---
title: "Nameserver Protocols — dhd.dk"
description: "Protocol support of .dk authoritative nameservers — DNS over TLS and HTTPS, TCP, EDNS compliance, DNS cookies, NSID, ECS, extended errors and open resolvers — dhd.dk"
url: "https://www.dhd.dk/?tool=nsprotocols"
source: "https://www.dhd.dk/"
---
# 🧩 Nameserver Protocols

Which protocols and RFCs .dk authoritative nameservers support: DNS over TLS/HTTPS, cookies, NSID, ECS, EDNS compliance, open resolvers · [all insights](?tool=insights)

Which protocols do the nameservers behind .dk actually speak? We probe every authoritative nameserver directly — TCP, EDNS and its version and option rules, DNS cookies, NSID, client subnet, extended errors, DNS over TLS and HTTPS — and count how many .dk domains can use each one on every nameserver. Data comes from our own scanners, which re-resolve every .dk domain in the zone roughly once a week.

Each nameserver is probed directly from our host about a zone it serves, about once a month (see any nameserver's own page, e.g. [ns01.one.com](?tool=reversens&ns=ns01.one.com)). So far **6,678** of **20,428** nameservers are probed, **6,110** of them answered authoritatively. **1,167,997** of 1,185,188 working delegations (98.5%) have every nameserver profiled; the domain columns count only those.

## 🧩 Adoption across the zone[#](#adoption-across-the-zone "Link to the Adoption across the zone section of Nameserver Protocols")

computed 2026-10-10 01:44

| Protocol / feature           | RFC                                                                                            | Nameservers  | Domains: every NS | Domains: at least one NS |
|------------------------------|------------------------------------------------------------------------------------------------|--------------|-------------------|--------------------------|
| DNS over TCP                 | [7766](https://www.rfc-editor.org/rfc/rfc7766), [9210](https://www.rfc-editor.org/rfc/rfc9210) | 6,052 100.0% | 99.6%             | 99.9%                    |
| EDNS(0)                      | [6891](https://www.rfc-editor.org/rfc/rfc6891)                                                 | 6,092 99.7%  | 100.0%            | 100.0%                   |
| EDNS version negotiation     | [6891](https://www.rfc-editor.org/rfc/rfc6891)                                                 | 6,046 99.1%  | 99.5%             | 99.7%                    |
| Ignores unknown EDNS options | [6891](https://www.rfc-editor.org/rfc/rfc6891)                                                 | 6,107 100.0% | 100.0%            | 100.0%                   |
| DNS cookies                  | [7873](https://www.rfc-editor.org/rfc/rfc7873), [9018](https://www.rfc-editor.org/rfc/rfc9018) | 978 16.0%    | 4.4%              | 5.9%                     |
| NSID                         | [5001](https://www.rfc-editor.org/rfc/rfc5001)                                                 | 4,566 74.7%  | 92.4%             | 92.8%                    |
| TCP keepalive                | [7828](https://www.rfc-editor.org/rfc/rfc7828)                                                 | 822 13.6%    | 3.4%              | 5.1%                     |
| Client subnet (ECS)          | [7871](https://www.rfc-editor.org/rfc/rfc7871)                                                 | 3,976 65.1%  | 18.3%             | 20.4%                    |
| Extended DNS errors          | [8914](https://www.rfc-editor.org/rfc/rfc8914)                                                 | 535 14.1%    | 3.5%              | 4.7%                     |
| ZONEVERSION                  | [9660](https://www.rfc-editor.org/rfc/rfc9660)                                                 | 313 6.2%     | 2.7%              | 4.2%                     |
| DNS error reporting          | [9567](https://www.rfc-editor.org/rfc/rfc9567)                                                 | 0 0.0%       | 0.0%              | 0.0%                     |
| DNS over TLS (DoT)           | [7858](https://www.rfc-editor.org/rfc/rfc7858), [9539](https://www.rfc-editor.org/rfc/rfc9539) | 32 0.5%      | 23.5%             | 25.4%                    |
| DNS over HTTPS (DoH)         | [8484](https://www.rfc-editor.org/rfc/rfc8484)                                                 | 3 0.0%       | 0.0%              | 0.0%                     |
| Open resolver fault          | [5358](https://www.rfc-editor.org/rfc/rfc5358)                                                 | 24 0.4%      | —                 | 1,753 0.15%              |

Nameservers: share of the profiled nameservers with a definite answer for that test. Domains: share of working .dk delegations whose nameservers all (or at least one) support it, the figure that decides what a resolver can actually use. For open resolvers the domain column counts domains with at least one such nameserver.

