rug.nl

.nl country-code · Rijksuniversiteit Groningen

Found

TLD

.nl (country-code)

ICANN policies apply

no

Registrar

Rijksuniversiteit Groningen

Registered

2 June 1988

Last changed

16 December 2025

Status

active

Registry nameservers

dns1.rug.nl, dns2.rug.nl, dns3.rug.nl, ns1.surfnet.nl, ns2.surfnet.nl

RDAP server

https://rdap.sidn.nl/

Checks

• i

  .nl is a country-code TLD (ccTLD)

  Country-code TLD: governed by its local registry under national policy, not by an ICANN contract. Registrar accreditation, dispute resolution and RDAP/WHOIS rules are set by the registry.

  #1
• ✓ TLD delegated and signed #2

  .nl is delegated in the root zone and DNSSEC-signed.
• i

  Expiry date not published

  The registry does not publish the expiry date in RDAP. Check it with your registrar.

  #3
• i

  No transfer lock

  The domain has no transfer lock (status: active). A registrar lock protects against unauthorized transfers.

  #4
• ✓ Registry and delegation match #5

  The nameservers registered at the registry are the ones published in DNS.

dns1.rug.nl, dns2.rug.nl, dns3.rug.nl, ns1.surfnet.nl, ns2.surfnet.nl

Found

Parent zone

nl

Delegation from

ns1.dns.nl (194.0.28.53)

NS at the parent

dns1.rug.nl, dns2.rug.nl, dns3.rug.nl, ns1.surfnet.nl, ns2.surfnet.nl

NS in the zone

dns1.rug.nl, dns2.rug.nl, dns3.rug.nl, ns1.surfnet.nl, ns2.surfnet.nl

Checks

• ✓ 5 nameservers #6

  Delegated to dns1.rug.nl, dns2.rug.nl, dns3.rug.nl, ns1.surfnet.nl, ns2.surfnet.nl.
• ✓ Parent and zone agree #7

  The parent delegation and the zone's NS records list the same nameservers.
• ✓ Glue present and correct #8

  Glue is published for the nameservers inside the zone: dns1.rug.nl, dns2.rug.nl, dns3.rug.nl.
• ✓ All names resolve #9

  Every nameserver name has an address and is not an alias.
• ✓ Nameservers in different networks #10

  The nameservers are spread over 4 IPv4 /24s and 3 IPv6 /48s.
• i

  All nameservers in one AS

  All nameserver addresses are announced by one network operator (AS1103 (SURFNET-NL - SURF B.V., NL): 10 addresses). An outage or attack on that network affects all nameservers; large anycast providers mitigate this, but a secondary DNS provider adds independence.

  #11
• i

  All nameserver names under .nl

  All nameserver names are under one TLD, so a problem with that TLD also makes the nameservers unreachable. Some operators use names under two TLDs for extra resilience.

  #12
• ✓ All reachable over IPv6 #13

  Every nameserver has an IPv6 address.

10 of 10 addresses answer authoritatively

Found

Checks

• ✓ All respond #14

  All 10 nameserver addresses answered.
• ✓ All authoritative #15

  Every responding nameserver answers authoritatively for the zone.
• ✓ No recursion #16

  The nameservers do not answer recursive queries for other domains.
• i

  Identifying string disclosed

  These nameservers answer version queries with a string that is not a version number: ns1.surfnet.nl: "This is a SURFnet nameserver - dns-beheer@surfnet.nl"; ns2.surfnet.nl: "This is a SURFnet nameserver - dns-beheer@surfnet.nl".

  #17
• ✓ Zone transfers refused #18

  No nameserver allows a zone transfer to the public.
• ✓ TCP supported #19

  All nameservers answer over TCP.
• ✓ EDNS supported #20

  All nameservers support EDNS(0).
• ✓ Public addresses #21

  All nameserver addresses are publicly routable.

serial 2026101600 · primary ns.rug.nl

Found

Primary (MNAME)

ns.rug.nl

Contact (RNAME)

hostmaster.nic.rug.nl

Serial

2026101600

Refresh / retry

14400 s / 3600 s

Expire

1209600 s

Negative TTL

600 s

Serial per nameserver

Checks

• ✓ Serial 2026101600 everywhere #22

  All nameservers serve the same version of the zone.
• ✓ Timers within recommendations #23

  SOA refresh 4h, retry 1h, expire 14d, negative TTL 10m.
• i

  Hidden master

  The primary nameserver ns.rug.nl is not listed as a nameserver: a hidden master that only feeds the public secondaries. That is a common setup; make sure it is not reachable for zone transfers from outside.

  #24
• ✓ Contact hostmaster@nic.rug.nl #25

  The SOA RNAME hostmaster.nic.rug.nl means hostmaster@nic.rug.nl.
• ✓ Date-based serial #26

  The serial 2026101600 follows the YYYYMMDDnn convention (2026-10-16).

21 records at the apex

Found

Read from

129.125.4.1:53

Checks

• ✓ TTLs within range #32

  TTLs: A 1d, AAAA 1d, MX 1d, NS 1d. The NS TTL at the parent is 1h and in the zone 1d; resolvers may use either.
• ✓ No CNAME at the apex #33

  The zone apex has no CNAME record.
• ✓ No wildcard #34

  Names that don't exist return NXDOMAIN.
• i

  No CAA records

  Without CAA records any certificate authority may issue certificates for this domain. A CAA record limits issuance to the CAs you use.

  #35