudflare.com 108.162.195.36 AS13335, 162.159.44.36 AS13335, 172.64.35.36 AS13335, 2606:4700:58::a29f:2c24 AS13335, 2803:f800:50::6ca2:c324 AS13335, 2a06:98c1:50::ac40:2324 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
zafeer.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
zafehealth.dkns-108-c.gandi.net 217.70.187.109 AS209453, 2604:3400:aaac::6d AS209453
ns-244-a.gandi.net 173.246.100.245 AS209453, 2001:4b98:aaaa::f5 AS209453
ns-90-b.gandi.net 2001:4b98:aaab::5b AS209453, 213.167.230.91 AS209453
zafehome.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
zafehouse.dkns1.simply.com 2a02:2339:1:15c::4562:4562 AS48854, 91.197.248.78
ns2.simply.com 185.25.141.15, 2a02:2339:4006:101::4562:4562
ns3.simply.com 91.197.248.79
ns4.simply.com 91.197.248.80
zafelock.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
zafer.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
zaffer.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
zafi.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
zafina-reiki-odense.dkns7.bricksite.net 35.246.226.10 AS396982
ns8.bricksite.net 35.242.190.82 AS396982
zafirclothing.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
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