## 🏢 The largest nameservers[#](#the-largest-nameservers "Link to the The largest nameservers section of Nameserver Protocols")

top 30 by domains

| Nameserver                                                          | Domains | EDNS buffer | TCP | Cookies | NSID | Keep­alive | ECS | EDE | DoT | DoH |
|---------------------------------------------------------------------|---------|-------------|-----|---------|------|------------|-----|-----|-----|-----|
| [ns2.simply.com](?tool=reversens&ns=ns2.simply.com)                 | 305,428 | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | ✗   | ✗   | ✗   |
| [ns1.simply.com](?tool=reversens&ns=ns1.simply.com)                 | 305,427 | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | ✗   | ✗   | ✗   |
| [ns3.simply.com](?tool=reversens&ns=ns3.simply.com)                 | 305,202 | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | ✗   | ✗   | ✗   |
| [ns02.one.com](?tool=reversens&ns=ns02.one.com)                     | 301,281 | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | ✗   | ✓   | ✗   |
| [ns01.one.com](?tool=reversens&ns=ns01.one.com)                     | 301,270 | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | ✗   | ✓   | ✗   |
| [ns4.simply.com](?tool=reversens&ns=ns4.simply.com)                 | 150,486 | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | ✗   | ✗   | ✗   |
| [ns2.dandomain.dk](?tool=reversens&ns=ns2.dandomain.dk)             | 113,637 | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | ✗   | ✗   | ✗   |
| [ns.dandomain.dk](?tool=reversens&ns=ns.dandomain.dk)               | 113,636 | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | ✗   | ✗   | ✗   |
| [ns1.curanet.dk](?tool=reversens&ns=ns1.curanet.dk)                 | 55,584  | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | ✗   | ✗   | ✗   |
| [ns2.curanet.dk](?tool=reversens&ns=ns2.curanet.dk)                 | 55,583  | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | ✗   | ✗   | ✗   |
| [ns2.scannet2.dk](?tool=reversens&ns=ns2.scannet2.dk)               | 24,509  | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | ✗   | ✗   | ✗   |
| [ns.scannet2.dk](?tool=reversens&ns=ns.scannet2.dk)                 | 24,508  | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | ✗   | ✗   | ✗   |
| [ns2.webhosting.dk](?tool=reversens&ns=ns2.webhosting.dk)           | 20,381  | 1,232       | ✓   | ✓       | ✗    | ✓          | ✓   | ✓   | ✗   | ✗   |
| [ns1pri.webhosting.dk](?tool=reversens&ns=ns1pri.webhosting.dk)     | 20,378  | 1,232       | ✓   | ✓       | ✗    | ✓          | ✓   | ✓   | ✗   | ✗   |
| [ns2.mywebtonet.com](?tool=reversens&ns=ns2.mywebtonet.com)         | 20,375  | 1,232       | ✓   | ✓       | ✗    | ✓          | ✓   | ✓   | ✗   | ✗   |
| [ns7.webhosting.dk](?tool=reversens&ns=ns7.webhosting.dk)           | 20,355  | 1,232       | ✓   | ✓       | ✗    | ✓          | ✓   | ✓   | ✓   | ✗   |
| [ns3.webhosting.dk](?tool=reversens&ns=ns3.webhosting.dk)           | 20,335  | 1,232       | ✓   | ✓       | ✗    | ✓          | ✓   | ✓   | ✓   | ✗   |
| [ns4.nordicway.dk](?tool=reversens&ns=ns4.nordicway.dk)             | 19,784  | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | ✗   | ✗   | ✗   |
| [ns3.nordicway.dk](?tool=reversens&ns=ns3.nordicway.dk)             | 19,784  | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | ✗   | ✗   | ✗   |
| [ns61.domaincontrol.com](?tool=reversens&ns=ns61.domaincontrol.com) | 18,668  | 1,232       | ✓   | ✗       | ✓    | ✗          | ✓   | —   | ✗   | ✗   |
| [ns62.domaincontrol.com](?tool=reversens&ns=ns62.domaincontrol.com) | 18,668  | 1,232       | ✓   | ✗       | ✓    | ✗          | ✓   | —   | ✗   | ✗   |
| [ns2.gigahost.dk](?tool=reversens&ns=ns2.gigahost.dk)               | 16,552  | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | —   | ✗   | ✗   |
| [ns1.gigahost.dk](?tool=reversens&ns=ns1.gigahost.dk)               | 16,552  | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | —   | ✗   | ✗   |
| [ns3.gigahost.dk](?tool=reversens&ns=ns3.gigahost.dk)               | 16,551  | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | —   | ✗   | ✗   |
| [ns4.gigahost.dk](?tool=reversens&ns=ns4.gigahost.dk)               | 16,551  | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | —   | ✗   | ✗   |
| [ns5.gigahost.dk](?tool=reversens&ns=ns5.gigahost.dk)               | 16,551  | 1,232       | ✓   | ✗       | ✓    | ✗          | ✗   | —   | ✗   | ✗   |
| [ns1.eurodns.com](?tool=reversens&ns=ns1.eurodns.com)               | 13,677  | 4,096       | ✓   | ✗       | ✗    | ✗          | ✓   | —   | ✗   | ✗   |
| [ns2.eurodns.com](?tool=reversens&ns=ns2.eurodns.com)               | 13,677  | 4,096       | ✓   | ✗       | ✗    | ✗          | ✓   | —   | ✗   | ✗   |
| [ns4.eurodns.com](?tool=reversens&ns=ns4.eurodns.com)               | 13,571  | 4,096       | ✓   | ✗       | ✗    | ✗          | ✓   | —   | ✗   | ✗   |
| [ns3.eurodns.com](?tool=reversens&ns=ns3.eurodns.com)               | 13,571  | 4,096       | ✓   | ✗       | ✗    | ✗          | ✓   | —   | ✗   | ✗   |

## 📋 Nameservers worth knowing about[#](#nameservers-worth-knowing-about "Link to the Nameservers worth knowing about section of Nameserver Protocols")

largest first, with their domain counts

### Answer over DNS over TLS (32 nameservers)

Port 853 answers authoritatively.

[ns02.one.com](?tool=reversens&ns=ns02.one.com) 301,281 · [ns01.one.com](?tool=reversens&ns=ns01.one.com) 301,270 · [ns7.webhosting.dk](?tool=reversens&ns=ns7.webhosting.dk) 20,355 · [ns3.webhosting.dk](?tool=reversens&ns=ns3.webhosting.dk) 20,335 · [ns02.no.brand.one.com](?tool=reversens&ns=ns02.no.brand.one.com) 1,660 · [ns01.no.brand.one.com](?tool=reversens&ns=ns01.no.brand.one.com) 1,660 · [ns1.powerhosting.dk](?tool=reversens&ns=ns1.powerhosting.dk) 1,484 · [ns01.hostnet.nl](?tool=reversens&ns=ns01.hostnet.nl) 756 · [ns02.hostnet.nl](?tool=reversens&ns=ns02.hostnet.nl) 756 · [ns2.desec.org](?tool=reversens&ns=ns2.desec.org) 649 · [dns1.namebay.com](?tool=reversens&ns=dns1.namebay.com) 144 · [dns2.namebay.com](?tool=reversens&ns=dns2.namebay.com) 144 · [c.ns.facebook.com](?tool=reversens&ns=c.ns.facebook.com) 58 · [parkdns1.ilkari.tech](?tool=reversens&ns=parkdns1.ilkari.tech) 58 · [d.ns.facebook.com](?tool=reversens&ns=d.ns.facebook.com) 58 · [a.ns.facebook.com](?tool=reversens&ns=a.ns.facebook.com) 58 · [b.ns.facebook.com](?tool=reversens&ns=b.ns.facebook.com) 58 · [ns2.nazwa.pl](?tool=reversens&ns=ns2.nazwa.pl) 57 · [ns3.nazwa.pl](?tool=reversens&ns=ns3.nazwa.pl) 57 · [ns1.nazwa.pl](?tool=reversens&ns=ns1.nazwa.pl) 57 · [ns2.one.com](?tool=reversens&ns=ns2.one.com) 26 · [ns1.one.com](?tool=reversens&ns=ns1.one.com) 26 · [ns2.m-online.net](?tool=reversens&ns=ns2.m-online.net) 14 · [ns2.iq.pl](?tool=reversens&ns=ns2.iq.pl) 14 · [ns1.iq.pl](?tool=reversens&ns=ns1.iq.pl) 14 · [ns1.m-online.net](?tool=reversens&ns=ns1.m-online.net) 14 · [ns4.m-online.net](?tool=reversens&ns=ns4.m-online.net) 12 · [ns3.m-online.net](?tool=reversens&ns=ns3.m-online.net) 12 · [ns1.validname.com](?tool=reversens&ns=ns1.validname.com) 11 · [ns2.validname.com](?tool=reversens&ns=ns2.validname.com) 11 · [puck.nether.net](?tool=reversens&ns=puck.nether.net) 11 · [ns3.iq.pl](?tool=reversens&ns=ns3.iq.pl) 7

### Answer over DNS over HTTPS (3 nameservers)

Port 443 /dns-query answers authoritatively.

[parkdns1.ilkari.tech](?tool=reversens&ns=parkdns1.ilkari.tech) 58 · [ns1.validname.com](?tool=reversens&ns=ns1.validname.com) 11 · [ns1.k-shopsystem.net](?tool=reversens&ns=ns1.k-shopsystem.net) 1

### Open resolvers (24 nameservers)

Resolve example.com for anyone (RFC 5358): an amplification risk.

[ns2.sedoparking.com](?tool=reversens&ns=ns2.sedoparking.com) 643 · [ns2.jetcom.dk](?tool=reversens&ns=ns2.jetcom.dk) 234 · [dns2.pro.dk](?tool=reversens&ns=dns2.pro.dk) 200 · [dns1.pro.dk](?tool=reversens&ns=dns1.pro.dk) 200 · [ns2.pixact.dk](?tool=reversens&ns=ns2.pixact.dk) 145 · [ns2.pharmakon.dk](?tool=reversens&ns=ns2.pharmakon.dk) 145 · [ns.pharmakon.dk](?tool=reversens&ns=ns.pharmakon.dk) 143 · [ns3.dns-service.dk](?tool=reversens&ns=ns3.dns-service.dk) 114 · [ns.dns-service.dk](?tool=reversens&ns=ns.dns-service.dk) 114 · [ns1.c3.sdc-hosting.com](?tool=reversens&ns=ns1.c3.sdc-hosting.com) 76 · [ns2.kontiki.dk](?tool=reversens&ns=ns2.kontiki.dk) 50 · [ns1.kontiki.dk](?tool=reversens&ns=ns1.kontiki.dk) 50 · [ns02.1sthosting.dk](?tool=reversens&ns=ns02.1sthosting.dk) 47 · [ns01.1sthosting.dk](?tool=reversens&ns=ns01.1sthosting.dk) 47 · [ns04.1sthosting.dk](?tool=reversens&ns=ns04.1sthosting.dk) 46 · [ns2.pcsys.dk](?tool=reversens&ns=ns2.pcsys.dk) 45 · [ns1.c3.nordic-backup.com](?tool=reversens&ns=ns1.c3.nordic-backup.com) 41 · [sl2.sedo.com](?tool=reversens&ns=sl2.sedo.com) 26 · [ns2.vsdata.dk](?tool=reversens&ns=ns2.vsdata.dk) 24 · [ns1.scf.dk](?tool=reversens&ns=ns1.scf.dk) 21 · [ns1.globusdata.dk](?tool=reversens&ns=ns1.globusdata.dk) 12 · [ns2.globusdata.dk](?tool=reversens&ns=ns2.globusdata.dk) 12 · [huamei.ns.giantpanda.com](?tool=reversens&ns=huamei.ns.giantpanda.com) 10 · [yalun.ns.giantpanda.com](?tool=reversens&ns=yalun.ns.giantpanda.com) 10

### No authoritative answer over TCP (2 nameservers)

TCP is mandatory (RFC 7766, 9210): large or truncated answers fail.

[dns2.teliko.net](?tool=reversens&ns=dns2.teliko.net) 9 · [dns1.teliko.net](?tool=reversens&ns=dns1.teliko.net) 9

### No EDNS (18 nameservers)

Answer without an OPT record: no DNSSEC-sized answers, no options.

[ns2.ordbogen.com](?tool=reversens&ns=ns2.ordbogen.com) 88 · [ns1.ordbogen.com](?tool=reversens&ns=ns1.ordbogen.com) 88 · [ns1.abovedomains.com](?tool=reversens&ns=ns1.abovedomains.com) 84 · [ns2.abovedomains.com](?tool=reversens&ns=ns2.abovedomains.com) 84 · [ns1.invent-it.dk](?tool=reversens&ns=ns1.invent-it.dk) 43 · [c1-160.akashield.net](?tool=reversens&ns=c1-160.akashield.net) 17 · [c2-160.akashield.net](?tool=reversens&ns=c2-160.akashield.net) 17 · [ns2.hansoft.dk](?tool=reversens&ns=ns2.hansoft.dk) 15 · [ns.ettnet.se](?tool=reversens&ns=ns.ettnet.se) 14 · [ns1.darkserv.net](?tool=reversens&ns=ns1.darkserv.net) 13 · [ns2.darkserv.net](?tool=reversens&ns=ns2.darkserv.net) 13 · [ns3.darkserv.net](?tool=reversens&ns=ns3.darkserv.net) 13 · [ns10.nameserverservice.de](?tool=reversens&ns=ns10.nameserverservice.de) 12 · [ns9.nameserverservice.de](?tool=reversens&ns=ns9.nameserverservice.de) 12 · [huamei.ns.giantpanda.com](?tool=reversens&ns=huamei.ns.giantpanda.com) 10 · [yalun.ns.giantpanda.com](?tool=reversens&ns=yalun.ns.giantpanda.com) 10 · [linux.cyber-net.dk](?tool=reversens&ns=linux.cyber-net.dk) 9 · [ns2.45ru.net.au](?tool=reversens&ns=ns2.45ru.net.au) 4

### Ignore the EDNS version (54 nameservers)

Answer EDNS version 1 as if it were 0 instead of BADVERS (RFC 6891 §6.1.3).

[ns7.sitnet.dk](?tool=reversens&ns=ns7.sitnet.dk) 2,486 · [ns6.sitnet.dk](?tool=reversens&ns=ns6.sitnet.dk) 2,486 · [ns01.hosit.dk](?tool=reversens&ns=ns01.hosit.dk) 446 · [ns02.hosit.dk](?tool=reversens&ns=ns02.hosit.dk) 446 · [ns03.hosit.dk](?tool=reversens&ns=ns03.hosit.dk) 446 · [ns04.hosit.dk](?tool=reversens&ns=ns04.hosit.dk) 277 · [ns3.site4now.net](?tool=reversens&ns=ns3.site4now.net) 114 · [ns2.site4now.net](?tool=reversens&ns=ns2.site4now.net) 114 · [ns2.ordbogen.com](?tool=reversens&ns=ns2.ordbogen.com) 88 · [ns1.ordbogen.com](?tool=reversens&ns=ns1.ordbogen.com) 88 · [ns1.abovedomains.com](?tool=reversens&ns=ns1.abovedomains.com) 84 · [ns2.abovedomains.com](?tool=reversens&ns=ns2.abovedomains.com) 84 · [ns2.antagus.de](?tool=reversens&ns=ns2.antagus.de) 65 · [ns2.bytebob.com](?tool=reversens&ns=ns2.bytebob.com) 64 · [ns1.bytebob.com](?tool=reversens&ns=ns1.bytebob.com) 64 · [parkdns1.ilkari.tech](?tool=reversens&ns=parkdns1.ilkari.tech) 58 · [parkdns2.ilkari.tech](?tool=reversens&ns=parkdns2.ilkari.tech) 58 · [ns2.kontiki.dk](?tool=reversens&ns=ns2.kontiki.dk) 50 · [ns2.ns-serve.net](?tool=reversens&ns=ns2.ns-serve.net) 50 · [ns1.kontiki.dk](?tool=reversens&ns=ns1.kontiki.dk) 50 · [ns1.cicoor.com](?tool=reversens&ns=ns1.cicoor.com) 49 · [ns1.invent-it.dk](?tool=reversens&ns=ns1.invent-it.dk) 43 · [ns1.f5clouddns.com](?tool=reversens&ns=ns1.f5clouddns.com) 37 · [ns2.f5clouddns.com](?tool=reversens&ns=ns2.f5clouddns.com) 37 · [ns6.dkhotel.dk](?tool=reversens&ns=ns6.dkhotel.dk) 33 · [ns1.flexonet.dk](?tool=reversens&ns=ns1.flexonet.dk) 23 · [ns.mainnameserver.com](?tool=reversens&ns=ns.mainnameserver.com) 16 · [ns2.mainnameserver.com](?tool=reversens&ns=ns2.mainnameserver.com) 16 · [ns2.hansoft.dk](?tool=reversens&ns=ns2.hansoft.dk) 15 · [ns2.kandinsky.net](?tool=reversens&ns=ns2.kandinsky.net) 15 · [ns.ettnet.se](?tool=reversens&ns=ns.ettnet.se) 14 · [ns.nscluster.fi](?tool=reversens&ns=ns.nscluster.fi) 14 · [ns3.darkserv.net](?tool=reversens&ns=ns3.darkserv.net) 13 · [ns2.darkserv.net](?tool=reversens&ns=ns2.darkserv.net) 13 · [ns1.darkserv.net](?tool=reversens&ns=ns1.darkserv.net) 13 · [ns10.nameserverservice.de](?tool=reversens&ns=ns10.nameserverservice.de) 12 · [ns9.nameserverservice.de](?tool=reversens&ns=ns9.nameserverservice.de) 12 · [ns10.az.pl](?tool=reversens&ns=ns10.az.pl) 11 · [ns12.az.pl](?tool=reversens&ns=ns12.az.pl) 11 · [ns11.az.pl](?tool=reversens&ns=ns11.az.pl) 11 · [huamei.ns.giantpanda.com](?tool=reversens&ns=huamei.ns.giantpanda.com) 10 · [ns1.pin.se](?tool=reversens&ns=ns1.pin.se) 10 · [ns2.pin.se](?tool=reversens&ns=ns2.pin.se) 10 · [yalun.ns.giantpanda.com](?tool=reversens&ns=yalun.ns.giantpanda.com) 10 · [dns1.regdom.it](?tool=reversens&ns=dns1.regdom.it) 9 · [dns2.regdom.it](?tool=reversens&ns=dns2.regdom.it) 9 · [linux.cyber-net.dk](?tool=reversens&ns=linux.cyber-net.dk) 9 · [b1.uberns.org](?tool=reversens&ns=b1.uberns.org) 9 · [ns1.myhost.ro](?tool=reversens&ns=ns1.myhost.ro) 4 · [ns4.tppns.com](?tool=reversens&ns=ns4.tppns.com) 4 …

### Drop queries with an unknown EDNS option (0 nameservers)

Unknown options must be ignored (RFC 6891 §6.1.2).

None so far.

dhd.dk **\[/]** search Domains, Hosts & DNS — .dk zone